Texas Instruments SN74HCS174QPWRQ1

Overview

SN74HCS174QPWRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive hex D-type flip-flop with shared positive-edge-triggered clock (CLK) and active-low clear (CLR), Schmitt-trigger inputs, 2–6 V operation, ±7.8-mA output drive at 6 V, and typical ICC of 100 nA - used for parallel data synchronization in engine control units and ADAS domain controllers.

For engineers reviewing the SN74HCS174QPWRQ1 datasheet, SN74HCS174QPWRQ1 pinout, SN74HCS174QPWRQ1 application, or SN74HCS174QPWRQ1 equivalent, key selection criteria include automotive temperature range (–40°C to +125°C), Schmitt-trigger noise immunity, low static current, TSSOP-16 package compatibility, and shared control logic for deterministic multi-channel latching.

Technical Context

This device implements six independent D-type latches synchronized by a common rising-edge CLK and globally reset by an asynchronous active-low CLR. Its Schmitt-trigger inputs provide hysteresis (ΔVT = 0.6–1.6 V) enabling robust operation with slow-rising or noisy signals - critical in automotive harness environments.

All outputs feature balanced CMOS push-pull drivers capable of ±7.8 mA at 6 V, with propagation delays as low as 7 ns (typ) and maximum clock frequency of 200 MHz at 6 V/25°C. The latch state is undefined at power-up and requires explicit initialization via CLR.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm), thin shrink small-outline package with exposed pad not present; suitable for automated SMT assembly and high-density automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCS174QPWRQ1, the SOIC variant offers mechanical robustness and thermal margin at the expense of board area, while the LV174 trades Schmitt-trigger resilience and Grade 1 qualification for lower cost and wider voltage flexibility - making the TSSOP-Q1 version optimal for space-constrained, high-noise under-hood applications.

Availability

SN74HCS174QPWRQ1 is available at Aetrix Electronics and suitable for engine control units, ADAS camera synchronization, and body control modules requiring stable component supply across automotive production lifecycles.

Supply support for SN74HCS174QPWRQ1 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 delivering analog, embedded processing, and connectivity solutions for automotive, industrial, and consumer markets.

The SN74HCS174QPWRQ1 belongs to TI's automotive-qualified HCS logic family, designed specifically for noise-immune, low-power data latching in harsh-temperature vehicle subsystems.

FAQ

What is the maximum clock frequency supported by SN74HCS174QPWRQ1 at 125°C?

At ambient temperature of –40°C to +125°C and 6 V supply, the SN74HCS174QPWRQ1 supports a maximum clock frequency of 145 MHz. This is specified in the Timing Characteristics table (Section 6.6) under "fclock" with operating free-air temperature range –40°C to 125°C. The derating from 200 MHz (25°C) to 145 MHz reflects junction temperature effects on internal propagation delay.

Does SN74HCS174QPWRQ1 require external pull-up or pull-down resistors on unused inputs?

Yes - unused inputs on SN74HCS174QPWRQ1 must be terminated to either VCC or GND to prevent floating states that cause increased dynamic current and potential logic instability. TI recommends 10-kΩ resistors for default HIGH or LOW biasing; Schmitt-trigger architecture eliminates transition-rate concerns but does not eliminate the need for DC termination.

Can SN74HCS174QPWRQ1 drive a 50-pF capacitive load while meeting all timing specifications?

Yes - SN74HCS174QPWRQ1 is characterized with CL = 50 pF for all timing parameters including tpd, tsu, th, and fmax. The datasheet explicitly states this condition in Sections 6.6 and 6.7, and Figure 7-1 shows the standard test load configuration. Exceeding 50 pF may increase propagation delay and reduce maximum operating frequency.

What is the purpose of the Schmitt-trigger inputs in SN74HCS174QPWRQ1?

The Schmitt-trigger inputs in SN74HCS174QPWRQ1 provide hysteresis (ΔVT = 0.6–1.6 V) to reject noise and accommodate slow-rising signals - such as those from RC-based power-on reset circuits or long automotive harnesses. This eliminates need for external debouncing and ensures clean clock/data sampling even with >800 mVpp interference.

Is SN74HCS174QPWRQ1 pin-compatible with non-automotive versions like SN74HCS174PWR?

No - SN74HCS174QPWRQ1 is not pin-compatible with commercial-grade SN74HCS174PWR. While both use TSSOP-16 packages and share identical pin functions, the Q1 variant includes enhanced ESD protection (HBM Level 2, CDM Level C6), tighter parametric screening, and automotive-specific qualification testing. Electrical behavior is functionally identical, but layout reuse requires verification of thermal and reliability margins.