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IC Pinouts / 74HC165

74HC165 Pinout

74HC165 PISO Shift Register · 8-bit parallel-in serial-out shift register; expands inputs (buttons/switches); complements the 74HC595.

DIP-16 Logic 16 pins No backend · 100% client-side
SH/LD(/PL) 1
CLK 2
D4 3
D5 4
D6 5
D7 6
Q7̄(/Q7) 7
GND 8
74HC165 DIP-16
16 VCC
15 CE(CLK INH)
14 D3
13 D2
12 D1
11 D0
10 SER(DS)
9 Q7(QH)
PowerGNDInputOutputI/OControl
PinNameTypeFunction
1 SH/LD · /PL Control Shift/load: low = parallel load, high = shift
2 CLK Control Shift clock (rising edge)
3 D4 Input Parallel input 4
4 D5 Input Parallel input 5
5 D6 Input Parallel input 6
6 D7 Input Parallel input 7
7 Q7̄ · /Q7 Output Serial output (inverted)
8 GND GND Ground
9 Q7 · QH Output Serial output (to MCU MISO / cascade)
10 SER · DS Input Serial input (cascade from the previous chip's Q7)
11 D0 Input Parallel input 0
12 D1 Input Parallel input 1
13 D2 Input Parallel input 2
14 D3 Input Parallel input 3
15 CE · CLK INH Control Clock inhibit (high ignores the clock)
16 VCC Power Supply + (2–6V)
How to · reading it

How to read the 74HC165 pinout

  1. 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.

  2. 02

    Count counter-clockwise

    Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.

  3. 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

Frequently asked questions

How do I read 8 buttons?

First pull SH/LD low to latch the parallel inputs, then pull it high, then apply 8 clocks to read out bit by bit from Q7 (pin 9) — 3 wires read 8 inputs.

Relationship to the 74HC595?

The 595 is serial-in parallel-out (expands outputs); the 165 is parallel-in serial-out (expands inputs); the two are often paired for IO expansion.

How do I connect CE (pin 15)?

Tie it to ground for normal operation; pull it high to temporarily freeze shifting.

Data source

Pinout data comes from NXP/TI 74HC165 datasheet (standard DIP-16 numbering). Refer to the actual device datasheet as authoritative for the pinout.

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