1 Features
• I2C to GPIO expander
• Operating power-supply voltage range of 1.65 V to
5.5 V
• 5-V Tolerant I/O ports
• Software Reset via I2C General Call
• Software-enabled integrated pull-up resistors on P
ports
• P3 can be repurposed as INT output
• 1-MHz Fast mode plus I2C bus
• Input and output configuration register
• Polarity inversion register
• Internal power-on reset
• Power-up with all channels configured as inputs
• Noise filter on SCL and SDA inputs
• Latched outputs with high-current drive maximum
capability for directly driving LEDs
• ESD protection exceeds JESD 22
– 2000-V Human-body model (A114-A)
– 1000-V Charged-device model (C101)

2 Applications
• Personal electronics
– Wearables
– Mobile phones
– Gaming consoles
• Servers
• Routers

3 Description
The TCA9536 is a 4-bit I/O expander for the I2C bus
and is designed for 1.65-V to 5.5-V VCC operation.
It provides general-purpose remote I/O expansion for
most microcontroller families via the I2C interface.
The system controller can enable the I/Os as either
inputs or outputs by writing to the I/O configuration
register bits. The data for each input or output is
kept in the corresponding input or output register. The
polarity of the Input Port register can be inverted with
the Polarity Inversion register. There is an additional
special function register that can be used to disable
the internal pull-up resistors and P3 override to an INT
output.
The TCA9536 open-drain interrupt output (when
P3 is configured as INT in the special function
register) is activated when any input differs from its
corresponding Input Port register state and is used to
indicate to the system controller that an input state
has changed.
The system processor can reset the TCA9536 in the
event of a timeout or other improper operation by
using an I2C soft reset command, which puts the
registers in their default state.