- This device is formed by a circuit that converts Binary-Coded-Decimal into a 1-of-10 output. The same device can be used to convert a 8-bit code into a 1-of-8 output.
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- Functional Diagram or/and Package:
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Pin Names:
Vdd - Positive Supply Voltage (3V to 15V)
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Vss - Ground
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A, B, C, D - BCD Inputs
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 - Decimal Outputs
- Truth Table
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Operation Mode:
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a) BCD to 1-of-10
- BCD codes are applied to the A, B, C, and D inputs. The least significant bit is applied to A and the most significant to D.
- The output that goes to the “'1” logic level depends on the input (see the truth table).
- An invalid state depends on the origin of the chip (manufacturer).
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b) 1-of-8 decoder
- The input D is grounded.
- The logic signals to be decoded are applied to inputs A, B, and C.
- The output depends on the logic levels applied to the input (see the truth table).
- Electrical Characteristics
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Applications:
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Code Conversion
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Address Deooding - Memory Controls
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Driver for Displays (tubes)
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Observations:
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Outputs can be relabeled for other codes.
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