Texas Instruments SN74LVTH574RGYR

Overview

SN74LVTH574RGYR from Texas Instruments is an octal edge-triggered D-type flip-flop with 3-state outputs, designed for 3.3-V ABT logic operation while supporting 5-V TTL-level inputs and outputs. It features bus-hold on all data inputs, I_off and power-up 3-state for hot insertion, and operates down to 2.7 V for unregulated battery systems. Used in high-speed data latching and bus interface applications in industrial control and communications backplanes.

For engineers reviewing the SN74LVTH574RGYR datasheet, SN74LVTH574RGYR pinout, SN74LVTH574RGYR application, or SN74LVTH574RGYR equivalent, key selection criteria include its 20-pin VQFN (RGY) package, 150-MHz maximum clock frequency, 2.4-ns setup time at 3.3 V, bus-hold input retention, and compatibility with mixed-voltage 3.3-V/5-V system interconnects.

Technical Context

This device implements eight independent positive-edge-triggered D flip-flops with a shared clock (CLK) and buffered output-enable (OE) control. Each flip-flop captures the logic state of its D input on the rising edge of CLK and holds it until the next clock edge.

The 3-state outputs support high-impedance mode when OE is high, enabling bidirectional bus driving without external pull resistors. Bus-hold circuitry actively maintains valid logic levels on unused D inputs, eliminating need for external biasing - a critical feature for robustness in floating-bus environments.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 3.5 mm × 4.5 mm, 0.5-mm pitch, 1-mm max height, with exposed thermal pad (Pin 21) requiring PCB solder connection for thermal and mechanical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC574APWR and 74ALVCH162374GR, the SN74LVTH574RGYR uniquely combines 5-V input tolerance, bus-hold, I_off, and 150-MHz performance in a compact 20-pin VQFN - making it the only option qualified for hot-pluggable, mixed-voltage industrial backplane designs without additional support circuitry.

Availability

SN74LVTH574RGYR is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and communications infrastructure requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LVTH574RGYR 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 decades of experience in high-reliability industrial and automotive-grade components.

The SN74LVTH574RGYR belongs to TI's ABT (Advanced BiCMOS Technology) logic family, engineered for high-speed, low-voltage operation with robust mixed-signal interfacing - specifically targeting industrial backplanes, telecom infrastructure, and automotive control modules.

FAQ

What is the operating temperature range for SN74LVTH574RGYR?

The SN74LVTH574RGYR is rated for −40°C to +85°C ambient operating temperature, matching industrial-grade requirements. This range is confirmed in the "recommended operating conditions" table of the SCBS688G datasheet and applies specifically to the RGY package variant. The device maintains full electrical specifications-including 150-MHz clock operation and 2.4-ns setup time-across this entire range.

Does SN74LVTH574RGYR support hot insertion, and how is it implemented?

Yes, SN74LVTH574RGYR supports hot insertion via two integrated features: I_off circuitry disables outputs when VCC = 0 V (preventing back-current), and power-up 3-state forces outputs into high-impedance during power ramp-up. These functions are explicitly documented in the "Features" section and validated per JESD 78 latch-up and JESD 22 ESD standards - ensuring safe live-board replacement in telecom and server chassis.

Can SN74LVTH574RGYR interface directly with 5-V logic systems?

Yes, SN74LVTH574RGYR supports true mixed-mode operation: its inputs accept 0–5.5 V signals and outputs drive 5-V-tolerant loads while powered from 3.3 V. This is achieved through ABT input structure and overvoltage-tolerant output buffers - verified by absolute maximum ratings (VI up to 7 V) and functional testing in the datasheet's "Support Mixed-Mode Signal Operation" feature statement.

What is the purpose of the exposed thermal pad (Pin 21) on the RGY package?

The exposed thermal pad (Pin 21) on SN74LVTH574RGYR is not electrically connected but serves critical thermal and mechanical functions: it must be soldered to a PCB copper pour to achieve the specified θ_JA = 37 °C/W and ensure reliable operation under sustained 64-mA output loading. TI's RGY package documentation (SLUA271) mandates this connection - omission risks thermal shutdown or accelerated parametric drift.

How does bus-hold functionality work on SN74LVTH574RGYR, and what design impact does it have?

SN74LVTH574RGYR integrates active bus-hold circuitry on all eight D inputs, drawing ±500 µA to retain the last-valid logic state when inputs float. This eliminates mandatory external pullup/pulldown resistors - reducing BOM cost, PCB real estate, and potential noise coupling. Per datasheet Section 6, using external resistors with enabled bus-hold is explicitly discouraged due to conflict risk.