IC Pinouts / 74HC4051

74HC4051 Pinout

74HC4051 8-Channel Analog Mux · 8-channel analog multiplexer/demultiplexer — connects one common pin to 1 of 8 channels selected by S0–S2.

DIP-16 Logic 16 pins No backend · 100% client-side

Y4 1

Y6 2

Z(COM) 3

Y7 4

Y5 5

E(/E) 6

VEE 7

VSS(GND) 8

74HC4051 DIP-16

16 VCC(VDD)

15 Y2

14 Y1

13 Y0

12 Y3

11 S0(A)

10 S1(B)

9 S2(C)

PowerGNDInputOutputI/OControl

Pin	Name	Type	Function
1	Y4	I/O	Channel 4
2	Y6	I/O	Channel 6
3	Z · COM	I/O	Common in/out
4	Y7	I/O	Channel 7
5	Y5	I/O	Channel 5
6	E · /E	Control	Enable (active-low; high disconnects all channels)
7	VEE	Power	Negative analog supply (tie to GND for single-supply use)
8	VSS · GND	GND	Ground
9	S2 · C	Control	Select bit 2 (MSB)
10	S1 · B	Control	Select bit 1
11	S0 · A	Control	Select bit 0 (LSB)
12	Y3	I/O	Channel 3
13	Y0	I/O	Channel 0
14	Y1	I/O	Channel 1
15	Y2	I/O	Channel 2
16	VCC · VDD	Power	Positive supply + (2–10V)

How to · reading it

How to read the 74HC4051 pinout

01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.

FAQ

How do I select a channel?

Set the binary value S2:S1:S0 (0–7) to pick channel Y0–Y7, and hold E low to enable. E.g. S2=1,S1=0,S0=1 → channel 5.

What is VEE for?

It is the negative rail so the mux can pass bipolar analog signals (e.g. ±5V). For ordinary single-supply digital switching, tie VEE to GND.

Can I use it as a demultiplexer?

Yes — the switch is bidirectional. Drive the common Z pin and the signal appears on the selected Y channel, or vice versa.

Data source

Pinout data comes from NXP/TI 74HC4051 datasheet (standard DIP-16 numbering). Refer to the actual device datasheet as authoritative for the pinout.