Texas Instruments CD74HC173MT

Overview

CD74HC173MT 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 synchronized data latching and controlled bus interfacing.

For engineers reviewing the CD74HC173MT datasheet, CD74HC173MT pinout, CD74HC173MT application, or CD74HC173MT equivalent, this page provides verified functional identity, validated SOIC-16 pin mapping, confirmed timing parameters (tpd ≤ 43 ns @ 6 V), true three-state leakage (IOZ ≤ ±10 µA), and two rigorously cross-checked alternative parts for bus-interface flip-flop selection.

Technical Context

The CD74HC173MT implements four edge-triggered D-type flip-flops sharing synchronous control logic - CP (positive-edge clock), MR (asynchronous active-high reset), and dual E1/E2 (data enable) inputs that feed Q back to D to hold state. Its three-state outputs are independently disabled via OE1/OE2, enabling bidirectional bus arbitration without disrupting internal latch operation.

Designed using silicon-gate CMOS technology, it achieves low ICC (≤160 µA at 6 V) while matching LS-TTL speed: propagation delay tpd is 43 ns max at 6 V, fMAX reaches 35 MHz at 6 V, and transition times tt are ≤15 ns. Input thresholds (VIH = 4.2 V, VIL = 1.8 V @ VCC = 6 V) and noise immunity (NIL/NIH = 30% of VCC) are fully specified across the full temperature range.

Key Specifications

Pinout & Package

CD74HC173MT is supplied in a 16-pin SOIC package (body size 9.90 mm × 3.90 mm, JEDEC MS-012, TI drawing D), RoHS-compliant with NiPdAu lead finish and moisture sensitivity level (MSL) Level-1 (unlimited floor life at ≤30°C/60% RH).

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 CD74HC173MT, CD74HC173M96 offers identical electrical and thermal performance in tape-and-reel form for SMT lines, while SN74HC173N sacrifices military-grade temperature range for lower cost in benign environments - making CD74HC173MT the sole choice for full-spec ruggedized designs.

Availability

CD74HC173MT is available at Aetrix Electronics and suitable for industrial bus interface, aerospace data acquisition, military communication backplane, and test equipment signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC173MT 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 over 90 years of innovation in high-reliability components.

CD74HC173MT belongs to TI's CDx4HC logic family - engineered for high-speed, low-power, extended-temperature digital interfacing in mission-critical systems where robustness and timing predictability are mandatory.

FAQ

What is the maximum clock frequency supported by CD74HC173MT?

The CD74HC173MT supports a maximum clock frequency of 35 MHz at VCC = 6 V and –55°C to +125°C, as specified in the switching characteristics table. At 4.5 V, fMAX is 30 MHz, and at 2 V it drops to 6 MHz. These values assume proper input rise/fall times (≤400 ns at 6 V) and CL = 50 pF load.

Does CD74HC173MT support direct connection to TTL logic inputs?

No, CD74HC173MT is an HC-family device and does not guarantee TTL input compatibility. Its VIH minimum is 4.2 V at VCC = 6 V, exceeding standard TTL's 2.0 V threshold. For TTL-compatible operation, use the pin-equivalent CD74HCT173M96 instead, which specifies VIH ≥ 2.0 V and VIL ≤ 0.8 V.

How do the E1 and E2 pins function in CD74HC173MT?

In CD74HC173MT, E1 and E2 are dual data enable inputs. When both are low, D inputs pass to the flip-flop inputs on the next CP rising edge. If either E1 or E2 is high, the corresponding Q output is fed back to its D input, holding the current state - enabling glitch-free hold mode without stopping the clock.

What is the purpose of OE1 and OE2 in CD74HC173MT?

OE1 and OE2 are OR-configured three-state output enables in CD74HC173MT. Either pin driven high places all four Q outputs (Q0–Q3) into high-impedance mode, disconnecting them from the bus. This allows safe bus sharing among multiple devices without affecting internal latch states or requiring clock suspension.

Is CD74HC173MT still in active production?

CD74HC173MT is marked as obsolete in TI's official packaging addendum; however, CD74HC173M96 (same die, SOIC-16, tape-and-reel) remains actively produced and functionally identical. Aetrix Electronics stocks and supports CD74HC173M96 as the direct replacement for new designs and legacy CD74HC173MT requirements.