Texas Instruments UA78M33CKTPR

Overview

UA78M33CKTPR from Texas Instruments is a fixed-output +3.3 V, 500 mA linear voltage regulator in TO-252 (PowerFLEX) package with thermal shutdown, short-circuit current limiting, and safe-area compensation. It operates from 5.3 V to 25 V input, delivers stable output under load up to 350 mA at 25°C, and supports on-card regulation in industrial power supplies.

For engineers reviewing the UA78M33CKTPR datasheet, UA78M33CKTPR pinout, UA78M33CKTPR application, or UA78M33CKTPR equivalent, key selection criteria include dropout voltage (2 V), ripple rejection (62 dB at 120 Hz), output voltage tolerance (±3.3% over temperature), thermal protection behavior, and compatibility with standard 0.33 µF input / 0.1 µF output decoupling.

Technical Context

The UA78M33CKTPR implements a monolithic series-pass transistor regulator architecture with internal current limiting, thermal overload protection, and output transistor safe-area compensation. Its functional block includes a precision voltage reference, error amplifier, and Darlington pass element - all integrated into a single silicon die.

It operates exclusively in fixed-output mode with no external feedback components required. Input-to-output differential must remain ≥2 V for regulation; output remains stable across –40°C to +125°C junction temperature when biased per recommended conditions and decoupled with specified capacitors.

Key Specifications

Pinout & Package

UA78M33CKTPR uses the TO-252 (KTP / PowerFLEX) surface-mount package: 6.60 mm × 6.10 mm body, 3-terminal configuration with exposed thermal pad on bottom side for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3480IM3-3.3/NOPB and TLV73333PDBVR, UA78M33CKTPR provides higher output current (500 mA), proven thermal robustness in TO-252, and integrated safe-area compensation - making it suitable for industrial environments where sustained load and ambient temperature variation are critical.

Availability

UA78M33CKTPR is available at Aetrix Electronics and suitable for industrial PLCs, embedded networking equipment, portable test instruments, and medical sensor signal chains requiring stable component supply and long-term manufacturability.

Supply support for UA78M33CKTPR 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

Texas Instruments is a global semiconductor company founded in 1930, specializing in analog ICs, embedded processors, and high-reliability power management solutions.

UA78M33CKTPR belongs to the µA78Mxx family of three-terminal positive-voltage regulators designed for on-card regulation, noise-sensitive analog systems, and cost-effective fixed-output power conversion in industrial and computing applications.

FAQ

What is the maximum input voltage for UA78M33CKTPR?

The absolute maximum input voltage for UA78M33CKTPR is 35 V DC. However, the recommended operating range is 5.3 V to 25 V. Exceeding 25 V continuously risks exceeding thermal limits under load, especially without adequate heatsinking. The 35 V rating is a stress limit - operation above 25 V should be avoided unless transient surge conditions are explicitly validated per TI's application notes for UA78M33CKTPR.

Does UA78M33CKTPR require external capacitors to operate?

Yes, UA78M33CKTPR requires two external capacitors: a 0.33 µF ceramic capacitor on the INPUT pin and a 0.1 µF ceramic capacitor on the OUTPUT pin. These are mandatory for stability, noise suppression, and compliance with electrical characteristics in the datasheet. Omitting either capacitor may cause oscillation, poor ripple rejection, or thermal instability - particularly under dynamic load conditions.

Is UA78M33CKTPR pin-compatible with other µA78Mxx variants?

Yes, UA78M33CKTPR shares identical pinout (INPUT–COMMON–OUTPUT) and package footprint (TO-252/KTP) with all µA78Mxx devices in the KTP variant, including UA78M05CKTPR and UA78M12CKTPR. However, output voltage and thermal performance differ - substituting without verifying input headroom, load current, and thermal margin will result in regulation failure or premature shutdown.

What is the thermal resistance of UA78M33CKTPR in its TO-252 package?

For UA78M33CKTPR in the KTP (TO-252) package, the junction-to-ambient thermal resistance (R_θJA) is 28°C/W, and junction-to-case (bottom) thermal resistance (R_θJC(bot)) is 1.4°C/W. Effective thermal performance depends on PCB copper area under the exposed pad - TI recommends ≥1 in² (6.45 cm²) of 2-oz copper connected to COMMON for reliable 500 mA operation at 70°C ambient.

Can UA78M33CKTPR be used in automotive applications?

UA78M33CKTPR is not qualified for automotive use (AEC-Q100). Its specified operating junction temperature range is –40°C to +125°C, but it lacks automotive-grade qualification, enhanced ESD robustness (HBM >2500 V), or PPAP documentation. For automotive infotainment or body control modules, consider TI's TPS7B6733QDDARQ1 or similar AEC-Q100-compliant alternatives instead of UA78M33CKTPR.