19-4566; Rev 0; 4/09
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
General Description
Features
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.
S Integrated ESD Protection
Q8kV IEC 61000-4-2 Contact Discharge
Q15kV IEC 61000-4-2 Air-Gap Discharge
S +14V Tolerant, Open-Drain I/O Ports Capable of
Constant-Current LED Drive
The key-switch drivers interface with metallic or resistive
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.
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
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.
S Key-Switch Interrupt (INTK) on Each Debounced
Event/FIFO Level, or End of Definable Time Period
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.
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
Ordering Information
PART
MAX7360ETL+
MAX7360EWX+**
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
40 TQFN-EP*
36 WLP
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.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
**Future product—contact factory for availability.
Simplfied Block Diagram
Applications
+1.8V
Cell Phones
+14V
ROTARY
SWITCH
PDAs
TO
FC
SCL
SDA
INTI
INTK
Handheld Games
Portable Consumer Electronics
Printers
PORT7
PORT6
MAX7360
PORT0
Instrumentation
AD0
ROW_(8x)
COL_(8x)
8 x 8
Pin Configurations appear at end of data sheet.
_______________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.