Texas Instruments CD74HC173NSRE4

Overview

CD74HC173NSRE4 from Texas Instruments is a high-speed CMOS quad D-type flip-flop with three-state outputs, shared clock (CP), master reset (MR), and dual data enable (E1/E2) and output enable (OE1/OE2) controls. It operates from 2 V to 6 V, delivers 15 LSTTL load drive capability, and supports –55°C to 125°C industrial/military temperature range. It is used in bus-oriented digital systems for synchronous data latching and controlled bus interfacing.

For engineers reviewing the CD74HC173NSRE4 datasheet, CD74HC173NSRE4 pinout, CD74HC173NSRE4 application, or CD74HC173NSRE4 equivalent, key selection factors include its three-state output control architecture, wide supply voltage tolerance, guaranteed propagation delay (≤50 ns at 4.5 V), and compatibility with legacy TTL bus loads while maintaining CMOS power efficiency.

Technical Context

The CD74HC173NSRE4 implements four independent edge-triggered D-type flip-flops sharing CP, MR, E1, E2, OE1, and OE2 control lines. Its synchronous operation on the rising edge of CP enables deterministic state capture across all four channels. The dual input enable (E1/E2) allows selective hold functionality without disrupting the clock signal.

Three-state output control is implemented via separate OE1 and OE2 pins - either high disables all Q outputs to high-impedance. This architecture supports bidirectional bus arbitration and eliminates contention in multi-driver systems. The device uses silicon-gate CMOS technology, delivering low ICC (≤160 µA at 6 V) and high noise immunity (NIL/NIH = 30% of VCC at 5 V).

Key Specifications

Pinout & Package

CD74HC173NSRE4 is supplied in a 16-pin SOIC (D) package with nominal body size 9.90 mm × 3.90 mm and standard JEDEC MO-153 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad D-type flip-flop with three-state output applications.

Compared with CD74HC173NSRE4, SN74HC173N offers identical logic behavior in PDIP but sacrifices surface-mount reliability and thermal efficiency, while CD74HCT173M96 trades wider supply flexibility for guaranteed TTL input compatibility - making CD74HC173NSRE4 optimal for new CMOS-native designs requiring 2–6 V operation and industrial temperature resilience.

Availability

CD74HC173NSRE4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, aerospace avionics data buffering, and military communication baseband processing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC173NSRE4 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 90 years of innovation in high-reliability components.

The CD74HC173NSRE4 belongs to TI's industry-standard HC logic family, designed for robust, low-power, wide-temperature digital interfacing in mission-critical industrial, defense, and space applications.

FAQ

What is the maximum clock frequency supported by CD74HC173NSRE4?

The CD74HC173NSRE4 supports a maximum clock frequency of 60 MHz at VCC = 5 V and 25°C, with guaranteed operation up to 24 MHz across the full –55°C to 125°C temperature range. This specification is validated per TI's switching characteristics table and applies under CL = 50 pF load conditions with input rise/fall times ≤400 ns at 6 V.

Does CD74HC173NSRE4 support 3.3 V operation?

Yes, CD74HC173NSRE4 fully supports 3.3 V operation within its specified 2 V to 6 V supply range. At 3.3 V, it maintains valid VIH (≥2.31 V) and VIL (≤1.1 V) thresholds, delivers ≥3.2 V VOH and ≤0.1 V VOL under light loads, and achieves typical tpd ≈30 ns - making it suitable for mixed-voltage 3.3 V/5 V system interfaces.

How does the dual output enable (OE1/OE2) function in CD74HC173NSRE4?

In CD74HC173NSRE4, either OE1 or OE2 asserted high places all Q0–Q3 outputs in high-impedance state - no OR-ing logic is required. This redundancy improves fault tolerance: if one OE line fails high due to noise or fault, the other can still maintain bus control. Both OE pins must be low to enable normal output driving.

What is the purpose of the dual data enable (E1/E2) inputs on CD74HC173NSRE4?

The E1 and E2 inputs on CD74HC173NSRE4 provide independent gating of data flow to the flip-flop inputs. When both are low, D inputs propagate to Q on the next CP edge; if either is high, the corresponding flip-flop holds its current state. This allows selective latching across subsets of the four channels without altering the clock or reset signals.

Is CD74HC173NSRE4 pin-compatible with CD74HCT173M96?

Yes, CD74HC173NSRE4 is pin-compatible with CD74HCT173M96 - both use identical SOIC-16 (D) packages and share identical pin assignments for CP, MR, D0–D3, Q0–Q3, E1, E2, OE1, OE2, VCC, and GND. However, they differ electrically: CD74HC173NSRE4 accepts CMOS-level inputs (VIH = 3.15 V @ 4.5 V), while CD74HCT173M96 accepts TTL-level inputs (VIH = 2 V min).