When your automation or robotics project requires driving multiple LEDs, 74-segment numeric readouts, or a bank of low-power relays, you can easily run out of hardware GPIO pins on an Arduino or ESP32. The 74HC164 is the industry-standard solution for expanding your digital output capacity. It is an 8-bit Serial-In/Parallel-Out (SIPO) shift register. Instead of dedicating 8 separate processor pins to toggle 8 individual outputs, you simply feed data sequentially down a single serial line clocked by a second pin, and the chip distributes those bits across its 8 parallel output pins.

What sets the 74HC164 apart from other shift registers (like the 74HC595) is its gated serial input and asynchronous master reset. It features two gated serial inputs, which allow you to use one line as an active data line and the other as an output-enable or gating control line. Every time the clock pintransitions from LOW to HIGH, the data shifts one position down the line. Additionally, the inclusion of a dedicated Master Resetpin allows your microcontroller to wipe all 8 outputs back to LOW instantly, providing an excellent safety override or initialization control in custom logic architectures.

Key Features & Functional Advantages:

• 8-Bit Pin Expansion: Effortlessly multiplies your available output control lines by turning 2 or 3 microcontroller GPIO pins into 8 independent digital outputs.

• Gated Serial Inputs: Dual data inputsprovide hardware-level gating control over incoming data streams without requiring external logic gates.

• Asynchronous Master Reset: Features an active-lowpin that instantly clears all internal registers and outputs to LOW, completely independent of the clock signal.

• High-Speed CMOS (HC) Architecture: Operates with blistering switching speeds up to 25 MHz (at 5V) while maintaining ultra-low quiescent power consumption, ideal for dense data telemetry.

• Breadboard Native (14-DIP): Standard 0.1-inch (2.54mm) pin pitch drops perfectly into any standard solderless breadboard or 14-pin IC socket for seamless prototyping.

Perfect For:

• Industrial LED Driver Matrices: The standard hardware-level block used to manage complex multi-LED diagnostic control panels and sequence lighting arrays.

• Microcontroller Pin Multiplexing: Dramatically extends the output capabilities of pin-constrained IoT boards like the ESP8266 or basic ATtiny microcontrollers.

• 7-Segment Display Drivers: Excellent for driving single or multi-digit numeric displays by sequentially shifting in the segment maps.

• Parallel-to-Serial Data Conversion Networks: Can be paired with downstream logic architectures to reconstruct parallel bytes from serial communication lines.

Technical Specifications:

• Logic Family: 74HC (High-Speed CMOS)

• Logic Function: Serial-In / Parallel-Out Shift Register

• Number of Output Bits: 8 Bits (Parallel Outputs)

• Operating Supply Voltage : 2.0V to 6.0V DC

• Clock Frequency: Up to 25 MHz (Typical at 5V)

• Maximum Output Current: 5.2 mA per pin

• Propagation Delay: ~18 ns (Typical at 5V)

• Package / Case: 14-DIP (0.300″, 7.62mm width)

• Mounting Type: Through-Hole (PTH)