Keypad Decoder and I/O Port Expander

The ADP5586 is a 10-input/output port expander with a built-in keypad matrix decoder, programmable logic, reset generator, and pulse generators. Input/output 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 ADP5586 handles all key scanning and decoding and can flag the main processor, via an interrupt line, that new key events have occurred. GPI changes and logic changes can also be tracked as events via the FIFO, eliminating the need to monitor different registers for event changes. The ADP5586 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 ADP5586 eliminates the need for the main processor to monitor the keypad, thus 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, thus saving board area and cost.

APPLICATIONS

* Keypad entries and input/output expansion capabilities

* Smart phones, remote controls, and cameras

* Healthcare, industrial, and instrumentation

* 16-element FIFO for event recording

* 10 configurable I/Os allowing for such functions as:

Keypad decoding for a matrix of up to 5 × 5

Key press/release interrupts

See datasheet for additional features