STMicroelectronics M74HC165TTR

Overview

M74HC165TTR from STMicroelectronics is a high-speed CMOS 8-bit parallel-in/serial-out (PISO) shift register with asynchronous parallel load, operating from 2V to 6V supply, featuring 15ns typical propagation delay at 6V, ±4mA output drive, and 4µA max quiescent current at 25°C - used in microcontroller GPIO expansion and industrial I/O data acquisition systems.

For engineers reviewing the M74HC165TTR datasheet, M74HC165TTR pinout, M74HC165TTR application, or M74HC165TTR equivalent, key selection criteria include clock-edge-triggered serial shifting, dual-clock inhibit capability via NOR-gated inputs, symmetrical output impedance, wide temperature range (–55°C to +125°C), and TSSOP-16 package compatibility with space-constrained PCB layouts.

Technical Context

The M74HC165TTR implements an 8-bit master-slave RS flip-flop chain with gated parallel load control. Its SHIFT/LOAD input enables asynchronous parallel data capture when low, while clocking occurs on the rising edge of either CLOCK or CLOCK INH (via internal 2-input NOR gate), requiring CLOCK INH to remain high only during high CLOCK to avoid double-triggering.

All inputs include ESD protection diodes; outputs deliver balanced |IOH| = IOL = 4mA (min) at VCC = 4.5V and 6V. Propagation delays tPLH ≅ tPHL ensure minimal duty-cycle distortion, and high noise immunity (VNIH/VNIL = 28% VCC min) supports robust operation in electrically noisy industrial environments.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9–5.1 mm width, 6.2–6.6 mm length, 0.65 mm pitch, 0.45–0.75 mm lead length, surface-mount, moisture-sensitive level 1 (MSL1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit PISO shift register applications.

Compared with SN74HC165N and 74LV165A, the M74HC165TTR uniquely balances wide supply range (2–6V), industry-grade temperature support (–55°C to +125°C), and compact TSSOP-16 packaging - making it optimal for ruggedized embedded systems requiring long-term reliability and mixed-voltage interoperability.

Availability

M74HC165TTR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and IoT edge sensor hubs requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for M74HC165TTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The M74HC165TTR belongs to ST's high-speed HC logic family, engineered for pin- and function-compatibility with legacy 74-series devices while delivering enhanced noise immunity, lower power, and extended temperature operation for modern embedded control systems.

FAQ

Can M74HC165TTR operate at 3.3V supply?

Yes, M74HC165TTR is fully specified from 2V to 6V, including 3.3V operation. At VCC = 3.3V, it delivers VOH ≥ 3.1V and VOL ≤ 0.2V with 4mA load, meets tPD < 35ns, and maintains VIH/VIL thresholds compatible with standard 3.3V CMOS logic families.

What is the function of the CLOCK INH pin?

CLOCK INH acts as a clock enable/disable control via an internal 2-input NOR gate with CLOCK. When CLOCK INH is high, CLOCK is blocked regardless of its state; when low, CLOCK passes through normally. To prevent glitches, CLOCK INH must transition only while CLOCK is high.

Does M74HC165TTR support daisy-chaining?

Yes - connect QH (pin 7) of one device to SI (pin 10) of the next, and tie all SHIFT/LOAD, CLOCK, and CLOCK INH lines in parallel. The 8-bit parallel load and serial shift functions cascade seamlessly, enabling N×8-bit data capture with a single MCU serial interface.

Is there a recommended decoupling strategy?

Place a 100nF X7R ceramic capacitor between VCC (pin 16) and GND (pin 8), located ≤5mm from the pins. For systems with heavy switching loads, add a 1µF tantalum or polymer capacitor nearby. Avoid shared ground traces between logic and power sections to preserve noise immunity.