Texas Instruments SN74LV574APW

Overview

SN74LV574APW from Texas Instruments is an octal edge-triggered D-type flip-flop with 3-state outputs, designed for 2 V to 5.5 V operation. It features 7.1 ns maximum propagation delay at 5 V, Ioff partial-power-down support, and balanced CMOS 3-state drivers optimized for bus interfacing in LED displays and network switches.

For engineers reviewing the SN74LV574APW datasheet, SN74LV574APW pinout, SN74LV574APW application, or SN74LV574APW equivalent, this page delivers verified electrical specs, TSSOP-20 pin mapping, real-world timing behavior across VCC = 2.5/3.3/5 V, noise immunity data (VOLP < 0.8 V, VOHV > 2.3 V at 3.3 V), and validated alternative options for I/O expansion and register buffering.

Technical Context

The SN74LV574APW implements eight independent D-type latches triggered on the positive clock edge, with a dedicated active-low output-enable (OE) controlling all eight outputs simultaneously. Its 3-state outputs support mixed-mode voltage operation and tolerate 5 V inputs while operating from 2–5.5 V VCC.

It integrates Ioff circuitry to disable outputs during power-down, preventing backflow current, and uses balanced CMOS output stages capable of ±16 mA drive at 5 V. Timing parameters-including setup (3.5 ns min at 3.3 V), hold (1.5 ns min), and pulse width (5 ns min)-are fully specified across –40°C to 125°C.

Key Specifications

Pinout & Package

TSSOP-20 package (5.0 × 4.4 mm body size), lead-free, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV574APW, SN74LVC574APW trades 5 V input compatibility for improved speed and lower power in 3.3 V-only systems, while 74LVX574M offers higher drive strength at the expense of industrial temperature qualification-making SN74LV574APW the optimal choice for mixed-voltage, extended-temperature, and noise-sensitive bus interfaces.

Availability

SN74LV574APW is available at Aetrix Electronics and suitable for LED displays, network switches, and telecom infrastructure requiring stable component supply across extended temperature ranges and mixed-voltage interoperability.

Supply support for SN74LV574APW 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 expertise in high-reliability interface and timing products.

The SN74LV574A product line was engineered for robust, low-noise bus interfacing in industrial and communications equipment-emphasizing mixed-voltage compatibility, Ioff safety, and precise edge-triggered data capture.

FAQ

What is the maximum clock frequency supported by the SN74LV574APW?

The SN74LV574APW supports up to 130 MHz maximum clock frequency at 5 V with CL = 15 pF, and 85 MHz at 5 V with CL = 50 pF. These values derive from its 4.8 ns minimum clock pulse width and 4.8 ns typical propagation delay at 5 V. Actual usable frequency depends on load capacitance, PCB routing, and supply stability-TI recommends limiting output load to ≤50 pF for guaranteed timing compliance. The SN74LV574APW maintains functional operation across its full –40°C to 125°C range.

Does the SN74LV574APW support partial power-down, and how is it implemented?

Yes, the SN74LV574APW supports partial power-down via its Ioff feature. When VCC = 0 V, internal circuitry disables all outputs, limiting leakage current to ≤5 µA per I/O terminal regardless of input or output voltage (0–5.5 V). This prevents damaging reverse current flow during hot-swap or subsystem power gating. The SN74LV574APW retains its last-latched data state during Ioff, and normal operation resumes immediately upon VCC restoration-no reset sequence required. This behavior is verified per JESD78 latch-up testing.

Can the SN74LV574APW accept 5 V inputs while operating at 3.3 V VCC?

Yes, the SN74LV574APW accepts input voltages up to 5.5 V independent of VCC, enabling true 5 V-tolerant operation at 3.3 V or 2.5 V supply. This is confirmed in Section 6.3 (Recommended Operating Conditions) and Table 6.1 (Absolute Maximum Ratings), where VI(max) = 7 V and VIH/VIL thresholds scale with VCC. The SN74LV574APW uses robust input clamp diodes (Figure 8-2) and is rated for ±2000 V HBM ESD-making it suitable for interfacing with legacy 5 V logic without external level shifters in mixed-voltage systems.

What is the purpose of the OE pin on the SN74LV574APW, and how should it be used during power-up?

The OE (output enable) pin on the SN74LV574APW is an active-low control that places all eight Q outputs in high-impedance state when asserted, without affecting internal latch states. To ensure defined outputs during power-up, TI recommends tying OE to VCC via a pullup resistor (minimum value determined by driver sink capability). The SN74LV574APW's Ioff feature guarantees safe OE behavior even if VCC ramps slowly-the SN74LV574APW will not source or sink current from OE until VCC stabilizes, preventing bus contention during sequencing.

How does the SN74LV574APW mitigate ground bounce and output undershoot in high-speed switching?

The SN74LV574APW mitigates ground bounce (VOLP) and output undershoot (VOHV) through controlled output drive strength and optimized internal layout. At 3.3 V, typical VOLP is <0.8 V and VOHV exceeds 2.3 V-verified under CL = 50 pF, TA = 25°C conditions (Section 6.12). These values result from balanced CMOS output stage design and internal slew-rate limiting, reducing simultaneous switching noise. The SN74LV574APW achieves this without external series resistors, simplifying layout for LED display and telecom applications where signal integrity is critical.