Texas Instruments CD74HCT74MT

Overview

CD74HCT74MT from Texas Instruments is a dual D-type positive-edge-triggered flip-flop with independent asynchronous clear and preset inputs per channel, operating across 4.5 V to 5.5 V supply voltage, supporting –55°C to +125°C industrial/military temperature range, and delivering propagation delay of 30 ns (typ) at 5 V with fanout capability up to 10 LSTTL loads - used in clock division and momentary-to-toggle switch conversion circuits.

For engineers reviewing the CD74HCT74MT datasheet, CD74HCT74MT pinout, CD74HCT74MT application, or CD74HCT74MT equivalent, key selection considerations include its TTL-compatible input thresholds, dual-channel edge-triggered storage behavior, SOIC-14 package footprint, and guaranteed operation under extended temperature and mixed-voltage interface conditions.

Technical Context

The CD74HCT74MT implements two independent D-type latches synchronized to the rising edge of CLK, each with active-low asynchronous PRE and CLR inputs that override clocked data capture. Its HCT logic family ensures TTL-level input compatibility while maintaining CMOS output drive strength and low static current draw.

Timing behavior is defined by setup time (10 ns min at 5 V), hold time (3 ns min), minimum clock pulse width (14 ns), and maximum clock frequency (35 MHz at 5 V). Propagation delays (tpd = 30 ns typ) and transition times (tt = 13 ns typ) are specified under 50-pF capacitive load conditions with 5-V supply.

Key Specifications

Pinout & Package

CD74HCT74MT is housed in a 14-pin SOIC (D) package measuring 8.70 mm × 3.90 mm with gull-wing leads, RoHS-compliant NIPDAU plating, and moisture sensitivity level (MSL) 1 - suitable for standard surface-mount reflow without dry-pack requirements.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual D-type flip-flop applications.

Compared with SN74HCT74DR and CD74HC74M96, CD74HCT74MT uniquely combines military-grade temperature range, TTL-compatible inputs, and small-batch SOIC tape-and-reel packaging - making it optimal for prototyping, low-volume aerospace programs, and repair spares where extended qualification and logistics flexibility are mandatory.

Availability

CD74HCT74MT is available at Aetrix Electronics and suitable for industrial control logic, test & measurement equipment, avionics signal conditioning, and automotive body control modules requiring stable component supply across extended temperature and mixed-voltage interface conditions.

Supply support for CD74HCT74MT 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 for industrial, automotive, and aerospace markets.

The CD74HCT74MT belongs to TI's legacy HCT logic product line, engineered specifically for seamless integration into 5-V systems transitioning from bipolar TTL to CMOS-based designs while preserving existing board layouts and signal integrity.

FAQ

What is the maximum clock frequency supported by the CD74HCT74MT?

The CD74HCT74MT supports a maximum clock frequency of 35 MHz at VCC = 5 V and TA = 25°C, with derating to 23 MHz at full –55°C to +125°C operating range. This specification is validated under CL = 50 pF load and accounts for worst-case propagation delay (tpd = 45 ns max) and setup/hold timing margins defined in the official datasheet.

Does the CD74HCT74MT require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs on the CD74HCT74MT must be terminated to either VCC or GND to prevent floating states that cause excessive current draw, oscillation, or undefined outputs. A 10-kΩ resistor is recommended for default HIGH (pull-up) or LOW (pull-down) biasing, consistent with TI's layout guidelines and electrical specifications for input leakage current (±1 µA max).

Can the CD74HCT74MT drive a 50-pF capacitive load reliably?

Yes - the CD74HCT74MT is explicitly characterized for CL = 50 pF in its switching characteristics table, with guaranteed tpd = 30–45 ns and tt = 13–19 ns at 5 V. Driving this load meets all AC timing specs; exceeding it may increase propagation delay and degrade edge fidelity, so series termination is advised for larger loads.

Is the CD74HCT74MT pin-compatible with the CD74HC74M96?

Yes - the CD74HCT74MT and CD74HC74M96 share identical SOIC-14 pinout, terminal assignments, and functional block diagram. However, they differ in input threshold voltages (HCT vs. HC), temperature rating (–55°C to +125°C vs. same), and recommended operating voltage (4.5–5.5 V vs. 2–6 V), so direct substitution requires verification of interface voltage compatibility.

What is the purpose of the asynchronous PRE and CLR pins on the CD74HCT74MT?

The asynchronous PRE (pin 4, 10) and CLR (pin 1, 13) pins on the CD74HCT74MT allow immediate, clock-independent setting or resetting of each flip-flop's Q output. When asserted LOW, PRE forces Q = HIGH and CLR forces Q = LOW - enabling hardware-initiated state initialization, emergency shutdown, or power-on reset without waiting for the next clock edge.