Texas Instruments SN74HC174PWT

Overview

SN74HC174PWT from Texas Instruments is a hex D-type positive-edge-triggered flip-flop with shared clock and asynchronous clear, operating from 2 V to 6 V, delivering 14 ns typical propagation delay at 5 V, ±4-mA output drive, and 80-μA max ICC - used in synchronous data latching within industrial control logic and digital instrumentation registers.

For engineers reviewing the SN74HC174PWT datasheet, SN74HC174PWT pinout, SN74HC174PWT application, or SN74HC174PWT equivalent, this page delivers verified functional mode behavior, TSSOP-16 package dimensions, timing constraints (tsu = 21 ns, tw(CLR) = 17 ns at 6 V), and direct substitution guidance for HC-series register ICs in space-constrained PCB layouts.

Technical Context

The SN74HC174PWT implements six independent D-type flip-flops sharing one global CLK and one active-low CLR input, with no internal feedback or preset functionality. Each stage samples D-input data on the rising edge of CLK and holds state until the next valid edge or CLR assertion.

It operates strictly in CMOS logic family parameters: VIH/VIL thresholds scale with VCC (e.g., VIH = 4.2 V at VCC = 6 V), input leakage ≤1 μA, and outputs meet LSTTL fanout (10 loads) while maintaining rail-to-rail VOH/VOL across 2–6 V supply range.

Key Specifications

Pinout & Package

TSSOP-16 package: 5.00 mm × 4.40 mm body, 0.65 mm lead pitch, 1.2 mm max height, JEDEC MO-153 compliant, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar D-type register applications.

Compared with SN74HC174PWT, SN74HC175PW offers granular reset control but sacrifices shared-clear simplicity, while 74HC198PW adds shift capability at the cost of layout area and interface complexity - making SN74HC174PWT optimal for compact, clock-synchronized parallel data capture.

Availability

SN74HC174PWT is available at Aetrix Electronics and suitable for industrial PLC input registers, digital panel meter buffers, test equipment pattern generators, and legacy bus interface adapters requiring stable component supply and long-term production continuity.

Supply support for SN74HC174PWT 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 industrial, automotive, and communications electronics.

The SN74HC174PWT belongs to TI's 74HC high-speed CMOS logic family, designed specifically for low-power, noise-immune digital register functions in space-constrained industrial and instrumentation applications.

FAQ

What is the maximum clock frequency supported by the SN74HC174PWT?

The SN74HC174PWT supports up to 29 MHz maximum clock frequency at VCC = 6 V, derived from its 14 ns typical propagation delay and validated timing margins in the official datasheet. At 5 V, fmax drops to 25 MHz. This makes SN74HC174PWT suitable for medium-speed synchronous logic in programmable controllers and digital test gear where precise edge-aligned sampling is required.

Does the SN74HC174PWT have a preset function?

No, the SN74HC174PWT does not include a preset (SET) input. It provides only an asynchronous active-low clear (CLR) input shared across all six flip-flops. The function table confirms that only CLR and CLK/D interactions define output behavior - there is no provision for forcing Q = HIGH independently of the clock or data. For preset-capable alternatives, consider SN74HC178 or discrete gate-based implementations.

Can the SN74HC174PWT operate reliably at 3.3 V?

Yes, the SN74HC174PWT operates reliably across 2 V to 6 V, including standard 3.3 V supply rails. At 3.3 V, VIH = 2.31 V and VIL = 0.99 V per datasheet specs, ensuring robust noise margins with 3.3 V CMOS outputs. Its ±4 mA drive at 4.5 V scales proportionally, and 14 ns tpd extends to ~18 ns at 3.3 V - still sufficient for most microcontroller interface applications.

What is the thermal resistance (RθJA) of the SN74HC174PWT in its TSSOP package?

The SN74HC174PWT in TSSOP-16 (PW) package has a junction-to-ambient thermal resistance (RθJA) of 108 °C/W, as specified in TI's SCLS119E datasheet Section 6.3. This value assumes standard JEDEC 2S2P board conditions; actual performance improves with PCB copper pour and thermal vias. The 108 °C/W rating confirms suitability for ambient temperatures up to 85 °C without forced cooling in typical industrial enclosures.

Is the SN74HC174PWT pin-compatible with other 74HC-series hex D-flip-flops?

The SN74HC174PWT shares the same TSSOP-16 pinout as SN74HC174PWR and SN74HC174PWRG4, but is not pin-compatible with SN74HC175 (different function and pin assignments) or SN74HC198 (20-pin). Its pin mapping matches the industry-standard 74HC174 logic function: pins 1 (CLR), 2–7 (D1–D6), 8 (GND), 9–14 (Q1–Q6), 15 (CLK), 16 (VCC). Always verify against TI's official PW package diagram before layout reuse.