(China (Mainland))
Product Summary
The MM74C922N 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 MM74C922N 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 MM74C922N needs only a single external capacitor and can be defeated by omitting the capacitor. A Data Available output goes to a high level when a valid keyboard entry has been made. The Data Available output returns to a low level when the entered key is released, even if another key is depressed. The Data Available will return high to indicate acceptance of the new key after a normal debounce period; this two-key roll-over is provided between any two switches.
Parametrics
MM74C922N 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
MM74C922N 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
| Image | Part No | Mfg | Description |  |
Pricing (USD) |
Quantity | ||||
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 MM74C922N |
Fairchild Semiconductor |
Encoders, Decoders, Multiplexers & Demultiplexers 16-Key Encoder |
Data Sheet |
Negotiable |
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MM74C922N_Q |
Fairchild Semiconductor |
Encoders, Decoders, Multiplexers & Demultiplexers 16-Key Encoder |
Data Sheet |
Negotiable |
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