onsemi MC74AC533N

Overview

MC74AC533N from ON Semiconductor is an octal transparent latch with 3-state inverted outputs, designed for bus-oriented digital systems. It features eight D-type latches, TTL-compatible inputs (per AC/ACT family), 5 V supply operation, and high-speed propagation delays down to 10 ns. It serves as a bidirectional bus interface buffer in microprocessor data bus applications.

For engineers reviewing the MC74AC533N datasheet, pinout, applications, or equivalent options, key selection criteria include latch enable timing (min 4.5 ns LE pulse width), output disable time (≤11.0 ns), 3-state current leakage (±5.0 µA), and compatibility with 50 pF load bus environments.

Technical Context

The MC74AC533N implements eight independent D-type transparent latches with active-low output enable (OE) and active-high latch enable (LE). When LE is HIGH, inputs D0–D7 pass directly to inverted outputs O0–O7; when LE goes LOW, the input state at that instant is captured and held until the next LE transition.

Its 3-state outputs support bus sharing by entering high-impedance mode when OE is HIGH. Unlike the MC74AC373, the MC74AC533N provides complementary (inverted) outputs - O0 = NOT(D0), etc. - enabling direct connection to inverting bus receivers without external inverters.

Key Specifications

Pinout & Package

MC74AC533N is housed in a 20-pin plastic dual in-line package (PDIP), case 738-03, with 0.3-inch width and through-hole mounting. Pin 1 is index corner, Pin 10 is GND, Pin 20 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC74ACT533N and SN74AC573N, the MC74AC533N uniquely delivers inverted outputs with AC-family speed and 2–6 V flexibility - making it optimal for legacy bus designs requiring polarity inversion without added gates.

Availability

MC74AC533N is available at Aetrix Electronics and suitable for microprocessor bus interfacing, memory address latching, and industrial PLC I/O expansion requiring stable component supply and long-term industrial-grade availability.

Supply support for MC74AC533N 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient, high-performance silicon solutions for automotive, industrial, cloud, and IoT applications.

The MC74AC533N belongs to the 74AC logic family - engineered for high-speed, low-power 5 V CMOS operation with TTL-compatible inputs and robust noise immunity in real-world industrial systems.

FAQ

What is the maximum clock frequency supported by the MC74AC533N?

The MC74AC533N is not a clocked register but a transparent latch controlled by LE and OE. Its usable data rate depends on propagation delay (10.0 ns max Dn→On @ 5 V) and setup/hold timing (ts = 4.5 ns, th = 1.0 ns). In practice, it supports reliable bus toggling up to approximately 50 MHz when used with appropriate timing margins and 50 pF loads.

Does the MC74AC533N support 3.3 V operation?

Yes, the MC74AC533N is fully specified for 3.3 V operation (VCC = 3.0–3.6 V per Recommended Operating Conditions). At 3.3 V, VIH = 2.1 V and VIL = 0.9 V ensure compatibility with 3.3 V LVTTL and mixed-voltage interfaces, with propagation delay increasing to 16.0 ns max (CL = 50 pF).

How does the MC74AC533N differ from the MC74AC373N?

The MC74AC533N is functionally identical to the MC74AC373N except for output polarity: MC74AC533N provides inverted outputs (O0 = NOT D0), whereas MC74AC373N provides true outputs. Both share identical pinout, timing, drive strength, and DC specifications - making them drop-in replacements where inversion is acceptable or required.

What is the purpose of the LE and OE pins on the MC74AC533N?

LE (Latch Enable) controls data transparency: when HIGH, D0–D7 pass through to O0–O7; on the falling edge, the current input state is latched. OE (Output Enable) controls bus access: when LOW, inverted latched data appears on O0–O7; when HIGH, all outputs enter high-impedance mode. This dual-control allows independent data capture and bus release timing in the MC74AC533N.

Is the MC74AC533N RoHS compliant and lead-free?

Yes, the MC74AC533N (N suffix) is manufactured in a lead-free, RoHS-compliant PDIP package per ON Semiconductor's standard industrial product line. The "N" suffix explicitly denotes lead-free finish and green molding compound, meeting JEDEC J-STD-020 and EU RoHS Directive 2011/65/EU requirements.