Texas Instruments CD54HC165F3A

Overview

CD54HC165F3A from Texas Instruments is a military-grade 8-bit parallel-in/serial-out shift register with asynchronous parallel load, complementary QH/QH outputs, and operation across –55°C to +125°C. It supports 2 V to 6 V supply voltage, delivers 10 LSTTL fanout, and enables daisy-chained parallel-to-serial conversion in rugged embedded control systems.

For engineers reviewing the CD54HC165F3A datasheet, CD54HC165F3A pinout, CD54HC165F3A application, or CD54HC165F3A equivalent, this page provides verified functional modes, timing constraints at extended temperature, package-specific thermal data, and direct alternatives for high-reliability logic design.

Technical Context

The CD54HC165F3A implements an 8-stage static CMOS shift register with dual serial output paths (QH and its complement QH), enabling simultaneous downstream clocking and inverted feedback. Its SH/LD input controls mode selection: LOW enables asynchronous parallel loading of A–H inputs; HIGH enables right-shift serial propagation on CLK rising edges.

CLK INH allows synchronous hold functionality-when HIGH, clock transitions are ignored regardless of SH/LD state. The device uses buffered inputs, exhibits balanced tPLH/tPHL propagation delays (e.g., 30 ns max at VCC = 6 V, –55°C to +125°C), and maintains noise immunity of NIL = NIH = 30% of VCC at 5 V.

Key Specifications

Pinout & Package

CD54HC165F3A is housed in a hermetically sealed 16-pin Ceramic Dual In-line Package (CDIP), body size 24.38 mm × 6.92 mm, with SNPB (tin-lead) lead finish and no MSL rating (non-reflowable, intended for through-hole soldering).

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 CD74HC165E, CD54HC165F3A offers guaranteed military screening and hermetic packaging for mission-critical longevity; compared with CD54HCT165F3A, it provides wider voltage flexibility and lower static power-critical for mixed-supply or battery-operated platforms.

Availability

CD54HC165F3A is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, aerospace sensor data aggregation, defense radar front-end control, and downhole oilfield instrumentation requiring stable component supply across extended temperature and long product lifecycles.

Supply support for CD54HC165F3A 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of high-reliability component development.

The CD54HC165F3A belongs to TI's military-grade HC logic family, designed specifically for ruggedized digital signal conditioning in defense, aerospace, and energy exploration systems demanding extended temperature operation and long-term supply assurance.

FAQ

What is the maximum clock frequency supported by CD54HC165F3A across its full operating temperature range?

The CD54HC165F3A supports up to 24 MHz maximum clock frequency at VCC = 6 V and over the full –55°C to +125°C range, as specified in Section 5.5 of the TI SCHS156D datasheet. This value reflects worst-case timing under extended temperature stress and ensures reliable operation in high-speed control loops without derating.

Does CD54HC165F3A require external pull-up or pull-down resistors on unused inputs?

Yes, CD54HC165F3A requires all unused inputs-including SER, CLK INH, and any unconnected A–H lines-to be tied to VCC or GND per TI layout guidelines (Section 9.1). Floating CMOS inputs can cause increased ICC, erratic shifting, or latch-up due to undefined threshold states, especially under temperature extremes.

Can CD54HC165F3A be used in a 3.3 V system without level-shifting circuitry?

Yes, CD54HC165F3A operates natively from 2 V to 6 V, making it fully compatible with 3.3 V logic systems. Its VIH(min) = 1.5 V at VCC = 3.3 V and VIL(max) = 0.5 V ensure robust noise margins and direct interface with standard 3.3 V microcontrollers and FPGAs.

How does the SH/LD and CLK INH interaction affect register behavior in CD54HC165F3A?

In CD54HC165F3A, SH/LD determines load vs. shift mode (LOW = parallel load, HIGH = serial shift), while CLK INH provides independent hold control (HIGH = ignore CLK edges). TI specifies that CLK and CLK INH must both be LOW before SH/LD transitions HIGH to prevent unintended shifts-a critical sequencing requirement for deterministic initialization.

Is CD54HC165F3A RoHS-compliant, and what is its lead finish?

No, CD54HC165F3A is not RoHS-compliant. It uses a SNPB (tin-lead) lead finish, consistent with its military CDIP packaging and MIL-PRF-38535 qualification. This finish ensures superior solder joint reliability under thermal cycling and mechanical shock-key for aerospace and defense deployments.