onsemi MC33269DR2-3.3

Overview

MC33269DR2-3.3 from onsemi is a fixed-output, low-dropout linear voltage regulator delivering 3.3 V at up to 800 mA with 1.0 V dropout at 500 mA, ±1% output voltage tolerance, and integrated thermal shutdown and short-circuit protection. It serves as a primary power supply for microcontroller I/O rails, FPGA core logic, and industrial sensor interfaces requiring stable low-noise DC.

For engineers reviewing the MC33269DR2-3.3 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage under full load, thermal resistance in SO-8 package, output tolerance across temperature, and compatibility with 10 µF minimum output capacitance.

Technical Context

The MC33269DR2-3.3 uses a composite PNP–NPN pass transistor architecture enabling low dropout while maintaining stability with 10 µF output capacitors. Its internal reference is trimmed to 1.25 V with ±1% accuracy over line, load, and temperature.

Thermal protection activates at ~170°C junction temperature without hysteresis, and current limiting holds output at ~800 mA during overload. The device operates across −40°C to +125°C ambient and supports input voltages up to 20 V.

Key Specifications

Pinout & Package

MC33269DR2-3.3 is housed in an SO-8 (Case 751) surface-mount package with exposed pad thermal enhancement. Pin 2 (Vout) connects internally to the heatsink surface (terminal 4 per case outline), enabling direct PCB copper thermal coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with MC33269DR2-3.3, NCV33269DR2-3.3 adds automotive qualification overhead without altering performance, while MCP1703T-3302E/MB trades 3× lower IQ for 3× less output current - making MC33269DR2-3.3 optimal for cost-sensitive industrial designs needing robust 800 mA capability in standard SO-8.

Availability

MC33269DR2-3.3 is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and networking edge devices requiring stable component supply with consistent SO-8 packaging and Pb-free compliance.

Supply support for MC33269DR2-3.3 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 was designed for low-input-voltage, medium-current applications where minimal dropout and high reliability are essential - targeting replacement of legacy 78xx regulators in space-constrained, thermally demanding environments.

FAQ

What is the maximum input voltage rating for MC33269DR2-3.3?

The MC33269DR2-3.3 supports a maximum input voltage of 20 V, as specified in the Absolute Maximum Ratings table. Operation above this level risks permanent damage. For 3.3 V output, recommended input range is 4.3 V to 15 V to maintain dropout margin and thermal safety under full 800 mA load.

Does MC33269DR2-3.3 require an input bypass capacitor?

While not mandatory for stability, MC33269DR2-3.3 benefits from a ≥0.33 µF input bypass capacitor placed directly across pins 3 (Vin) and 1 (GND). This improves transient response and reduces sensitivity to high-frequency line impedance - especially critical when routing from distant DC/DC converters or long PCB traces.

Can MC33269DR2-3.3 be used with ceramic output capacitors?

No - MC33269DR2-3.3 is not stable with low-ESR ceramic capacitors. The datasheet explicitly warns against using ceramics due to potential oscillation. It requires 10 µF output capacitance with ESR between 0.2 Ω and 10 Ω, met by tantalum or aluminum electrolytic types across the operating temperature range.

How does thermal shutdown behave in MC33269DR2-3.3?

MC33269DR2-3.3 activates thermal shutdown at approximately 170°C junction temperature with no hysteresis. When triggered, output disables until junction cools below threshold - causing apparent output oscillation under sustained overload. This is a fail-safe mechanism, not a regulated thermal management feature.

Is MC33269DR2-3.3 pin-compatible with other SO-8 LDOs?

MC33269DR2-3.3 follows standard SO-8 pinout (Vin–GND–Vout–NC–NC–NC–NC–NC), but pin compatibility alone does not guarantee functional equivalence. Substitutes must match dropout, current, protection features, and capacitor requirements - e.g., NCV33269DR2-3.3 is electrically identical but qualified for automotive use.