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