SN74HC165D 8 Bit Parallel Load Shift Register SMD SOP 16PIN

Description

SN74HC165D Key Specifications

Family: 74HC (High-Speed CMOS)
Package: SOP-16 (150-mil body width)

1. Electrical Characteristics

• Supply Voltage: 2V to 6V (HC family)

• Input Voltage: 0V to VCC

• Output Current: ±7mA (max, per pin)

• Propagation Delay: 13ns (typical, CL=15pF)

• Clock Frequency: Up to 50MHz (typical)

• Power Consumption: 80µA (quiescent, typical)

2. Functional Description

• Inputs: 8 parallel data inputs (A-H)

• Outputs: Serial output (QH), complemented serial output (QH’)

• Control Pins:

  • SH/LD (Shift/Load): Loads parallel data when LOW

  • CLK (Clock): Shifts data on rising edge

  • CLK INH (Clock Inhibit): HIGH disables clock

3. Pinout (SOP-16)

4. Key Features

• Parallel-to-Serial Conversion: Reads 8 inputs, outputs serially

• Cascade Capability: Connect multiple chips for 16+ bit inputs

• Schmitt Trigger Inputs: Improved noise immunity

• Wide Operating Range: Compatible with 3.3V/5V systems

5. Logic Table

Arduino Example Code

#define DATA_PIN 11 // QH (pin 9) → Arduino D11
#define CLOCK_PIN 12 // CLK (pin 2) → Arduino D12
#define LATCH_PIN 10 // SH/LD (pin 1) → Arduino D10

void setup() {
Serial.begin(9600);
pinMode(DATA_PIN, INPUT);
pinMode(CLOCK_PIN, OUTPUT);
pinMode(LATCH_PIN, OUTPUT);
}

byte readShiftRegister() {
// Load parallel data
digitalWrite(LATCH_PIN, LOW);
delayMicroseconds(5);
digitalWrite(LATCH_PIN, HIGH);

// Shift in 8 bits
byte data = 0;
for(int i=0; i<8; i++) {
digitalWrite(CLOCK_PIN, HIGH);
delayMicroseconds(1);
data |= digitalRead(DATA_PIN) << (7-i);
digitalWrite(CLOCK_PIN, LOW);
}
return data;
}

void loop() {
byte inputs = readShiftRegister();
Serial.print(“Inputs: 0b”);
Serial.println(inputs, BIN);
delay(100);
}

Cascading Multiple Chips

Connect:

1. QH (pin 9) of first chip → SER (pin 10) of second chip

2. CLK, SH/LD, CLK INH pins shared

3. Cascade output: Read 16+ bits sequentially

SOP-16 Package Dimensions

• Body Width: 150 mil (3.81mm)

• Lead Pitch: 1.27mm