onsemi MC74F533N

Overview

MC74F533N from Motorola is an octal transparent latch with 3-state inverted outputs, designed for bus-oriented TTL systems. It features eight independent latches, 3-state output control via OE and LE pins, guaranteed 5V ±10% supply operation, 24 mA sink capability, and operates across 0°C to +70°C ambient temperature.

For engineers reviewing the MC74F533N datasheet, pinout, applications, or equivalent options, key selection considerations include its inverted output logic versus F373, 3-state bus interface timing (tPLH ≤ 4.0 ns), DC drive strength (IOL = 24 mA), and plastic DIP-20 packaging for through-hole mounting in legacy industrial control and data acquisition systems.

Technical Context

The MC74F533N implements eight edge-triggered-transparent latches with dual active-low control: Latch Enable (LE) enables transparency when HIGH and captures data on transition to LOW; Output Enable (OE) controls 3-state bus drive-LOW enables inverted outputs, HIGH places them in high-impedance state. Its inverted output architecture differentiates it functionally from the MC74F373.

Designed for FAST™ Schottky TTL compatibility, it meets strict DC electrical specs including VIH ≥ 2.0 V, VIL ≤ 0.8 V, VOL ≤ 0.5 V at IOL = 24 mA, and supports AC timing with tPZH ≤ 2.0 ns (enable time) and tPHZ ≤ 1.5 ns (disable time) under CL = 50 pF load conditions.

Key Specifications

Pinout & Package

MC74F533N uses a 20-pin plastic dual in-line package (PDIP), case 738-03, with 0.3-inch body width and standard through-hole footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC74F533N, MC74F373N delivers identical speed and drive but requires external inversion for functional equivalence, while SN74F573N offers true functional and mechanical compatibility with verified long-term availability from Texas Instruments.

Availability

MC74F533N is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy test equipment data paths, and automotive ECU diagnostic interfaces requiring stable component supply despite end-of-life status.

Supply support for MC74F533N 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

Motorola Semiconductor (now part of NXP Semiconductors) was a pioneer in TTL and advanced logic families, delivering high-reliability components for aerospace, automotive, and industrial markets.

The MC74F533N belongs to the 74F FAST™ Schottky TTL product line, engineered for high-speed, low-power bus interfacing in mission-critical embedded systems where timing predictability and noise immunity were essential.

FAQ

What is the function of the LE pin on the MC74F533N?

The LE (Latch Enable) pin on the MC74F533N is an active-HIGH control signal that determines latch transparency: when LE is HIGH, the device operates in transparent mode, passing D0–D7 directly to internal latches; when LE transitions LOW, the current input values are captured and held. This behavior is confirmed in the logic diagram and AC timing specifications, where setup and hold times (ts = 2.0 ns, th = 3.0 ns) are defined relative to the LE falling edge. The MC74F533N relies on this precise edge-sensitive capture for synchronous bus operations.

Does the MC74F533N have non-inverting or inverted outputs?

The MC74F533N has inverted outputs - O0 through O7 are logical complements of their corresponding D0 through D7 inputs. This is explicitly stated in the datasheet: "The F533 is the same as the F373, except that the outputs are inverted." The logic symbol and connection diagram confirm inverted output labeling (e.g., D0 → O0 with bubble). This inversion is intrinsic to the MC74F533N silicon design and cannot be disabled or bypassed.

What is the maximum operating temperature range for the MC74F533N?

The MC74F533N is rated for commercial-grade operation from 0°C to +70°C ambient temperature, as specified under the "74" prefix in the Guaranteed Operating Ranges table. This differs from the military-grade MC54F533J variant, which supports –55°C to +125°C. The MC74F533N's thermal limits are validated by DC and AC characterization across this range, including VOL ≤ 0.5 V and tPLH ≤ 10 ns at +70°C.

Can the MC74F533N be used with a 3.3 V supply?

No, the MC74F533N is not rated for 3.3 V operation. Its guaranteed supply voltage range is strictly 4.5 V to 5.5 V, and all DC and AC specifications - including VOH ≥ 2.7 V and VOL ≤ 0.5 V - are characterized only at VCC = 4.5–5.5 V. Applying 3.3 V violates the Absolute Maximum Ratings and will result in undefined logic states, excessive ICCZ current, or complete functional failure. For 3.3 V systems, consider modern CMOS alternatives like SN74LVC573A.

Is the MC74F533N pin-compatible with the SN74F573N?

Yes, the MC74F533N is pin-compatible with the SN74F573N: both are 20-pin PDIP devices with identical pin assignments for VCC (pin 20), GND (pins 9 and 10), D0–D7 (pins 1–8), O0–O7 (pins 11–18), LE (pin 19), and OE (pin 1). Their AC and DC electrical specifications are functionally identical, and Texas Instruments documents SN74F573N as a direct functional replacement. However, always verify solder profile and moisture sensitivity level (MSL) differences before substitution in production.