onsemi MC33269T-012G

Overview

MC33269T-012G from onsemi is a fixed-output, low-dropout linear voltage regulator delivering 12 V at up to 800 mA, featuring 1.0 V dropout at 500 mA, ±1% output voltage tolerance, and integrated thermal shutdown and short-circuit protection. It is housed in a TO-220AB package and designed for automotive and industrial power supply applications where input voltage margin is constrained.

For engineers reviewing the MC33269T-012G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage under load, thermal resistance (θ_JC = 5.0 °C/W), output stability with ≥10 µF output capacitance, and compatibility with 20 V maximum input voltage.

Technical Context

The MC33269T-012G employs a composite PNP–NPN pass transistor architecture enabling low dropout operation while maintaining robust current limiting and thermal foldback. Its internal reference is trimmed to 1.25 V with ±1% accuracy over temperature and load, supporting stable regulation across −40°C to +125°C ambient.

Unlike standard LDOs, it does not require an external bypass capacitor for stability but mandates ≥10 µF output capacitance with ESR between 0.2 Ω and 10 Ω. Ripple rejection is 55 dB at 120 Hz, and line/load regulation are specified at ≤0.3% and ≤0.5%, respectively.

Key Specifications

Pinout & Package

MC33269T-012G uses the TO-220AB (Case 221AB) package with exposed heatsink tab electrically connected to Pin 2 (V_OUT). The package provides low thermal resistance (θ_JC = 5.0 °C/W) and mechanical mounting capability via the tab.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Compared with LM2940CT-12/NOPB, MC33269T-012G offers 8× lower quiescent current and AEC-Q100 compliance; compared with NCV33269T-012G, it lacks automotive-specific process controls but shares identical performance and footprint - ideal for industrial and medical designs requiring automotive-grade margins without certification overhead.

Availability

MC33269T-012G is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and medical diagnostic equipment requiring stable component supply and long-term manufacturability.

Supply support for MC33269T-012G 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

onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The MC33269 series was developed to address low-input-margin linear regulation needs in automotive and industrial environments, emphasizing dropout performance, thermal robustness, and AEC-Q100-ready variants.

FAQ

What is the maximum input voltage rating for MC33269T-012G?

The MC33269T-012G has an absolute maximum input voltage of 20 V. However, due to its 12 V nominal output, the input–output differential is limited to 8.0 V maximum per datasheet Note 1 - meaning the practical maximum input is 20 V, but sustained operation above 13.35 V at full load should consider thermal limits. This constraint ensures safe junction temperature under worst-case power dissipation.

Does MC33269T-012G require an external output capacitor, and what type is recommended?

Yes, MC33269T-012G requires an external output capacitor of at least 10 µF with ESR between 0.2 Ω and 10 Ω for stability. Tantalum or aluminum electrolytic capacitors meeting these ESR specifications are recommended; low-ESR ceramic capacitors may cause oscillation and are not advised unless validated per Figure 11 application circuit guidelines in the datasheet.

Is MC33269T-012G pin-compatible with other packages in the MC33269 family?

No - MC33269T-012G uses the TO-220AB (3-pin) package with heatsink tab tied to Pin 2 (V_OUT), whereas SO-8 (D suffix), DPAK (DT suffix), and SOT-223 (ST suffix) variants have different pin counts, layouts, and thermal paths. Electrical functionality is identical, but PCB layout and thermal design are not interchangeable.

What is the thermal shutdown threshold and behavior of MC33269T-012G?

MC33269T-012G activates thermal shutdown at approximately 170°C junction temperature. The circuit disables the output with no hysteresis, causing output oscillation if overheating persists. This is a fault-protection feature - not a thermal regulation mode - and proper heatsinking must be designed to keep T_J below 150°C under worst-case load and ambient conditions.

Can MC33269T-012G be used in adjustable-output configurations?

No - MC33269T-012G is a fixed 12 V output variant. Only the base part number MC33269 (without voltage suffix) supports adjustable output via external resistors on the ADJ pin. The "T-012" suffix denotes factory-trimmed 12 V output; attempting to modify feedback externally will not yield stable regulation and violates the device's internal reference configuration.