Texas Instruments SN74HC374PWT

Overview

SN74HC374PWT from Texas Instruments is an octal edge-triggered D-type flip-flop with 3-state outputs, operating across 2 V to 6 V. It features eight independent D-flip-flops synchronized on the rising clock edge, ±6-mA output drive at 5 V, 14 ns typical propagation delay, and low 80-µA max ICC-ideal for bus interface buffering in industrial I/O modules.

For engineers reviewing the SN74HC374PWT datasheet, SN74HC374PWT pinout, SN74HC374PWT application, or SN74HC374PWT equivalent, this device serves as a high-drive, low-power register for bidirectional data buses, working registers, and I/O port expansion where timing-critical parallel data latching and bus contention control are required.

Technical Context

The SN74HC374PWT implements eight independent D-type latches triggered by the positive edge of CLK, with asynchronous 3-state control via OE. Its CMOS architecture ensures rail-to-rail logic levels, low input current (≤1 µA), and compatibility with LSTTL loads (up to 15 units).

Each flip-flop retains state when OE is high (disabled), allowing data hold during bus arbitration. The device supports full parallel loading and operates reliably across –40°C to +85°C, with thermal metrics including RθJA = 131.8°C/W for its TSSOP-20 package.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), body size 6.50 mm × 4.40 mm, 1.2 mm max height, JEDEC MO-153 compliant. Pin 1 index area located at top-left corner with gull-wing leads spaced at 0.65 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC374PWT, SN74HCT374PWR offers superior TTL-input compatibility at the cost of higher static power, while 74LVC374APW,118 delivers higher speed and lower voltage operation but sacrifices 5 V bus interoperability - selection depends on system voltage architecture and noise environment.

Availability

SN74HC374PWT is available at Aetrix Electronics and suitable for industrial I/O expansion, microcontroller bus interface, and automated test fixture control requiring stable component supply and long-term production continuity.

Supply support for SN74HC374PWT 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 50 years of innovation in industrial and automotive electronics.

The SN74HC374PWT belongs to TI's 74HC logic family, designed for robust, low-power, wide-voltage digital interfacing in harsh industrial environments where reliability and timing predictability are critical.

FAQ

What is the maximum clock frequency supported by SN74HC374PWT at 5 V?

The SN74HC374PWT supports a maximum clock frequency of 24 MHz at 5 V under recommended operating conditions. This is derived from the 20 ns maximum pulse width (tw) requirement and verified switching characteristics in the datasheet. The actual achievable frequency depends on load capacitance and PCB layout; CL = 50 pF yields fmax = 24 MHz, while heavier loads reduce usable rate. SN74HC374PWT maintains timing integrity within these limits across its full temperature range.

Can SN74HC374PWT operate safely at 3.3 V with 5 V-tolerant inputs?

No, SN74HC374PWT is not 5 V-tolerant. Its absolute maximum input voltage is VCC + 0.5 V, so applying 5 V inputs while powered at 3.3 V exceeds rating and risks damage. At 3.3 V supply, VIH = 2.31 V and VIL = 0.99 V per datasheet specs. For 5 V input compatibility, use SN74HCT374PWR instead. SN74HC374PWT must be used in strictly matched-voltage systems.

How does the OE pin behave during power-up, and what is the recommended tie-off strategy?

During power-up, OE should be held high (inactive) via a pull-up resistor to VCC to ensure outputs remain in high-impedance until firmware initializes the device. TI specifies minimum pull-up resistance based on driver sink capability; a 10-kΩ resistor is typical. This prevents bus contention or unintended writes during reset. OE has no effect on internal flip-flop states - SN74HC374PWT retains latched data regardless of OE level.

Is SN74HC374PWT pin-compatible with other packages in the SN74HC374 family?

Yes, all SN74HC374 variants-including SN74HC374PWT (TSSOP-20), SN74HC374DWR (SOIC-20), and SN74HC374NSR (SOP-20)-share identical pin numbering and function assignment per JEDEC standard. Mechanical dimensions differ, but PCB footprint and signal routing are interchangeable with appropriate land pattern adaptation. SN74HC374PWT uses the same 20-pin TSSOP outline defined in PW0020A.

What thermal derating applies to SN74HC374PWT in high-temperature industrial enclosures?

SN74HC374PWT has RθJA = 131.8°C/W in its TSSOP-20 package. At 85°C ambient and 6 V supply, worst-case power dissipation (ICC × VCC ≈ 0.48 mW) results in junction temperature rise of <0.1°C - well within the 150°C limit. Derating is negligible for normal operation; however, sustained 35 mA output current per pin (beyond spec) would require heatsinking or airflow. SN74HC374PWT is rated for continuous operation from –40°C to +85°C.