Texas Instruments CD74HC173MG4

Overview

CD74HC173MG4 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 CD74HC173MG4 datasheet, CD74HC173MG4 pinout, CD74HC173MG4 application, or CD74HC173MG4 equivalent, this page provides verified functional identity, validated pin functions, confirmed operating conditions, real-world timing parameters, and qualified alternative options - all specific to the CD74HC173MG4 SOIC-16 package with NiPdAu lead finish and Level-1 moisture sensitivity rating.

Technical Context

The CD74HC173MG4 implements four independent edge-triggered D-type flip-flops sharing CP, MR, E1, E2, OE1, and OE2 control lines. Its three-state outputs are enabled only when both OE1 and OE2 are low; either OE high forces high-impedance output without affecting internal state retention.

Input enables E1/E2 gate data flow into the flip-flops: when either is high, Q outputs feed back to D inputs, holding current state regardless of clock activity. Reset is asynchronous and active-high on MR, forcing all Q outputs low independently of clock or enable states.

Key Specifications

Pinout & Package

CD74HC173MG4 is supplied in a 16-pin SOIC (D) package measuring 9.90 mm × 3.90 mm, with NiPdAu lead finish and moisture sensitivity Level-1 (260°C peak reflow).

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 CD74HC173MG4, CD74HC173M96 offers identical performance in a production-optimized reel format, while SN74HC173N trades military temperature range and drive strength for lower cost and through-hole assembly - making CD74HC173MG4 the sole choice for high-reliability, wide-temperature, high-drive applications.

Availability

CD74HC173MG4 is available at Aetrix Electronics and suitable for industrial bus interface, aerospace data acquisition, military control panel logic, and automotive powertrain diagnostics requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD74HC173MG4 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 ICs, with decades of heritage in high-reliability logic families including the 74HC series.

The CD74HC173MG4 belongs to TI's industry-standard 74HC logic family, designed specifically for robust, low-power, wide-temperature digital interfacing in mission-critical systems where timing predictability and bus integrity are paramount.

FAQ

What is the maximum clock frequency supported by CD74HC173MG4?

The CD74HC173MG4 supports a maximum clock frequency of 24 MHz at VCC = 6 V and TA = –55°C to +125°C, as specified in the switching characteristics table. This value is derived from the minimum clock pulse width requirement (14 ns) and accounts for worst-case propagation delays across the full temperature range. The CD74HC173MG4 must be operated within this limit to guarantee setup/hold timing compliance and avoid metastability.

Does CD74HC173MG4 support direct connection to 5 V TTL logic inputs?

Yes, CD74HC173MG4 outputs meet TTL voltage thresholds when loaded with 6 mA: VOH ≥ 3.7 V and VOL ≤ 0.4 V at VCC = 4.5 V to 5.5 V. Its 15-LSTTL load drive capability allows direct fanout to multiple TTL inputs without buffering. However, CD74HC173MG4 inputs are CMOS-compatible only - for driving it from TTL sources, ensure VIH ≥ 3.15 V and VIL ≤ 1.35 V at VCC = 4.5 V.

How does the dual output enable (OE1/OE2) architecture improve bus reliability in CD74HC173MG4?

The CD74HC173MG4 uses OR-combined OE1 and OE2: if either is high, all Q outputs enter high-impedance mode. This redundancy prevents bus contention during partial control signal failure - for example, if OE1 is shorted to VCC, OE2 still permits active bus control. Unlike single-enable devices, this design eliminates single-point failure modes in safety-critical bus arbitration circuits.

Can CD74HC173MG4 be used without external bypass capacitors?

No. TI's datasheet mandates a 0.1-μF ceramic bypass capacitor placed as close as possible to the VCC pin of CD74HC173MG4. Without it, supply rail instability during output transitions causes increased propagation delay variation, potential logic errors, and degraded noise immunity. For best results, pair the 0.1-μF cap with a 1-μF capacitor in parallel to suppress broadband noise.

Is CD74HC173MG4 pin-compatible with CD74HCT173M variants?

Yes - CD74HC173MG4 and CD74HCT173M share identical pinout, package dimensions, and functional block diagram. However, they differ electrically: CD74HC173MG4 operates from 2 V to 6 V and has CMOS input thresholds, while CD74HCT173M is 4.5 V to 5.5 V only and features TTL-compatible inputs (VIH = 2 V min, VIL = 0.8 V max). Interchange requires verifying supply voltage and driver compatibility.