October 1987
Revised January 1999
CD4028BC
BCD-to-Decimal Decoder
General Description
The CD4028BC is a BCD-to-decimal or binary-to-octal decoder consisting of 4 inputs, decoding logic gates, and 10 output buffers. A BCD code applied to the 4 inputs, A, B, C, and D, results in a high level at the selected 1-of-10 decimal decoded outputs. Similarly, a 3-bit binary code applied to inputs A, B, and C is decoded in octal at outputs 0–7. A high level signal at the D input inhibits octal decoding and causes outputs 0–7 to go LOW.
All inputs are protected against static discharge damage by diode clamps to VDD and VSS.
Features
■Wide supply voltage range: 3.0V to 15V
■High noise immunity: 0.45 VDD (typ.)
■Low power TTL compatibility: fan out of 2 driving 74L or 1 driving 74LS
■Low power
■Glitch free outputs
■“Positive logic” on inputs and outputs
Applications
•Code conversion
•Address decoding
•Indicator-tube decoder
Ordering Code:
Order Number |
Package Number |
Package Description |
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|
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CD4028BCM |
M16A |
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body |
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CD4028BCN |
N16E |
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide |
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Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Pin Assignments for DIP and SOIC
Top View
Decoder Decimal-to-BCD CD4028BC
© 1999 Fairchild Semiconductor Corporation |
DS005959.prf |
www.fairchildsemi.com |
CD4028BC
Truth Table
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D |
C |
B |
A |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
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0 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
|
|
0 |
0 |
0 |
1 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
|
|
0 |
0 |
1 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
|
|
0 |
0 |
1 |
1 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
|
|
|
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
BCD States |
|
|
0 |
1 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
|
|
|
0 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
|
1 = HIGH Level |
0 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
0 |
|
|
0 = LOW Level |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
|
|
|
|
1 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
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1 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
|
|
|
1 |
0 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
|
|
|
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
Extraordinary States |
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|
1 |
1 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
|
|
|
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
|
|
|
1 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
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Logic Diagram
www.fairchildsemi.com |
2 |