BC557CBK - DIOTEC SEMICONDUCTOR AG

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

Future Technology Devices

International Ltd.

FT260

(HID-class USB to UART/I2C

Bridge IC)

FT260 is a HID-class USB to I2C/UART interface

Device Controller with the following advanced

features:

 Single chip USB to UART/I2C bridge with

standard Human Interface Device (HID) class

support

 USB2.0 compliant Full Speed device with entire

USB protocol handled on the chip.

 Support 2 USB HID Interfaces, each

corresponding to the on-chip physical

interfaces, I2C and UART

 Pin configuration of enabling HID interface for

variety of application

 HID over I2C specification support

 Configurable I2C Master Interface controller

conforming to I2C v2.1 and v3.0 specification.

 Support 4 speed modes defined in I2C-bus

Specification, standard mode (SM), fast mode

(FM), Fast mode plus (FM+), and High Speed

mode (HS)

 Robust FTDI UART controller with hardware and

software flow control

 Data transfer rate from 1.2 Kbuad to 12 Mbaud

(RS422, RS485, RS232) at TTL levels

 Configurable GPIOs can be easily controlled by

software applications under HID class via the

USB bus

 Fully integrated oscillator PLL with no external

crystal required

 On-chip eFUSE for USB Vendor ID (VID),

Product ID (PID), and other vendor specific

parameters.

 Unique USB serial number generation engine

and programming path to external EEPROM.

 Integrated 5V-3.3V-1.8V level converter for

USB I/O.

 +5V USB VBUS detection engine

 USB Power Configurations; supports bus-

powered, self-powered and bus-powered with

power switching.

 USB2.0 Low operating and suspend current;

24mA (active-typ) and 385µA (suspend-typ).

 True 3.3V CMOS drive output and TTL input.

(operates down to 1V8 with external pull-ups)

 Multiple I/O operating voltage level +3.3V,

+2.5V, +1.8V

 pin output drive strength; 4 mA(min) and 16

mA(max)

 Integrated power-on-reset circuit.

 USB Battery Charger Detection.

 UHCI / OHCI / EHCI / XHCI host controller

compatible.

 Extended operating temperature range; -40 to

85⁰C.

 Available in compact Pb-free 28 Pin WQFN or

TSSOP packages (RoHS compliant).

Neither the whole nor any part of the information contained in, or the product described in this manual, may be adapted or reproduced

in any material or electronic form without the prior written consent of the copyright holder. This product and its documentation are

supplied on an as-is basis and no warranty as to their suitability for any particular purpose is either made or implied. Future Technology

Devices International Ltd will not accept any claim for damages howsoever arising as a result of use or failure of this product. Your

statutory rights are not affected. This product or any variant of it is not intended for use in any medical appliance, device or system in

which the failure of the product might reasonably be expected to result in personal injury. This document provides preliminary

information that may be subject to change without notice. No freedom to use patents or other intellectual property rights is implied by

the publication of this document. Future Technology Devices International Ltd, Unit 1, 2 Seaward Place, Centurion Business Park, Glasgow

G41 1HH United Kingdom. Scotland Registered Company Number: SC136640

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

1 Typical Applications

 HID class Device controller

 USB to HID-over-I2C Bridge

 USB to I2C master controller

 USB to RS232/RS422/RS485 Converters

 Interfacing MCU/PLD/FPGA based designs to

USB

 USB Instrumentation

1.1 Driver Support

The USB Human Interface Device (HID) class is natively supported by most operation systems. A custom

driver is not required to be installed for the FT260.

 Windows 10 32, 64-bit

 Windows 8.1 32, 64-bit

 Windows 8 32, 64-bit

 Windows 7 32, 64-bit

 Windows Vista and Vista 64-bit

 Windows XP and XP 64-bit

 Windows CE 4.2, 5.0, 5.2, 6.0

 Windows Server 2008, 2003, 2000

 Windows Embedded Operating Systems

 Mac OS X

 Linux

 Android

1.2 Part Numbers

Part Number

Package

FT260Q-x

28 Pin WQFN

FT260S-x

28 Pin TSSOP

Note: Packing codes for x is:

- R: Taped and Reel, 2,500pcs per reel

- T: Tray packing, 490pcs per tray (WQFN only)

- U: Tube packing, 50pcs per tube (TSSOP only)

For example: FT260Q-R is 2,500pcs taped and reel packing

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

1.3 USB Compliant

The FT260 is fully compliant with the USB 2.0 specification and has been given the USB-IF Test-ID (TID)

40001720.

.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

2 FT260 Block Diagram

Figure 2.1 FT260 Block Diagram

For a description of each function please refer to Function Description.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

Table of Contents

1 Typical Applications ...................................................... 2

1.1 Driver Support .......................................................................... 2

1.2 Part Numbers ............................................................................ 2

1.3 USB Compliant .......................................................................... 3

2 FT260 Block Diagram .................................................... 4

3 Device Pin Out and Signal Description .......................... 7

3.1 WQFN-28 Package Pin Out ........................................................ 7

3.2 TSSOP-28 Package Pin Out ....................................................... 8

3.3 Pin Description .......................................................................... 9

4 Function Description ................................................... 12

4.1 Key Features ........................................................................... 12

4.2 Functional Block Descriptions ................................................. 13

5 FT260 Configuration and Bus Interfaces ..................... 17

5.1 Device Interface Configuration ............................................... 17

5.2 I2C Bus Interface .................................................................... 18

5.2.1 I2C Pin Definition ........................................................................................ 18

5.2.2 I2C Bus Protocol .......................................................................................... 18

5.2.3 I2C Slave Address ....................................................................................... 20

5.2.4 I2C Timing ................................................................................................. 20

5.3 UART Interface ....................................................................... 22

5.3.1 UART Pin Definition ..................................................................................... 24

5.3.2 UART Bus Protocol ...................................................................................... 24

5.3.3 UART Flow Control ...................................................................................... 26

5.3.4 UART Timing .............................................................................................. 26

5.4 GPIOs ..................................................................................... 27

6 Devices Characteristics and Ratings ........................... 28

6.1 Absolute Maximum Ratings ..................................................... 28

6.2 ESD and Latch-up Specifications ............................................. 28

6.3 DC Characteristics ................................................................... 29

6.4 USB Characteristics ................................................................. 33

7 FT260 Power Configurations ....................................... 34

7.1 USB Bus Powered Configuration ............................................ 34

7.2 Self Powered Configuration with 5V Source Input .................. 35

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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7.3 Self Powered Configuration with 3.3V Source In .................... 36

7.4 Bus Powered Configuration with +1.8V/+2.5V I/O Voltage ... 37

7.5 Configuration for System Pins ................................................. 38

7.6 Power for Programming eFUSE ............................................... 39

8 Application Examples .................................................. 40

8.1 USB HID-over-I2C ................................................................... 40

8.2 USB to RS232 Converter ......................................................... 41

8.3 USB to RS485 Converter ......................................................... 42

8.4 USB to RS422 Converter ......................................................... 43

9 User Configuration ...................................................... 44

9.1 Programming the embedded eFUSE over USB ......................... 44

9.1.1 Default Values ............................................................................................ 44

9.2 Programming the external EEPROM over USB ......................... 47

9.2.1 Supported EEPROM Spec ............................................................................. 47

9.2.2 Default Values ............................................................................................ 48

10 Package Parameters ................................................... 51

10.1 WQFN-28 Package Mechanical Dimensions .......................... 51

10.2 WQFN-28 Package Markings ................................................ 52

10.3 TSSOP-28 Package Mechanical Dimensions .......................... 53

10.4 TSSOP-28 Package Markings ................................................ 54

10.5 Solder Reflow Profile ............................................................ 55

11 Contact Information ................................................... 56

Appendix A – References ................................................... 57

Document References ...................................................................... 57

Acronyms and Abbreviations ............................................................ 58

Appendix B - List of Figures and Tables ............................. 59

List of Figures .................................................................................. 59

List of Tables .................................................................................... 59

Appendix C - Revision History ............................................ 61

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

3 Device Pin Out and Signal Description

3.1 WQFN-28 Package Pin Out

Figure 3.1 Pin Configuration WQFN-28 (top-down view)

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

3.2 TSSOP-28 Package Pin Out

Figure 3.2 Pin Configuration TSSOP-28 (top-down view)

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

3.3 Pin Description

FT260Q

Pin No.

FT260S

Pin No.

Pin Name

(Function)

Type

Description

1

5

DEBUGGER

I/O

Debugging pin.

Should be reserved and tied to high

2

6

STEST_RSTN

I

Chip reset input for test mode. Active low.

Should be reserved and tied to high.

3

7

RESETN

I

Chip reset input. Active low.

Can be tied to high if external reset function is not required.

4

8

DCNF0

I

Device Interface Configuration Selection bit-0 for the HID interface

selection. Refer to Section 5.1

5

9

DCNF1

I

Device Interface Configuration Selection bit-1 for the HID interface

selection. Refer to Section 5.1

6

10

VCCIO

P **

+3.3V/2.5V/1.8V supply voltage.

This is the supply voltage for all the I/O ports. This pin shall be

connected to VOUT3V3(pin 22/26) when I/O ports are working at

3.3V

7

11

DIO0

( TX_ACTIVE /

TX_LED /

GPIOA )

I/O

O

I/O

DIO0, Digital Input/Output Pin 0.

This pin can be configured as one of the following three functions via

embedded eFUSE or external EEPROM.

TX_ACTIVE is set as the default function to indicate the UART

transmitting is active.-

TX_LED is set as the LED driving source when data is transmitted on

UART TX port.

GPIOA, General Purpose I/O. GPIOA is another optional function.

8

12

DIO1

( GPIOB /

RTSN )

I/O

O

DIO1, Digital Input/Output Pin 1.

GPIOB, General Purpose I/O. is set as the default function.

RTSN, Request To Send Handshake, can be enabled via a USB

command for the UART interface.

9

13

DIO2

( GPIOE /

CTSN )

I/O

I

DIO2, Digital Input/Output Pin 2.

GPIOE, General Purpose I/O. is set as the default function.

CTSN, Clear To Send Handshake, can be enabled via a USB command

for the UART interface.

10

14

DIO3

( RXD /

GPIOC )

I/O

I

I/O

DIO3, Digital Input/Output Pin 3.

RXD, Receive Asynchronous Data Input, is set as default function

when the UART interface is selected via {DCNF1, DCNF0}.

GPIOC, General Purpose I/O, is set as the default function when UART

interface is not configured.

11

15

DIO4

( TXD /

GPIOD )

I/O

O

I/O

DIO4, Digital Input/Output Pin 4.

TXD, Transmit Asynchronous Data Output, is set as default when the

UART interface is selected via {DCNF1, DCNF0}.

GPIOD, General Purpose I/O, is set as default when the UART

interface is not configured.

12

16

DIO5

I/O

DIO5, Digital Input/Output Pin 5.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

FT260Q

Pin No.

FT260S

Pin No.

Pin Name

(Function)

Type

Description

( SCL /

GPIO0 )

I/O

SCL, Serial clock for I2C bus with open drain output, is set as the

default function

GPIO0, General Purpose I/O. GPIO0 is another optional function and

can be enabled via a USB command.

13

17

DIO6

( SDA /

GPIO1 )

I/O

DIO6, Digital Input/Output Pin 6.

SDA, Serial data for I2C mode with open drain output, is set as the

default function.

GPIO1, General Purpose I/O. GPIO1 is another optional function and

can be enabled via a USB command.

14

18

DIO7

( SUSPOUT_N /

PWREN_N /

GPIO2 )

I/O

O

I/O

DIO7, Digital Input/Output Pin 7.

This pin can be configured as one of the following three functions via

embedded eFUSE or external EEPROM.

SUSPOUT_N is set as the default function as the indicator when

entering the USB suspending state. _N means active low. This

indicator can also be configured as active high via EEPROM and

symbolled as SUSPOUT.

PWREN_N is as the power enable indicator when the FT260 is USB

enumerated. Active low.

GPIO2, General Purpose I/O. GPIO2 is another optional function and

can be enabled.

15

19

DIO8

( INTRIN /

WAKEUP /

GPIO3 )

I/O

I

I/O

DIO8, Digital Input/Output Pin 8.

INTRIN is the default function as the external interrupt input source

WAKEUP functions as the USB remote wakeup input source.

GPIO1, General Purpose I/O. GPIO1 is another optional function and

can be enabled via a USB command.

16

20

DIO9

( GPIOF /

DTRN )

I/O

O

DIO9, Digital Input/Output Pin 9.

GPIOF, General Purpose I/O. is set as the default function.

DTRN, Data Terminal Ready, can be enabled via a USB command for

the UART interface.

17

21

DIO10

( GPIO4 /

DCD )

I/O

I

DIO10, Digital Input/Output Pin 10.

GPIO4, General Purpose I/O, is set as the default function.

DCD, Data Carrier Detection, can be enabled via a USB command for

the UART interface.

18

22

DIO11

( GPIO5/

RI )

I/O

I

DIO11, Digital Input/Output Pin 11.

GPIO5, General Purpose I/O, is set as the default function.

RI, Ring Indicator, can be enabled via a USB command for the UART

interface. RI may be used as an alternative to WAKEUP for waking up

the USB host. WAKEUP feature accompanied with RI can be enabled

via the parameter defined in an external EEPROM.

19

23

GND

P

Ground

20

24

DM

AI/O

USB peripheral bidirectional DM line.

21

25

DP

AI/O

USB peripheral bidirectional DP line.

22

26

VOUT3V3

P **

+3.3V voltage Out

May be used to power VCCIO. When VCCIN is supplied with 3.3V, this

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

FT260Q

Pin No.

FT260S

Pin No.

Pin Name

(Function)

Type

Description

pin is a power input pin and should be connected to pin 23 / 27.

23

27

VCCIN

P **

+5.0V(or 3.3V) supply voltage In

Power source-in to embedded regulator.

24

28

AGND

P

Analog Ground

25

1

FSOURCE

AP

+3.8V supply voltage In

Power source for programming embedded eFUSE. It should be kept

floating or 0V when not in programming mode

26

2

VBUS_DET

I

VBUS detection input. It is a +5.0V tolerant pin

27

3

DIO12

( BCD_DET/

RX_LED/

PWREN_N/

GPIOG )

I/O

O

I/O

DIO12, Digital Input/Output Pin 12.

This pin can be configured as one of the following three functions via

embedded eFUSE or external EEPROM.

BCD_DET is the default function as the battery charger detection

indicator output when the device is connected to a dedicated battery

charger port. Polarity can be defined.

RX_LED is as the LED driving source when data is received on UART

RX port.

PWREN_N is as the power enable indicator when FT260 is USB

enumerated. Low active.

GPIOG, General Purpose I/O, is another optional function.

28

4

DIO13

GPIOH/

DSRN

I/O

I

DIO13, Digital Input/Output Pin 13.

GPIOH, General Purpose I/O, is set as the default function

DSRN, Data Set Ready, can be enabled via USB command for UART

interface.

Table 3.1 FT260 Pin Description

**If VCCIN is supplied with 3.3V power input, then VOUT3V3 and VCCIO must also be driven with this

3.3V power source. For details refer to Section 7.3.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

4 Function Description

The FT260 is a USB device which supports I²C and UART communication through standard USB HID class

interfaces. The USB HID class is natively supported by most operating systems. A custom driver is not

required to be installed for the FT260.

4.1 Key Features

Highly Functional Integration. FT260 is highly integrated, with a USB2.0 compliant full-speed

transceiver, oscillator PLL as the source of the operating clock, LDO regulator for full chip operating

power source, eFUSE for basic customization and automatic scanning mechanism of EEPROM for

advanced customization. It also includes Power-On-Reset (POR) and VBUS detection input with 5V-

tolerance. These embedded functions simplify external circuit design and reduce external component

count.

HID class USB to I2C/UART Bridge. FT260 provides the bridge function between standard a USB HID

class driver and an I2C slave device and/or UART device. The standard USB HID class driver is natively

supported by most operating systems meaning the FT260, does not need a customized driver to be

installed. The USB HID class exchanges data between a host and a device by HID reports, which are the

actual data blobs follow HID format, and the application developers have to communicate with the FT260

via the HID reports. Please refer to Application Notes for detail formats. In order to help the developers,

FTDI also provides a Windows DLL with easy-to-use API for FT260 application development.

There are 2 USB interfaces corresponding to HID class in the FT260. One is for the I2C bus and the other

is for the UART bus. These two interfaces can exist concurrently and can be selected independently

according to the application. For each interface, there exists one Interrupt IN pipe and Interrupt OUT pipe

with a max packet size equal to 64 bytes. With the fastest polling frequency, one time in 1 ms, the

Interrupt pipes can operate with maximum data throughput up to 64kB/sec. Users can also utilize the

HID class commands through the Control pipe to configure the setting and to control the functions in the

FT260. Digital function pins can be programmed as GPIO and can be controlled by HID class commands

through Endpoint 0.

The I2C bus can run at common I2C bus speeds, standard mode (SM), fast mode (FM), Fast mode plus

(FM+), and High Speed mode (HS). A higher bit rate on the I2C bus is also configurable up to 3Mbit/s.

Clock stretching is supported to conform to v2.1 and v3.0 of the I2C specification. The default

configuration is for standard mode speed (SM). All the configurable settings can be changed over USB

before the I2C bus starts any transferring.

The robust FTDI UART bus is embedded in the FT260. The baud rate can be supported from 1200 baud to

12M baud. RTSN/CTSN, DSRN/DTRN and XON/XOFF handshaking options are also supported and can be

enabled by associated APIs defined in the DLL for the FT260. Data can be received from the RX pin and

delivered to the HID driver via the Interrupt IN pipe. Data can also be delivered from the USB host

through the Interrupt OUT pipe and transmitted on to the TX pin.

An remote wake up function is also supported. If the operating system supports remote wake up and

allows external hardware to wake it, the FT260 can be resumed by the pin DIO8 which is set by default

as WAKEUP triggering a resume signal on USB bus to wake up USB host. DIO11 can also be a remote

wake up source when the pin function is set as RI and the parameter, RI as Wake-Up; defined in external

EEPROM is enabled.

HID over I2C Bridge Human Interface Device (HID) is one of the most popular USB devices. It was a

protocol developed to simplify the process of connecting accessories such as mouse, keyboard and

touchpad to the PC. HID was originally developed to run over USB or Bluetooth. For Windows 8, Microsoft

created a new device type called “HID over I2C”, which allows the device to communicate HID protocol

over an Inter-Integrated Circuit (I²C) bus. The new “HID over I2C” devices are only supported natively by

Microsoft Windows 8 or above.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Document No.: FT_001272 Clearance No.: FTDI#484

The FT260 provides a bridge which connects a “HID-over-I²C” device via an I²C bus, helps to translate

USB HID requests from a PC to the device, and makes it work as a normal USB HID class device. With

the FT260, an I2C slave function compliant to HID-over-I2C protocol can directly communicate to USB

HID class driver through the USB connection.

Configurable Settings for Customization. An electrical poly-fuse (eFUSE) is embedded in the FT260.

This embedded eFUSE provides the configurable settings of the Vendor Specific Parameters for basic

customization. These Vendor Specific Parameters are the settings about USB, I/O and HID-over-I2C.

Users can utilize this embedded eFUSE to achieve basic customization.

For advanced settings, the FT260 also reserves the programming interface of an external EEPROM via an

I2C interface to record the Vendor Specific Parameters. The FT260 will automatically scan for the

presence of an EEPROM. (See Supported EEPROM Spec for suitable devices). When the FT260 is powered

up, these Vendor Specific Parameters will be automatically loaded and the FT260 will operate with the

parameter setting. When both eFUSE and EEPROM exist at the same time, the Vendor Specific

Parameters in the EEPROM will dominate. Both eFUSE and EEPROM can be programmed using the FTDI

utility software called FT_PROG, which can be downloaded from the FTDI Utilities page on the FTDI

website

(http://www.ftdichip.com/Support/Utilities.htm#FT_Prog).

Configurable Digital I/Os. There are 14 digital pins in the FT260 that can be configured for different

purposes, such as UART/I2C bus signals, General Purpose Input/Output (GPIO), LED indicator for data

transfer over UART, a USB suspend indicator output, remote wake up input, an interrupt input or power

enable indicator. Functions for each pin will be determined during Chip Configuration, with parameters

from the eFUSE or EEPROM, or via USB commands.

The signal drive strength of these Digital I/Os can be configured via the FT_Prog utility for different

design needs.

Power management. The operating clock for the FT260 can be set as 48MHz, 24MHz, 12MHz. Higher

operating frequencies allow higher data throughput. And, lower operating frequencies allow lower power

consumption. IDLE mode is also supported and can be enabled via the parameters in eFUSE or EEPROM.

The system operating clock will be switched to 30 kHz when no data is transferred between USB and

I2C/UART bus for a period of 5 seconds. Any UART RX signalling will trigger the whole chip exiting from

the IDLE mode to normal operating status.

USB suspend/resume and remote wakeup are fully supported. The FT260 will be set to a power saving

status and the clock to most of the digital circuits will be stopped when the device is suspended.

Source Power and Power Consumption. The FT260 is capable of operating with a voltage supply of

+3.3V or +5.0V with a nominal operational mode current of 24mA, a nominal idle mode current of 5.6mA

and a nominal USB suspend mode current of 405µA. This allows greater margin for peripheral designs to

meet the USB suspend mode current limit of 2.5mA. An integrated level converter within the FT260

allows the device to interface with logic running at +1.8V, 2.5V or +3.3V. (Note: External pull-ups are

recommended for IO <3V3).

4.2 Functional Block Descriptions

The following paragraphs detail each function within the FT260. Please refer to the block diagram shown

in Figure 2.1 .

Internal Oscillator. The Internal Oscillator cell generates a 48MHz reference clock. With internal

trimming mechanisms and an adaptive algorithm, this oscillator provides a stable clock source to the USB

DPLL block for generating a recovered clock to Clock Synthesizer block for functional operating.

Clock Synthesizer. The Clock Synthesizer takes the 48MHz clock from the Internal Oscillator and

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

Version 1.1

Document No.: FT_001272 Clearance No.: FTDI#484

generates 48MHz, 24MHz and 12MHz as reference clocks. The user can select one of these reference

clocks as the system operating clock through software over USB. The system operating clock will be the

clock source for embedded functions to generate the required interface clock. Higher frequencies should

be chosen for higher data throughput demand and lower frequencies for lower power operation. Users

can choose the system operating frequency based on the application.

USB Transceiver. The USB Transceiver cell provides the USB 1.1 / USB 2.0 full-speed physical interface.

Output drivers provide +3.3V level slew rate control , while a differential input and two single ended

input receivers provide data in, Single-Ended-0 (SE0) and USB reset detection conditions respectfully. A

1.5kΩ pull up resistor on USBDP is incorporated.

USB DPLL. The DPLL cell locks on to the incoming NRZI USB data and generates recovered clock and

data signals for the Serial Interface Engine (SIE) block.

Serial Interface Engine (SIE). The Serial Interface Engine (SIE) block performs the parallel to serial

and serial to parallel conversion of the USB data. In accordance with the USB 2.0 specification, it

performs bit stuffing/un-stuffing and CRC5/CRC16 generation. It also checks the CRC on the USB data

stream.

USB HID Protocol Engine. The USB HID Protocol Engine manages the standard commands from the

device control pipe when enumerating. It also handles the Human Interface Device (HID) class

commands between the standard HID host driver and the device with I2C or/and UART functions. With

the Device Interface Configuration pins, DCNF0 and DCNF1, it can easily connect HID functions via UART

or I2C interfaces to a PC host driver. Additionally, it can simultaneously support 2 HID functions via UART

and I2C interfaces. This Protocol Engine also includes an IN and OUT Buffer management memory unit

which handles the data between USB endpoints and function interfaces such as UART and I2C.

The USB HID Protocol Engine includes:

 Endpoint-0 for a control pipe with max packet size 64 Bytes

 2 endpoints for interrupt-in pipe with max packet size equal to 64 Bytes

 2 endpoints for interrupt-out pipe with max packet size up to 64 Bytes

 Multiple interfaces configuration support

 HID class-specific request parsing and transporting to I2C/UART bus interface

 command Suspend detection and power management

 Remote wake-up support

 Fully compatible to USB2.0 specification requirement in full speed mode

OUT Buffer. Data sent from the USB host controller to the FT260 via the USB data OUT endpoint is

stored in the OUT buffer. Data is removed from the OUT buffer to function interfaces under the control of

the USB HID protocol engines. The endpoint buffer size is 64 bytes as the maximum packet size defined

for full speed transferring. For the interrupt pipe, the buffer is double buffered for increased throughput.

IN Buffer. Data from the function interfaces is stored in the IN buffer. The USB host controller removes

data from the IN buffer by sending a USB request for data from the device data IN endpoint. The

endpoint buffer size is 64 bytes as the maximum packet size defined for full speed transferring. For the

interrupt pipe, the buffer is double buffered for increased throughput.

UART Controller. When the data and control bus are configured in UART mode, the interface

implements a standard asynchronous serial UART port with flow control. The UART performs

asynchronous 7/8 bit Parallel to Serial and Serial to Parallel conversion of the data on the RS232 (RS422

and RS485) interface. Control signals supported by the UART include RTS, CTS, DTR, DSR, DCD and RI.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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The UART provides a transmitter enable control signal (TX_ACTIVE) on the pin DIO0 to assist with

interfacing to RS485 transceivers. The UART can support baud rates from 1.2 Kbaud to 12 Mbaud.

UART in the FT260 functions include:

 Full RS232 support

 7 or 8 data bits, an optional parity bit and 1 or 2 stop bits support

 Baud rate from 1.2 Kbaud to 12 Mbaud support

 Baud rate accuracy within +-1.5%

 Optional hardware flow control via RTS / CTS and DTR / DSR

 Optional software flow control via XON / XOFF characters

I2C Master Controller. I2C (Inter Integrated Circuit) is a multi-master serial bus invented by Philips. I2C

uses two bi-directional open-drain wires called serial data (SDA) and serial clock (SCL). Common I2C bus

speeds are the standard mode (SM) with bit rate up to 100 Kbit/s, fast mode (FM) with the bit rate up to

400 Kbit/s, Fast mode plus (FM+) with the bit rate up to 1 Mbit/s, and High Speed mode (HS) with the bit

rate up to 3.4 Mbit/s. Refer to the I2C specification for more information on the protocol.

The FT260 device can operates as I2C master, and the major functions include:

 Fully compatible to v2.1 and v3 specification

 7-bit address support

 Support 4 speed configurations defined in I2C-bus specification

 Support bit rate up to 3Mbit/s

 Clock stretching support

GPIOs. The FT260 contains 14 digital function pins. Each pin can be set as I2C/UART related function or

GPIO (General Purpose Input/Output). Some GPIO functions are implemented in the FT260 for various

applications like TX_ACTIVE, TX_LED, RX_LED for UART; SUSPOUT_N, WAKEUP for USB; PWREN and

BCD_DET indicator for power management. GPIO functions can also be directly controlled by applications

over USB via the Control pipe. The drive strength, slew rate control and pull high/low resistors can be

configured in the Vendor Specific Parameters defined in embedded eFUSE or external EEPROM by

FT_PROG.

GPIO functions for each pin in the FT260 include:

 DIO0 (pin 7 @ WQFN28) can be configured as TX_ACTIVE, TX_LED, GPIOA

 DIO1 (pin 8 @ WQFN28) will be set as GPIOB function by default

 DIO2 (pin 9 @ WQFN28) will be set as GPIOE function by default

 DIO3 (pin 10 @ WQFN28) will be set as GPIOC function by default when the UART interface in

not enabled

 DIO4 (pin 11 @ WQFN28) will be set as GPIOD function by default when the UART interface in

not enabled

 DIO5 (pin 12 @ WQFN28) can be set as GPIO0 function when the I2C interface and external

EEPROM are not supported

 DIO6 (pin 13 @ WQFN28) can be set as GPIO1 function when the I2C interface and external

EEPROM are not supported

 DIO7 (pin 14 @ WQFN28) can be configured as SUSPOUT_N, SUSPOUT, PWREN_N, GPIO2

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 DIO8 (pin 15 @ WQFN28) can be configured as WAKEUP, GPIO3

 DIO9 (pin 16 @ WQFN28) will be set as GPIOF function by default

 DIO10 (pin 17 @ WQFN28) will be set as GPIO4 function by default

 DIO11 (pin 18 @ WQFN28) will be set as GPIO5 function by default

 DIO12 (pin 27 @ WQFN28) can be configured as BCD_DET, RX_LED, PWREN_N and GPIOG

 DIO13 (pin 28 @ WQFN28) will be set as GPIOH function by default

eFUSE Controller + Internal eFUSE. The internal eFUSE (electrical poly fuse) provides storage for the

Vendor Specific Parameters. These Vendor specific Parameters are for the purpose of cost-effective

customization. When FT260 is powered up, all the parameters will be automatically loaded into and taken

effective before operation. The embedded eFUSE can be programmed over USB with an external voltage

requirement on the pin FSOURCE with 3.8V power source. These parameters can be programmed using

the FTDI utility software called FT_PROG, which can be downloaded from FTDI Utilities on the FTDI

website (http://www.ftdichip.com/Support/Utilities.htm#FT_Prog).

Vendor Specific Parameters in eFUSE include:

 USB Vendor ID (VID), Product ID (PID), power type selection

 DIO0, DIO7, DIO12 function selection

 Digital pins driving strength selection (4mA, 8mA, 12mA, 16mA)

 HID-over-I2C Slave Address

 HID-over-I2C Interrupt type

 HID-over-I2C SET_/GET_IDLE, SET_/GET_PROTOCOL, SET_POWER enable control

For further details refer to section 9.1.

5V-3.3V-1.8V LDO regulator. The LDO will regulate out 2 reference voltages for use within the FT260.

The +3.3V LDO regulator generates the +3.3V reference voltage for driving the USB transceiver cell

output buffers. It requires an external decoupling capacitor to be attached to the VOUT3V3 regulator

output pin. Another +1.8V LDO regulator generates the +1.8V reference voltage for driving the internal

core of the IC.

POR RESET Generator. POR is the integrated Power on Reset Generator Cell providing a reliable power-

on reset to the device internal circuitry at power up. There is also a RESETN input pin allowing an

external device to reset the FT260. RESETN can be tied to VCCIO (+3.3v) if not being used.

Embedded BCD Detection. Supports Battery Charger Detection. When the pin DIO12 is set as

BCD_DET function, it will be active if the device is connected to a dedicated charger instead of a standard

USB Host.

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5 FT260 Configuration and Bus Interfaces

5.1 Device Interface Configuration

The FT260 has 2 HID interfaces and can be selected by {DCNF1, DCNF0}. The first HID Interface is for

the bridge function from USB HID driver to I2C bus interface. And, the second HID Interface is for the

bridge function from USB HID driver to UART bus interface. The following table shows the USB interfaces

corresponding to the chip configuration mode.

DCNF1

DCNF0

HID Interfaces

0

Both interfaces for I2C and UART are enabled. Interfaces will be created as :

- Interface-0 is set as the interface for I2C to send and receive data via I2C connection

- Interface-1 is set as the interface for UART to send and receive data via UART connection

- DIO3 and DIO4 are set as RXD and TXD for UART by default

0

1

Only the interface for I2C is enabled. The interface will be created as :

- Interface-0 is set as the interface for I2C to send and receive data via an I2C connection

- DIO3 and DIO4 are set as GPIO functions by default.

1

0

Only the interface for UART is enabled. The interface will be created as :

- Interface-0 is set as the interface for UART to send and receive data via a UART connection

- DIO3 and DIO4 are set as RXD and TXD for UART by default

1

Both Interfaces for I2C and UART are enabled. Interfaces will be created as :

- Interface-0 is set as the interface for I2C to send and receive data via an I2C connection

- Interface-1 is set as the interface for UART to send and receive data via a UART connection

- DIO3 and DIO4 are set as RXD and TXD for UART by default

Table 5.1 FT260 USB Device Interface Configuration

Note that the default functions for the pins, GPIOC and GPIOD, will be determined by Device Interface

Configuration. When the interface for UART is enabled, the pin DIO3 is assigned as RXD for UART and

DIO4 is assigned as TXD for UART.

DIO5 and DIO6 are default designed as SCL and SDA for the I2C bus. It means that the I2C master

controller is enabled by default no matter if the interface for I2C is enabled or not. Users can set the DIO5

and DIO6 as the GPIO functions via USB commands if the interface for the I2C is disabled and

connectivity to the external I2C devices is not required.

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5.2 I2C Bus Interface

I2C (Inter Integrated Circuit) is a multi-master serial bus invented by Philips. I2C uses two bi-directional

open-drain wires called serial data (SDA) and serial clock (SCL). Common I²C bus speeds are standard

mode (SM) with a bit rate up to 100 Kbit/s, fast mode (FM) with a bit rate up to 400 Kbit/s, Fast mode

plus (FM+) with a bit rate up to 1 Mbit/s, and High Speed mode (HS) with the bit rate up to 3.4 Mbit/s.

An I2C bus node can operate either as a master or a slave:

 Master node – issues the clock and addresses slaves

 Slave node – receives the clock line and address.

The FT260 operates as an I2C master and is capable of being set to the speed modes defined in the I2C

bus specification. Besides the speed mode defined in the I2C standard specification, the I2C controller of

the FT260 can support flexible SCL frequencies defined by the following function

𝑺𝑪𝑳 𝑭𝒓𝒆𝒒 = 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐧𝐠 𝐂𝐥𝐨𝐜𝐤 𝐅𝐫𝐞𝐪𝐮𝐞𝐧𝐜𝐲

𝐌∗(𝐍+𝟏) 𝑴 = 𝟔 𝒐𝒓 𝟖; 𝑵 = 𝟏, 𝟐, 𝟑, … … , 𝟏𝟐𝟕

When the target frequency is below 100 KHz or higher than 1MHz, M will be equal to 8; otherwise, M will

be equal to 6. For example, to generate a 3MHz frequency on SCL, M will be selected as 8. With the

operating clock frequency equal to 48MHz, the user can set N as 1. The SCL frequency of the I2C master

mode for the FT260 can be set via USB commands. Details can be referenced in the FT260 Application

Notes.

5.2.1 I2C Pin Definition

The I2C function in the FT260 is an I2C master device. It is enabled by default when the FT260 is powered

up and the operating speed on the I2C bus is designed as 60 KHz for connectivity to most of the external

I2C slave devices. The I2C pins of the FT260 are

 Clock – SCL (DIO5, pin 12 @ WQFN28), as clock output with open-drain design

 Data – SDA (DIO6, pin 13 @ WQFN28), command/address/data transfer between master and

slave with open-drain design

5.2.2 I2C Bus Protocol

There are four potential modes of operation for a given bus device, although most devices only use a

single role (Master or Slave) and its two modes (Transmit and Receive):

 Master transmit – sending data to a slave

 Master receive – receiving data from a slave

 Slave transmit – sending data to a master

 Slave receive – receiving data from the master

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The following figure shows the basic I2C bus protocol

Figure 5.1 I2C Bus Protocol

The master is initially in master transmit mode by sending a start bit followed by the 7-bit address of the

slave it wishes to communicate with, which is finally followed by a single bit representing whether it

wishes to write(0) to or read(1) from the slave.

If the slave exists on the bus then it will respond with an ACK bit (active low for acknowledged) for that

address. The master then continues in either transmit or receive mode (according to the read/write bit it

sent), and the slave continues in its complementary mode (receive or transmit, respectively).

The address and the data bytes are sent most significant bit first. The start bit is indicated by a high-to-

low transition of SDA with SCL high; the stop bit is indicated by a low-to-high transition of SDA with SCL

high.

If the master wishes to write to the slave then it repeatedly sends a byte with the slave sending an ACK

bit. (In this situation, the master is in master transmit mode and the slave is in slave receive mode.)

If the master wish to read from the slave then it repeatedly receives a byte from the slave, the master

sends an ACK bit after every byte but the last one. (In this situation, the master is in master receive

mode and the slave is in slave transmit mode.). The master then ends transmission with a stop bit, or it

may send another START bit if it wishes to retain control of the bus for another transfer (a "combined

message").

I²C defines three basic types of message, each of which begins with a START and ends with a STOP:

 Single message where a master writes data to a slave;

 Single message where a master reads data from a slave;

 Combined messages, where a master issues at least two reads and/or writes to one or more

slaves

In a combined message, each read or write begins with a START and the slave address. After the first

START, these are also called repeated START bits; repeated START bits are not preceded by STOP bits,

which is how slaves know the next transfer is part of the same message.

Users can refer to the I2C specification for more information on the protocol.

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5.2.3 I2C Slave Address

The FT260 is configured as a USB to I²C master bridge and is able to issue any value of 7-bits slave

address. Users can issue I2C commands towards an I2C slave device to read or write data via the

applications defined in USB host side. For details, refer to the FT260 Application Notes.

When the FT260 is powered up, the I2C master controller will start to scan the external I2C device. The

scanning address range is from 50h to 57h for the types of EEPROM. For further details refer to section

9.2.

5.2.4 I2C Timing

Figure 5.2 I2C Bus Timing

Parameter

Min(ns)

Typ(ns)

Max(ns)

Description

T0@12MHz

83.333

T0 is the period when operating clock=12MHz

T0@24MHz

41.666

T0 is the period when operating clock=24MHz

T0@48MHz

20.833

T0 is the period when operating clock=48MHz

T1@SM/HM

16*T0

8*(1+N)*T0

SCK Period when I2C as master with standard speed

mode(SM) and HS speed mode

T1@FM/HM

12*T0

6*(1+N)*T0

SCK Period when I2C as master with FM, FM+ speed

mode

T2

8*T0

4*(1+N)*T0

SCK high pulse width when I2C as master with

standard speed mode(SM) and HS speed mode

T2

4*T0

2*(1+N)*T0

SCK high pulse width when I2C as master with FM,

FM+ speed mode

T3

2*(1+N)*T0

SDA output setup time to SCL rising edge when I2C as

master

T4

2*(1+N)*T0

SDA output hold time to SCL falling edge when I2C as

master

T5

＞＝0

input setup time requirement from SDA to SCL rising

edge when I2C as master

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T6

＞＝0

input hold time requirement from SDA to SCL falling

edge when I2C as master

T7

2*(1+N)*T0

Start bit setup time to SCL falling edge

T8

4*(1+N)*T0

Start bit hold time to SCL falling edge

T9

2*(1+N)*T0

Stop bit setup time to SCL rising edge

T10

2*(1+N)*T0

Stop bit hold time to SCL rising edge

T11

4*(1+N)*T0

Bus free time between Start and Stop bit

Table 5.2 I2C Timing for VCCIO=3.3V

*Note that N can be ranged from 1 to 255

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5.3 UART Interface

A universal asynchronous receiver/transmitter (UART) is a computer hardware device that translates data

between parallel and serial forms. UARTs are commonly used in conjunction with communication

standards such as TIA (formerly EIA) RS-232, RS-422 or RS-485.

The UART can support baud rates from 1.2 Kbaud to 12 Mbaud defined by the following function.

𝐁𝐚𝐮𝐝 𝐑𝐚𝐭𝐞 = 𝑶𝒑𝒆𝒓𝒂𝒕𝒊𝒏𝒈 𝑪𝒍𝒐𝒄𝒌 𝑭𝒓𝒆𝒒𝒖𝒆𝒏𝒄𝒚

𝑩𝒂𝒖𝒅 𝑫𝒊𝒗𝒊𝒔𝒐𝒓

The baud divisor is used to divide the operating clock frequency to the desired baud rate. It can take any

value between 4 and 40000 with the added option of adding a fractional component in the order of

1/8ths.

Example: To generate an 115200 baud rate in the FT260, the operating clock frequency to the UART

controller equals to 48MHz. The baud divisor can be calculated as shown in the below equation.

𝐁𝐚𝐮𝐝 𝐃𝐢𝐯𝐢𝐬𝐨𝐫 = 𝟒𝟖𝑴𝑯𝒛

𝟏𝟏𝟓𝟐𝟎𝟎𝑯𝒛 =𝟒𝟏𝟔.𝟔𝟔𝟕

Due to the fractional component is the order of 1/8ths, the baud divisor must be selected as 416.625. It

is obvious that the difference of baud divisors will produce a percentage error. A comparison of standard

baud rates and the divisor values can be seen in Table 5.3 below. This shows the baud rate required,

followed by the divisor value needed to achieve this if the UART is running off a 48MHz clock. Then it lists

the actual baud rate achieved and finally the percentage error this produces.

Target

Baud Rate

Ideal

Baud Divisor

Actual

Baud Divisor

Actual

Baud Rate

Baud

Error Rate

12,000,000

4

12,000,000

0.00%±0.25%*Note

9,600,000

5

9,600,000

0.00%±0.25%

8,000,000

6

8,000,000

0.00%±0.25%

6,000,000

8

6,000,000

0.00%±0.25%

3,000,000

16

3,000,000

0.00%±0.25%

2,000,000

24

2,000,000

0.00%±0.25%

1,500,000

32

1,500,000

0.00%±0.25%

1,000,000

48

1,000,000

0.00%±0.25%

921,600

52.083

52

923,076.9231

0.16%±0.25%

460,800

104.16

104.125

460,984.3938

0.04%±0.25%

230,400

208. 3

208.250

230,492.1969

0.04%±0.25%

115,200

416. 6

416.625

115,211.5212

0.01%±0.25%

57,600

833. 3

833.250

57,605.7606

0.01%±0.25%

38,400

1,250

1250

38,400

0.00%±0.25%

19,200

2,500

2500

19,200

0.00%±0.25%

9,600

5,000

5000

9,600

0.00%±0.25%

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4,800

10,000

10000

4,800

0.00%±0.25%

2,400

20,000

20000

2,400

0.00%±0.25%

1,200

40,000

40000

1,200

0.00%±0.25%

Table 5.3 Baud Rate Comparison

*Note that the baud error rate with ±0.25% is from the internal oscpll.

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5.3.1 UART Pin Definition

The UART function in the FT260 can be configured as UART-only or I2C plus UART mode by DCNF0 and

DCNF1 pins. The mode selection is as shown in the Table 5.2.

The pins of the FT260 will be mapped accordingly. The UART pins are

 Receive Data (RXD) – DIO3 (pin-10 @ WQFN28)

serial data input.

 Transmit Data (TXD) – DIO4 (pin-11 @ WQFN28)

serial data output.

 Transmit Active signal (TX_ACTIVE) – DIO0 (pin-7 @ WQFN28)

active high when data transmission is in progress. Asserted one clock cycle before start bit and

de-asserted with final stop bit.

 Request To Send Signal (RTSN) – DIO1 (pin-8 @ WQFN28)

active low handshaking bit. When low it indicates that the UART can start receiving Rx Data.

 Clear To Send Signal (CTSN) – DIO2 (pin-9 @ WQFN28)

active low handshaking bit. When this bit is ‘1’, the UART should stop sending TX Data.

 Data Terminal Ready (DTRN) – DIO9 (pin-16 @ WQFN28)

active low and when ‘0’, indicates that the UART can be connected and receive RX Data.

 Data Set Ready (DSRN) – DIO13 (pin-28 @ WQFN28)

active low indicating an active connection. When this bit is ‘1’, the UART should not send TX Data.

 Data Carrier Detect (DCD) – DIO10 (pin-17 @ WQFN28)

asserted when a connection has been established with external device.

 Ring Indicator (RI) – DIO11 (pin-18 @ WQFN28)

asserted when requested to wake up.

5.3.2 UART Bus Protocol

Data transferring uses NRZ (Non-Return to Zero) data format consisting of 1 start bit, 7 or 8 data bits, an

optional parity bit, and one or two stop bits.

 Data Bits - 7 data bits or 8 data bits.

 Parity Bit - No parity.

- Odd parity. This means that the parity bit is set to either ‘1’ or ‘0’ so that an odd

number of 1’s are sent.

- Even parity. This means that the parity bit is set to either ‘1’ or ‘0’ so that an even

number of 1’s are sent.

- High parity. This simply means that the parity bit is always High.

- Low parity. This simply means that the parity bit is always Low.

 Stop Bits - one bit or two bits.

When transmitting the data bits, the least significant bit is transmitted first. UART transmitting and

receive waveforms are illustrated in the below figures.

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Figure 5.3 UART RX Waveform consist of 8 data bits, 1 optional parity bit and 1 stop bit

Figure 5.4 UART TX Waveform consist of 7 data bits, no parity bit and 1 stop bit

Figure 5.5 UART TX Waveform consist of 7 data bits, 1 optional parity bit and 1 stop bit

Figure 5.6 UART TX Waveform consisting 7 data bits, 1 optional parity bit and 2 stop bits

Figure 5.7 UART TX Waveform consisting 8 data bits, 1 optional parity bit and 2 stop bits

TX_ACTIVE is default function of the pin DIO0 as the transmitting indicator for UART; this output may be

used in RS485 designs to control the transmitting of the line driver.

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5.3.3 UART Flow Control

The UART interface needs to implement proper flow control to prevent data from being lost by the

external device. This will be done using either hardware or software flow control. The FT260 UART

supports the modes listed below.

 OFF, and switch UART pins to GPIO

 RTS_CTS mode (hardware flow control)

 DTR_DSR mode (hardware flow control)

 XON_XOFF (software flow control)

 No flow control mode

RTS/CTS Hardware Flow Control

When RTS / CTS flow control is used, the CTS input indicate to the FT260 that the data communications

equipment (DCE) is ready to receive data. If it is active (low), then the FT260 is free to transmit data on

the TX data line, otherwise it has to hold the data until CTS goes low. The RTS output is used to indicate

that The FT260 is capable of receiving data (active low). Thus, it should be set inactive by the FT260

when both the UART receive register and receive holding register are full.

DTR/DSR Hardware Flow Control

These signals are provided to give information about the status of each UART. When this mode is enabled

and the DTS input is high, the FT260 UART should not send any data on the TX line. DTR will be enabled

on reset and a register bit will allow the IO Bus to alter the state at any time.

Software Flow Control

When software flow control is enabled the XON character and XOFF character are used to stop and start

the flow of data. The XON character tells the downstream device to start sending data. The XOFF

character tells the downstream device to stop sending data. Typical defaults for XON is `11’ and for XOFF

is `13’.

5.3.4 UART Timing

Figure 5.8 UART Timing

Parameter

Min(ns)

Typ(ns)

Max(ns)

Description

T0@48MHz

-2500ppm

20.833

+2500ppm

T0 is the period when operating clock=48MHz

T1

4*T0

40000*T0

Baud clock period of txd

Table 5.4 UART Timing

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5.4 GPIOs

Most of the digital I/O pins of the FT260 have a GPIO function as an alternative function. For example,

pin 10 can be RXD or GPIOC, and RXD is the main function of pin 10. Usually, if the main function of a

pin is switched off, the pin will be switched to a GPIO pin. Therefore, if UART is turned off, all UART pins

will become GPIO pins. The FT260 has 3 pins which have more than 2 functions. They are GPIO 2(pin

14), GPIOA (pin 7), and GPIOG (pin 27). The working function of these 3 pins can be configured by

eFUSE, EEPROM, or via USB commands. Please refer to the eFUSE and EEPROM sections for more details.

The FT260 has two sets of GPIO pins: GPIO0~5 and GPIOA~H. After the pins are configured as GPIO,

users can set or get the direction and pin status via the USB control pipe, i.e. HID SET_REPORT and

GET_REPORT requests. The FT260 also provides an interrupt input source on GPIO3/Interrupt (pin

15). If the interrupt is triggered, the FT260 will generate an interrupt report with report ID 0xB1 via the

interrupt IN pipe from the UART interface. The FT260 interrupt provides 4 trigger types: rising edge,

falling edge, level-high, and level-low. By default, it is configured as level-high for 30ms. Note, that GPIO

and interrupt are two different functions, which means if interrupt is the working function of pin 15, users

cannot set and get GPIO3 status. Switching pin 15 to be either GPIO or interrupt and trigger settings can

be done via EEPROM or USB commands.

The FT260 has flexible settings for suspend behaviour of all digital I/O pins. During suspend, these pins

can perform pushing high, pushing low, tristate, or no-change. No-change means to keep the original

function and value during suspend. The suspend behaviour can be configured in an external EEPROM.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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6 Devices Characteristics and Ratings

6.1 Absolute Maximum Ratings

The absolute maximum ratings for the FT260 devices are as follows. These are in accordance with the

Absolute Maximum Rating System (IEC 60134). Exceeding these may cause permanent damage to the

device.

Parameter

Value

Unit

Conditions

Storage Temperature

-65°C to 150°C

Degrees C

Floor Life (Out of Bag) At Factory Ambient

(30°C / 60% Relative Humidity)

168 Hours

(IPC/JEDEC J-

STD-033A MSL

Level 3

Compliant)*

Hours

Ambient Operating Temperature (Power

Applied)

-40°C to 85°C

Degrees C

MTTF FT260

TBD

Hours

VCCIN Supply Voltage

-0.3 to +5.5

V

VCCIO IO Voltage

-0.3 to +4.0

V

FSOURCE Supply Voltage

3.8±0.4

V

DC Input Voltage – USBDP and USBDM

-0.5 to +3.63

V

DC Input Voltage – High Impedance

Bi-directional (powered from VCCIO)

-0.3 to

+(VCCIO+0.5V)

V

DC Output Voltage

3.3±0.15

V

VOUT3V3

DC Output Current – Outputs

100 **

mA

Table 6.1 Absolute Maximum Ratings

* If devices are stored out of the packaging beyond this time limit the devices should be baked before

use. The devices should be ramped up to a temperature of +125°C and baked for up to 17 hours.

** This DC output current on VOUT3V3 is also the power supply source for FT260 operation. If it must be

the source for other components in the system, it can only supply 75mA or less.

6.2 ESD and Latch-up Specifications

Description

Specification

Human Body Mode (HBM)

> ± 2kV

Machine mode (MM)

> ± 200V

Charged Device Mode (CDM)

> ± 500V

Latch-up

> ± 200mA

Table 6.2 ESD and Latch-Up Specifications

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6.3 DC Characteristics

DC Characteristics (Ambient Temperature = -40°C to +85°C)

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

VCC1

VCCIN Operating Supply

Voltage

4.5

5

5.5

V

VCCIN is supplied

with 5V

2.97

3.3

3.63V

V

VCCIN is supplied

with 3.3V

VCC2

VCCIO Operating Supply

Voltage

2.97

3.3

3.63

V

VCCIO is supplied

with 3.3V

2.25

2.5

2.75

V

VCCIO is supplied

with 2.5V

1.62

1.8

1.98

V

VCCIO is supplied

with 1.8V

Inormal

Operating Supply

Current

9.6*

mA

Normal Operation at

12MHz

14.5*

mA

Normal Operation at

24MHz

23.6*

mA

Normal Operation at

48MHz

Iidle

Idle Supply Current

4.17

mA

IDLE Operation at

30KHz

Isusp

Suspend Supply Current

356

μA

USB Suspend

3V3

3.3v regulator output

2.97

3.3

3.63

V

VCCIN must be

greater than 3V3

otherwise VOUT3V3

is an input which

must be driven with

3.3V

VFSOURCE

eFUSE Blowing Supply

Voltage

3.4

3.8

4.2

V

Table 6.3 Operating Voltage and Current

* The current measurement is with the regular data transferring speed between USB and I2C/UART

interface. All the pins are with 4mA driving strength and without heavy loading.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

Voh

Output Voltage High

2.97

VCCIO

V

Ioh = +/-2mA

I/O Drive strength*

= 4mA

2.97

VCCIO

V

I/O Drive strength*

= 8mA

2.97

VCCIO

V

I/O Drive strength*

= 12mA

2.97

VCCIO

V

I/O Drive strength*

= 16mA

Vol

Output Voltage Low

0

0.4

V

Iol = +/-2mA

I/O Drive strength*

= 4mA

0

0.4

V

I/O Drive strength*

= 8mA

0

0.4

V

I/O Drive strength*

= 12mA

0

0.4

V

I/O Drive strength*

= 16mA

Vil

Input low Switching

Threshold

0.8

V

LVTTL

Vih

Input High Switching

Threshold

2.0

V

LVTTL

Vt

Switching Threshold

1.49

V

LVTTL

Vt-

Schmitt trigger negative

going threshold voltage

1.15

V

Vt+

Schmitt trigger positive

going threshold voltage

1.64

V

Rpu

Input pull-up resistance

40

75

190

KΩ

Vin = 0

Rpd

Input pull-down

resistance

40

75

190

KΩ

Vin =VCCIO

Iin

Input Leakage Current

-10

+/-1

10

μA

Vin = 0

Ioz

Tri-state output leakage

current

-10

+/-1

10

μA

Vin = 5.5V or 0

Table 6.4 I/O Pin Characteristics VCCIO = +3.3V (except USB PHY pins)

* The I/O drive strength and slow slew-rate are configurable in eFUSE or external EEPROM

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

Voh

Output Voltage High

2.25

VCCIO

V

Ioh = +/-2mA

I/O Drive strength*

= 4mA

2.25

VCCIO

V

I/O Drive strength*

= 8mA

2.25

VCCIO

V

I/O Drive strength*

= 12mA

2.25

VCCIO

V

I/O Drive strength*

= 16mA

Vol

Output Voltage Low

0

0.4

V

Iol = +/-2mA

I/O Drive strength*

= 4mA

0

0.4

V

I/O Drive strength*

= 8mA

0

0.4

V

I/O Drive strength*

= 12mA

0

0.4

V

I/O Drive strength*

= 16mA

Vil

Input low Switching

Threshold

0.8

V

LVTTL

Vih

Input High Switching

Threshold

1.7

V

LVTTL

Vt

Switching Threshold

1.1

V

LVTTL

Vt-

Schmitt trigger negative

going threshold voltage

0.8

V

Vt+

Schmitt trigger positive

going threshold voltage

1.2

V

Rpu

Input pull-up resistance

40

75

190

KΩ

Vin = 0

Rpd

Input pull-down

resistance

40

75

190

KΩ

Vin =VCCIO

Iin

Input Leakage Current

-10

+/-1

10

μA

Vin = 0

Ioz

Tri-state output leakage

current

-10

+/-1

10

μA

Vin = 5.5V or 0

Table 6.5 I/O Pin Characteristics VCCIO = +2.5V (except USB PHY pins)

* The I/O drive strength and slow slew-rate are configurable in eFUSE or external EEPROM

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

Voh

Output Voltage High

1.62

VCCIO

V

Ioh = +/-2mA

I/O Drive strength*

= 4mA

1.62

VCCIO

V

I/O Drive strength*

= 8mA

1.62

VCCIO

V

I/O Drive strength*

= 12mA

1.62

VCCIO

V

I/O Drive strength*

= 16mA

Vol

Output Voltage Low

0

0.4

V

Iol = +/-2mA

I/O Drive strength*

= 4mA

0

0.4

V

I/O Drive strength*

= 8mA

0

0.4

V

I/O Drive strength*

= 12mA

0

0.4

V

I/O Drive strength*

= 16mA

Vil

Input low Switching

Threshold

0.63

V

LVTTL

Vih

Input High Switching

Threshold

1.17

V

LVTTL

Vt

Switching Threshold

0.77

V

LVTTL

Vt-

Schmitt trigger negative

going threshold voltage

0.557

V

Vt+

Schmitt trigger positive

going threshold voltage

0.893

V

Rpu

Input pull-up resistance

40

75

190

KΩ

Vin = 0

Rpd

Input pull-down

resistance

40

75

190

KΩ

Vin =VCCIO

Iin

Input Leakage Current

-10

+/-1

10

μA

Vin = 0

Ioz

Tri-state output leakage

current

-10

+/-1

10

μA

Vin = 5.5V or 0

Table 6.6 I/O Pin Characteristics VCCIO = +1.8V (except USB PHY pins)

* The I/O drive strength and slow slew-rate are configurable in eFUSE or external EEPROM

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6.4 USB Characteristics

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

DC Characteristics

URo

Output impedance

3.5

7

14

Ω

URpu

Internal Pull Up

resistance

0.976

1.24

1.574

Ω

UVOH

High level Output on DP

and DM

2.8

V

UVOL

Low level Output on DP

and DM

0.3

V

AC Characteristics

UTrise

Rise Time on DP/DM

4

10

20

ns

UTfall

Fall Time on DP/DM

4

10

20

ns

UVcr

Cross point

1.3

2.0

V

UVth

Single-ended receiver

threshold

0.8

2.0

V

Table 6.7 USB I/O Pin (DP, DM) Characteristics

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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7 FT260 Power Configurations

Section 7.1 to section 7.4 illustrates possible USB power configurations for the FT260. Section 7.5 shows

the configuration for system pins about DCNF0, DCNF1, XRESETN and other system pins. Section 7.6

shows the power for programming eFUSE.

7.1 USB Bus Powered Configuration

Figure 7.1 Bus Powered Configuration

Figure 7.1 illustrates the FT260 in a typical USB2.0 bus powered design configuration. A USB bus

powered device gets its power from the USB bus. Basic rules for USB bus powered devices are as follows

i) On plug-in to USB, the device should draw no more current than 100mA.

ii) In USB Suspend mode the device should draw no more than 2.5mA.

iii) A bus powered, high power USB device (one that draws more than 100mA) can use the

SUSPOUT_N function on the pin DIO7 as a power disable function and use it to keep the

current below 2.5mA on USB suspend.

iv) A device that consumes more than 100mA cannot be plugged into a USB bus powered hub.

v) No device can draw more than 500mA from the USB bus.

The VCCIN pin is the power source for the FT260 and can directly connect to VBUS. When the I/O voltage

level is as +3.3V, users can directly connect VOUT3V3 to VCCIO without an external regulator. The

VBUS_DET pin is a 5V-tolerant input pin and can directly connect to VBUS without an on-board voltage

divider circuit. The power descriptors in the embedded eFUSE of the FT260 or in the external EEPROM

should be programmed to match the current drawn by the device.

A ferrite bead is connected in series with the USB power supply to reduce EMI noise from the FT260 and

associated circuitry being radiated down the USB cable to the USB host. The value of the Ferrite Bead

depends on the total current drawn by the application. A suitable range of Ferrite Beads is available from

Steward (www.steward.com), for example Laird Technologies Part # MI0805K400R-10.

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7.2 Self Powered Configuration with 5V Source Input

Figure 7.2 Self Powered Configuration with 5V Source Input

Figure 7.2 illustrates the FT260 in a typical USB2.0 self-powered configuration. A USB self-powered

device gets its power from its own power supply, 5V, and does not draw current from the USB bus. The

basic rules for USB self-powered devices are as follows –

i) A self-powered device should not force current down the USB bus when the USB host or hub

controller is powered down.

ii) A self-powered device can use as much current as it needs during normal operation and USB

suspend as it has its own power supply.

iii) A self-powered device can be used with any USB host, a bus powered USB hub or a self-

powered USB hub.

VCCIN is the power source for the FT260 and will source power from its own power supply. When the I/O

voltage level is +3.3V, users can directly connect VOUT3V3 to VCCIO without an external regulator. The

power descriptors in the embedded eFUSE of the FT260 or in the external EEPROM should be

programmed as self-powered.

In order to comply with the first requirement above, the USB bus power (USB connector pin 1) is used to

control the VBUS_DET pin of the FT260 device. VBUS_DET is a 5V-tolerant input pin and can directly

connect to VBUS without an on-board voltage divider circuit. When the USB host or hub is powered up an

internal 1.5kΩ resistor on DP is pulled up to +3.3V, thus identifying the device to the USB host or hub.

When the USB host or hub is powered off, the VBUS_DET pin will be low and the FT260 is held in a

suspend state. In this state the internal 1.5kΩ resistor is not pulled up to any power supply (hub or host

is powered down), so no current flows down DP via the 1.5kΩ pull-up resistor. Failure to do this may

cause some USB host or hub controllers to power up erratically.

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7.3 Self Powered Configuration with 3.3V Source In

Figure 7.3 Self Powered Configuration with 3.3V Source Input

Figure 7.3 illustrates the FT260 in a typical USB self-powered configuration similar to Figure 7.2. The

difference here is that the self-power source is 3.3V. If using 3.3V as the power source in, remember to

connect it to VOUT3V3 to supply an operating voltage for USB signalling in the FT260.

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7.4 Bus Powered Configuration with +1.8V/+2.5V I/O Voltage

Figure 7.4 Bus Powered Configuration with +1.8V/+2.5V I/O voltage Level

Figure 7.4 illustrates the FT260 in a typical USB bus-powered configuration similar to Figure 7.1. The

difference here is that the I/O pin voltage source is 2.5V or 1.8V, not 3.3V. An external regulator can

source the power from VBUS and regulate out the required I/O voltage level. Then, VCCIO can connect to

the output of the regulator to achieve I/O voltage level operating at +1.8V or +2.5V. VCCIN should be

connected to VBUS to supply the power source for FT260 operation.

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7.5 Configuration for System Pins

Figure 7.5 Recommended FT260 Configuration of System Pins

The pins, DCNF0 and DCNF1, will determine one of 3 configurations for the FT260 as defined in Section

5.1. These 2 pins have internal pull-down resistors; these 2 pins can be left floating for logic-0. If logic-1

is applied for DCNF0 and/or DCNF1, a 10K Ohm resistor should be connected to VCCIO as shown in

Figure7.5.

The pin RESETN is the external reset source for the FT260. There is also a power-on-reset (POR) design

in the FT260. If there is no requirement for an external reset, RESETN can be left floating or weakly tied

to logic-high. If an external reset is required in the design, the related circuit in Figure 7.5 can be used

for reference.

The DEBUGGER pin is reserved for debugging purposes and should be tied to VCCIO, the I/O power

domain for the FT260. The pin, STEST_RESETN, is also a reserved pin and should be tied to logic-high.

Note that the GND pin located at pin-29 in Figure 7.5 is the paddle in the bottom side of the WQFN28

package. It should be tied together with the GND for FT260.

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7.6 Power for Programming eFUSE

Figure 7.6 FSOURCE for eFUSE

When the FT260 is in normal operation without programming the eFUSE, the FSOURCE pin can be left

floating. If the programming mechanism is required in the system, a power source with 3.8V should be

applied. Figure 7.6 shows the related components for FSOURCE.

The programmer module, UMFTPD3A, which is developed by FTDI, can supply the power source for

FSOURCE. With the programming utility FT_PROG, it can control the programming procedure and timing

to the embedded eFUSE in the FT260. Users can easily set the vendor specifying parameters which are

defined in eFUSE for customizing the FT260.

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8 Application Examples

The following diagrams show the possible applications of the FT260. The illustrations have omitted the

electrical design for the power domain plan. For power details refer to Section 7.

8.1 USB HID-over-I2C

Figure 8.1 Application Example 1: HID over I2C

In Figure 8.1, a HID-over-I2C device can easily connect to USB by integrating the FT260 into the system.

With an on-board EEPROM for customization, the FT260 can connect to both EEPROM and a HID class

device with I2C slave interface simultaneously. DIO8 can be set as INTRIN, an interrupt input source from

a HID class device for the requirement of the HID-over-I2C specification. With 1K Ohm pull up resistors

on SCL and SDA, the I2C bus can run at HS mode.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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8.2 USB to RS232 Converter

Figure 8.2 Application Example 2: USB to RS232 Converter

An example of using the FT260 as a USB to RS232 converter is illustrated in Figure 8.2. In this

application, a TTL to RS232 Level Converter IC is used on the serial UART interface of the FT260 to

convert the TTL levels of the FT260 to RS232 levels. This level shift can be done using the popular “213”

series of TTL to RS232 level converters. These “213” devices typically have 4 transmitters and 5 receivers

in a 28-LD SSOP package and feature an in-built voltage level converter to convert the +5V (nominal)

VCC to the +/- 9 volts required by RS232.

The Shut Down control (SHDN) signal of the converter device is the suspend control. The pin DIO7 of the

FT260 can be set to function as SUSPOUT_N with active-low output and can be the control source to the

converter IC. Note that the power source for the converter IC in Figure 8.2 is not supplied from the

VOUT3V3 of the FT260 since the current consumption of this kind of converter is high. The supply current

of VOUT3V3 is limited. Details can be referred to Table 6.1.

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8.3 USB to RS485 Converter

Figure 8.3 Application Example 3: USB to RS485 Converter

An example of using the FT260 as a USB to RS485 converter is shown in Figure 8.3. In this application, a

TTL to RS485 level converter IC is used on the serial UART interface of the FT260 to convert the TTL

levels of the FT260 to RS485 levels.

The converter device requires separate enable signals on both the transmitter and receiver. With RS485,

the transmitter is only enabled when a character is being transmitted from the UART. Setting DIO0 as

TX_ACTIVE is provided for exactly the same purpose and wired to the transmitter enable (DE) of

converter device. The pin DIO12 of FT260 can be configured as PWREN_N and wired to the receiver

enable (RE) of the converter device. With these configurations of the pins, the FT260 can be used as the

USB to RS485 converter.

RS485 is a multi-drop network; so many devices can communicate with each other over a two wire cable

interface. The RS485 cable requires to be terminated at each end of the cable. A link (which provides the

120Ω termination) allows the cable to be terminated if the converter device is physically positioned at

either end of the cable.

In this example, the data transmitted by the FT260 is also present on the receive path of the converter

device. This is a common feature of RS485 and requires the application software to remove the

transmitted data from the received data stream. With the FT260, it is possible to do this entirely in

hardware by modifying the example shown in Figure 8.3 by logically OR-ing the FT260 TX_ACTIVE and

the receiver output (RO) of converter device then connecting the output of the OR gate to the RXD of

FT260.

Note that the TX_ACTIVE is activated 1 bit ahead the start bit. TX_ACTIVE is de-activated at the same

time as the stop bit. This is not configurable.

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8.4 USB to RS422 Converter

Figure 8.4 Application Example 4 : USB to RS422 Converter

An example of using the FT260 as a USB to RS422 converter is shown in Figure 8.4. In this application,

two TTL to RS422 Level Converter ICs are used on the serial UART interface of the FT260 to convert the

TTL levels of the FT260 to RS422 levels.

There are many suitable level converter devices available. In Figure 8.4, the converter devices have an

enable control (EN) to activate the data lines. Setting DIO7 as SUSPOUT_N allows the FT260 to disable

the level converters when the system is in suspend. SUSPENDOUT_N is an active-low signal. The DIO0

and DIO12 of the FT260 can be configured as TX_LED and RX_LED. The FT260 can toggle LEDs with

these signals when the UART interface is transmitting and receiving data.

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9 User Configuration

The FT260 provides two storage paths for customization. One is eFUSE which is embedded in the FT260;

another is the executable path to an external EEPROM. Parameters are defined for the customization and

are categorized into several groups. The groups are USB-related, GPIO function selection, pin feature

settings, UART settings and HID-over-I2C.

Embedded eFUSE provides a cost-effective customization. Without external devices, the FT260 can have

customised VID/PID for USB, driving strength for digital pins, GPIOA, GPIOG, GPIO2 configurations and

HID-over-I2C basic settings.

For customization demand, an EEPROM is required in the application. With this external EEPROM, more

parameters are defined for customization. In this storage area, parameters in eFUSE are all included.

USB string descriptor, pins status when USB suspending, and detailed pin configurations are included in

EERPOM. Details can refer to Section 9.2.2.

There is already a default value for each parameter in the design of the FT260. When the parameters in

eFUSE are programmed and enabled, the parameters in eFUSE will be loaded when the FT260 is powered

up or reset.

Both eFUSE and EEPROM for the FT260 can be programmed over USB. This method is the same as for

the MTP on other FTDI devices such as the FT-X series. Please note that in order to program eFUSE, the

FT260 requires an additional programming voltage (3.8V) on its FSOURCE pin. The programming board,

UMFTPD3A, supplies an easy connection bridge between the FT260 and a USB host for supplying the

power source, for timing control of eFUSE, and for communicating with the programming utility FT_Prog.

Further details may be found in the UMFTPD3A datasheet.

The FT_Prog utility is provided free-of-charge from the FTDI website, and can be found at the link below.

The user guide is also available at this link.

http://www.ftdichip.com/Support/Utilities.htm#FT_Prog

9.1 Programming the embedded eFUSE over USB

The eFUSE in the FT260 can be programmed over USB. This method is the same as for the MTP on other

FTDI devices such as the FT-X series. Note that in order to program eFUSE, the FT260 requires an

additional programming voltage (3.8V) on FSOURCE (pin-25 @ WQFN28 ; pin-1 @ TSSOP28). The

programming board, UMFTPD3A, can supply an easy connection bridge between the FT260 and a USB

host for supplying the power source to FSOURCE and for communicating with the programming utility

FT_Prog.

9.1.1 Default Values

The parameters defined in eFUSE are shown in Table 9.1. Default values are defined in the hardware

design of the FT260. If the parameters defined in eFUSE are enabled, the settings in eFUSE will replace

the default value.

Parameter

Default Value

Notes

USB Vendor ID (VID)

0403h

USB Vendor ID. Defined in the USB device descriptor. The

format is 16-bit hex coded and default is set as FTDI VID.

USB Product ID (PID)

6030h

USB Product ID. Defined in the USB device descriptor The

format is 16-bit hex coded and default is set as 6030h for

FT260.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Default Value

Notes

Power Source

Bus Powered

Define whether the power source is from the USB bus or a local

source.

Max Bus Power Current

100mA

The max power that will be drawn from VBUS when using bus

power. Range from 0~500mA. If the power source is defined as

self-powered, it must be set as 0mA.

Remote Wake Up

Enable

Define if the FT260 supports remote wake up or not.

GPIO2 Function

SUSPOUT_N

The GPIO2 pin can be set as one of the alternative functions:

- GPIO2

- PWREN# (low active), device ready indicator

- TX_LED, UART TX transferring indicator

- SUSPOUT_N, USB suspend low-active indicator.

GPIOA Function

TX_ACTIVE

The GPIOA pin can be set as one of the alternative functions:

- GPIOA

- TX_LED, UART TX transferring indicator

- TX_ACTIVE

GPIOG Function

BCD_DET

The GPIOG pin can be set as one of the alternative functions:

- GPIOG

- PWREN# (low active), device ready indicator

- RX_LED, UART RX receiving indicator

- BCD_DET, Battery Charger Detection indicator

UART Drive Strength

4mA

Adjustable drive strength for UART related pins TXD/RXD,

CTS/RTS, DTR/DSR, TX_ACTIVE. Drive strength can be set as

4mA, 8mA, 12mA and 16mA

GPIO Drive Strength

4mA

Adjustable drive strength for GPIO related pins GPIO0, GPIO1,

GPIO2, GPIO3, GPIO4, and GPIO5. Drive strength can be set as

4mA, 8mA, 12mA and 16mA

BCD_DET Function Disable?

No

Battery Charger Detection function can be disabled on

BCD_DET pin.

BCD_DET Drive Strength

4mA

Adjustable drive strength for BCD_DET pin. Drive strength can

be set as 4mA, 8mA, 12mA and 16mA

BCD_DET Polarity

Active-high

Set the polarity on BCD_DET pin for indicating battery charge

detected. Default is set as active-high.

Power Saving Mode

Enable

If power saving mode is enable and the FT260 is idle for 5

seconds, it will switch the system clock to 30KHz for saving

power.

HID over I²C address

0h

The I²C slave address of the target HID-over-I²C device. The

address 0h means no HID-over-I²C device connected.

HID over I²C Descriptor

Address

0h

The start address of the descriptor of the target HID-over-I²C

device.

HID over I²C Interrupt

Rising Edge

Define the interrupt trigger type of the target HID-over-I²C

device. It can be: rising edge, falling edge, level-high, level-

low.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Default Value

Notes

HID over I²C Option

Supported

According to Microsoft HID over I²C Protocol Specification, the

following requests are optional:

- GET_IDLE/SET_IDLE supported or not?

- GET_PROTOCOL/SET_PROTOCOL supported or not?

- SET_POWER supported or not?

Table 9.1 Parameters defined in internal eFUSE for FT260

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9.2 Programming the external EEPROM over USB

The external EEPROM can be programmed over USB, which is supported by FT_PROG as most FTDI chips

do.

The FT_Prog utility is provided free-of-charge from the FTDI website, and can be found at the link below.

The user guide is also available at this link.

http://www.ftdichip.com/Support/Utilities.htm#FT_Prog

Please note that a user needs to specify the data address type as one-byte or two-byte when

programming the external EEPROM.

9.2.1 Supported EEPROM Spec

The FT260 supports an external EEPROM with I²C interface, slave address 0x50~0x57, and data size

larger than 256 bytes. When the FT260 powers on, it will scan the I²C bus and try to find if an external

EEPROM is present. If it is present, it will check the content and load the configuration data from the

EEPROM into the FT260. Note that loading data from an external EEPROM is the last step of power-on,

and it will overwrite the configuration data from eFUSE.

There are two different types of EEPROM. One has one-byte data address; the other one has two-byte

data address. Usually, the first one has a data size smaller than 256 bytes, and the second one has a

data size more than 256 bytes. It is not possible for the FT260 to automatically identify the EEPROM type,

therefore, FT_prog will require the user’s input to specify the type of the external EEPROM.

In summary, the supported external EEPROM has:

 I²C interface with slave address 0x50~0x57

 256 bytes at least

 One-byte data address or two-byte data address

The protocol of one-byte data address EEPROM

Write:

Start

7 bit slave

address

write

ACK

8 bit

data addr

ACK

8 bit data

ACK

STOP

Read:

Start

7 bit slave

address

write

ACK

8 bit

data addr

ACK

SR

7 bit slave

address

read

ACK

8 bit data

ACK

STOP

Figure 9.1 Protocol Format for EEPROM with One Byte Data Address

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The protocol of two-byte data address EEPROM

Write:

Start

7 bit slave

address

write

ACK

1st 8 bit

data addr

ACK

2nd 8 bit

data addr

ACK

8 bit data

ACK

STOP

Read:

Start

7 bit slave

address

write

ACK

1st 8 bit

data addr

ACK

2nd 8 bit

data addr

ACK

SR

7 bit slave

address

read

ACK

8 bit data

ACK

STOP

Figure 9.2 Protocol Format for EEPROM with Two Bytes Data Address

Table9.2 shows the list of the external EEPROMs that are tested with the FT260.

Manufacturer

Part Number

Type

Atmel

AT24CS04-SSHM-TCT-ND 512 x 8

One-byte data address

Atmel

AT24C08D-PUM-ND 1K x 8

One-byte data address

Atmel

AT24CS16-SSHM-TCT-ND 2K x 8

One-byte data address

Atmel

AT24CM01 (1M bit)

Two-byte data address

On Semiconductor

CAT24C04WI-G-ND 512 x 8

One-byte data address

On Semiconductor

CAT24C08WI-GT3CT-ND 1k x 8

One-byte data address

On Semiconductor

CAT24C08WI-GT3CT-ND 2k x 8

One-byte data address

On Semiconductor

CAT24C512

Two-byte data address

Microchip

24AA08-I/SN-ND 1k x 8

One-byte data address

Microchip

24AA16-I/SN-ND 2k x 8

One-byte data address

Table 9.2 Tested EEPROM List for FT260

9.2.2 Default Values

The parameters defined in the EEPROM are shown in Table9.3. Default values are defined in the FT260. If

an EEPROM exists in the application, the priority of the EEPROM is higher than default values.

Parameter

Default Value

Notes

Device Type

FT260

Read-Only. Indicate the Chip is FT260.

USB Vendor ID (VID)

0403h

USB Vendor ID. Defined in the USB device descriptor. The

format is 16-bit hex coded and default is set as FTDI VID.

USB Product ID (PID)

6030h

USB Product ID. Defined in the USB device descriptor The

format is 16-bit hex coded and default is set as 6030h for

FT260.

USB Version

0200h

Read-only. Returns the USB 2.0 device descriptor to the host.

Note: FT260 is a Full-speed USB2.0 device.

Power Source

Bus Powered

Define whether the power source is from the USB bus or a local

source.

Max Bus Power Current

100mA

The max power that will be drawn from VBUS when using bus

power. Range from 0~500mA. If the power source is defined as

self-powered, it must be set as 0mA.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Default Value

Notes

Remote Wake Up

Enable

Define if the FT260 supports remote wake up or not.

Manufacturer Name

FTDI

Describing the manufacturer. A string descriptor defined in USB

device descriptors

Product Description

FT260

Describing the product. A string descriptor defined in USB

device descriptors

Serial Number Enabled?

No

Enable the string descriptor for serial number or not.

Serial Number

None

A unique serial number is generated and programmed into the

EEPROM. Refer to the Utility FT_Prog for details.

Suspend Out Polarity

Active-low

Set the polarity on GPIO2 pin for indicating suspend out.

Default is set as active-low.

RI as Wake-Up

Disable

UART RI can be the source to remote wakeup the USB host

when this remote wake up is allowed.

- Disable (default)

- Enable

RI Wake-Up Config

Falling Edge

Specify the criteria for RI to trigger a remote wake-up.

- Falling Edge(default), RI from Logic-High to Low

- Rising Edge, RI from Logic-Low to High

GPIO2 Function

SUSPOUT_N

The GPIO2 pin can be set as one of the alternative functions:

- GPIO2

- PWREN# (low active), device ready indicator

- TX_LED, UART TX transferring indicator

- SUSPOUT_N/SUSPOUT, USB suspend indicator

GPIOA Function

TX_ACTIVE

The GPIOA pin can be set as one of the alternative functions:

- GPIOA

- TX_LED, UART TX transferring indicator

- TX_ACTIVE

GPIOG Function

BCD_DET

The GPIOG pin can be set as one of the alternative functions:

- GPIOG

- PWREN# (low active), device ready indicator

- RX_LED, UART RX receiving indicator

- BCD_DET, Battery Charger Detection indicator

UART Drive Strength

4mA

Adjustable drive strength for UART related pins TXD/RXD,

CTS/RTS, DTR/DSR, TX_ACTIVE. Drive strength can be set as

4mA, 8mA, 12mA and 16mA

UART Slew Rate Enable?

Disable

Set the slew rate control for UART related pins TXD/RXD,

CTS/RTS, DTR/DSR, TX_ACTIVE. Default is disabled

GPIO Drive Strength

4mA

Adjustable drive strength for GPIO related pins GPIO0, GPIO1,

GPIO2, GPIO3, GPIO4, and GPIO5. Drive strength can be set as

4mA, 8mA, 12mA and 16mA

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Parameter

Default Value

Notes

GPIO Weak Pullup/Pulldown

Disable

Enable the weak pullup / pulldown resistor on the pins GPIO0,

GPIO1, GPIO2, GPIO3, GPIO4, and GPIO5. Default is disabled

(without any pull).

GPIO Slew Rate Enable?

Disable

Set the slew rate control for GPIO related pins GPIO0, GPIO1,

GPIO2, GPIO3, GPIO4, and GPIO5. Default is disabled

BCD_DET Function Disable?

No

Battery Charger Detection function can be disabled on

BCD_DET pin.

BCD_DET Drive Strength

4mA

Adjustable drive strength for BCD_DET pin. Drive strength can

be set as 4mA, 8mA, 12mA and 16mA

BCD_DET Polarity

Active-high

Set the polarity on BCD_DET pin for indicating battery charge

detected. Default is set as active-high.

Interrupt Trigger

Level-high

Define the interrupt trigger type when GPIO3 is set as

INTR/WAKEUP function. The possible settings are: rising edge,

falling edge, level-high, level-low.

Trigger Level Setting

30ms

Interrupt level width select. When the interrupt is set to level

trigger and it exceeds the specified level width, the interrupt

signal will be generated. The level width can be set as 1ms,

5ms and 30ms.

Power Saving Mode

Enable

If power saving mode is enable and the FT260 is idle for 5

seconds, it will switch the system clock to 30KHz for saving

power.

Pin Status During Suspend

No change

During suspend , each digital I/O pin of the FT260 can be set

as

- No change, keep the original pin function

- tristate

- push low when suspend

- push high when suspend

HID over I²C address

0h

The I²C slave address of the target HID-over-I²C device. The

address 0h means no HID-over-I²C device connected.

HID over I²C Descriptor

Address

0h

The start address of the descriptor of the target HID-over-I²C

device.

HID over I²C Interrupt

Rising Edge

Define the interrupt trigger type of the target HID-over-I²C

device. It can be: rising edge, falling edge, level-high, level-

low.

HID over I²C Option

Not supported

According to Microsoft HID over I²C Protocol Specification, the

following requests are optional:

- GET_IDLE/ SET_IDLE supported or not

- GET_PROTOCOL/ SET_PROTOCOL supported or not

- SET_POWER supported or not

HID over I²C Subclass

No Subclass

The HID subclass description. It can be:

- No Subclass

- Boot Interface Subclass

HID over I²C Protocol

None

The HID protocol code description. It can be:

- None

- Keyboard

- Mouse

Table 9.3 Parameters defined in external EEPROM for FT260

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10 Package Parameters

The FT260 is available in WQFN-28 and TSSOP-28 package. The solder reflow profile for WQFN-28 and

TSSOP-28 is described in Section 10.5.

10.1 WQFN-28 Package Mechanical Dimensions

Figure 10.1 WQFN-28 Package Dimensions

The FT260Q is supplied in a RoHS2.0 compliant leadless WQFN-28 package. The package is lead (Pb)

free, and uses a ‘green’ compound. The package is fully compliant with European Union REACH

2006/121/EC.

This package is nominally 5.00mm x 5.00mm. The solder pads are on a 0.5mm pitch. The above

mechanical drawing shows the WQFN-28 package. All dimensions are in millimetres.

The centre pad on the base of the FT260Q is internally connected to GND and the PCB should not have

signal tracking on the top layer under this area. Connect to GND.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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10.2 WQFN-28 Package Markings

Figure 10.2 WQFN-28 Package Markings

The date code format is YYWW where WW = 2 digit week number, YY = 2 digit year number. This is

followed by the revision number.

The code XXXXXXXX is the manufacturing LOT code

FTDI

XXXXXXXX

FT260Q

Line 1 – FTDI Logo

Line 4 – Date Code, Revision

Line 2 – Wafer Lot Number

1

21

Line 3 – FTDI Part Number

YYWW-B

8

14

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10.3 TSSOP-28 Package Mechanical Dimensions

Figure 10.3 TSSOP-28 Package Dimensions

The FT260S is supplied in a RoHS2.0 compliant leadless TSSOP-28 package. The package is lead (Pb)

free, and uses a ‘green’ compound. The package is fully compliant with European Union REACH

2006/121/EC.

This package is nominally 9.70mm x 4.40mm. The above mechanical drawing shows the TSSOP-28

package. All dimensions are in millimetres.

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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10.4 TSSOP-28 Package Markings

Figure 10.4 TSSOP-28 Package Markings

The date code format is YYWW where WW = 2 digit week number, YY = 2 digit year number. This is

followed by the revision number.

The code XXXXXXXX is the manufacturing LOT code

FTDI

XXXXXXXXXX

FT260S

Line 1 – FTDI Logo

Line 4 – Date Code, Revision

Line 2 – Wafer Lot Number

1

28

Line 3 – FTDI Part Number

YYWW-B

14

15

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10.5 Solder Reflow Profile

The FT260 is supplied in a Pb free WQFN-28 and TSSOP-28 package. The recommended solder reflow

profile is shown in Figure 10.3.

Figure 10.5 FT260 Solder Reflow Profile

The recommended values for the solder reflow profile are detailed in Table 10.1. Values are shown for

both a completely Pb free solder process (i.e. the FT260 is used with Pb free solder), and for a non-Pb

free solder process (i.e. the FT260 is used with non-Pb free solder).

Profile Feature

Pb Free Solder Process

Non-Pb Free Solder Process

Average Ramp Up Rate (Ts to Tp)

3°C / second Max.

3°C / Second Max.

Preheat

- Temperature Min (Ts Min.)

- Temperature Max (Ts Max.)

- Time (ts Min to ts Max)

150°C

200°C

60 to 120 seconds

100°C

150°C

60 to 120 seconds

Time Maintained Above Critical Temperature

TL:

- Temperature (TL)

- Time (tL)

217°C

60 to 150 seconds

183°C

60 to 150 seconds

Peak Temperature (Tp)

260°C

240°C

Time within 5°C of actual Peak Temperature

(tp)

20 to 40 seconds

Ramp Down Rate

6°C / second Max.

Time for T= 25°C to Peak Temperature, Tp

8 minutes Max.

6 minutes Max.

Table 10.1 Reflow Profile Parameter Values

Critical Zone: when

T is in the range

T to T

Temperature, T (Degrees C)

Time, t (seconds)

25 P

T = 25º C to T

tp

Tp

TL

t

Preheat

S

tL

Ramp Up Lp

Ramp

Down

T Max

S

T Min

S

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11 Contact Information

Head Office – Glasgow, UK

Branch Office – Tigard, Oregon, USA

Future Technology Devices International Limited

Unit 1, 2 Seaward Place, Centurion Business Park

Glasgow G41 1HH

United Kingdom

Tel: +44 (0) 141 429 2777

Fax: +44 (0) 141 429 2758

Future Technology Devices International Limited (USA)

7130 SW Fir Loop

Tigard, OR 97223-8160

USA

Tel: +1 (503) 547 0988

Fax: +1 (503) 547 0987

E-mail (Sales)

sales1@ftdichip.com

E-mail (Sales)

us.sales@ftdichip.com

E-mail (Support)

support1@ftdichip.com

E-mail (Support)

us.support@ftdichip.com

E-mail (General Enquiries)

admin1@ftdichip.com

E-mail (General Enquiries)

us.admin@ftdichip.com

Branch Office – Taipei, Taiwan

Branch Office – Shanghai, China

Future Technology Devices International Limited (Taiwan)

2F, No. 516, Sec. 1, NeiHu Road

Taipei 114

Taiwan , R.O.C.

Tel: +886 (0) 2 8797 1330

Fax: +886 (0) 2 8751 9737

Future Technology Devices International Limited (China)

Room 1103, No. 666 West Huaihai Road,

Shanghai, 200052

China

Tel: +86 21 62351596

Fax: +86 21 62351595

E-mail (Sales)

tw.sales1@ftdichip.com

E-mail (Sales)

cn.sales@ftdichip.com

E-mail (Support)

tw.support1@ftdichip.com

E-mail (Support)

cn.support@ftdichip.com

E-mail (General Enquiries)

tw.admin1@ftdichip.com

E-mail (General Enquiries)

cn.admin@ftdichip.com

Web Site

http://ftdichip.com

Distributor and Sales Representatives

Please visit the Sales Network page of the FTDI Web site for the contact details of our distributor(s) and sales

representative(s) in your country.

System and equipment manufacturers and designers are responsible to ensure that their systems, and any Future Technology Devices

International Ltd (FTDI) devices incorporated in their systems, meet all applicable safety, regulatory and system-level performance

requirements. All application-related information in this document (including application descriptions, suggested FTDI devices and other

materials) is provided for reference only. While FTDI has taken care to assure it is accurate, this information is subject to customer

confirmation, and FTDI disclaims all liability for system designs and for any applications assistance provided by FTDI. Use of FTDI

devices in life support and/or safety applications is entirely at the user’s risk, and the user agrees to defend, indemnify an d hold

harmless FTDI from any and all damages, claims, suits or expense resulting from such use. This document is subject to change without

notice. No freedom to use patents or other intellectual property rights is implied by the publication of this document. Neither the whole

nor any part of the information contained in, or the product described in this document, may be adapted or reproduced in any material

or electronic form without the prior written consent of the copyright holder. Future Technology Devices International Ltd, Un it 1, 2

Seaward Place, Centurion Business Park, Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640

FT260 HID-CLASS USB TO UART/I2C BRIDGE IC

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Appendix A – References

Document References

Application Notes

AN_394 User Guide for FT260

AN_395 User Guide for LibFT260

AN_124 User Guide for FTDI FT_Prog Utility

AN_184 FTDI Device Input Output Pin States

AN_175 Battery Charger Detection Over USB with FT-X Devices

Technical Notes

TN_100 USB Vendor ID/Product ID Guidelines

TN_111 What is UART

Datasheets

DS_UMFT260EV

UMFTPD3A Program Module Datasheet

FT_PROG Utility

http://www.ftdichip.com/Support/Utilities.htm#FT_Prog