DESCRIPTION
The LTC4307 hot swappable, 2-wire bus buffer allows
I/O card insertion into a live backplane without corrup-
tion of the data and clock busses. The LTC4307 provides
bidirectional buffering, keeping the backplane and card
capacitances isolated. Low offset and high tolerance
allows multiple devices to be cascaded on the clock and
data busses. If SDAOUT or SCLOUT are low for 30ms, the
LTC4307 will automatically break the bus connection. At
this time the LTC4307 automatically generates up to 16
clock pulses on SCLOUT in an attempt to free the bus. A
connection will resume if the stuck bus is cleared.
During insertion, the SDA and SCL lines are pre-charged
to 1V to minimize bus disturbances. When driven high,
the ENABLE input allows the LTC4307 to connect after a
stop bit or bus idle. Driving ENABLE low breaks the con-
nection between SDAIN and SDAOUT, SCLIN and SCLOUT.
READY is an open-drain output which indicates that the
backplane and card sides are connected.
FEATURES
Bidirectional Buffer with Stuck Bus Recovery
60mV Buffer Offset Independent of Load
30ms Stuck Bus Timeout
Compatible with Non-Compliant V 2 C Devices
Prevents SDA and SCL Corruption During Live
Board Insertion and Removal from Backplane
±5kV Human Body Model ESD Protection
Isolates Input SDA and SCL Line from Output
Compatible with IC, I 2 C Fast Mode and SMBus
READY Open-Drain Output
1V Precharge on All SDA and SCL Lines
High Impedance SDA, SCL Pins for V=0V
Small 8-Lead (3mm×3mm) DFN and 8-Lead MSOP
Packages.
APPLICATIONS
Live Board Insertion
Servers
Capacitance Buffer/Bus Extender
RAID Systems
ATCA
TYPICAL APPLICATION
Rising Edge from Asserted Low
DD PACKAGE
MS8 PACKAGE
TYPICAL APPLICATIONS
High V Application
P/N PACKAGE
LTC4307CMS8 MSOP-8
LTC4307IMS8 MSOP-8
LTC4307CDD DFN-8
LTC4307IDD DFN-8