PCA9554

Features:

*Operating power supply voltage range of 2.3 to 5.5 V
*5 V tolerant I/Os
*Polarity inversion register
*Active-LOW interrupt output
*Low stand-by current
*Noise filter on SCL/SDA inputs
*No glitch on power-up
*Internal power-on reset
*8 I/O pins which default to 8 inputs
*0 to 400 kHz clock frequency
*ESD protection exceeds 2000 V HBM per JESD22-A114,200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101
*Latch-up testing is done to JESDEC Standard JESD78 which exceeds 100 mA
*Six packages offered: DIP16, SO16, SSOP16, SSOP20,TSSOP16, and HVQFN16


Pinout




Specifications

SYMBOL	PARAMETER	CONDITIONS	MIN	MAX	UNIT
VDD	Supply voltage		0.5	6.0	V
II	DC input current		-	±20	mA
VI/O	DC voltage on an I/O		VSS0.5	5.5	V
II/O	DC output current on an I/O		-	±50	mA
IDD	Supply current		-	85	mA
ISS	Supply current		-	100	mA
Ptot	Total power dissipation		-	200	mW
Tstg	Storage temperature range		65	+150	°C
Tamb	Operating ambient temperature		40	+85	°C

Description

The PCA9554 and PCA9554A are 16-pin CMOS devices that provide 8 bits of General Purpose parallel Input/Output (GPIO)expansion for I² C/SMBus applications and were developed to enhance the Philips family of IC I/O expanders. The improvements include higher drive capability, 5V I/O tolerance, lower supply current, individual I/O configuration, 400 kHz clock frequency, and smaller packaging. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors,pushbuttons, LEDs, fans, etc.

The PCA9554/54A consist of an 8-bit Configuration register (Input or Output selection); 8-bit Input register, 8-bit Output register and an 8-bit Polarity inversion register (Active-HIGH or Active-LOW operation). The system master of PCA9554 can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each Input or Output is kept in the corresponding Input or Output register.

The polarity of the read register of PCA9554 can be inverted with the Polarity Inversion Register. All registers can be read by the system master.Although pin to pin and I² C address compatible with the PCF8574 series, software changes are required due to the enhancements and are discussed in Application Note AN469.

The PCA9554/54A open-drain interrupt output is activated when any input state differs from its corresponding input port register state and is used to indicate to the system master that an input state has changed. The power-on reset sets the registers to their default values and initializes the device state machine.

Three hardware pins (A0, A1, A2) vary the fixed I² C address and allow up to eight devices to share the same I²C/SMBus. The PCA9554A is identical to the PCA9554 except that the fixed I²C address is different allowing up to sixteen of these devices (eight of each) on the same I² C/SMBus.