KBDGRAY Datasheet, PDF (1/6 Pages) ABCircuits – Serial output encoder for Grayhill and other keyboards

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KBDGRAY IC
Serial output encoder for Grayhill and other keyboards
up to 16 switches
General Description
The KBDGRAY IC is designed to provide a serial ASCII output encoder for Grayhill 96 series and
other keyboards up to 16 keys. The KBDGRAY 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 KBDGRAY 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. ASCII 0-9, #, *, and A-D (on 16 key keypads)
• 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 KBDGRAY
December 2012 Page 1 of 6