DC1986A - ANALOG DEVICES - Datasheet.Live

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DEMO MANUAL DC1986A

DESCRIPTION

LTM2892-I

I2C µModule Isolator

Demonstration circuit 1986A is an I2C µModule

Isolator

featuring the LTM2892-I. The demo circuit operates from

external supply voltages on VCC1, VL1, VCC2, and VL2. It

communicates all necessary signaling across the isolation

barrier through LTC’s Isolator™ µModule Technology.

L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks

and Isolator is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

PERFORMANCE SUMMARY

OPERATING PRINCIPLES

Design files for this circuit board are available at

http://www.linear.com/demo

Specifications are at TA = 25°C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VCC1, VCC2 Input Supply Range 3.0 5.5 V

VL1, VL2 Logic Supply Range 3.0 5.5 V

fMAX Maximum Data Rate INx → OUTx, CL = 15pF 20 MHz

I2C Communication 400 kHz

VIORM Maximum Working Insulation Voltage GND1 to GND2 850 VDC

600 VRMS

Common Mode Transient Immunity 50 kV/µs

The LTM2892-I requires two to four external power sup-

plies for operation, one for power and one for the signal

interface, on each side of the isolation barrier. The logic

supplies may be tied to the input supplies. Isolation is

maintained by the separation of GND1 and GND2 where

significant operating voltages and transients can exist

without affecting the operation of the LTM2892-I. The ON1

and/or ON2 pins enable or shut down the LTM2892-I, both

must be driven to their respective logic supply voltage for

proper operation. All I2C or digital signals are referenced

to the logic supply pins VL1 or VL2.

I2C signaling does not require any additional components.

The demo board includes pull-up resistors on SDA1 and

SCLIN. SCLOUT and SDA2 do not require external pull-ups,

SCLOUT is a push-pull output and SDA2 is pulled high

through an integral current source within the LTM2892-I.

Do not use external pull-up resistors or current sources

on SCLOUT or SDA2.

I2C signaling is configured by defining the LTM2892-I

pins as follows:

Logic Side: SCLIN = SCL(IN), and SDA1 = SDA(IN).

Isolated Side: SCLOUT = SCL(OUT), SDA2 = SDA(OUT).

Reference Figure 1 for schematic representation.

No special precautions are required for low RF emissions.

EMI performance is shown in Figure 2, measured using

a gigahertz transverse electromagnetic (GTEM) cell and

method detailed in IEC 61000-4-20, Testing and Measure-

ment Techniques – Emission and Immunity Testing in

Transverse Electromagnetic Waveguides.

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DEMO MANUAL DC1986A

Figure 1. I2C Operation

Figure 2. DC1986A Radiated Emissions

OPERATING PRINCIPLES

VCC1

VL1

ON1

SCLIN

SDA1

INA

OUTB

SDA1

OUTC

SCL(IN)

SDA(IN)

SCL(OUT)

SDA(OUT)

VCC2

VL2

ON2

SCLOUT

SDA2

OUTA

INB

SDA2

INC

LTM2892-I

NOTE: INA, INB AND INC ARE

OPTIONAL CONNECTIONS

GND2GND1

ISOLATION BARRIER

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FREQUENCY (MHz)

dBµV/m

–20

–10

–30 500 900300 700

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1000400 800200 600100

CISPR 22 CLASS B LIMIT

DUT

DETECTOR = PEAK HOLD

RBW = 120kHz

VBW = 300kHz

SWEEP TIME = 680ms, ≥ 10 SWEEPS

NUMBER OF POINTS = 501

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DEMO MANUAL DC1986A

QUICK START PROCEDURE

Demonstration circuit 1986A is easy to set up and evalu-

ate the performance of the LTM2892-I. Refer to Figure 3

for proper measurement equipment setup and follow the

procedure below.

NOTE: When measuring the input or output voltage ripple

or high speed signals, care must be taken to avoid a long

ground lead on the oscilloscope probe.

1. Install jumpers as shown in Figure 3 and the schematic

diagram.

2. With power off, connect the input power supplies to

VCC1 - GND1 and VCC2 - GND2 as shown.

3. Turn on the power at the input.

NOTE: Make sure that the input voltage does not ex-

ceed6V.

4. Configure jumpers or connect signals to turrets as ap-

propriate. If a signal is connected to an input channel

turret the associated channel jumper must be removed

for proper operation.

Figure 3. Demo Board Setup

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DEMO MANUAL DC1986A

PARTS LIST

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

1 1 U1 I.C., LTM2892CY-I LINEAR LTM2892CY-I#PBF

Hardware: For Demo Board Only

2 4 C1-4 CAP., TANT 4.7F 10V 20% 0805 NICHICON F921A475MPA

3 12 E4-15 TURRET, 0.065" MILL-MAX 2308-2-00-80-00-00-07-0

4 6 E1-3, E16-18 TURRET, 0.095" MILL-MAX 2501-2-00-80-00-00-07-0

5 2 JP3-4 2mm SINGLE ROW HEADER, 2 X 1 PIN SAMTEC TMM-102-02-L-S

6 5 JP1-2, JP5-7 2mm SINGLE ROW HEADER, 3 x 1 PIN SAMTEC TMM-103-02-L-S

7 7 JP1-7 2mm SHUNT SAMTEC 2SN-BK-G

8 2 R1-R2 RES., CHIP 4.7k 5% 0805 VISHAY CRCW08054K70JNEA

9 5 R3-R7 RES., CHIP 100 5% 1206 AAC CR18-101JM

PCB LAYOUT

Top Copper Bottom Copper

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DEMO MANUAL DC1986A

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

SCHEMATIC DIAGRAM

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DEMO MANUAL DC1986A

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com

LT 0912 • PRINTED IN USA

DEMONSTRATION BOARD IMPORTANT NOTICE

Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:

This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT

OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete

in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety

measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union

directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.

If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date

of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU

OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS

FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR

ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.

The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims

arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all

appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or

agency certified (FCC, UL, CE, etc.).

No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,

customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.

LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.

Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and

observe good laboratory practice standards. Common sense is encouraged.

This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC applica-

tion engineer.

Mailing Address:

Linear Technology

1630 McCarthy Blvd.

Milpitas, CA 95035