1 Features
• Supports bidirectional data transfer of I2C bus
signals
• Operating power-supply voltage range of 2.3 V to
5.5 V
• TA ambient air temperature range of
-40 °C to 125 °C
• Stuck bus recovery featuring automatic bus
recovery
• 1-V Precharge on all SDA and SCL lines prevents
corruption during live insertion
• Accommodates standard mode and fast mode I2C
devices
• Supports clock stretching, arbitration and
synchronization
• Powered-off high-impedance I2C pins

2 Applications
• Servers
• Enterprise Switching
• Telecom switching equipment
• Base stations
• Industrial automation equipment

3 Description
The TCA4307 is a hot-swappable I2C bus buffer
that supports I/O card insertion into a live backplane
without corruption of the data and clock lines. Control
circuitry prevents the backplane-side I2C lines (in)
from being connected to the card-side I2C lines (out)
until a stop command or bus idle condition occurs
on the backplane without bus contention on the card.
When the connection is made, this device provides
bidirectional buffering, keeping the backplane and
card capacitance isolated. During insertion, the SDA
and SCL lines are pre-charged to 1 V to minimize the
current required to charge the parasitic capacitance of
the device.
The TCA4307 has stuck bus recovery, which
automatically disconnects the bus if it detects either
SDAOUT or SCLOUT are low for about 40 ms. Once
the bus is disconnected, the device automatically
generates up to 16 pulses on SCLOUT to attempt to
reset the device which is holding the bus low.
When the I2C bus is idle, the TCA4307 can be put into
shutdown mode by setting the EN pin low, reducing
power consumption. When EN is pulled high, the
TCA4307 resumes normal operation. It also includes
an open drain READY output pin, which indicates that
the backplane and card sides are connected together.
When READY is high, the SDAIN and SCLIN are
connected to SDAOUT and SCLOUT. When the two
sides are disconnected, READY is low.