74C923 Datasheet - Fairchild Semiconductor

74C923 16-Key Encoder 20-Key Encoder

The MM74C922 and MM74C923 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 pull-up devices which permit switches with up to 50 kΩ on re.

74C923 Features

* s 50 kΩ maximum switch on resistance s On or off chip clock s On-chip row pull-up devices s 2 key roll-over s Keybounce elimination with single capacitor s Last key register at outputs s 3-STATE output LPTTL compatible s Wide supply range: 3V to 15V s Low power consumption Ordering Code: Order Numb

74C923_FairchildSemiconductor.pdf