CM2500-05 Datasheet, PDF (1/5 Pages) California Micro Devices Corp – CMOS Multiplexer for Keypad Switches

CM2500-05
CMOS Multiplexer for Keypad Switches
Features
• Functionally equivalent to a five-diode pair network
• Up to 60% space saving vs. discrete solution
• Flexibility in design with "separate" outputs
• 100kΩ pull-up resistors on outputs
• Voltage drop of less than 10mV under light loads
• 16-lead QFN package - 3mm x 3mm, 0.5mm pitch
• Lead-free version available
Applications
• Enables more keys from current keyboard control-
ler without extra I/O from chipset
• Keypad switches in mobile electronics
• Roller pad or joystick in mobile electronic products
• Wireless Handsets
• MP3 Players
• Digital Cameras
Product Description
The CM2500-05 is a CMOS multiplexer for keypad
switches. The device is functionally equivalent to a
five-diode pair network. However, each channel in this
network has virtually no voltage drop from input to out-
put under light load. All inputs and outputs have an
internal pull up to V_CC.
This device is particularly well suited for portable elec-
tronics (e.g. mobile handsets, PDAs, notebook com-
puters) because of its small package format. This
product is ideal for converting the logic of keypad
switches where each switch pulls two sense lines low.
The keypad multiplexer channels are set up in series
on the keypad sense lines such that it will interface
directly to the CPU chipset.
The CM2500-05 is available in a space-saving, low-
profile 16-lead QFN package. This presents a 60%
saving in space when compared with a discrete imple-
mentation. The CM2500-05 is available with optional
lead-free finishing.
Simplified Block Schematic
GND IN1 IN2 IN3 IN4 IN5
VCC
R
R
R
R
R
IN
IN
IN
IN
IN
BA BA BA BA BA
R
R
R
R
R
R
R
Simplified Module Schematic
(One channel pair only)
IN
GND
A
B
N1
N2
OUTA OUT1 OUT2 OUT3 OUT4 OUT5 OUTB
© 2004 California Micro Devices Corp. All rights reserved.
09/21/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: [phone] ● Fax: [phone] ● www.calmicro.com 1