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 to 5.5 V and
2.7 V to 5.5 V
• Footprint and Function Replacement for
PCA9515A
• Active-High Repeater-Enable Input
• Open-Drain I2C I/O
• 5.5-V Tolerant I2C and Enable Input Support
Mixed-Mode Signal Operation
• Lockup-Free Operation
• Accommodates Standard Mode and Fast Mode
I2C Devices and Multiple Masters
• Powered-Off High-Impedance I2C Pins
• 400-kHz Fast I2C Bus
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)

2 Description
This dual bidirectional I2C buffer is operational at
2.7 V to 5.5 V.
The PCA9517 is a BiCMOS integrated circuit
intended for I2C bus and SMBus systems. It can also provide bidirectional voltage-level translation (up-
translation/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 similar bus systems to be extended, without
degradation of performance even during level shifting.
The PCA9517 buffers both the serial data (SDA) and
the serial clock (SCL) signals on the I2C bus, thus
allowing two buses of 400-pF bus capacitance to be connected in an I2C application. This device can also
be used to isolate two halves of a bus for voltage and
capacitance.
The PCA9517 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).
The PCA9517 doesnot support clock stretching and
arbitration across the repeater.