1

LTC4301

4301fb

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

Supply Independent Hot

Swappable 2-Wire Bus Buffer

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■

Bidirectional Buffer* for SDA and SCL Lines

Increases Fanout

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Prevents SDA and SCL Corruption During Live Board

Insertion and Removal from Backplane

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Isolates Input SDA and SCL Line from Output

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10kV Human Body Model ESD Protection

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1V Precharge On All SDA and SCL Lines

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Supports Clock Stretching, Arbitration and

Synchronization

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CS Gates Connection from Input to Output

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Standards (Up to 400kHz Operation)

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Small 8-Pin MSOP and DFN (3mm

× 3mm) Packages

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Hot Board Insertion

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Servers

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Capacitance Buffer/Bus Extender

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Desktop Computers

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CompactPCI

The LTC

bus buffer allows I/O card insertion into a live backplane

without corruption of the data and clock busses. In addi-

up voltage and the SDAOUT and SCLOUT pull-up voltage

to be independent from each other. Control circuitry

prevents the backplane from being connected to the card

until a stop bit or a bus idle is present. When the connec-

tion is made, the LTC4301 provides bidirectional buffer-

ing, keeping the backplane and card capacitances isolated.

During insertion, the SDA and SCL lines are precharged to

1V to minimize bus disturbances. When driven low, the CS

input pin allows the part to connect after a stop bit or bus

idle occurs. Driving CS high breaks the connection be-

tween SCLIN and SCLOUT and between SDAIN and

SDAOUT. The READY output pin indicates that the back-

plane and card sides are connected together.

The LTC4301 is offered in 8-pin DFN (3mm

× 3mm) and

MSOP packages.

10k

10k

5V

BACK_SCL

BACKPLANE

CONNECTOR

CARD

BACK_SDA

3.3V

10k

5V

CS

CARD_SCL

CARD_SDA

SCLOUT

SCLIN

SDAOUT

SDAIN

GND

LTC4301

READY

0.01

µF

10k

10k

Input-Output Connection

4301 TA01b

OUTPUT

SIDE

20pF

INPUT

SIDE

55pF

1

µs/DIV

1V/DIV

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

All other trademarks are the property of their respective owners.

Protected by U.S. Patents including 7032051.