PCA9538

INTEGRATED CIRCUITS PCA9538 8-bit I2C and SMBus low power I/O port with interrupt and reset Product data sheet Supersedes data of 2004 Sep 30 2004 Oct 05 Philips Semiconductors Philips Semiconductors Product data sheet 8-bit I2C and SMBus low power I/O port with interrupt and reset PCA9538 DESCRIPTION The PCA9538 is a 16-pin CMOS device that provide 8 bits of General Purpose parallel Input/Output (GPIO) expansion with interrupt and reset for I2C/SMBus applications and was developed to enhance the Philips family of I2C I/O expanders. I/O expanders provides a simple solution when additional I/O is needed for ACPI power switches, sensors, pushbuttons, LEDs, fans, etc. The PCA9538 consists 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 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 input port register can be inverted with the Polarity Inversion Register. All registers can be read by the system master. The PCA9538 is identical to the PCA9554 except for the removal of the internal I/O pull-up resistor which greatly reduces power consumption when the I/Os are held LOW, replacement of A2 with RESET and different address range. The PCA9538 open-drain interrupt output is ac...