7442.md

7442: 4-bit BCD to 10-line decoder, active low output

• Type: decoder
• DIP: 16-pin
• Input: 4-bit BCD
• Output: 10 lines

Description

Decodes a 4-bit BCD to ten output lines.

Inputs and outputs

Label	Description	Signal
Dn	input lines	active high
Yn	output lines	active low

Function table

D4	D3	D2	D1	Y0	Y1	Y2	Y3	Y4	Y5	Y6	Y7	Y8	Y9
L	L	L	L	L	H	H	H	H	H	H	H	H	H
L	L	L	H	H	L	H	H	H	H	H	H	H	H
L	L	H	L	H	H	L	H	H	H	H	H	H	H
L	L	H	H	H	H	H	L	H	H	H	H	H	H
L	H	L	L	H	H	H	H	L	H	H	H	H	H
L	H	L	H	H	H	H	H	H	L	H	H	H	H
L	H	H	L	H	H	H	H	H	H	L	H	H	H
L	H	H	H	H	H	H	H	H	H	H	L	H	H
H	L	L	L	H	H	H	H	H	H	H	H	L	H
H	L	L	H	H	H	H	H	H	H	H	H	H	L
H	L	H	X	H	H	H	H	H	H	H	H	H	H
H	H	X	X	H	H	H	H	H	H	H	H	H	H

• H: HIGH voltage level
• L: LOW voltage level
• X: don't care

Pin layout

Datasheets

• 74HC42, 74HCT42 by Nexperia
• 7442A, 74LS42 by Texas Instruments