1

2

3

4

EN

SCLOUT

SCLIN

GND

8

7

6

5

V

CC

SDAOUT

SDAIN

READY

TCA4311A

www.ti.com

SCPS226 – JANUARY 2011

HOT SWAPPABLE 2-WIRE BUS BUFFERS

Check for Samples: TCA4311A

1

FEATURES

•

Operating Power-Supply Voltage Range of

•

Applications Include Hot Board Insertion and

2.7-V to 5.5-V

Bus Extension

•

•

Bus Signals

•

READY Open-Drain Output

•

SDA and SCL Lines Are Buffered Which

•

Supports Clock Stretching, Arbitration, and

Increases Fanout

Synchronization

•

1-V Precharge on All SDA and SCL Lines

•

Prevents Corruption During Live Board

•

Insertion and Removal From Backplane

•

Latch-Up Performance Exceeds 100 mA Per

•

SDA and SCL Input Lines Are Isolated From

JESD 78, Class II

Outputs

•

ESD Protection Exceeds JESD 22

•

Accommodates Standard Mode and Fast Mode

–

8000-V Human-Body Model (A114-A)

–

200-V Machine Model (A115-A)

•

Improved Noise Immunity

–

1000-V Charged-Device Model (C101)

D OR DGK PACKAGES

(TOP VIEW)

DESCRIPTION/ORDERING INFORMATION

corruption of the data and clock busses. Control circuitry prevents the backplane from being connected to the

card until a stop command or bus idle occurs on the backplane without bus contention on the card. When the

connection is made, this device provides bidirectional buffering, keeping the backplane and card capacitances

isolated. During insertion, the SDA and SCL lines are precharged to 1 V to minimize the current required to

charge the parasitic capacitance of the chip.

high, the TCA4311A resumes normal operation. It also includes an open drain READY output pin, which

indicates that the backplane and card sides are connected together. When READY is high, the SDAIN and

SCLIN are connected to SDAOUT and SCLOUT. When the two sides are disconnected, READY is low.

Both the backplane and card may be powered with supply voltages ranging from 2.7 V to 5.5 V, with no

restrictions on which supply voltage is higher.

The TCA4311A has standard open-drain I/Os. The size of the pullup resistors to the I/Os depends on the

system, but each side of this buffer must have a pullup resistor. The device is designed to work with Standard

high termination currents can be used.

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.