Copyright © Future Technology Devices International Limited 1
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Future Technology
Devices International Ltd.
FT240X
(USB 8-BIT FIFO IC)
The FT240X is a USB to parallel FIFO
interface with the following advanced
features:
Single chip USB to parallel FIFO bidirectional
data transfer interface.
Entire USB protocol handled on the chip. No
USB specific firmware programming required.
Fully integrated 2048 byte multi-time-
programmable (MTP) memory, storing device
descriptors and FIFO I/O configuration.
Fully integrated clock generation with no
external crystal required plus optional clock
output selection enabling glue-less interface to
external MCU or FPGA.
Data transfer rates up to 1Mbyte / second.
512 byte receive buffer and 512 byte transmit
buffer utilising buffer smoothing technology to
allow for high data throughput.
FTDI’s royalty-free Virtual Com Port (VCP) and
Direct (D2XX) drivers eliminate the
requirement for USB driver development in
most cases.
Configurable FIFO interface I/O pins.
Synchronous and asynchronous bit bang
interface options.
USB Battery Charger Detection. Allows for USB
peripheral devices to detect the presence of a higher
power source to enable improved charging.
Device supplied pre-programmed with unique USB serial
number.
USB Power Configurations; supports bus- powered, self-
powered and bus-powered with power switching.
Integrated +3.3V level converter for USB I/O.
True 3.3V CMOS drive output and TTL input; operates
down to 1V8 with external pull-ups.
Configurable I/O pin output drive strength; 4 mA(min)
and 16 mA(max).
Integrated power-on-reset circuit.
Fully integrated AVCC supply filtering - no external
filtering required.
+5V Single Supply Operation.
Internal 3V3/1V8 LDO regulators
Low operating and USB suspend current; 8mA (active-
typ) and 125uA (suspend-typ).
UHCI/OHCI/EHCI host controller compatible.
USB 2.0 Full Speed capable.
Extended operating temperature range; -40 to 85⁰C.
Available in compact Pb-free 24 Pin SSOP and QFN-24
packages (both 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
Copyright © Future Technology Devices International Limited 2
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
1 Typical Applications
Upgrading Legacy Peripherals to USB
Utilising USB to add system modularity
Incorporate USB interface to enable PC
transfers for development system
communication
Cellular and Cordless Phone USB data transfer
cables and interfaces
Interfacing MCU/PLD/FPGA based designs to
USB
USB Audio and Low Bandwidth Video data
transfer
USB Smart Card Readers
USB Industrial Control
USB MP3 Player Interface
USB FLASH Card Reader and Writers
Set Top Box PC - USB interface
USB Digital Camera Interface
USB Software and Hardware Encryption
Dongles
USB Instrumentation
USB dongle implementations for Software/
Hardware Encryption and Wireless Modules
Provides detection of dedicated charging ports
for charging batteries in portable devices.
1.1 Driver Support
Royalty free VIRTUAL COM PORT
(VCP) DRIVERS for...
Windows 10 32, 64-bit
Windows 8 / 8.1 32, 64-bit
Windows 7 32,64-bit
Windows Vista and Vista 64-bit
Windows XP and XP 64-bit
Windows XP Embedded
Server XP / 2003 /2008 / 2016
Windows CE 4.2-5.2, 6.0/7.0, 2013
Mac OS-X
Linux 3.2 and greater
Android
Royalty free D2XX Direct Drivers
(USB Drivers + DLL S/W Interface)
Windows 10 32, 64-bit
Windows 8 / 8.1 32, 64-bit
Windows 7 32,64-bit
Windows Vista and Vista 64-bit
Windows XP and XP 64-bit
Windows XP Embedded
Server XP / 2003 /2008 / 2016
Windows CE 4.2-5.2, 6.0/7.0, 2013
Mac OS-X
Linux 3.2 and greater
Android
The drivers listed above are all available to download for free from FTDI website (www.ftdichip.com).
Various 3rd party drivers are also available for other operating systems - see FTDI website
(www.ftdichip.com) for details.
For driver installation, please refer to http://www.ftdichip.com/Documents/InstallGuides.htm
1.2 Part Numbers
Package
24 Pin QFN
24 Pin SSOP
Note: Packaging codes for x is:
-R: Taped and Reel, (SSOP is 3,000pcs per reel, QFN is 5,000pcs per reel).
- U: Tube packing, 58pcs per tube (SSOP only)
- T: Tray packing, 490pcs per tray (QFN only)
For example: FT240XQ-R is 5,000pcs taped and reel packing
Copyright © Future Technology Devices International Limited 3
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
1.3 USB Compliant
The FT240X is fully compliant with the USB 2.0 specification and has been given the USB-IF Test-ID (TID)
40001337 (Rev B).
Copyright © Future Technology Devices International Limited 4
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
2 FT240X Block Diagram
3.3 Volt LDO
Regulator 1.8 Volt LDO
Regulator
USB
Transceiver
with
Integrated
1.5k pullups
and battery
charge
detection
USB DPLL
Internal
12MHz
Oscillator
X4 Clock
Multiplier
Serial Interface
Engine
(SIE)
USB
Protocol Engine FIFO Interface
Controller
Reset
Generator
FIFO TX Buffer
(512 bytes)
FIFO RX Buffer
(512 bytes)
Internal MTP
Memory
48MHz
GND
RESET#
To USB Transceiver Cell
3V3OUT
VCCIO
3V3OUT
VCC
USBDP
USBDM
1V8 Internal
Core Supply
DATA[0]
DATA[1]
DATA[2]
DATA[3]
DATA[4]
DATA[5]
DATA[6]
DATA[7]
RXF#
TXE#
RD#
WR
SIWUA
CBUS5
CBUS6
Figure 2.1 FT240X Block Diagram
For a description of each function please refer to Section 4.
Copyright © Future Technology Devices International Limited 5
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Table of Contents
1 Typical Applications ....................................................... 2
1.1 Driver Support ........................................................................... 2
1.2 Part Numbers ............................................................................. 2
1.3 USB Compliant ........................................................................... 3
2 FT240X Block Diagram .................................................. 4
3 Device Pin Out and Signal Description ........................... 7
3.1 24-LD SSOP Package .................................................................. 7
3.2 SSOP Package Pin Out Description ............................................. 7
3.3 QFN-24 Package ...................................................................... 10
3.4 QFN-24 Package Signal Description ......................................... 10
3.5 CBUS Signal Options ................................................................ 12
3.6 FT240X FIFO READ Timing Diagrams ....................................... 13
3.7 FT240X FIFO WRITE Timing Diagrams ..................................... 14
4 Function Description ................................................... 15
4.1 Key Features ............................................................................ 15
4.2 Functional Block Descriptions .................................................. 16
5 Devices Characteristics and Ratings ............................ 17
5.1 Absolute Maximum Ratings ...................................................... 17
5.2 ESD and Latch-up Specifications .............................................. 17
5.3 DC Characteristics .................................................................... 18
5.4 MTP Memory Reliability Characteristics ................................... 21
5.5 Internal Clock Characteristics .................................................. 22
6 USB Power Configurations ........................................... 23
6.1 USB Bus Powered Configuration ............................................. 23
6.2 Self Powered Configuration ..................................................... 24
6.3 USB Bus Powered with Power Switching Configuration ........... 25
7 Application Examples .................................................. 27
7.1 USB to MCU FIFO Interface ...................................................... 27
7.2 Battery Charge Detection ......................................................... 27
8 Internal MTP Memory Configuration ............................ 30
8.1 Default Values ......................................................................... 30
Copyright © Future Technology Devices International Limited 6
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
8.2 Methods of Programming the MTP Memory .............................. 31
8.2.1 Programming the MTP memory over USB ..................................................... 31
8.3 Memory Map ............................................................................ 32
9 Package Parameters .................................................... 33
9.1 SSOP-24 Package Mechanical Dimensions ............................... 33
9.2 SSOP-24 Package Markings ..................................................... 34
9.3 QFN-24 Package Mechanical Dimensions ................................. 35
9.4 QFN-24 Package Markings ....................................................... 36
9.5 Solder Reflow Profile ............................................................... 36
10 Contact Information .................................................... 38
11 Appendix A - References ............................................. 39
Document References ...................................................................... 39
Acronyms and Abbreviations ............................................................ 39
Appendix B - List of Figures and Tables ............................. 40
List of Figures .................................................................................. 40
List of Tables .................................................................................... 40
Appendix C - Revision History ............................................ 42
Copyright © Future Technology Devices International Limited 7
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
3 Device Pin Out and Signal Description
3.1 24-LD SSOP Package
Figure 3.1 SSOP Package Pin Out and Schematic Symbol
3.2 SSOP Package Pin Out Description
Note: The convention used throughout this document for active low signals is the signal name followed
by a #
Pin No.
Name
Type
Description
13
USBDP
I/O
USB Data Signal Plus, incorporating 1.5kΩ pull up resistor to 3.3V.
14
USBDM
I/O
USB Data Signal Minus.
Table 3.1 USB Interface Group
Pin No.
Name
Type
Description
3
VCCIO
PWR
1V8 - 3V3 supply for the IO cells
6, 19
GND
PWR
Device ground supply pins
15
**
3V3OUT
Output
3V3 output at 50mA. May be used to power VCCIO.
When VCC is 3V3; pin 15 is an input pin and should be connected to pin 18.
18
**
VCC
PWR
+5V (or 3V3) supply to the device core.
17
VCORE
PWR
+1V8 Output. May be left unterminated
Table 3.2 Power and Ground Group
** If VCC is 3V3 then 3V3OUT must also be driven with 3V3 input
Copyright © Future Technology Devices International Limited 8
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Pin No.
Name
Type
Description
16
RESET#
Input
Active low reset pin. This can be used by an external device to reset the
FT240X. If not required can be left unconnected, or pulled up to VCC.
10
SIWU#
Input
Active low input. May be used to flush the IC buffer back to the PC (Send
Immediate) or if the PC is in suspend mode it can be used as a Wake Up
signal.
23
CBUS5
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device MTP memory. See CBUS Signal Options, Table 3.9.
22
CBUS6
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device MTP memory. See CBUS Signal Options, Table 3.9.
Table 3.3 Miscellaneous Signal Group
Pin
No.
Name
Type
Description
24
D0
I/O
FIFO Data Bus Bit 0
4
D1
I/O
FIFO Data Bus Bit 1
2
D2
I/O
FIFO Data Bus Bit 2
9
D3
I/O
FIFO Data Bus Bit 3
1
D4
I/O
FIFO Data Bus Bit 4
7
D5
I/O
FIFO Data Bus Bit 5
8
D6
I/O
FIFO Data Bus Bit 6
5
D7
I/O
FIFO Data Bus Bit 7
11
RD#
Input
Enables the current FIFO data byte on D0...D7 when low. Fetched the next FIFO
data byte (if available) from the receive FIFO buffer when RD# goes from high
to low. See Section Error! Reference source not found. for timing diagram.
12
WR
Input
Writes the data byte on the D0...D7 pins into the transmit FIFO buffer when WR
goes from high to low. See Section 3.7 for timing diagram.
20
TXE#
Output
When high, do not write data into the FIFO. When low, data can be written into
the FIFO by strobing WR high, then low. During reset this signal pin is tristate.
See Section 3.7 for timing diagram.
21
RXF#
Output
When high, do not read data from the FIFO. When low, there is data available in
the FIFO which can be read by strobing RD# low, then high again. During reset
this signal pin is tristate. See Section Error! Reference source not found. for
timing diagram. If the Remote Wakeup option is enabled in the internal MTP
memory, during USB suspend mode (PWREN# = 1) RXF# becomes an input.
This can be used to wake up the USB host from suspend mode by strobing this
pin low for a minimum of 20ms which will cause the device to request a resume
on the USB bus.
Table 3.4 FIFO Interface Group (see note 2)
Notes:
Copyright © Future Technology Devices International Limited 9
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
When used in Input Mode, the input pins are pulled to VCCIO via internal 200kΩ resistors. These pins can
be programmed to gently pull low during USB suspend (PWREN# = “1”) by setting an option in the
internal MTP memory.
Copyright © Future Technology Devices International Limited 10
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
3.3 QFN-24 Package
Figure 3.2 QFN-24 Package Pin Out and Schematic Symbol
3.4 QFN-24 Package Signal Description
Note: The convention used throughout this document for active low signals is the signal name followed
by a #
Pin No.
Name
Type
Description
10
USBDP
I/O
USB Data Signal Plus, incorporating 1.5kΩ pull up resistor to 3.3V.
11
USBDM
I/O
USB Data Signal Minus.
Table 3.5 USB Interface Group
Pin No.
Name
Type
Description
24
VCCIO
PWR
1V8 - 3V3 supply for the IO cells
3, 16
GND
PWR
Device ground supply pins
12
**
3V3OUT
Output
3V3 output at 50mA. May be used to power VCCIO.
When VCC is 3V3; pin 12 is an input pin and should be connected to
pin 15.
15
**
VCC
PWR
+5V (or 3V3) supply to the device core.
14
VCORE
PWR
+1V8 Output. May be left unterminated
Table 3.6 Power and Ground Group
*Pin 25 is the centre pad on package base. Connect to GND.
**If VCC is 3V3 then 3V3OUT must also be driven with 3V3 input
Copyright © Future Technology Devices International Limited 11
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Pin No.
Name
Type
Description
13
RESET#
Input
Active low reset pin. This can be used by an external device to reset the
FT240X. If not required can be left unconnected, or pulled up to VCC.
7
SIWU#
Input
Active low input. May be used to flush the IC buffer back to the PC (Send
Immediate) or if the PC is in suspend mode it can be used as a Wake Up
signal.
20
CBUS5
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device MTP memory. See CBUS Signal Options, Table 3.9.
19
CBUS6
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device MTP memory. See CBUS Signal Options, Table 3.9.
Table 3.7 Miscellaneous Signal Group
Pin No.
Name
Type
Description
21
D0
I/O
FIFO Data Bus Bit 0
1
D1
I/O
FIFO Data Bus Bit 1
23
D2
I/O
FIFO Data Bus Bit 2
6
D3
I/O
FIFO Data Bus Bit 3
22
D4
I/O
FIFO Data Bus Bit 4
4
D5
I/O
FIFO Data Bus Bit 5
5
D6
I/O
FIFO Data Bus Bit 6
2
D7
I/O
FIFO Data Bus Bit 7
8
RD#
Input
Enables the current FIFO data byte on D0...D7 when low. Fetched the
next FIFO data byte (if available) from the receive FIFO buffer when RD#
goes from high to low. See Section Error! Reference source not
found. for timing diagram.
9
WR
Input
Writes the data byte on the D0...D7 pins into the transmit FIFO buffer
when WR goes from high to low. See Section 3.7 for timing diagram.
17
TXE#
Output
When high, do not write data into the FIFO. When low, data can be
written into the FIFO by strobing WR high, then low. During reset this
signal pin is tristate. See Section 3.7 for timing diagram.
18
RXF#
Output
When high, do not read data from the FIFO. When low, there is data
available in the FIFO which can be read by strobing RD# low, then high
again. During reset this signal pin is tristate. See Section Error!
Reference source not found. for timing diagram.
If the Remote Wakeup option is enabled in the internal MTP memory,
during USB suspend mode (PWREN# = 1) RXF# becomes an input. This
can be used to wake up the USB host from suspend mode by strobing
this pin low for a minimum of 20ms which will cause the device to
request a resume on the USB bus.
Table 3.8 FIFO Interface Group (see note 2)
Copyright © Future Technology Devices International Limited 12
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Notes:
When used in Input Mode, the input pins are pulled to VCCIO via internal 200kΩ resistors. These pins can
be programmed to gently pull low during USB suspend (PWREN# = “1”) by setting an option in the
internal MTP memory.
3.5 CBUS Signal Options
The following options can be configured on the CBUS I/O pins. CBUS signal options are common to both
package versions of the FT240X. These options can be configured in the internal MTP memory using the
software utility FT_PPROG, which can be downloaded from the FTDI Utilities (www.ftdichip.com). The
default configuration is described in Section 8.
CBUS Signal
Option
Available
On CBUS
Pin
Description
TRI-STATE
CBUS5,
CBUS6
IO Pad is tri-stated
DRIVE 1
CBUS5,
CBUS6
Output a constant 1
DRIVE 0
CBUS5,
CBUS6
Output a constant 0
PWREN#
CBUS5,
CBUS6
Output is low after the device has been configured by USB, then high
during USB suspend mode. This output can be used to control power to
external logic P-Channel logic level MOSFET switch. Enable the
interface pull-down option when using the PWREN# in this way.
TXLED#
CBUS5,
CBUS6
Transmit data LED drive – pulses low when transmitting data via USB.
See Section 3.5 for more details.
RXLED#
CBUS5,
CBUS6
Receive data LED drive – pulses low when receiving data via USB. See
Section 3.5 for more details.
TX&RXLED#
CBUS5,
CBUS6
LED drive – pulses low when transmitting or receiving data via USB.
See Section 3.5 for more details.
SLEEP#
CBUS5,
CBUS6
Goes low during USB suspend mode. Typically used to power down an
external TTL to RS232 level converter IC in USB to RS232 converter
designs.
CLK24MHz
CBUS5,
CBUS6
24 MHz Clock output.*
CLK12MHz
CBUS5,
CBUS6
12 MHz Clock output.*
CLK6MHz
CBUS5,
CBUS6
6 MHz Clock output.*
BCD Charger
CBUS5,
CBUS6
Battery charge Detect, indicates when the device is connected to a
dedicated battery charger host. Active high output.
BCD Charger#
CBUS5,
CBUS6
Inverse of BCD Charger
BitBang_WR#
CBUS5,
CBUS6
Synchronous and asynchronous bit bang mode WR# strobe output.
Copyright © Future Technology Devices International Limited 13
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
CBUS Signal
Option
Available
On CBUS
Pin
Description
BitBang_RD#
CBUS5,
CBUS6
Synchronous and asynchronous bit bang mode RD# strobe output.
VBUS Sense
CBUS5,
CBUS6
Input to detect when VBUS is present.
Time Stamp
CBUS5,
CBUS6
Toggle signal which changes state each time a USB SOF is received
Keep_Awake#
CBUS5,
CBUS6
Prevents the device from entering suspend state when unplugged.
Table 3.9 CBUS Configuration Control
*When in USB suspend mode the outputs clocks are also suspended.
3.6 FT240X FIFO READ Timing Diagrams
RXF#
RD#
D[7...0]
T3
T1
T5 T6
T2
T4
Valid Data
Figure 3.3 FIFO Read Cycle
Time
Description
Minimum
Maximum
Unit
T1
RD# Active Pulse Width
50
-
ns
T2
RD# to RD# Pre-Charge Time
50 + T6
-
ns
T3
RD# Active to Valid Data*
20
50
ns
T4
Valid Data Hold Time from RD# Inactive*
0
-
ns
T5
RD# Inactive to RXF#
0
25
ns
T6
RXF# Inactive After RD Cycle
80
-
ns
Table 3.10 FIFO Read Cycle Timings
*Load = 30pF
Copyright © Future Technology Devices International Limited 14
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
3.7 FT240X FIFO WRITE Timing Diagrams
Valid Data
D[7...0]
WR
TXE# T7
T12
T11
T8
T9 T10
Figure 3.4 FIFO Write Cycle
Time
Description
Minimum
Maximum
Unit
T7
WR Active Pulse Width
50
-
ns
T8
WR to WR Pre-Charge Time
50
-
ns
T9
Valid data setup to WR falling edge*
20
-
ns
T10
Valid Data Hold Time from WR Inactive*
0
-
ns
T11
WR Inactive to TXE#
5
25
ns
T12
TXE# Inactive After WR Cycle
80
-
ns
Table 3.11 FIFO Write Cycle
*Load = 30pF
Copyright © Future Technology Devices International Limited 15
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
4 Function Description
The FT240X is a USB to parallel FIFO interface device which simplifies USB implementations and reduces
external component count by fully integrating into the device an MTP memory and an integrated clock
circuit which requires no external crystal. It has been designed to operate efficiently with USB host
controllers by using as little bandwidth as possible when compared to the total USB bandwidth available.
4.1 Key Features
Functional Integration. Fully integrated MTP memory, clock generation, AVCC filtering, power-on-reset
(POR) and LDO regulator.
Configurable CBUS I/O Pin Options. The fully integrated MTP memory allows configuration of the
Control Bus (CBUS) functionality and drive strength selection. There are 2 configurable CBUS I/O options.
The configurable options are defined in section 3.5.
The CBUS lines can be configured with any one of these output options by setting bits in the internal MTP
memory. The device is shipped with the most commonly used pin definitions pre-programmed - see
Section 8 for details.
Asynchronous Bit Bang Mode. In asynchronous bit-bang mode, the eight FIFO lines can be switched
from the regular interface mode to an 8-bit general purpose I/O port. Data packets can be sent to the
device and they will be sequentially sent to the interface at a rate controlled by an internal timer
(equivalent to the baud rate pre-scaler. This option will be described more fully in a separate application
note available from FTDI website (www.ftdichip.com).
Synchronous Bit Bang Mode. The FT240X supports synchronous bit bang mode. This mode differs from
asynchronous bit bang mode in that the interface pins are only read when the device is written to. This
makes it easier for the controlling program to measure the response to an output stimulus as the data
returned is synchronous to the output data. An application note, AN232R-01, available from FTDI website
(www.ftdichip.com) describes this feature.
High Output Drive Option. The parallel FIFO interface and the four FIFO handshake pins can be made
to drive out at three times the standard signal drive level thus allowing multiple devices to be driven, or
devices that require a greater signal drive strength to be interfaced to the FT240X. This option is
configured in the internal MTP memory.
Programmable FIFO RX Buffer Timeout. The FIFO RX buffer timeout is used to flush remaining data
from the receive buffer. This timeout defaults to 16ms, but is programmable over USB in 1ms increments
from 2ms to 255ms, thus allowing the device to be optimised for protocols that require fast response
times from short data packets.
Wake Up Function. If USB is in suspend mode, and remote wake up has been enabled in the internal
MTP memory (it is enabled by default). Strobing the SIWU# pin low for a minimum of 20ms will cause
the FT240X to request a resume from suspend on the USB bus. Normally this can be used to wake up the
host PC from suspend.
Source Power and Power Consumption. The FT240X is capable of operating at a voltage supply
between +3.3V and +5.25V with a nominal operational mode current of 8mA and a nominal USB suspend
mode current of 125µA. This allows greater margin for peripheral designs to meet the USB suspend mode
current limit of 2.5mA. An integrated level converter within allows the FT240X to interface to logic
running at +1.8V to +3.3V (5V tolerant).
Copyright © Future Technology Devices International Limited 16
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
4.2 Functional Block Descriptions
The following paragraphs detail each function within the FT240X. Please refer to the block diagram shown
in Figure 2.1.
Internal MTP Memory. The internal MTP memory in the FT240X is used to store USB Vendor ID (VID),
Product ID (PID), device serial number, product description string and various other USB configuration
descriptors. The FT240X is supplied with the internal MTP memory pre-programmed as described in
Section 8. A user area of the internal MTP memory is available to system designers to allow storing
additional data from the user application over USB. The internal MTP memory descriptors can be
programmed in circuit, over USB without any additional voltage requirement. The descriptors can be
programmed using the FTDI utility software called FT_PROG, which can be downloaded from FTDI Utilities
on the FTDI website (www.ftdichip.com).
+1.8V LDO Regulator. The +1.8 LDO regulator generates the +1.8V reference voltage for driving the
internal core of the IC.
+3.3V LDO Regulator. 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
3V3OUT regulator output pin. It also provides +3.3V power to the 1.5kΩ internal pull up resistor on
USBDP. The main function of the LDO is to power the USB Transceiver and the Reset Generator Cells
rather than to power external logic. However, it can be used to supply external circuitry requiring a
+3.3V nominal supply with a maximum current of 50mA.
USB Transceiver. The USB Transceiver Cell provides the USB 1.1 / USB 2.0 full-speed physical interface
to the USB cable. The output drivers provide +3.3V level slew rate control signalling, whilst a differential
input receiver and two single ended input receivers provide USB data in, Single-Ended-0 (SE0) and USB
reset detection conditions respectfully. This function also incorporates a 1.5kΩ pull up resistor on USBDP.
The block also detects when connected to a USB power supply which will not enumerate the device but
still supply power and may be used for battery charging.
USB DPLL. The USB DPLL cell locks on to the incoming NRZI USB data and generates recovered clock
and data signals for the Serial Interface Engine (SIE) block.
Internal 12MHz Oscillator. The Internal 12MHz Oscillator cell generates a 12MHz reference clock. This
provides an input to the x4 Clock Multiplier function. The 12MHz Oscillator is also used as the reference
clock for the SIE, USB Protocol Engine and FIFO controller blocks.
Clock Multiplier / Divider. The Clock Multiplier / Divider takes the 12MHz input from the Internal
Oscillator function and generates the 48MHz. The 48Mz clock reference is used by the USB DPLL and the
Baud Rate Generator blocks.
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 verifies the CRC on the USB data
stream.
USB Protocol Engine. The USB Protocol Engine manages the data stream from the device USB control
endpoint. It handles the low level USB protocol requests generated by the USB host controller and the
commands for controlling the functional parameters of the FIFO in accordance with the USB 2.0
specification Section 9.
FIFO RX Buffer (512 bytes). Data sent from the USB host controller to the FIFO via the USB data OUT
endpoint is stored in the FIFO RX (receive) buffer and is removed from the buffer by reading the contents
of the FIFO using the RD# pin. (Rx relative to the USB interface).
FIFO TX Buffer (512 bytes). Data written into the FIFO using the WR pin is stored in the FIFO TX
(transmit) Buffer. The USB host controller removes data from the FIFO TX Buffer by sending a USB
request for data from the device data IN endpoint. (Tx relative to the USB interface).
FIFO Controller with Programmable High Drive. The FIFO Controller handles the transfer of data
between the FIFO RX, the FIFO TX buffers and the external FIFO interface pins (D0 - D7).
Additionally, the FIFO signals have a configurable high drive strength capability which is configurable in
the MTP memory.
RESET Generator. The integrated Reset Generator Cell provides a reliable power-on reset to the device
internal circuitry at power up. The RESET# input pin allows an external device to reset the FT240X.
RESET# can be tied to VCC or left unconnected if not being used.
Copyright © Future Technology Devices International Limited 17
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
5 Devices Characteristics and Ratings
5.1 Absolute Maximum Ratings
The absolute maximum ratings for the FT240X 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 FT240XS
TBD
Hours
MTTF FT240XQ
TBD
Hours
VCC Supply Voltage
-0.3 to +5.5
V
VCCIO IO Voltage
-0.3 to +4.0
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 +5.8
V
DC Output Current – Outputs
22
mA
Table 5.1 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.
5.2 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 5.2 ESD and Latch-Up Specifications
Copyright © Future Technology Devices International Limited 18
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
5.3 DC Characteristics
DC Characteristics (Ambient Temperature = -40°C to +85°C)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
VCC
VCC Operating
Supply Voltage
2.97
5
5.5
V
Normal Operation
VCC2
VCCIO
Operating
Supply Voltage
1.62
---
3.63
V
Icc1
Operating
Supply Current
8
8
8.4
mA
Normal Operation
Icc2
Operating
Supply Current
125
μA
USB Suspend
3V3
3.3v regulator
output
2.97
3.3
3.63
V
VCC must be
greater than 3V3
otherwise 3V3OUT
is an input which
must be driven
with 3.3V
Table 5.3 Operating Voltage and Current
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.97
VCCIO
VCCIO
V
Ioh = +/-2mA
I/O Drive
strength* = 4mA
2.97
VCCIO
VCCIO
V
I/O Drive
strength* = 8mA
2.97
VCCIO
VCCIO
V
I/O Drive
strength* =
12mA
2.97
VCCIO
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
Copyright © Future Technology Devices International Limited 19
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
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 5.4 FIFO I/O Pin Characteristics VCCIO = +3.3V, (except USB PHY pins)
* The I/O drive strength and slow slew-rate are configurable in the MTP memory.
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.25
VCCIO
VCCIO
V
Ioh = +/-2mA
I/O Drive
strength* = 4mA
2.25
VCCIO
VCCIO
V
I/O Drive
strength* = 8mA
2.25
VCCIO
VCCIO
V
I/O Drive
strength* =
12mA
2.25
VCCIO
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
Copyright © Future Technology Devices International Limited 20
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Vil
Input low Switching
Threshold
0.8
V
LVTTL
Vih
Input High Switching
Threshold
0.8
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 5.5 FIFO I/O Pin Characteristics VCCIO = +2.5V, (except USB PHY pins)
* The I/O drive strength and slow slew-rate are configurable in the MTP memory.
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
1.62
VCCIO
VCCIO
V
Ioh = +/-2mA
I/O Drive
strength* = 4mA
1.62
VCCIO
VCCIO
V
I/O Drive
strength* = 8mA
1.62
VCCIO
VCCIO
V
I/O Drive
strength* =
12mA
1.62
VCCIO
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
0.77
V
LVTTL
Copyright © Future Technology Devices International Limited 21
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Vih
Input High Switching
Threshold
1.6
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
Tristate output leakage
current
-10
+/-1
10
μA
Vin = 5.5V or 0
Table 5.6 FIFO I/O Pin Characteristics VCCIO = +1.8V (except USB PHY pins)
* The I/O drive strength and slow slew-rate are configurable in the MTP memory
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
VCC-0.2
V
Vol
Output Voltage Low
0.2
V
Vil
Input low Switching Threshold
-
0.8
V
Vih
Input High Switching Threshold
2.0
-
V
Table 5.7 USB I/O Pin (USBDP, USBDM) Characteristics
5.4 MTP Memory Reliability Characteristics
The internal 2048 Byte MTP memory has the following reliability characteristics:
Parameter
Value
Unit
Data Retention
10
Years
Write Cycle
2,000
Cycles
Read Cycle
Unlimited
Cycles
Table 5.8 MTP Memory Characteristics
Copyright © Future Technology Devices International Limited 22
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
5.5 Internal Clock Characteristics
The internal Clock Oscillator has the following characteristics:
Parameter
Value
Unit
Minimum
Typical
Maximum
Frequency of Operation
(see Note 1)
11.98
12.00
12.02
MHz
Clock Period
83.19
83.33
83.47
ns
Duty Cycle
45
50
55
%
Table 5.9 Internal Clock Characteristics
Note 1: Equivalent to +/-1667ppm
Copyright © Future Technology Devices International Limited 23
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
6 USB Power Configurations
The following sections illustrate possible USB power configurations for the FT240X. The illustrations have
omitted pin numbers for ease of understanding since the pins differ between the FT240XS and FT240XQ
package options.
All USB power configurations illustrated apply to both package options for the FT240X device. Please refer
to Section 0 for the package option pin-out and signal descriptions.
6.1 USB Bus Powered Configuration
FT240X
1
2
3
4
5
SHIELD
Ferrite
Bead
GND
GND
VCC
GND
VCC
3V3OUT
USBDM
USBDP
VCCIO
VCC
AGND
GND
RESET#
100nF
100nF
10nF
4.7uF+
27R
27R
GND
47pF
47pF
Figure 6.1 Bus Powered Configuration
Figure 6.1 illustrates the FT240X in a typical USB bus powered design configuration. A USB bus powered
device gets its power from the USB bus. Basic rules for USB bus power 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) should use the
PWREN# to keep the current below 100mA on plug-in and 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 power descriptors in the internal MTP memory of the FT240X 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 FT240X 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 Steward Part # MI0805K601R-10.
Copyright © Future Technology Devices International Limited 24
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
6.2 Self Powered Configuration
FT240X
1
2
3
4
5
SHIELD
GND
GND
VCC
GND
VCC
3V3OUT
USBDM
USBDP
VCCIO
VCC(3.3-5.25V)
AGND
GND
RESET#
100nF
100nF
100nF
4.7uF
+
GND
4k7
10k
27R
27R
GND
47pF 47pF
VBUS_SENSE
Figure 6.2 Self-Powered Configuration
Figure 6.2 illustrates the FT240X in a typical USB self-powered configuration. A USB self-powered device
gets its power from its own power supply, VCC, 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.
The power descriptor in the internal MTP memory of the FT240X should be programmed to a value of
zero (self-powered).
In order to comply with the first requirement above, the USB bus power (pin 1) is used to control the
VBUS_Sense pin of the FT240X device. When the USB host or hub is powered up an internal 1.5kΩ
resistor on USBDP is pulled up to +3.3V, thus identifying the device as a full speed device to the USB
host or hub. When the USB host or hub is powered off, VBUS_Sense pin will be low and the FT240X 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 USBDP via the 1.5kΩ pull-up resistor. Failure to
do this may cause some USB host or hub controllers to power up erratically.
Figure 6.3 illustrates a self-powered design which has a +3.3V to +5.25V supply.
Note:
1. When the FT240X is in reset, the interface I/O pins are tri-stated. Input pins have internal 200kΩ
pull-up resistors to VCCIO, so they will gently pull high unless driven by some external logic.
Copyright © Future Technology Devices International Limited 25
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
6.3 USB Bus Powered with Power Switching Configuration
FT240X
1
2
3
4
5
SHIELD
Ferrite
Bead
GND
GND
VCC
GND
VCC
3V3OUT
USBDM
USBDP
VCCIO
AGND
GND
RESET#
100nF
100nF
10nF
4.7uF+
CBUS5
PWREN#
10k
1k
Switched 5V Power to
External Logic
0.1uF0.1uF
P Channel Power
MOSFET
27R
27R
47pF 47pF
Figure 6.4 Bus Powered with Power Switching Configuration
A requirement of USB bus powered applications, is when in USB suspend mode the application draws a
total current of less than 2.5mA. This requirement includes external logic. Some external logic has the
ability to power itself down into a low current state by monitoring the PWREN# signal. For external logic
that cannot power itself down in this way, the FT240X provides a simple but effective method of turning
off power during the USB suspend mode.
Figure 6.4 shows an example of using a discrete P-Channel MOSFET to control the power to external
logic. A suitable device to do this is an International Rectifier (www.irf.com) IRLML6402, or equivalent. It
is recommended that a “soft start” circuit consisting of a 1kΩ series resistor and a 0.1μF capacitor is used
to limit the current surge when the MOSFET turns on. Without the soft start circuit it is possible that the
transient power surge, caused when the MOSFET switches on, will reset the FT240X or the USB host/hub
controller. The soft start circuit example shown in Figure 6.4 powers up with a slew rate of
approximaely12.5V/Ms. Thus supply voltage to external logic transitions from GND to +5V in
approximately 400 microseconds.
As an alternative to the MOSFET, a dedicated power switch IC with inbuilt “soft-start” can be used. A
suitable power switch IC for such an application is the Micrel (www.micrel.com) MIC2025-2BM or
equivalent.
With power switching controlled designs the following should be noted:
i) The external logic to which the power is being switched should have its own reset circuitry to
automatically reset the logic when power is re-applied when moving out of suspend mode.
ii) Set the Pull-down on Suspend option in the internal FT240X MTP memory.
iii) The PWREN# pin should be used to switch the power to the external circuitry.
iv) For USB high-power bus powered applications (one that consumes greater than 100mA, and up
to 500mA of current from the USB bus), the power consumption of the application must be set in
Copyright © Future Technology Devices International Limited 26
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
the Max Power field in the internal FT240X MTP memory. A high-power bus powered application
uses the descriptor in the internal FT240X MTP memory to inform the system of its power
requirements.
v) PWREN# gets its VCC from VCCIO. For designs using 3V3 logic, ensure VCCIO is not powered
down using the external logic. In this case use the +3V3OUT.
Copyright © Future Technology Devices International Limited 27
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
7 Application Examples
The following sections illustrate possible applications of the FT240X. The illustrations have omitted pin
numbers for ease of understanding since the pins differ between the FT240XS and FT240XQ package
options.
7.1 USB to MCU FIFO Interface
Figure 7.1 USB to MCU FIFO Interface
A typical example of using the FT240X as a USB to Microcontroller (MCU) FIFO interface is illustrated in
Figure 7.1. This example uses two MCU I/O ports: one port (8 bits) to transfer data and the other port (4
or 5 bits) to monitor the TXE# and RXF# status bits and generate the RD# and WR strobes to the
FT240X, when required.
Using PWREN# for this function is optional.
7.2 Battery Charge Detection
An addition to the USB specification (http://www.usb.org/developers/docs/devclass_docs/) is to allow for
additional charging profiles to be used for charging batteries in portable devices. These charging profiles
do not enumerate the USB port of the peripheral. The FT240X device will detect that a USB compliant
dedicated charging port (DCP) is connected. Once detected while in suspend mode a battery charge
detection signal is provided to allow external logic to switch to charging mode as opposed to operation
mode.
Copyright © Future Technology Devices International Limited 28
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
X-Chip Pin Function
EEPROM Setting
CBUS0 BCD Battery Options
Battery Charger Enable
Force Power Enable
De-acticate Sleep
X
GND
GND
0.1uF 0.1uF
GND
GND
600R/2A
10nF
VBUS 3V3OUT
0.1uF
0R
GNDSLD GND
27R
27R
VBUS 1
D- 2
D+ 3
GND 5
ID 4
CN USB
VCC
2
FAULT
3
TIMER
4
GND
5NTC 6
PROG 7
SHDN 8
BAT 9
ACPR 10
CHRG
1
GND 11
LTC4053EDD
GND
3V3OUT 3V3OUT
4.7uF
0.1uF
GND
VBUSVBUS
GND
VBATT
GND
GND
1K5
GND
1
TB3.5mm
VBUS VBUS
NTC
0.1uF
GND
VBUS
1uF
1R
GND
VBUS
BCD
2K2
GND
JP1
1-2
2-3 NCT Enabled
NCT Available
JP1
SIP-3
NTC
GND
NCT Disabled (Default)
JUMPER-2mm
4K32 1%
GND
DP
DM
3V3OUT
RESET#
VCC
GND
CBUS0
VCCIO
FT240X
BCD
1A when connected to a dedicated charger port
0A when enumerated
0A when in sleep
0A when not enumerated and not in sleep
+
-
NCT
N.F.
Figure 7.2 USB Battery Charging Detection (1 pin)
To use the FT240X with battery charging detection the CBUS pins must be reprogrammed to allow for the
BCD Charger output to switch the external charger circuitry on. The CBUS pins are configured in the
internal MTP memory with the free utility FTPROG. If the charging circuitry requires an active low signal
to enable it, the CBUS pin can be programmed to BCD Charger# as an alternative.
When connected to a USB compliant dedicated charging port (DCP, as opposed to a standard USB host)
the device USB signals will be shorted together and the device suspended. The BCD charger signal will
bring the LTC4053 out of suspend and allow battery charging to start. The charge current in the example
above is 1A as defined by the resistance on the PROG pin.
Alternatively the PWREN# And SLEEP pins may be used to control the LTC4053 such that a battery may
be charged from a standard host (low current) or from a dedicated charging port (high current). In such
a design as shown above the charge current would need to be limited to 0.4A to ensure that the USB
host power limit is not exceeded.
Copyright © Future Technology Devices International Limited 29
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
X-Chip Pin Function
EEPROM Setting
CBUS5
CBUS6 SLEEP#
PWREN#
Battery Options
Battery Charger Enable
Force Power Enable
De-acticate Sleep X
X
X
SLEEP#
PWREN#
DP
DM
3V3OUT
VCORE
RESET#
VCC
CBUS6
CBUS5
VCCIO
U1
FT240X
0.4A when connected to a dedicated charger port
GND
GND
0.1uF 0.1uF
GND
GND
600R/2A
10nF
VBUS 3V3OUT
0.1uF
0R
GNDSLD GND
27R
27R
VBUS 1
D- 2
D+ 3
GND 5
ID 4
CN USB
3V3OUT 3V3OUTVBUS VBUS
N.F.
16K5 1%
GND
4K32 1%
PWREN#
0.4A when enumerated
0A when in sleep mode
0.1A when not enumerated and not in sleep mode
VCC
2
FAULT
3
TIMER
4
GND
5NTC 6
PROG 7
SHDN 8
BAT 9
ACPR 10
CHRG
1
GND 11
LTC4053EDD
GND
4.7uF
0.1uF
GND
VBUSVBUS
GND
VBATT
GND
GND 1
TB3.5mm
NTC
0.1uF
GND
VBUS
1uF
1R
GND
VBUS
2K2
GND
JP1
1-2
2-3 NCT Enabled
NCT Available
JP1
SIP-3
NTC
GND
NCT Disabled (Default)
JUMPER-2mm
4K32 1%
+
-
NCT
SLEEP#
Figure 7.3 USB Battery Charging Detection (2 pin)
In the example above the FT240X SLEEP pin is used to enable/disable the LTC4053, while the PWREN#
signal alters the charging current by altering the resistance on the LTC4053 PROG pin.
To calculate the equivalent resistance on the LTC4053 PROG pin select a charge current, then Res =
1500V/Ichg
For more configuration options of the LTC4053 refer to:
AN_175 Battery Charger Detection over USB with FT-X Devices
Note: If the FT240X is connected to a standard host port such that the device is enumerated the battery
charge detection signal is inactive as the device will not be in suspend.
Copyright © Future Technology Devices International Limited 30
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
8 Internal MTP Memory Configuration
The FT240X includes an internal MTP memory which holds the USB configuration descriptors, other
configuration data for the chip and also user data areas. Following a power-on reset or a USB reset the
FT240X will scan its internal MTP memory and read the USB configuration descriptors stored there.
In many cases, the default values programmed into the MTP memory will be suitable and no re-
programming will be necessary. The defaults can be found in Section 8.1.
The MTP memory in the FT240X can be programmed over USB if the values need to be changed for a
particular application. Further details of this are provided from section 8.2 onwards.
Users who do not have their own USB Vendor ID but who would like to use a unique Product ID in their
design can apply to FTDI for a free block of unique PIDs. See TN_100 USB Vendor ID/Product ID
Guidelines for more details.
8.1 Default Values
The default factory programmed values of the internal MTP memory are shown in Table 8.1.
Parameter
Value
Notes
USB Vendor ID (VID)
0403h
FTDI default VID (hex)
USB Product UD (PID)
6015h
FTDI default PID (hex)
Serial Number
Enabled
Yes
Serial Number
See Note
A unique serial number is generated and programmed into the
MTP memory during device final test.
Pull down I/O Pins in
USB Suspend
Disabled
Enabling this option will make the device pull down on the
FIFO interface lines when in USB suspend mode (PWREN# is
high).
Manufacturer Name
FTDI
Product Description
FT240X USB
FIFO
Max Bus Power
Current
90mA
Power Source
Bus Powered
Device Type
FT240X
USB Version
0200
Returns USB 2.0 device description to the host.
Note: The device is a USB 2.0 Full Speed device (12Mb/s) as
opposed to a USB 2.0 High Speed device (480Mb/s).
Remote Wake Up
Disabled
Taking SIWU# low will wake up the USB host controller from
suspend in approximately 20 Ms. When enabled.
DBUS Drive Current
Strength
4mA
Options are 4mA, 8mA, 12mA, 16mA
Copyright © Future Technology Devices International Limited 31
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Parameter
Value
Notes
DBUS slew rate
Slow
Options are slow or fast
DBUS Schmitt Trigger
Enable
Normal
Options are normal or Schmitt
CBUS Drive Current
Strength
4mA
Options are 4mA, 8mA, 12mA, 16mA
CBUS slew rate
Slow
Options are slow or fast
CBUS Schmitt Trigger
Enable
Normal
Options are normal or Schmitt
High Current I/Os
Disabled
Enables the high drive level on the FIFO data bus and control
I/O pins.
Load VCP Driver
Disabled
Enabling this will load the VCP driver interface for the device.
CBUS5
VBUS_Sense
Used to detect when the device is connected to a USB host
and power is available.
CBUS6
Keep_Awake#
Prevents the device from entering suspend state when
unplugged.
Table 8.1 Default Internal MTP Memory Configuration
8.2 Methods of Programming the MTP Memory
8.2.1 Programming the MTP memory over USB
The MTP memory on all FT-X devices can be programmed over USB. This method is the same as for the
EEPROM on other FTDI devices such as the FT232R. No additional hardware, connections or programming
voltages are required. The device is simply connected to the host computer in the same way that it would
be for normal applications, and the FT_Prog utility is used to set the required options and program the
device.
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. Note that the FT-X devices require FT_Prog version 2.5 or
later.
http://www.ftdichip.com/Support/Utilities.htm#FT_Prog
Additionally, D2XX commands can be used to program the MTP memory from within user applications.
For more information on the commands available, please see the D2XX Programmers Guide.
Copyright © Future Technology Devices International Limited 32
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
8.3 Memory Map
The FT-X family MTP memory has various areas which come under three main categories:
User Memory Area
Configuration Memory Area (writable)
Configuration Memory Area (non-writable)
Memory Area Description
Word Address
User Memory Area 2
Accessible via USB
0x3FF - 0x80
Configuration Memory Area
Accessible via USB
0x7E - 0x50
Configuration Memory Area
Cannot be written
0x4E - 0x40
User Memory Area 1
Accessible via USB
0x3E - 0x12
Configuration Memory Area
Accessible via USB
0x10 - 0x00
Figure 8.1: Simplified memory map for the FT-X
User Memory Area
The User Memory Areas are highlighted in Green on the memory map. They can be read and written via
USB on the FT240X. All locations within this range are freely programmable; no areas have special
functions and there is no checksum for the user area.
Note: The application should take into account the specification for the number of write cycles in Section
5.4 if it will be writing to the MTP memory multiple times.
Configuration Memory Area (writable)
This area stores the configuration data for the device, including the data which is returned to the host in
the configuration descriptors (e.g. the VID, PID and string descriptions) and also values which set the
hardware configuration (the signal assigned to each CBUS pin for example).
These values can have a significant effect on the behaviour of the device. Steps must be taken to ensure
that these locations are not written to un-intentionally by an application which is intended to access only
the user area.
This area is included in a checksum which covers configuration areas of the memory, and so changing
any value can also cause this checksum to fail.
Configuration Memory Area (non-writable)
This is a reserved area and the application should not write to this area of memory. Any attempt to write
these locations will fail.
Copyright © Future Technology Devices International Limited 33
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
9 Package Parameters
The FT240X is available in two different packages. The FT240XS is the SSOP-24 option and the FT240XQ
is the QFN-24 package option. The solder reflow profile for both packages is described in Section 9.5.
9.1 SSOP-24 Package Mechanical Dimensions
Figure 9.1 SSOP-24 Package Dimensions
The FT240XS is supplied in a RoHS compliant 24 pin SSOP package. The package is lead (Pb) free and
uses a ‘green’ compound. The package is fully compliant with European Union directive 2002/95/EC.
This package is nominally 8.66mm x 3.91 mm body (8.66mm x 5.99mm including pins). The pins are on
a 0.635 mm pitch. The above mechanical drawing shows the SSOP-24 package.
The date code format is YYXX where XX = 2 digit week number, YY = 2 digit year number.
The code XXXXXXXXXXXX is the manufacturing LOT code.
Copyright © Future Technology Devices International Limited 34
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
9.2 SSOP-24 Package Markings
Figure 9.2 SSOP-24 Package Markings
Notes:
1. YYWW = Date Code, where YY is year and WW is week number
2. Marking alignment should be centre justified
3. Laser marking should be used
4. All marking dimensions should be marked proportionally. Marking font should be using Greatek
standard font (Roman Simplex)
Line 1 – FTDI Logo
Line 2 – Date Code, Revision
Line 3 – Wafer Lot Number
Line 4 – FTDI Part Number
FT240XS
1 12
1324
-B
Copyright © Future Technology Devices International Limited 35
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
9.3 QFN-24 Package Mechanical Dimensions
Figure 9.3 QFN-24 Package Dimensions
The FT240XQ is supplied in a RoHS compliant leadless QFN-24 package - WQFN(X424), with pad size
114x114. The package is lead (Pb) free, and uses a ‘green’ compound. The package is fully compliant
with European Union directive 2002/95/EC.
This package is nominally 4.0mm x 4.0mm. The solder pads are on a 0.50mm pitch. The above
mechanical drawing shows the QFN-24 package. All dimensions are in millimetres.
The centre pad on the base of the FT240XQ is internally connected to GND, and the PCB should not have
tracking on the top layer in this area.
The date code format is YYXX where XX = 2 digit week number, YY = 2 digit year number.
The code XXXXXXX is the manufacturing LOT code.
Copyright © Future Technology Devices International Limited 36
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
9.4 QFN-24 Package Markings
Figure 9.4 QFN-24 Package Markings
Notes:
1. YYWW = Date Code, where YY is year and WW is week number
2. Marking alignment should be centre justified
3. Laser Marking should be used
4. All marking dimensions should be marked proportionally. Marking font should be using
Greatek standard font (Roman Simplex)
9.5 Solder Reflow Profile
The FT240X is supplied in Pb free 24 LD SSOP and QFN-24 packages. The recommended solder reflow
profile for both package options is shown in 9.5.
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
Figure 9.5 FT240X Solder Reflow Profile
FTD
I
XXXXXXXXXX
FT240XQ
Line 1 – FTDI Logo
Line 4 – Date Code, Revision
Line 2 – Wafer Lot Number
7
1
Line 3 – FTDI Part Number
YYWW-B
12
18
19
Copyright © Future Technology Devices International Limited 37
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
The recommended values for the solder reflow profile are detailed in Table 9.1. Values are shown for both
a completely Pb free solder process (i.e. the FT240X is used with Pb free solder), and for a non-Pb free
solder process (i.e. the FT240X 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
20 to 40 seconds
Ramp Down Rate
6°C / second Max.
6°C / second Max.
Time for T= 25°C to Peak
Temperature, Tp
8 minutes Max.
6 minutes Max.
Table 9.1 Reflow Profile Parameter Values
Copyright © Future Technology Devices International Limited 38
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
10 Contact Information
Head Office – Glasgow, UK
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
E-mail (Sales)
sales1@ftdichip.com
E-mail (Support)
support1@ftdichip.com
E-mail (General Enquiries)
admin1@ftdichip.com
Branch Office – Taipei, Taiwan
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
E-mail (Sales)
tw.sales1@ftdichip.com
E-mail (Support)
tw.support1@ftdichip.com
E-mail (General Enquiries)
tw.admin1@ftdichip.com
Branch Office – Tigard, Oregon, USA
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)
us.sales@ftdichip.com
E-Mail (Support)
us.support@ftdichip.com
E-Mail (General Enquiries)
us.admin@ftdichip.com
Branch Office – Shanghai, China
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)
cn.sales@ftdichip.com
E-mail (Support)
cn.support@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, a nd the
user agrees to defend, indemnify and 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, Unit 1, 2 Seaward Place, Centurion Business Park,
Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640
Copyright © Future Technology Devices International Limited 39
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
11 Appendix A - References
Document References
AN232R-01 FT232RBitBangModes
AN_107 Advanced Driver Options
AN_121 FTDI Device EEPROM User Area Usage
AN_120 Aliasing VCP Baud Rates
AN_100 Using the FT232_245R with External Osc
AN_126 User Guide for FT232 Factory Test Utility
AN_167 FT1248 Parallel Serial Interface Basics
AN232B-05 BaudRates
http://www.ftdichip.com/Documents/InstallGuides.htm
TN_100 USB VID-PID Guidelines
AN_175 Battery Charging Over USB with FTEX Devices
http://www.usb.org/developers/docs/devclass_docs/
Acronyms and Abbreviations
Terms
Description
DCP
Dedicated Charging Port
FIFO
First In First Out
LSB
Least Significant Bit First
MSB
Most Significant Bit First
MTP
Multi-time Programmable memory
QFN
Quad Flat Non-leaded package
SIE
Serial Interface Engine
USB
Universal Serial Bus
UART
Universal Asynchronous Receiver / Transmitter
Copyright © Future Technology Devices International Limited 40
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Appendix B - List of Figures and Tables
List of Figures
Figure 2.1 FT240X Block Diagram ................................................................................................... 4
Figure 3.1 SSOP Package Pin Out and Schematic Symbol ................................................................... 7
Figure 3.2 QFN-24 Package Pin Out and Schematic Symbol .............................................................. 10
Figure 3.3 FIFO Read Cycle .......................................................................................................... 13
Figure 3.4 FIFO Write Cycle ......................................................................................................... 14
Figure 6.1 Bus Powered Configuration ........................................................................................... 23
Figure 6.2 Self Powered Configuration ........................................................................................... 24
Figure 6.3 illustrates a self powered design which has a +3.3V to +5.25V supply. .............................. 24
Figure 6.4 Bus Powered with Power Switching Configuration ............................................................ 25
Figure 7.1 USB to MCU FIFO Interface ........................................................................................... 27
Figure 7.2 USB Battery Charging Detection (1 pin).......................................................................... 28
Figure 7.3 USB Battery Charging Detection (2 pin).......................................................................... 29
Figure 8.1: Simplified memory map for the FT-X ............................................................................ 32
Figure 9.1 SSOP-24 Package Dimensions ....................................................................................... 33
Figure 9.2 SSOP-24 Package Markings .......................................................................................... 34
Figure 9.3 QFN-24 Package Dimensions ......................................................................................... 35
Figure 9.4 QFN-24 Package Markings ............................................................................................ 36
Figure 9.5 FT240X Solder Reflow Profile......................................................................................... 36
List of Tables
Table 3.1 USB Interface Group ....................................................................................................... 7
Table 3.2 Power and Ground Group ................................................................................................. 7
Table 3.3 Miscellaneous Signal Group .............................................................................................. 8
Table 3.4 FIFO Interface Group (see note 2) .................................................................................... 8
Table 3.5 USB Interface Group ..................................................................................................... 10
Table 3.6 Power and Ground Group ............................................................................................... 10
Table 3.7 Miscellaneous Signal Group ............................................................................................ 11
Table 3.8 FIFO Interface Group (see note 2) .................................................................................. 11
Table 3.9 CBUS Configuration Control ........................................................................................... 13
Table 3.10 FIFO Read Cycle Timings ............................................................................................. 13
Table 3.11 FIFO Write Cycle ......................................................................................................... 14
Table 5.1 Absolute Maximum Ratings ............................................................................................ 17
Table 5.2 ESD and Latch-Up Specifications .................................................................................... 17
Table 5.3 Operating Voltage and Current ....................................................................................... 18
Table 5.4 FIFO I/O Pin Characteristics VCCIO = +3.3V, (except USB PHY pins) .................................. 19
Table 5.5 FIFO I/O Pin Characteristics VCCIO = +2.5V, (except USB PHY pins) .................................. 20
Table 5.6 FIFO I/O Pin Characteristics VCCIO = +1.8V (except USB PHY pins) ................................... 21
Table 5.7 USB I/O Pin (USBDP, USBDM) Characteristics .................................................................. 21
Copyright © Future Technology Devices International Limited 41
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Table 5.8 MTP Memory Characteristics ........................................................................................... 21
Table 5.9 Internal Clock Characteristics ......................................................................................... 22
Table 8.1 Default Internal MTP Memory Configuration ..................................................................... 31
Table 9.1 Reflow Profile Parameter Values ..................................................................................... 37
Copyright © Future Technology Devices International Limited 42
FT240X USB 8-BIT FIFO IC Datasheet
Version 1.4
Document No.: FT_000626 Clearance No.: FTDI# 259
Appendix C - Revision History
Document Title: FT240X USB 8-BIT FIFO IC Datasheet
Document Reference No.: FT_000626
Clearance No.: FTDI# 259
Product Page: http://www.ftdichip.com/FT-X.htm
Document Feedback: Send Feedback
Revision
Changes
Date
Version 1.0
Initial Datasheet Created
2012-02-07
Version 1.1
Replaced VCC_CORE with VCORE
Updated 24 pin SSOP dimensions
2012-02-22
Version 1.2
Clarified MTP Reliability in table 5.8
Edited Table 8.1, changed “Load
VCP Driver” to Disabled
2012-04-17
Version 1.3
Edited figure 3.1, 3.2 and 7.1 –
WR# to WR
Updated US Office Address
2013-02-14
Version 1.4
Updated document template
2018-05-08
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
FTDI:
FT240XQ-R FT240XQ-T FT240XS-R FT240XS-U