Texas Instruments SN74HC74ANS

Overview

SN74HC74ANS from Texas Instruments is a dual D-type positive-edge-triggered flip-flop with independent asynchronous preset (PRE) and clear (CLR) inputs, operating across 2 V to 6 V supply, with 25 ns max propagation delay at 4.5 V, ±4 mA output drive, and rated for –40°C to 85°C industrial temperature range. It serves as a synchronous storage element in digital control logic, clock-domain synchronization, and state-machine sequencing.

For engineers reviewing the SN74HC74ANS datasheet, SN74HC74ANS pinout, SN74HC74ANS application, or SN74HC74ANS equivalent, key selection criteria include its dual independent flip-flop architecture, CMOS input/output compatibility, 14-pin PDIP (N) package, guaranteed setup/hold timing, and industrial-temperature qualification - critical for reliable edge-triggered data latching in embedded control systems.

Technical Context

The SN74HC74ANS implements two identical, electrically isolated D-type flip-flops, each with active-low asynchronous PRE and CLR inputs that override clocked operation. Its triggering is voltage-level–sensitive on the rising edge of CLK, independent of input slew rate, enabling robust timing in mixed-slew environments.

Each flip-flop features complementary Q and Q̅ outputs, supports TTL- and CMOS-compatible input thresholds, and maintains valid output states during power-up via defined reset behavior when PRE/CLR are held low - essential for deterministic initialization in microcontroller peripheral interfaces and sequencer circuits.

Key Specifications

Pinout & Package

SN74HC74ANS is supplied in a 14-pin plastic dual in-line package (PDIP), designated "N" package per TI documentation, with 0.300-inch body width and through-hole mounting. Pin spacing is 0.100 inch, compatible with standard 0.025-inch pitch PCB footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC74ANS, SN74HCT74N offers tighter input threshold compatibility with TTL but sacrifices 2 V–6 V supply range flexibility, while MC74HC74ANG delivers identical electrical and timing behavior with alternate sourcing - making SN74HC74ANS optimal for new 3.3 V/5 V hybrid designs requiring wide VCC tolerance and single-supplier traceability.

Availability

SN74HC74ANS is available at Aetrix Electronics and suitable for industrial motor control, digital power supply sequencing, and programmable logic interface applications requiring stable component supply, long-term obsolescence management, and consistent parametric performance across production lots.

Supply support for SN74HC74ANS 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 decades of heritage in high-reliability logic families.

The SN74HC74ANS belongs to the 74HC high-speed CMOS logic series, designed for low-power, pin-compatible upgrades to legacy TTL logic in industrial, automotive, and communications infrastructure applications.

FAQ

What is the maximum clock frequency supported by the SN74HC74ANS?

The SN74HC74ANS supports up to 25 MHz maximum clock frequency at VCC = 4.5 V and TA = 25°C, as specified in the switching characteristics table. At full industrial temperature range (–40°C to 85°C), the guaranteed maximum is 21 MHz. This limit derives from propagation delay (tpd ≤ 37 ns) and setup/hold timing constraints - actual system-level frequency depends on board layout, load capacitance, and supply stability. The SN74HC74ANS remains functional below this threshold with full timing margin compliance.

Does the SN74HC74ANS support 3.3 V operation?

Yes, the SN74HC74ANS fully supports 3.3 V operation within its specified 2.0 V to 6.0 V supply range. At VCC = 3.3 V, input thresholds scale proportionally (VIH ≈ 2.1 V, VIL ≈ 1.1 V), output VOH/VOL meet CMOS-compatible levels, and timing parameters remain valid per the recommended operating conditions table. This makes the SN74HC74ANS suitable for mixed-voltage systems interfacing with 3.3 V microcontrollers and FPGAs without level-shifting circuitry.

How does the asynchronous clear and preset function on the SN74HC74ANS?

The SN74HC74ANS features active-low asynchronous clear (CLR) and preset (PRE) inputs on each flip-flop. When either input is driven low, the corresponding outputs force immediately: CLR sets Q = 0 and Q̅ = 1; PRE sets Q = 1 and Q̅ = 0 - overriding clock and data inputs entirely. These functions operate independently per section and require no clock edge. The SN74HC74ANS guarantees this behavior across the full –40°C to 85°C temperature range and 2 V–6 V supply, making it ideal for fail-safe initialization and emergency reset in safety-critical logic.

Is the SN74HC74ANS pin-compatible with other 74xx74 variants?

Yes, the SN74HC74ANS shares identical pinout and functionality with all industry-standard 14-pin dual D-flip-flop devices in the 74xx74 family, including SN74LS74A, SN74HCT74N, and MC74HC74ANG. All use the same 1–14 pin assignment for 1CLR, 1D, 1CLK, 1PRE, 1Q, 1Q̅, GND, VCC, 2CLR, 2D, 2CLK, 2PRE, 2Q, 2Q̅. However, electrical characteristics (e.g., drive strength, propagation delay, input thresholds) differ by logic family - direct substitution requires verification of voltage, speed, and loading compatibility in the target application.

What is the power dissipation of the SN74HC74ANS under typical operating conditions?

The SN74HC74ANS exhibits very low static power consumption: ICC ≤ 40 µA at VCC = 6 V and TA = 25°C. Dynamic power depends on switching frequency and load capacitance, with typical power dissipation capacitance (Cpd) of 35 pF per flip-flop. At 10 MHz operation with 50 pF load, total supply current is approximately 1.8 mA - resulting in <11 mW total power at 6 V. This efficiency makes the SN74HC74ANS suitable for thermally constrained designs and battery-powered instrumentation where the SN74HC74ANS operates reliably without heatsinking.