General Description
These CMOS key encoders provide all the necessary logic to fully encode an array of SPST switches. The keyboard scan can be implemented by either an external clock or external capacitor. These encoders also have on-chip pullup devices which permit switches with up to 50 kXon resistance to be used. No diodes in the switch array are needed to eliminate ghost switches.

FEATUREs
50 kXmaximum switch on resistance
On or off chip clock
On-chip row pull-up devices
2 key roll-over
Keybounce elimination with single capacitor
Last key register at outputs
TRI-STATE outpust LPTTL compatible
Wide supply range                              3V to 15V
Low power consumption