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I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
MAX7360
EVALUATION KIT AVAILABLE
General Description
The MAX7360 I2C-interfaced peripheral provides micro-
processors with management of up to 64 key switches,
with an additional eight LED drivers/GPIOs that feature
constant-current, PWM intensity control, and rotary
switch control options.
The key-switch drivers interface with metallic or resis-
tive switches with on-resistances up to 5kI. Key inputs
are monitored statically, not dynamically, to ensure
low-EMI operation. The MAX7360 features autosleep
and autowake modes to further minimize the power
consumption of the device. The autosleep feature puts
the device in a low-power state (1FA typ) after a sleep
timeout period. The autowake feature configures the
MAX7360 to return to normal operating mode from sleep
upon a keypress.
The key controller debounces and maintains a FIFO of
keypress and release events (including autorepeat, if
enabled). An interrupt (INTK) output can be configured
to alert keypresses, as they occur, or at maximum rate.
There are eight open-drain I/O ports, which can be used
to drive LEDs. The maximum constant-current level for
each open-drain port is 20mA. The intensity of the LED
on each open-drain port can be individually adjusted
through a 256-step PWM control. An input port pair
(PORT6, PORT7) can be configured to accept 2-bit gray
code inputs from a rotary switch. In addition, if not used
for key-switch control, up to six column pins can be used
as general-purpose open-drain outputs (GPOs) for LED
drive or logic control.
The MAX7360 is offered in a 40-pin (5mm x 5mm)
thin QFN package with an exposed pad, and a small
36-bump wafer level package (WLP) for cell phones,
pocket PCs, and other portable consumer electronic
applications. The MAX7360 operates over the -40NC to
+85NC extended temperature range.
Applications
Cell Phones
PDAs
Handheld Games
Portable Consumer Electronics
Printers
Instrumentation
Features
S
Integrated ESD Protection
±8kV IEC 61000-4-2 Contact Discharge
±15kV IEC 61000-4-2 Air-Gap Discharge
S
+14V Tolerant, Open-Drain I/O Ports Capable of
Constant-Current LED Drive
S
Rotary Switch-Capable Input Pair (PORT6, PORT7)
S
256-Step PWM Individual LED Intensity Control
S
Individual LED Blink Rates and Common LED
Fade In/Out Rates from 256ms to 4096ms
S
FIFO Queues Up to 16 Debounced Key Events
S
User-Configurable Key Debounce (9ms to 40ms)
S
Keyscan Uses Static Matrix Monitoring for Low
EMI Operation
S
+1.62V to +3.6V Operation
S
Monitors Up to 64 Keys
S
Key-Switch Interrupt (INTK) on Each Debounced
Event/FIFO Level, or End of Definable Time Period
S
Port Interrupt (INTI) for Input Ports for Special-Key
Functions
S
400kbps, +5.5V Tolerant 2-Wire Serial Interface
with Selectable Bus Timeout
S
Four I2C Address Choices
19-4566; Rev 2; 1/13
Simplified Block Diagram
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Pin Configurations appear at end of data sheet.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX7360ETL+
-40°C to +85°C
40 TQFN-EP*
MAX7360EWX+
-40°C to +85°C
36 WLP
MAX7360
AD0
PORT7
PORT6
PORT0
COL_(8x)
ROW_(8x)
INTK
INTI
SDA
SCL
ROTARY
SWITCH
+14V
8 x 8
TO
F
C
+1.8V
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.