Texas Instruments CD74HC573E

Overview

CD74HC573E from Texas Instruments is an octal transparent D-type latch with 3-state outputs, designed for bus interface and data hold functions in 2-V to 6-V digital systems. It features latch-enable (LE) and output-enable (OE) control, operates across –55°C to 125°C, supports up to 15 LS-TTL loads, and delivers balanced propagation delays (30–45 ns at 6 V). It is commonly used in microcontroller I/O expansion and address/data bus latching.

For engineers reviewing the CD74HC573E datasheet, CD74HC573E pinout, CD74HC573E application, or CD74HC573E equivalent, key selection criteria include its 3-state bus-driving capability, wide supply voltage range, industrial temperature rating, and compatibility with HC logic families in memory-mapped peripheral interfacing.

Technical Context

The CD74HC573E implements eight independent D-type transparent latches with synchronous parallel loading controlled by LE: when LE is high, Q follows D; when LE goes low, outputs retain the last D value. Its OE input independently places all eight outputs into high-impedance state without affecting internal latch operation.

This architecture enables non-intrusive bus sharing-data can be latched while outputs remain tri-stated-and supports hot-swap-safe operation when OE is pulled high during power-up. Timing parameters are fully specified across –55°C to 125°C, with tpd ≤ 45 ns (6 V), tsu ≥ 11 ns, and th ≥ 9 ns.

Key Specifications

Pinout & Package

CD74HC573E uses a 20-pin PDIP (Plastic Dual In-line Package) with 0.300-inch body width and 0.100-inch lead pitch. Pin 1 is marked by a notch or dot; package meets JEDEC MS-001 standards and is RoHS-compliant with NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC573N and MC74HC573ADW, CD74HC573E provides the widest temperature range and tightest propagation delay specification, making it the preferred choice for mission-critical industrial and aerospace latching where reliability and timing determinism are non-negotiable.

Availability

CD74HC573E is available at Aetrix Electronics and suitable for microcontroller I/O expansion, memory-mapped peripheral interface, industrial PLC modules, and test equipment digital pattern generation requiring stable component supply across extended temperature ranges.

Supply support for CD74HC573E 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 reliable, high-performance ICs.

The CD74HC573E belongs to TI's CD74HC high-speed CMOS logic family, engineered for robust bus-interface applications in industrial, automotive, and defense systems demanding wide voltage operation and extreme temperature resilience.

FAQ

What is the maximum clock-equivalent frequency supported by CD74HC573E?

The CD74HC573E does not operate on a clock signal but responds to LE and OE edges. Its maximum usable data rate is governed by tpd (≤45 ns at 6 V) and tsu/th (≥11 ns/≥9 ns), enabling reliable operation in systems with bus cycle times ≥100 ns - equivalent to 10 MHz sustained throughput in transparent-latch mode. CD74HC573E timing is fully characterized from –55°C to 125°C.

Can CD74HC573E drive a 50-pF bus load while maintaining timing specifications?

Yes. All switching characteristics in the CD74HC573E datasheet - including tpd, ten, and tdis - are measured with CL = 50 pF, matching typical PCB trace + receiver input capacitance. At 6 V, CD74HC573E achieves tpd ≤ 45 ns and ten ≤ 33 ns under this exact load condition, ensuring guaranteed timing compliance in real-world layouts.

Is CD74HC573E pin-compatible with CD74HC373?

No. CD74HC573E and CD74HC373 share functional similarity but differ in pinout: CD74HC373 uses OE on pin 1 and LE on pin 11, whereas CD74HC573E places OE on pin 10 and LE on pin 11. Swapping them without board revision causes incorrect logic behavior. CD74HC573E is pin-compatible only with SN74HC573N and MC74HC573ADW.

How should unused inputs be handled on CD74HC573E?

All unused D inputs on CD74HC573E must be tied to a valid logic level - either VCC or GND - to prevent floating nodes that cause increased ICC, erratic output states, or EMI. OE and LE should never float; OE is typically pulled high via resistor to VCC for default high-Z on power-up, and LE is driven actively by controller logic.

Does CD74HC573E support mixed-voltage operation between input and output sides?

No. CD74HC573E is a single-supply device: all inputs and outputs reference the same VCC rail (2–6 V). It does not provide level translation. For mixed-voltage interfaces (e.g., 3.3 V MCU driving 5 V bus), external level-shifting circuitry or a dedicated translator IC is required upstream of CD74HC573E inputs.