Keypad Decoder and I/O Expansion
Data Sheet
ADP5589
FEATURES
FUNCTIONAL BLOCK DIAGRAM
VDD
GND
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
ADP5589
UVLO
POR
OSCILLATOR
RST
SDA
SCL
2
I C INTERFACE
INT
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
R0
R1
R2
R3
R4
R5
R6
R7
C0
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
KEY SCAN
AND
DECODE
GPI SCAN
AND
DECODE
REGISTERS
I/O
CONFIG
LOGIC 1
LOGIC 2
CLK DIV
PWM
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
RESET 1
GEN
APPLICATIONS
Devices requiring keypad entry and I/O expansion
capabilities
RESET 2
GEN
Figure 1.
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.
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 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
The programmable logic functions allow common logic
requirements to be integrated as part of the GPIO expander,
saving board area and cost.
Rev. B
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