1 Features
• Two-channel bidirectional I2C buffer
• Support for standard mode, fast mode (400kHz),
and fast mode+ (1MHz) I2C operation
• Operating supply voltage range of 0.8V to 5.5V on
A-side
• Operating supply voltage range of 2.2V to 5.5V on
B-side
• Voltage-level translation from 0.8V to 5.5V and
2.2V to 5.5V
• Footprint and function replacement for TCA9517
• Active-high repeater-enable input
• Open-drain I2C I/O
• 5.5V Tolerant I2C and enable input support
• Lockup-free operation
• Powered-off high-impedance I2C bus pins
• Support for clock stretching and multiple controller
arbitration across the device
• Latch-up performance exceeds 100mA per JESD
78, class II
• ESD protection exceeds JESD 22
– 4000V Human-body model
– 1500V Charged-device model

2 Applications
• Servers
• Routers (Telecom Switching Equipment)
• Industrial Equipment
• Products with many I2C targets and/or long PCB
traces

3 Description
The TCA9617B is a BiCMOS dual bidirectional buffer
intended for I2C bus and SMBus systems. The
device provides bidirectional voltage-level translation
(up-translation and down-translation) between low
voltages (down to 0.8V) and higher voltages
(2.2V to 5.5V) in mixed-mode applications. This
device enables I2C and similar bus systems to be
extended, without degradation of performance even
during level shifting.
The TCA9617B buffers both the serial data (SDA) and
the serial clock (SCL) signals on the I2C bus, allowing
two buses of 550pF to be connected in an I2C
application. This device can also be used to separate
two halves of a bus for voltage and capacitance.