KBDSER16 Datasheet, PDF (1/6 Pages) ABCircuits – Serial output encoder keyboards up to 16 switches

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KBDSER16 IC
Serial output encoder keyboards up to 16 switches
General Description
The KBDSER16 IC is designed to provide a serial ASCII output encoder for keyboards up to 16
keys. The KBDSER16 IC contains all the logic necessary to encode a SPST keyboard switch
array up to 4 by 4 in size and provide a serial ASCII output. The output is standard asynchronous
format, using 8 bits, 1 stop and no parity at 9600 BPS. Other formats and encoding are available,
contact the factory. The array can be a 4 x 4 array, but smaller arrays such as a 3 x 4 array or
any smaller size may be used. The KBDSER16 IC handles debouncing and encodes the keys
with no external parts. All timing is internally generated. No external diodes are required in the
array to prevent key ghosting in a two key rollover situation. A .1 uF bypass capacitor is
suggested across the VDD and VSS pins. The part uses the standard 20 pin .3 inch width SOIC
package.
Features
• Asynchronous serial output.
• Fully encodes a key switch array. (up to 4 x 4)
• No external parts required.
• Low power consumption 2 mA typical.
• Supply voltage 2.4 to 5.25 volts.
• All timing internally generated.
• 2 Key rollover.
• On chip row input resistors.
• Internal key bounce elimination.
• TTL and CMOS compatible outputs.
• Part is in full production.
• SOIC 20 Pin Package.
• Low EMI
• ROHS Compliant
Part Number KBDSER16
December 2012 Page 1 of 6