1 Features
. I2C to Parallel port expander
. Wide power supply voltage range of 1.65 V to
5 V
. Low standby-current consumption
. Open-drain active-low interrupt output
. 5-V tolerant I/O ports
. 400-kHz Fast I2C bus
. Polarity inversion register
. Address by three hardware address pins for use of
up to eight devices
. Latched outputs with high-current drive capability
for directly driving LEDs
. Latch-up performance exceeds 100 mA per
JESD 78, class II
. ESD protection exceeds JESD 22
. 2000-V Human-Body Model (A114-A)
. 1000-V Charged-Device Model (C101)

2 Applications
. Servers
. Routers (telecom switching equipment)
. Personal computers
. Personal electronics (for example, gaming
consoles)
. Industrial automation
. Products with GPIO-limited processors

3 Description
The TCA9535 is a 24-pin device that provides 16
bits of general purpose parallel input and output (I/O)
expansion for the two-line bidirectional I2C bus or
(SMBus) protocol. The device can operate with a
power supply voltage ranging from 1.65 V to 5.5 V.
The TCA9535 consists of two 8-bit Configuration
(input or output selection), Input Port, Output Port,
and Polarity Inversion (active-high or active-low
operation) registers. At power on, the I/Os are
configured as inputs. The system controller can
enable the I/Os as either inputs or outputs by writing
to the I/O configuration bits.
The TCA9535 is identical to the TCA9555, except that
the TCA9535 does not include the internal I/O pull-up
resistor, which requires pull-ups and pull-downs on
unused I/O pins when configured as an input and
undriven.