MM74C923 Datasheet - National

MM74C923 16 / 20-Key Encoder

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 kX on resistance to be used No .

MM74C923 Features

* Y Y Y Y Y Y Y Y Y 50 kX maximum 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 Low power consumption 3V to 15V Connection Diagrams P

MM74C923_NationalSemiconductor.pdf