Diodes Incorporated 74LVC573AQ20-13

Overview

74LVC573AQ20-13 from Diodes Incorporated is an octal transparent D-type latch with 3-state outputs in a 20-pin V-QFN4525-20 package, operating from 1.65V to 3.6V supply, supporting 5.5V-tolerant inputs and ±24mA output drive at 3.0V. It functions as a bus-isolated data latching interface in mixed-voltage digital systems such as notebook motherboard I/O expansion.

For engineers reviewing the 74LVC573AQ20-13 datasheet, 74LVC573AQ20-13 pinout, 74LVC573AQ20-13 application, or 74LVC573AQ20-13 equivalent, key selection criteria include latch-enable timing (tSU = 1.0–4.0 ns), 3-state enable/disable speed (tEN/tDIS ≤ 9.5 ns at 3.3V), IOFF partial-power-down capability, and V-QFN thermal resistance (θJA = 67°C/W).

Technical Context

This device implements eight independent edge-transparent D-latches with asynchronous 3-state control via separate LE (latch-enable) and OE (output-enable) inputs. LE controls data capture timing while OE independently places outputs in high-impedance without affecting internal latch state - enabling concurrent data retention and bus release.

It features true 5.5V-tolerant inputs on all pins, IOFF circuitry that disables outputs during power-down to prevent backflow current, and Schmitt-trigger inputs for noise immunity. The V-QFN4525-20 package supports high-density PCB layout with exposed thermal pad and 0.50 mm pitch.

Key Specifications

Pinout & Package

V-QFN4525-20 package: 2.5 mm × 4.5 mm × 0.95 mm body, 0.50 mm lead pitch, exposed thermal pad (pin 20), JEDEC-compliant footprint per AP02001.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal transparent latch applications.

Compared with SN74LVC573APWR, the 74LVC573AQ20-13 delivers 10% lower thermal resistance and smaller footprint; versus 74LVCH16373ADGG, it avoids unnecessary pin count and leakage overhead for pure 8-bit latching tasks.

Availability

74LVC573AQ20-13 is available at Aetrix Electronics and suitable for notebook motherboard I/O expansion, industrial PLC digital input modules, and network switch management ASIC interfaces requiring stable component supply across extended temperature and long production lifecycles.

Supply support for 74LVC573AQ20-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, low-power, and mixed-signal solutions for computing, industrial, and communications markets.

The 74LVC logic family targets cost-sensitive, space-constrained applications needing 1.65–3.6V operation, 5.5V tolerance, and robust ESD/latch-up performance - optimized for portable and embedded digital systems.

FAQ

Can 74LVC573AQ20-13 operate reliably at 1.65V supply while driving 24mA loads?

No. At VCC = 1.65V, the maximum guaranteed output drive is ±4mA (IOL/IOH). Full ±24mA capability is specified only at VCC ≥ 3.0V. Operating at 1.65V with heavy loads violates the Recommended Operating Conditions table and risks VOL/VOH violations beyond 0.45V/1.2V limits.

Does OE assertion affect internal latch state when LE is low?

No. The OE input controls only the output drivers - it has no effect on the internal latch storage elements. When LE is low, Q outputs retain their last captured D-input values regardless of OE state; OE simply determines whether those values appear on the pins or enter high-impedance.

Is the exposed thermal pad on V-QFN4525-20 electrically connected internally?

No. The exposed pad (terminal 20) is a mechanical thermal interface only - it is not connected to any internal die node. Per Diodes' AP02002, it must be soldered to a dedicated PCB thermal plane tied to GND for optimal θJA performance, but no electrical connection is required or recommended.

What is the minimum pulse width required on LE for reliable latching at 125°C?

The minimum LE pulse width (tW) is 5.5 ns at VCC = 1.8V and TA = –40°C to +125°C. At 125°C ambient, this value applies directly - no derating is needed. Pulse widths below 5.5 ns risk metastability or incomplete capture, especially under worst-case voltage and process corners.