LTC4301CDD Supply Independent Hot Swappable 2 Wire Bus Buffer

DESCRIPTION

The LTC4301 supply independent, hot swappable, 2-wire
bus buffer allows I/O card insertion into a live backplane
without corruption of the data and clock busses. In addi-
tion, the LTC4301 allows the VCC, SDAIN and SCLIN pull-
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.

FEATURES

Allows Bus Pull-Up Voltages Above or Below V
Bidirectional Buffer* for SDA and SCL Lines
Increases Fanout
Prevents SDA and SCL Corruption During Live Board
Insertion and Removal from Backplane
Isolates Input SDA and SCL Line from Output
10kV Human Body Model ESD Protection
1V Precharge On All SDA and SCL Lines
Supports Clock Stretching, Arbitration and
Synchronization
High Impedance SDA, SCL Pins for V= 0V
CS Gates Connection from Input to Output
Compatible with IC, I 2 C Fast Mode and SMBus
Standards (Up to 400kHz Operation)
Small 8-Pin MSOP and DFN (3mm��3mm) Packages.

APPLICATIONS

Hot Board Insertion
Servers
Capacitance Buffer/Bus Extender
Desktop Computers
CompactPCI and ATCA Systems

TYPICAL APPLICATION