LTC4302-1/LTC4302-2

1

sn430212 430212fs

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

The LTC

SMBus compatible bus buffers allow a peripheral board

to be inserted and removed from a live backplane without

corruption of the bus. The LTC4302-1/LTC4302-2 main-

tain electrical isolation between the backplane and periph-

device on the backplane side addresses the LTC4302-1/

LTC4302-2 and commands them to connect. The

LTC4302-1/LTC4302-2’s ADDRESS pin provides 32 pos-

sible addresses set by an external resistive divider be-

with supply voltages ranging from 2.7V to 5.5V. The SDA

and SCL inputs and outputs do not load the bus lines when

Rise time accelerator circuitry* allows for heavier capaci-

tive bus loading while still meeting system timing require-

ments. During insertion, the SDA and SCL lines are

precharged to 1V to minimize bus disturbances. Two

general purpose input/output pins (GPIOs) on the

LTC4302-1 can be configured as inputs, open-drain out-

puts or push-pull outputs. The LTC4302-2 option replaces

providing level shifting between systems with different

supply voltages. The LTC4302-1/LTC4302-2 are available

in a 10-pin MSOP package.

s

Live Board Insertion

s

5V/3.3V Level Translator

s

Servers

s

Capacitance Buffer/Bus Extender

s

Nested Addressing

, LTC and LT are registered trademarks of Linear Technology Corporation.

s

Bidirectional Buffer for SDA and SCL Lines

Increases Fanout

s

Connect SDA and SCL Lines with 2-Wire Bus

Commands

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Prevents SDA and SCL Corruption During Live Board

Insertion and Removal from Backplane

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Mode and SMBus Standards

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Rise Time Accelerators on SDA, SCL Lines

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1V Precharge on SDA and SCL Lines

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32 Unique Addresses from a Single ADDRESS Pin

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Two General Purpose Inputs-Outputs (LTC4302-1)

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Translates Between 5V and 3.3V Systems

(LTC4302-2)

s

Small 10-Pin MSOP Package

Addressable

2-Wire Bus Buffers

LTC4302-1

SDAIN

C1

0.01

µF

CARD SDA

CARD SCL

R7

10k

R6

10k

R8

1k

R9

1k

2.7V

to

5.5V

R3

10k

R4

10k

R5

10k

R1

1870

Ω

R2

2000

Ω

SDA

SCL

SCLIN

CONN

ADDRESS

GND

LED

LED

4203 TA01a

SDAOUT

SCLOUT

GPIO1

GPIO2

*U.S. Patent No. 6,650,174

4032 F10

OUTPUT

SIDE

50pF

INPUT

SIDE

150pF

0.1

µs/DIV