Texas Instruments SN74AS175BDRG4

Overview

SN74AS175BDRG4 from Texas Instruments is a quad D-type flip-flop with complementary (Q and Q̅) outputs, direct-clear input, and positive-edge clock triggering. It operates at 5 V, supports 100 MHz maximum clock frequency, delivers ±2 mA output drive, and features fully buffered inputs/outputs for noise immunity in TTL-compatible systems. It is used in synchronous data latching within industrial control registers and digital pattern generators.

For engineers reviewing the SN74AS175BDRG4 datasheet, SN74AS175BDRG4 pinout, SN74AS175BDRG4 application, or SN74AS175BDRG4 equivalent, key selection criteria include its 4-bit double-rail storage capability, 3.5 ns typical CLK-to-Q propagation delay, 3 ns setup time, and SOIC-16 package compatibility with legacy TTL board layouts.

Technical Context

This device implements four independent edge-triggered D flip-flops using advanced Schottky (AS) TTL circuitry. Each stage includes buffered clock and clear inputs, plus true/complement outputs - enabling simultaneous access to both logic states without external inverters.

It requires strict adherence to setup (3 ns min) and hold (1 ns min) timing relative to the rising clock edge. Output switching is characterized under 50 pF load and 500 Ω termination, with VOL ≤ 0.5 V at IOL = 20 mA and VOH ≥ VCC–2 V at IOH = –2 mA.

Key Specifications

Pinout & Package

SN74AS175BDRG4 is housed in a 16-pin SOIC (D) package with 1.27 mm pitch, 7.5 mm body width, and 2.00 mm max height - suitable for automated SMT assembly and space-constrained PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALS175DR, SN74AS175BDRG4 delivers 2× clock speed and 4.3× faster propagation - critical for real-time response; versus SN74AS174DR, it trades two extra bits for guaranteed Q/Q̅ pairs per stage, simplifying differential signaling and state machine design.

Availability

SN74AS175BDRG4 is available at Aetrix Electronics and suitable for industrial control registers, digital pattern generators, buffer/storage registers, and shift register stages requiring stable component supply and long-term obsolescence management.

Supply support for SN74AS175BDRG4 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 markets.

SN74AS175BDRG4 belongs to TI's 74AS logic family - engineered for high-speed, low-noise TTL-compatible digital interfacing in demanding industrial and test equipment applications.

FAQ

What is the function of the CLR pin on SN74AS175BDRG4?

The CLR (clear) pin on SN74AS175BDRG4 is an active-low asynchronous input that forces all four flip-flop outputs (Q and Q̅) to their reset states-Q = LOW and Q̅ = HIGH-regardless of clock or data conditions. This allows immediate, deterministic initialization of the entire register without waiting for a clock edge, which is essential for system startup and fault recovery sequences in SN74AS175BDRG4-based designs.

Does SN74AS175BDRG4 support mixed-voltage interfacing with 3.3 V logic?

SN74AS175BDRG4 is designed for 5 V operation and does not support direct 3.3 V logic interfacing. Its VIH minimum is 2.0 V and VIL maximum is 0.8 V, but input structures are TTL-compatible-not 3.3 V CMOS tolerant. Driving SN74AS175BDRG4 from 3.3 V outputs may result in marginal or non-functional high-level recognition; level-shifting or buffer ICs are required for reliable interoperation with 3.3 V systems using SN74AS175BDRG4.

What is the recommended decoupling for SN74AS175BDRG4?

A 0.1 µF ceramic capacitor placed as close as possible between VCC (pin 16) and GND (pin 8) is the minimum recommended decoupling for SN74AS175BDRG4. For boards with multiple AS-family devices or high-frequency clock distribution, adding a bulk 4.7 µF–10 µF tantalum or aluminum electrolytic capacitor nearby further stabilizes the 5 V rail and suppresses switching noise induced by SN74AS175BDRG4's fast edges and 22.5–34 mA ICC consumption.

Can SN74AS175BDRG4 be used in place of SN74AS174DR?

No-SN74AS175BDRG4 and SN74AS174DR are not functionally interchangeable. SN74AS175BDRG4 provides four flip-flops with dual-rail (Q/Q̅) outputs, while SN74AS174DR offers six flip-flops with single-rail (Q-only) outputs. Their pinouts differ significantly: SN74AS175BDRG4 dedicates pins to Q̅ outputs, whereas SN74AS174DR uses those positions for additional Q outputs. Substituting one for the other would require PCB redesign and logic re-architecting in any SN74AS175BDRG4 application.

What is the meaning of "B" in SN74AS175BDRG4?

The "B" suffix in SN74AS175BDRG4 denotes a specific revision of the SN74AS175 device with enhanced electrical characteristics and updated internal design-particularly improved propagation delay consistency and tighter timing parameter distributions compared to earlier versions. This revision is explicitly documented in TI's SDAS207E datasheet and applies to all package variants including SN74AS175BDRG4, confirming its qualification for high-reliability timing-critical applications.