The 74165 is an 8-bit parallel-in/serial-out shift register. It converts parallel data to serial output, ideal for expanding microcontroller input ports. Data is loaded via parallel inputs when the parallel load (PL) is low. Serial data shifts out on clock pulses when shift/load (SH/LD) is high. It operates at 2-6V, with high-speed CMOS technology, and is commonly used in digital systems for data acquisition.
| Supply Voltage (VCC) | 2V to 6V |
|---|---|
| Operating Temperature | -40°C to +125°C |
| Propagation Delay | 15 ns |
| Clock Frequency | Up to 25 MHz |
| Power Dissipation | 500 mW (maximum) |
📄 SN74HC165 datasheet (1591 kB)
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | PL | "Parallel Load" (active low) |
| 2 | CP / CLK | "Clock" |
| 3 | D4 | Input pin #4 |
| 4 | D5 | Input pin #5 |
| 5 | D6 | Input pin #6 |
| 6 | D7 | Input pin #7 |
| 7 | Q7 | "Serial Out" (active low) |
| 8 | GND | Ground / Ground connection |
| 9 | Q7 | "Serial Out" |
| 10 | SER / DS | "Serial In": for cascading multiple shift registers |
| 11 | D0 | Input pin #0 |
| 12 | D1 | Input pin #1 |
| 13 | D2 | Input pin #2 |
| 14 | D3 | Input pin #3 |
| 15 | CE | "Clock Enable" (active low) |
| 16 | VCC | Power supply (5V) |