MC74HC165ADR2G

Updated: 2026-09-15

Overview

The MC74HC165ADR2G is a high-speed CMOS 8-bit parallel-in/serial-out shift register manufactured by ON Semiconductor. It belongs to the 74HC logic family, offering compatibility with both CMOS and TTL voltage levels. This 16-pin SOIC-packaged IC is designed for applications requiring serial data expansion or parallel-to-serial conversion, commonly interfaced with microcontrollers. The device features synchronous serial output with asynchronous parallel load capability, making it versatile for digital systems. Its wide operating voltage range (2V to 6V) and low power consumption (typical ICC of 80µA) suit battery-powered and industrial applications. The MC74HC165ADR2G is widely stocked in Shanghai's electronics markets, serving OEMs and PCB assemblers.

Structure and Working Principle

The IC consists of eight parallel D-type flip-flops with a common clock (CLK) and shared serial output (Q7). Data can be loaded in parallel via the PL (parallel load) pin or shifted serially through the DS (serial data) input. When PL is low, parallel data (P0-P7) transfers to the registers on the next clock rising edge. During serial shifting (PL high), data moves from DS to Q0 on each clock pulse, propagating through all stages to Q7. An optional clock inhibit (CE) pin allows gating of the clock signal. The internal design ensures clean signal transitions with typical propagation delays of 13ns at 5V, supporting high-speed data transfer up to 30MHz.

Key Features

1. **Voltage Compatibility**: Operates from 2V to 6V DC with TTL-compatible input thresholds (VIL=1.5V max, VIH=3.5V min at 4.5V VCC), enabling mixed-voltage system design. 2. **Low Power Consumption**: Typical static current of 80µA makes it suitable for portable devices, with dynamic current increasing linearly with clock frequency (0.8mA/MHz at 5V). 3. **Robust Outputs**: Buffered outputs can source/sink 4mA while maintaining voltage levels, allowing direct drive of LEDs or other peripherals without additional buffers.

Application Areas

**Industrial Controls**: Used in PLCs for input expansion, collecting multiple sensor signals into a single serial stream for microcontroller processing. The wide temperature range (-40°C to 125°C) ensures reliability in harsh environments. **Consumer Electronics**: Commonly interfaces with Arduino and Raspberry Pi for button matrix scanning or additional GPIO expansion. Its small SOIC-16 package (3.9mm x 9.9mm) fits space-constrained designs. **Automotive Systems**: Employed in dashboard controls and infotainment systems where multiple switches need monitoring through limited microcontroller pins, though automotive-grade versions (e.g., NCV74HC165) are recommended for critical applications.

Maintenance and Precautions

**ESD Protection**: Always handle with anti-static precautions. Use grounded wrist straps when installing, as the CMOS structure is sensitive to electrostatic discharge (HBM rating: 2kV). **Power Sequencing**: Avoid applying signals when VCC is below 1V to prevent latch-up. Decoupling capacitors (100nF ceramic) should be placed within 10mm of the VCC pin. **Thermal Management**: While the SOIC package has low thermal resistance (θJA≈73°C/W), continuous operation at maximum clock rates may require airflow in high ambient temperatures (>85°C).

B2B Procurement Guide

**Supplier Verification**: In Shanghai's Huaqiangbei market, confirm vendor authenticity by checking ON Semiconductor authorized distributor certificates. Counterfeit parts may exhibit higher leakage currents or fail at temperature extremes. **Packaging Options**: Available in tape-and-reel (2500 units) or tubes (75 units). Specify packaging needs to avoid manual handling during SMT assembly. **Lead Time**: Standard stock typically delivers within 2 weeks, but validate inventory claims during component shortages. Alternatives like SN74HC165N (TI) may require PCB redesign due to differing pinouts.