Nexperia USA Inc. 74HCT573BQ,115

Overview

74HCT573BQ,115 from Nexperia is an octal D-type transparent latch with 3-state outputs, designed for bus-oriented digital systems requiring data latching and controlled output isolation. It features TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), operates from 4.5 V to 5.5 V, supports -40 °C to +125 °C ambient range, and delivers propagation delay of 20–53 ns (Dn→Qn) under 50 pF load. It serves as an I/O port interface in microprocessor-based control systems.

For engineers reviewing the 74HCT573BQ,115 datasheet, 74HCT573BQ,115 pinout, 74HCT573BQ,115 application, or 74HCT573BQ,115 equivalent, key selection criteria include its TTL-level input compatibility, 3-state output enable timing (ten = 17–45 ns), latch transparency behavior under LE HIGH, thermal-enhanced DHVQFN20 package (2.5 × 4.5 × 0.85 mm), and guaranteed operation across industrial and extended temperature ranges.

Technical Context

The 74HCT573BQ,115 implements eight independent D-type latches with shared LE (latch enable, active HIGH) and OE (output enable, active LOW) controls. Its TTL-compatible inputs allow direct interfacing with legacy 5 V logic families without level translation, while CMOS output drivers provide rail-to-rail swing and 3-state capability for bidirectional bus sharing.

Operation is strictly defined by the function table: when LE = HIGH, Qn follows Dn (transparent mode); when LE transitions LOW, data is latched; OE independently places outputs in high-impedance state without affecting latch contents. Input clamp diodes support safe interfacing with voltages exceeding VCC when used with current-limiting resistors.

Key Specifications

Pinout & Package

DHVQFN20 (SOT764-1) package: 2.5 mm × 4.5 mm × 0.85 mm body, 20-terminal quad flat no-lead with exposed thermal pad; optimized for high-density PCB layouts and improved thermal performance over SO20/TSSOP20 variants.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT573PWR and 74LVC573APW,118, the 74HCT573BQ,115 uniquely combines 5 V TTL compatibility, extended temperature operation, and thermally optimized QFN packaging-making it optimal for retrofitting legacy industrial hardware and space-constrained 5 V embedded controllers.

Availability

74HCT573BQ,115 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller parallel port interfacing, and legacy system bus isolation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT573BQ,115 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

Nexperia is a global semiconductor expert focused on essential semiconductors for power management, logic, analog, and MOSFET solutions, serving automotive, industrial, computing, and consumer markets with high-reliability components.

The 74HCT573BQ,115 belongs to Nexperia's 74HCT logic family, engineered specifically for robust 5 V TTL-compatible interfacing in industrial automation, factory control, and instrumentation systems where noise immunity and wide temperature operation are critical.

FAQ

What is the maximum clock frequency supported by the 74HCT573BQ,115?

The 74HCT573BQ,115 is not a clocked register but a transparent latch with no internal clock input. Its effective data throughput depends on LE pulse width (min 4 ns at VCC = 4.5 V) and propagation delay (20–53 ns). For repetitive latching, the minimum LE period is ~100 ns, supporting up to 10 MHz burst rates in tightly timed systems.

Can the 74HCT573BQ,115 be used with a 3.3 V microcontroller?

No - the 74HCT573BQ,115 requires 4.5–5.5 V supply and has TTL input thresholds (VIH ≥ 2.0 V), but its outputs swing rail-to-rail at 5 V. Direct connection to 3.3 V logic risks overvoltage damage. A level-shifting buffer or 3.3 V–compatible alternative like 74LVC573 is required for 3.3 V systems.

Is the thermal pad on the DHVQFN20 package required to be soldered?

The exposed thermal pad (terminal 1 index area) has no electrical function and may remain unsoldered. If soldered, it must be either left electrically floating or connected to GND - never to VCC or any other voltage. Proper pad layout and solder paste stencil design are essential to ensure mechanical reliability and thermal performance.

How does the 74HCT573BQ,115 differ from the 74HC573 variant?

The 74HCT573BQ,115 uses TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), enabling direct interface with 5 V TTL and older microcontrollers. The 74HC573 uses CMOS thresholds (VIH ≈ 0.7×VCC), requiring ≥3.15 V for reliable HIGH detection at 4.5 V supply - making the HCT version more robust in mixed-logic or marginal-noise environments.