參數(shù)資料
型號: MM74C922
廠商: National Semiconductor Corporation
英文描述: 16, 20-Key Encoder
中文描述: 16,20鍵編碼器
文件頁數(shù): 1/10頁
文件大小: 114K
代理商: MM74C922
October 1987
Revised January 1999
M
1999 Fairchild Semiconductor Corporation
DS006037.prf
www.fairchildsemi.com
MM74C922 MM74C923
16-Key Encoder 20-Key Encoder
General Description
The MM74C922 and MM74C923 CMOS key encoders pro-
vide 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 k
on resistance to be used. No
diodes in the switch array are needed to eliminate ghost
switches. The internal debounce circuit 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.
An internal register remembers the last key pressed even
after the key is released. The 3-STATE outputs provide for
easy expansion and bus operation and are LPTTL compat-
ible.
Features
I
50 k
maximum switch on resistance
I
On or off chip clock
I
On-chip row pull-up devices
I
2 key roll-over
I
Keybounce elimination with single capacitor
I
Last key register at outputs
I
3-STATE output LPTTL compatible
I
Wide supply range:
I
Low power consumption
3V to 15V
Ordering Code:
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Connection Diagrams
Pin Assignment for DIP
Top View
MM94C922
Pin Assignment for SOIC
Top View
MM74C922
Order Number
MM74C922N
MM74C922WM
MM74C923WM
MM74C923N
Package Number
N18A
M20B
M20B
N20A
Package Description
18-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
相關(guān)PDF資料
PDF描述
MM74C923 16, 20-Key Encoder
MM74C922N 16-Key Encoder 20-Key Encoder
MM74C922WM 16-Key Encoder 20-Key Encoder
MM74C923 16-Key Encoder 20-Key Encoder
MM74C923N 16-Key Encoder 20-Key Encoder
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MM74C922N 功能描述:編碼器、解碼器、復(fù)用器和解復(fù)用器 16-Key Encoder RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray
MM74C922N 制造商:Fairchild Semiconductor Corporation 功能描述:IC 74C CMOS 74C922 DIP18
MM74C922N_Q 功能描述:編碼器、解碼器、復(fù)用器和解復(fù)用器 16-Key Encoder RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray
MM74C922N-G 制造商:Rochester Electronics LLC 功能描述:
MM74C922WM 功能描述:編碼器、解碼器、復(fù)用器和解復(fù)用器 16-Key Encoder RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray