STMicroelectronics M74HC573B1R

Overview

M74HC573B1R from STMicroelectronics is a high-speed CMOS octal D-type transparent latch with 3-state non-inverting outputs in 20-pin plastic DIP package. It features 13 ns typical propagation delay at 6 V, ±6 mA output drive, 2 V to 6 V operating voltage, and pin/function compatibility with standard 74-series 573 devices. Used for bidirectional bus interfacing in industrial control and embedded data acquisition systems.

For engineers reviewing the M74HC573B1R datasheet, M74HC573B1R pinout, M74HC573B1R application, or M74HC573B1R equivalent, key selection criteria include latch enable timing (tW(L) = 7 ns min at 6 V), 3-state output disable time (tPHZ = 13 ns max), symmetrical output impedance, wide VCC range, and high noise immunity (VNIH/VNIL = 28% VCC min).

Technical Context

The M74HC573B1R implements an 8-bit transparent latch architecture controlled by independent LE (latch enable, active-high) and OE (output enable, active-low) inputs. Its C2MOS silicon gate process enables low static current (ICC ≤ 4 µA at 25°C) while supporting rail-to-rail input/output operation across 2–6 V.

Propagation delays are balanced (tPLH ≅ tPHL), and output transition times remain consistent across supply voltages (6 ns typ at 6 V, CL = 50 pF). The device integrates input protection diodes and supports high-impedance bus sharing via fast output enable/disable (tPZH = 14 ns, tPHZ = 15 ns at 6 V).

Key Specifications

Pinout & Package

Package: Plastic Dual In-line Package (DIP-20), 0.3 inch body width, through-hole mounting. Pin pitch: 2.54 mm. RoHS-compliant 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 74VHC573N, the M74HC573B1R offers superior cold-temperature performance (-55°C), lowest ICC (4 µA max), and guaranteed 28% noise margin - making it optimal for long-life, wide-temperature industrial deployments.

Availability

M74HC573B1R is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy bus interface adapters, and embedded data acquisition modules requiring stable component supply across extended temperature ranges and multi-decade product lifecycles.

Supply support for M74HC573B1R 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with vertical manufacturing capability and AEC-Q100 qualified processes.

The M74HC573B1R belongs to ST's high-speed HC logic family, designed specifically for robust, low-power, pin-compatible replacements of legacy 74-series logic in industrial control, instrumentation, and infrastructure equipment.

FAQ

What is the maximum operating frequency supported by the M74HC573B1R?

The M74HC573B1R does not specify a maximum clock frequency, as it is a transparent latch-not a clocked register. Its usable data rate depends on setup/hold timing: with tW(L) = 7 ns min and ts = 3 ns min at 6 V, it reliably supports bus cycles down to ~35 ns period (≈28 MHz), assuming proper PCB layout and load capacitance ≤50 pF.

Can M74HC573B1R operate safely at 3.3 V with 5 V-tolerant inputs?

No. The M74HC573B1R has standard CMOS inputs-not 5 V tolerant. At VCC = 3.3 V, VIH(min) = 2.31 V and VIL(max) = 0.99 V per datasheet. Applying 5 V signals risks damaging inputs. For mixed-voltage interfacing, use level translators or select 74LVC573 instead.

Is thermal derating required for continuous operation at 85°C?

Yes. Absolute maximum power dissipation drops from 500 mW at 65°C to 300 mW at 85°C, derated linearly at 10 mW/°C. At 85°C ambient, ensure total dynamic + static power remains ≤300 mW-achievable with typical loads (CL ≤ 50 pF, f ≤ 10 MHz) and proper PCB copper area for heat spreading.

Does the M74HC573B1R support hot insertion into a live bus?

No. While inputs include ESD protection diodes, the device lacks hot-swap circuitry or power-on reset. Inserting powered M74HC573B1R into a live bus may cause transient current surges, latch-up, or data corruption. Always power-cycle the board or isolate VCC/GND before insertion.