LTC4309
Level Shifting Low Offset Hot
Swappable 2-Wire Bus Buffer
with Stuck Bus Recovery
DESCRIPTION FEATURES n The LTC®4309 hot swappable 2-wire bus buffer allows
I/O card insertion into a live backplane without corruption of the data and clock busses. The LTC4309 provides
bidirectional buffering, keeping the backplane and card
capacitances isolated. Low offset and high VOL tolerance
allows cascading of multiple devices on the clock and data
busses. If SDAOUT or SCLOUT are low for 30ms, FAULT
will pull low indicating a stuck bus low condition. If DISCEN
is tied high, the LTC4309 will automatically break the bus
connection and generate up to 16 clock pulses and a stop
bit in an attempt to free the bus. A connection will resume
if the stuck bus is cleared. If DISCEN is connected to GND,
the busses will remain connected with no clock or stop
bit generation. ACC input enables rise-time accelerators
for high capacitively loaded busses. Bidirectional Buffer Increases Fanout
60mV Buffer Offset Independent of Load
Optional Disconnect when Bus is Stuck Low
Prevents SDA and SCL Corruption During Live
Board Insertion and Removal from Backplane
Level Shift 2.5V, 3.3V and 5V Busses …