TCA9555 Datasheet, PDF (2/32 Pages) Texas Instruments – LOW VOLTAGE 16-BIT I2C AND SMBus I/O EXPANDER WITH INTERRUPT OUTPUT AND CONFIGURATION REGISTERS

TCA9555
SCPS200A – JULY 2009 – REVISED JULY 2009 .............................................................................................................................................................. www.ti.com
INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the
remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via
the I²C bus. Thus, the TCA9555 can remain a simple slave device.
The device outputs (latched) have high-current drive capability for directly driving LEDs.
Although pin-to-pin and I²C-address is compatible with the PCF8575, software changes are required due to the
enhancements.
The TCA9555 is identical to the TCA9535, except for the inclusion of the internal I/O pullup resistor, which pulls
the I/O to a default high when configured as an input and undriven.
Three hardware pins (A0, A1, and A2) are used to program and vary the fixed I²C address and allow up to eight
devices to share the same I²C bus or SMBus. The fixed I²C address of the TCA9555 is the same as the
PCF8575, PCF8575C, and PCF8574, allowing up to eight of these devices in any combination to share the same
I²C bus or SMBus.
T_A
–40°C to 85°C
TSSOP – PW
QFN – RTW
ORDERING INFORMATION⁽¹⁾
PACKAGE ⁽²⁾
ORDERABLE PART NUMBER
Reel of 2000
TCA9555PWR
Reel of 3000
TCA9555RTWR
TOP-SIDE MARKING
PW555
PW555
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
2
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