onsemi MC33269TG

Overview

MC33269TG from onsemi is an adjustable-output, low-dropout linear voltage regulator delivering ≥800 mA output current with 1.0 V typical dropout at 500 mA and ±1.0% initial output voltage tolerance. It integrates thermal shutdown and current limiting, and is designed for low-input-voltage systems such as battery-powered instrumentation and industrial control power rails.

For engineers reviewing the MC33269TG datasheet, pinout, applications, or equivalent options, key selection factors include its 1.0 V dropout at 500 mA, 1.25 V internal reference accuracy (±1.2%), SO−8 package thermal resistance (JA = 160°C/W), and compatibility with 10 µF minimum output capacitance for stability.

Technical Context

The MC33269TG employs a composite PNP−NPN pass transistor architecture to achieve low dropout while maintaining high output current capability. Its internal 1.25 V reference is trimmed to ±1.0% at 25°C and exhibits ±0.025 V variation over −40°C to +125°C ambient.

It features fixed thermal shutdown activation at ~170°C with no hysteresis, and foldback current limiting that reduces output current under short-circuit conditions. The device requires external output capacitance (≥10 µF, ESR 0.2–10 Ω) for loop stability across temperature and load.

Key Specifications

Pinout & Package

MC33269TG is supplied in SO−8 (Case 751) package with exposed heatsink pad connected internally to Pin 2 (Vout). The package measures 4.9 × 6.0 mm and supports surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable LDO regulator applications.

Compared with LM317LDR2G and NCP1117ST50T3G, the MC33269TG uniquely combines SO-8 packaging, 800 mA output, 1.0 V dropout, and ±1.0% tolerance-enabling compact, high-accuracy, high-current LDO designs without redesigning PCB layout or compromising regulation performance.

Availability

MC33269TG is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body electronics, programmable test equipment, and portable medical devices requiring stable component supply and long-term manufacturability.

Supply support for MC33269TG 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 supplier specializing in energy-efficient power management, analog, and sensing solutions for automotive, industrial, and cloud infrastructure markets.

The MC33269 series belongs to onsemi's precision linear regulator product line, engineered for low-dropout operation in battery-powered and thermally constrained applications where regulation accuracy and reliability are critical.

FAQ

What is the maximum input voltage rating for MC33269TG?

The MC33269TG has an absolute maximum input voltage rating of 20 V. Exceeding this value risks permanent damage. For the 12 V output variant, Vin is further limited to Vout + 8.0 V (i.e., ≤20 V) due to internal voltage constraints. Always maintain at least 1.5 V headroom between Vin and Vout for guaranteed regulation.

Does MC33269TG require an input bypass capacitor?

While not required for stability, MC33269TG benefits from a ≥0.33 µF input bypass capacitor placed directly across Pins 3 (Vin) and 1 (GND) to improve transient response and reduce sensitivity to high-frequency input impedance. Tantalum, ceramic, or mylar capacitors with low ESR are recommended, mounted with minimal trace length.

How does the thermal shutdown behavior of MC33269TG affect system operation?

MC33269TG activates thermal shutdown at approximately 170°C junction temperature with no hysteresis. If overheating persists, the output cycles on/off - appearing as oscillation. This is a fault-protection mechanism, not a regulated mode. Proper PCB copper area (≥25 mm² 2 oz. copper) and heatsinking are required to avoid repeated shutdown in 800 mA applications.

Can MC33269TG be used in adjustable configurations with very low output voltages?

MC33269TG's internal 1.25 V reference sets the minimum practical output voltage. With R2 = 0 Ω and R1 selected for Vout = 1.25 V × (1 + R2/R1), the lowest stable output is ~1.25 V. Outputs below this require external reference injection or alternative architectures - MC33269TG is not specified for sub-1.25 V operation.

What is the minimum load current requirement for MC33269TG in fixed-output mode?

In fixed-output versions (e.g., MC33269TG-3.3), MC33269TG requires a minimum load current of 8.0 mA to maintain regulation and stability. For adjustable configurations, no minimum load is required at the output, but the ADJ pin current (≤120 µA) must be accounted for in R1/R2 divider design to avoid output drift.