The PCA9501PW is an 8-bit I/O Expander with an on-board 2-kbit EEPROM. The I/O expandable eight quasi-bidirectional data pins can be independently assigned as inputs or outputs to monitor board level status or activate indicator devices such as LEDs. The system master writes to the I/O configuration bits in the same way as for the PCF8574. The data for each input or output is kept in the corresponding input or output register. The system master can read all registers. The EEPROM can be used to store error codes or board manufacturing data for read-back by application software for diagnostic purposes and are included in the I/O expander package. The PCA9501 active LOW open-drain interrupt output is activated when any input state differs from its corresponding input port register state. It is used to indicate to the system master that an input state has changed and the device needs to be interrogated.
Self-timed write cycle
16-byte Page write operation
I2C-bus and SMBus Interface logic
Internal power-ON reset
Active low interrupt output
6 Address pins allowing up to 64 devices on the I2C-bus/SMBus
No glitch on power-up
Supports hot insertion
Power-up with all channels configured as inputs
Low standby current consumption
Latch-up testing is done to JEDEC standard JESD78 which exceeds 100mA