MC74HC139A

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6

PIN DESCRIPTIONS

ADDRESS INPUTS

Address inputs. These inputs, when the respective 1−of−4

decoder is enabled, determine which of its four active−low

outputs is selected.

CONTROL INPUTS

Active−low select inputs. For a low level on this input, the

outputs for that particular decoder follow the Address

inputs. A high level on this input forces all outputs to a high

level.

OUTPUTS

Active−low outputs. These outputs assume a low level

when addressed and the appropriate Select input is active.

These outputs remain high when not addressed or the

appropriate Select input is inactive.

SELECT

A0

A1

Y0

Y1

Y2

Y3

Figure 6. Expanded Logic Diagram

(1/2 of Device)