CM2500-05 CMOS Multiplexer for Keypad Switches Features 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 output under light load. All inputs and outputs have an internal pull up to VCC. 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 controller 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 Simplified Block Schematic GND IN1 IN2 IN3 This device is particularly well suited for portable electronics (e.g. mobile handsets, PDAs, notebook computers) 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, lowprofile 16-lead QFN package. This presents a 60% saving in space when compared with a discrete implementation. The CM2500-05 is available with optional lead-free finishing. Simplified Module Schematic (One channel pair only) IN4 IN5 VCC A R R IN B R R IN A B R R IN A B R R IN A B R IN IN A B R B A N1 R R N2 GND 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: 408.263.3214 ● Fax: 408.263.7846 ● www.calmicro.com 1 CM2500-05 PACKAGE / PINOUT DIAGRAM 7 IN4 8 IN5 11 OUTB 14 13 12 OUT5 OUT4 1 OUT3 2 NC 10 GND 15 OUTA 9 NC QFN16 3X3 16 3 OUT2 4 OUT1 IN1 VCC 6 IN3 5 IN2 Bottom View 16-Lead QFN Package Note: This drawing is not to scale. PIN DESCRIPTIONS PINS NAME DESCRIPTION 1 NC 2 OUTA No internal connection. 3 VCC Positive supply voltage. 4 IN1 Input 1 from switch to be multiplexed. 5 IN2 Input 2 from switch to be multiplexed. 6 IN3 Input 3 from switch to be multiplexed. 7 IN4 Input 4 from switch to be multiplexed. 8 IN5 Input 5 from switch to be multiplexed. No internal connection. Combined "Functional OR" output of IN1, IN2 and IN3. 9 NC 10 GND Negative supply voltage. 11 OUTB Combined "Functional OR" output of IN4 and IN5. 12 OUT5 Output 5 to keypad interface lines. 13 OUT4 Output 4 to keypad interface lines. 14 OUT3 Output 3 to keypad interface lines. 15 OUT2 Output 2 to keypad interface lines. 16 OUT1 Output 1 to keypad interface lines. Ordering Information PART NUMBERING INFORMATION Standard Finish Lead-free Finish Pads Package Ordering Part Number1 Part Marking Ordering Part Number1 Part Marking 16 QFN-16 CM2500-05QF CM250005QF CM2500-05QE CM250005QE Note 1: Parts are shipped in Tape & Reel form unless otherwise specified. © 2004 California Micro Devices Corp. All rights reserved. 2 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: 408.263.3214 ● Fax: 408.263.7846 ● www.calmicro.com 09/21/04 CM2500-05 Specifications ABSOLUTE MAXIMUM RATINGS PARAMETER RATING UNITS +2000 V [GND - 0.5] to +6.0 V [GND - 0.5] to [VCC + 0.5] V ESD Protection (HBM, All Pins, See Note 1) VCC VI (Inputs and Outputs) Storage Temperature Range -65 to +150 °C Operating Temperature Range - Junction -40 to +150 °C 0.5 W DC Package Power rating Note 1: Equivalent to discharging a 100pF capacitor via a 1.5kΩ resistor (Human body model). STANDARD (RECOMMENDED) OPERATING CONDITIONS SYMBOL PARAMETER MIN VCC Supply Voltage 1.5 VI TAMB DC Input Voltage Ambient Operating Temperature Range TYP MAX UNITS 5.5 V 0 - VCC V -40 - 85 °C ELECTRICAL OPERATING CHARACTERISTICS (NOTE 1) Supply Pins (VBUS = 4.1V to 5.5V; VCC = 1.65V to 3.6V) SYMBOL PARAMETER CONDITIONS ICC Supply quiescent current All inputs/outputs floating ROUT OUTx Pull-up Resistance RIN2.7 INx Pull-up Resistance RIN1.8 MIN TYP MAX UNITS 0.1 10.0 µA 50 100 150 kΩ VCC=2.7V, PIN at GND 50 100 150 kΩ INx Pull-up Resistance VCC=1.8V, PIN at GND 100 240 500 kΩ VD Voltage Drop (OUTx to GND) VCC=2.7V, INx = GND 10 100 mV VIL Maximum Low-level Input Voltage VCC x 0.3 V VIH Minimum High-level Input Voltage VCC x 0.7 V IL OUTx Leakage Current INx floating 1.0 µA CP OUTx / INx Pin Capacitance At 2.5 Volt bias, 1 MHz 15 pF Note 1: Operating Characteristics are over Standard Operating Conditions unless otherwise specified. © 2004 California Micro Devices Corp. All rights reserved. 09/21/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: 408.263.3214 ● Fax: 408.263.7846 ● www.calmicro.com 3 CM2500-05 Applications Information VCC Col1 GPIO Interface Lines Col2 Col3 Col4 SW4 SW3 SW2 SW1 SW8 SW7 SW6 SW5 CM2500-05 Row1 OUTA VCC OUT1 IN1 OUT2 IN2 OUT3 IN3 OUT4 IN4 OUT5 IN5 OUTB GND Row2 SW12 SW11 SW10 SW9 SW16 SW15 SW14 SW13 Row3 Row4 SW17 SW18 SW19 SW20 SW21 Figure 1. Typical Application for Extended 4X4 Keyboard The CM2500-05 can be used with just about any keypad configuration. The diagram below gives an example of an interface for a 4 column x 4 row implementation. The outputs of the CM2500-05 have been designed to interface with nearly any type of keyboard setup provided the same methodology is used. Basically if any one of the switches 17 to 21 are closed, it will pull down 2 row lines rather than 1. All outputs on the CM2500-05 are open drain. It follows in the above implementation that: • If SW17 is closed, row 1 and 2 are pulled low. • If SW18 is closed, row 1 and 3 are pulled low. • If SW19 is closed, row 1 and 4 are pulled low. • If SW20 is closed, row 2 and 3 are pulled low. • If SW21 is closed, row 2 and 4 are pulled low. • If SW17-SW21 are not closed, the standard scan routine is in effect (i.e., one row is pulled low) In larger keypad implementations, multiple CM2500-05 can be used to yield more switches. © 2004 California Micro Devices Corp. All rights reserved. 4 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: 408.263.3214 ● Fax: 408.263.7846 ● www.calmicro.com 09/21/04 CM2500-05 Mechanical Details QFN-16 Mechanical Specifications Mechanical Package Diagrams Dimensions for CM2500-05 devices supplied in 16lead QFN packages are presented below. For complete information on the QFN-16 package, see the California Micro Devices QFN Package Information document. D PACKAGE DIMENSIONS QFN Leads Dim. E Package 16 Millimeters Pin 1 Marking Inches Min Nom Max Min Nom Max A 0.70 0.75 0.80 .028 .030 .031 0.15 C A1 0.00 0.02 0.05 0.00 .001 .002 0.15 C A3 0.20 REF .008 b 0.20 0.25 0.30 .008 .010 .012 D 2.9 3.0 3.1 .114 .118 .122 D1 1.50 REF 0.10 C .059 REF D2 1.00 1.10 1.20 .039 .043 .047 E 2.9 3.0 3.1 .114 .118 .122 E1 1.50 REF E2 1.00 e 1.10 0.30 # per tape and reel 0.40 0.08 C .059 REF 1.20 .039 0.50 TYP. L TOP VIEW .043 A3 A1 SIDE VIEW .047 A .020 TYP. 0.50 .012 .016 D1 .020 2500 pieces* D2 * This is an approximate number which may vary. E2 E1 Controlling dimension: millimeters L DAP SIZE 1.8 X 1.8 b e 16X 0.10 M CAB BOTTOM VIEW Package Dimensions for 16-Lead QFN © 2004 California Micro Devices Corp. All rights reserved. 09/21/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: 408.263.3214 ● Fax: 408.263.7846 ● www.calmicro.com 5