GENERAL DESCRIPTION
The ADP5589 is a 19 I/O port expander with built-in keypad matrix decoder, programmable logic, reset generator, and PWM generator. I/O expander ICs are used in portable devices (phones, remote controls, and cameras) and nonportable applications (healthcare, industrial, and instrumentation). I/O expanders can be used to increase the number of I/Os available to a processor or to reduce the number of I/Os required through interface connectors for front panel designs.
The ADP5589, which handles all key scanning and decoding, can flag the main processor via an interrupt line when new key events have occurred. In addition, GPI changes and logic changes can be tracked as events via the FIFO, eliminating the
need to monitor different registers for event changes. The ADP5589 is equipped with a FIFO to store up to 16 events. Events can be read back by the processor via an I2C compatible interface.
The ADP5589 frees up the main processor from having to monitor the keypad, thereby reducing power consumption and/or increasing processor bandwidth for performing other functions.
The programmable logic functions allow common logic requirements to be integrated as part of the GPIO expander, saving board area and cost.

FEATURES
16-element FIFO for event recording
19 configurable I/Os allowing functions such as
Keypad decoding for matrix up to 11 × 8
Key press/release interrupts
Key pad lock/unlock
GPIO functions
GPI with selectable interrupt level
100 kΩ or 300 kΩ pull-up resistors
300 kΩ pull-down resistors
GPO with push-pull or open drain
Dual programmable logic blocks
PWM generator
Internal PWM generation
External PWM with internal PWM AND function
Clock divider
Reset generators
I2C interface with fast-mode plus (Fm+) support up to 1 MHz
Open-drain interrupt output
24-lead LFCSP 3.5 mm × 3.5 mm
25-ball WLCSP 1.99 mm × 1.99 mm

APPLICATIONS
Devices requiring keypad entry and I/O expansion capabilities