1 Features
1. Two-Channel Bidirectional Buffer
. I2C Bus and SMBus Compatible
. Operating Supply Voltage Range of 0.9 V to 5.5 V
on A-side
. Operating Supply Voltage Range of 2.7 V to 5.5 V
on B-side
. Voltage-Level Translation From 0.9 V - 5.5 V to
2.7 V - 5.5 V
. Footprint and Functional Replacement for
PCA9515B
. Active-High Repeater-Enable Input
. Open-Drain I2C I/O
. 5.5-V Tolerant I2C and Enable Input Support
Mixed-Mode Signal Operation
. Accommodates Standard Mode and Fast Mode
I2C Devices and Multiple Masters
. High-Impedance I2C Pins When Powered-Off
. Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
. ESD Protection Exceeds JESD 22
. 5500 V Human-Body Model (A114-A)
. 200 V Machine Model (A115-A)
. 1000 V Charged-Device Model (C101)

2 Applications
• Servers
• Routers (Telecom Switching Equipment)
• Industrial Equipment
• Products with Many I2C Slaves and/or Long PCB
Traces

3 Description
The TCA9517 is a bidirectional buffer with level
shifting capabilities for I2C and SMBus systems. It
provides bidirectional voltage-level translation (uptranslation/
down-translation) between low voltages
(down to 0.9 V) and higher voltages (2.7 V to 5.5 V)
in mixed-mode applications. This device enables I2C
and SMBus systems to be extended without
degradation of performance, even during level
shifting.
The TCA9517 buffers both the serial data (SDA) and
the serial clock (SCL) signals on the I2C bus, thus
allowing two buses of up to 400-pF bus capacitance
to be connected in an I2C application.
The TCA9517 has two types of drivers: A-side drivers
and B-side drivers. All inputs and I/Os are overvoltage
tolerant to 5.5 V, even when the device is
unpowered (VCCB and/or VCCA = 0 V).