Nexperia USA Inc. 74HCT166D,653

Overview

74HCT166D,653 from Nexperia is an 8-bit parallel-in/serial-out shift register with TTL-compatible inputs, synchronous parallel load (PE active LOW), serial shift (DS input), and single-bit serial output (Q7). It operates from 4.5 V to 5.5 V, supports -40 °C to +125 °C ambient range, and features asynchronous master reset (MR) and clock enable (CE). Used in microcontroller I/O expansion, LED matrix drivers, and industrial control logic.

For engineers reviewing the 74HCT166D,653 datasheet, 74HCT166D,653 pinout, 74HCT166D,653 application, or 74HCT166D,653 equivalent, key selection criteria include TTL-level input compatibility, SO16 package thermal performance, CP-to-Q7 propagation delay (23–60 ns at VCC = 4.5 V), MR asynchronous reset timing, and CE-controlled clock gating behavior.

Technical Context

This device implements a synchronous 8-stage shift register with dual-path data entry: parallel load occurs on the rising edge of CP when PE is LOW; serial shift occurs on the same edge when PE is HIGH and CE is LOW. The internal architecture uses edge-triggered D-type flip-flops with gated clock distribution and asynchronous reset overriding all clocked operations.

Input clamping diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors. The output stage provides CMOS-level drive capability (±4 mA at VCC = 4.5 V), with VOH ≥ 3.98 V and VOL ≤ 0.26 V under specified loads, ensuring robust noise margins in mixed-logic systems.

Key Specifications

Pinout & Package

74HCT166D,653 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads and 3.9 mm body width. Pin 1 is marked by a notch or dot; pin numbering follows standard counter-clockwise convention from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel-in/serial-out shift register applications.

Compared with 74HC166D,653 and SN74LS166N, the 74HCT166D,653 uniquely balances TTL input compatibility, low static current (<160 μA), and industrial temperature support - making it optimal for modern 5 V embedded systems requiring long-term reliability and minimal board space.

Availability

74HCT166D,653 is available at Aetrix Electronics and suitable for microcontroller I/O expansion, LED matrix scanning, industrial sensor interface, and legacy bus protocol bridge applications requiring stable component supply across extended temperature ranges.

Supply support for 74HCT166D,653 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74HCT series is designed specifically for seamless integration between TTL-based legacy systems and modern CMOS logic, delivering pin-compatible functionality with optimized power-performance trade-offs for industrial control and embedded interfaces.

FAQ

What is the maximum clock frequency supported by 74HCT166D,653?

The 74HCT166D,653 supports a maximum clock frequency of 25 MHz at VCC = 4.5 V and ambient temperature up to +85 °C, and 17 MHz at +125 °C. This is derived from the maximum propagation delay (60 ns) and minimum pulse width (25 ns) specifications in the datasheet's dynamic characteristics table.

Can 74HCT166D,653 operate with a 3.3 V supply?

No - the 74HCT166D,653 is specified only for 4.5 V to 5.5 V operation. Its TTL-compatible inputs require VIH ≥ 2.0 V, but the internal circuitry does not guarantee correct function below 4.5 V. For 3.3 V systems, use the 74HC166 variant instead, which supports 2.0–6.0 V and has CMOS input thresholds.

How does the master reset (MR) interact with clock enable (CE)?

The MR input is asynchronous and overrides all other controls including CE. When MR is pulled LOW, all eight register stages clear to logic LOW immediately - regardless of CE state, CP activity, or PE level. CE only gates the clock; it cannot inhibit MR assertion or its effect on register contents.

Is the SO16 package (SOT109-1) RoHS-compliant and lead-free?

Yes - the 74HCT166D,653 in SO16 (SOT109-1) packaging is RoHS-compliant and lead-free per Nexperia's product documentation and EU Directive 2011/65/EU. The device carries the "P" suffix in ordering codes indicating lead-free finish, and meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL3) requirements.