Keypad Decoder and I/O Expansion

Data Sheet

ADP5585

Rev. C

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FEATURES

16-element FIFO for event recording

10 configurable I/Os allowing functions such as

Key pad decoding for a matrix of up to 5 × 5

11 GPIOs (5 × 6) with ADP5585ACxZ-01-R7 models

Key press/release interrupts

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

Programmable logic block

PWM generator

Internal PWM generation

External PWM with internal PWM AND function

Reset generators

Open-drain interrupt output

16-ball WLCSP, 1.59 mm × 1.59 mm

16-lead LFCSP, 3 mm × 3 mm

APPLICATIONS

Keypad entries and input/output expansion capabilities

Smart phones, remote controls, and cameras

Healthcare, industrial, and instrumentation

FUNCTIONAL BLOCK DIAGRAM

SDA

GPI SCAN

AND

DECODE

UVLO

POR

OSCILLATOR

REGISTERS

KEY SCAN

AND

DECODE

LOGIC

I/O

CONFIG

INT

RST/R5

PWM

SCL

VDD

ADP5585

GND

RESET1

GEN

RESET2

GEN

R0

R3

R1

R2

R4

C0

C1

C2

C3

C4

Figure 1.

GENERAL DESCRIPTION

The ADP5585 is a 10 input/output port expander with a built in

keypad matrix decoder, programmable logic, reset generator, and

PWM generator. 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 ADP5585 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 ADP5585 is equipped with a

FIFO to store up to 16 events. Events can be read back by the

The ADP5585 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 require-

ments to be integrated as part of the GPIO expander, thus saving

board area and cost.