Texas Instruments SN74S175N3

Overview

SN74S175N from Texas Instruments is a quadruple D-type flip-flop with asynchronous clear, implemented in TTL-Schottky logic. It provides four independent edge-triggered storage elements, operates at VCC = 4.75 V to 5.25 V, features tPLH/tPHL ≤ 4 ns typical propagation delay, and supports fan-out of 10 LSTTL loads. It is used in synchronous data latching, register staging, and clock-domain synchronization in legacy industrial control logic.

For engineers reviewing the SN74S175N datasheet, SN74S175N pinout, SN74S175N application, or SN74S175N equivalent, this page delivers verified electrical parameters, validated PDIP-16 pin mapping, confirmed timing behavior under 5 V supply, and direct alternatives for register-level replacement in TTL-based digital systems.

Technical Context

The SN74S175N implements four identical D-type flip-flops sharing a common clock (CLK) and asynchronous master clear (MR̄), with individual D inputs and Q outputs. Each stage uses positive-edge triggering and Schottky-clamped bipolar transistors to achieve high-speed operation without sacrificing noise margin.

Its logic family is TTL-Schottky (74S), distinguishing it from LS (lower power) and standard TTL variants. It requires a 5 V ±5% supply, draws ICC = 38 mA max at 5 V, and guarantees output drive capability of IOH = –1.0 mA / IOL = 20 mA per Q output - sufficient to directly drive multiple LSTTL inputs.

Key Specifications

Pinout & Package

SN74S175N is supplied in a 16-pin plastic dual in-line package (PDIP-N), with 0.3-inch body width and through-hole mounting. Pin 1 is located at the top-left corner when the notch faces upward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS175N, SN74S175N trades 60% higher supply current for 3.75× faster propagation - making it optimal for speed-critical legacy TTL systems. Against SN74F175N, it offers slightly relaxed drive strength and lower cost while delivering nearly identical timing, favoring long-lifecycle industrial replacements.

Availability

SN74S175N is available at Aetrix Electronics and suitable for industrial control sequencing, legacy computer bus interfacing, digital test equipment pattern generation, and programmable logic controller output registration requiring stable component supply and long-term obsolescence management.

Supply support for SN74S175N 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs with broad industrial, automotive, and aerospace qualification.

SN74S175N belongs to TI's legacy 74S logic family, designed specifically for high-speed digital systems requiring TTL-compatible performance with improved speed over standard 74xx and LS-series devices.

FAQ

What is the maximum clock frequency supported by SN74S175N?

The SN74S175N does not specify a maximum clock frequency in its datasheet; instead, it guarantees tPLH/tPHL ≤ 4 ns typical and tW = 4 ns minimum pulse width for CLK and MR̄. Based on these values, reliable operation is achievable up to approximately 100 MHz in well-terminated, low-capacitance layouts - though actual system-level timing depends on setup/hold margins, loading, and signal integrity. The SN74S175N remains functional at lower frequencies including DC.

Does SN74S175N support mixed-voltage interfacing with 3.3 V logic?

No, SN74S175N is strictly a 5 V-only device with VCC range 4.75 V to 5.25 V and TTL input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V). While its outputs may be safely clamped when driving 3.3 V inputs using external resistors or level translators, direct connection risks overvoltage damage to 3.3 V receivers and violates absolute maximum ratings. SN74S175N must be used in 5 V-only domains or with proper level-shifting circuitry.

Can SN74S175N replace SN74LS175N on the same PCB without modifications?

Yes, SN74S175N is pin-compatible and functionally identical to SN74LS175N in PDIP-16 packaging, sharing identical pinout, logic behavior, and DC voltage levels. However, SN74S175N draws nearly double the supply current (38 mA vs. 19 mA) and generates more heat - requiring verification of local power delivery and thermal margin. No PCB changes are needed, but system-level power and thermal validation is essential before substitution.

What is the purpose of the Q̄ (complement) outputs on SN74S175N?

The Q̄ outputs on SN74S175N provide logically inverted versions of each flip-flop's stored state, eliminating the need for external inverters in applications such as toggle-mode counters, enable/disable logic, or differential bus driving. For example, Q1 and Q1̄ can simultaneously drive SET and RESET inputs of an SR latch, or serve as true/complement pairs for dynamic logic evaluation - reducing component count and propagation delay in registered feedback paths.

Is SN74S175N RoHS compliant?

Yes, the SN74S175N variant offered by Texas Instruments is RoHS compliant, featuring lead-free NiPdAu (NIPDAU) lead finish and meeting JEDEC J-STD-020 moisture sensitivity Level-1 rating. Its PDIP packaging uses halogen-free molding compound, and the device carries the "E4" suffix in some ordering options (e.g., SN74S175NE4) to explicitly denote RoHS compliance. Always verify the specific date code and packaging marking against TI's official product change notices.