Product Summary

The MM74C923WM is a key encoder providing 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. The MM74C923WM has on-chip pull-up devices which permits switches with up to 50 kΩ on resistance to be used. No diodes in the switch array are needed to eliminate ghost switches. The internal debounce circuit of the MM74C923WM needs only a single external capacitor and can be defeated by omitting the capacitor.

Parametrics

MM74C923WM absoltue maximum ratings: (1)Voltage at Any Pin VCC: -0.3V to VCC + 0.3V; (2)Operating Temperature Range: -40 to +85℃; (3)Storage Temperature Range: -65 to +150℃; (4)Power Dissipation, PD: 700 mW; (5)Operating VCC Range: 3V to 15V; (6)Lead Temperature (Soldering, 10 seconds): 260℃.

Features

MM74C923WM features: (1)50 kΩ maximum switch on resistance; (2)On or off chip clock; (3)On-chip row pull-up devices; (4)2 key roll-over; (5)Keybounce elimination with single capacitor; (6)Last key register at outputs; (7)3-STATE output LPTTL compatible; (8)Wide supply range: 3V to 15V; (9)Low power consumption.

Diagrams

MM74C923WM block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
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MM74C923WM
MM74C923WM

Fairchild Semiconductor

Encoders, Decoders, Multiplexers & Demultiplexers 20-Key Encoder

Data Sheet

Negotiable 
MM74C923WM_Q
MM74C923WM_Q

Fairchild Semiconductor

Encoders, Decoders, Multiplexers & Demultiplexers 20-Key Encoder

Data Sheet

Negotiable 
MM74C923WMX
MM74C923WMX

Fairchild Semiconductor

Encoders, Decoders, Multiplexers & Demultiplexers 20-Key Encoder

Data Sheet

Negotiable