STMicroelectronics L78M10ABDT-TR

Overview

L78M10ABDT-TR from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 10 V at up to 500 mA output current, with ±2 % output voltage tolerance over −40 °C to +125 °C operating junction temperature, thermal overload protection, and short-circuit protection. It serves as a local on-card power supply in industrial control modules requiring stable low-noise 10 V bias for analog front-ends and microcontroller peripherals.

For engineers reviewing the L78M10ABDT-TR datasheet, L78M10ABDT-TR pinout, L78M10ABDT-TR application, or L78M10ABDT-TR equivalent, key selection criteria include dropout voltage (2 V), load regulation (200 mV max over 5–500 mA), supply voltage rejection (56 dB at 120 Hz), output noise (64 µV RMS, 10 Hz–100 kHz), and DPAK package thermal resistance (R_thJA = 100 °C/W).

Technical Context

This regulator employs an internal pass transistor with safe-area compensation, enabling robust operation under output short-circuit and transient overload conditions without external components. Its architecture integrates thermal shutdown, current limiting, and SOA protection-eliminating need for external foldback or sensing circuitry in standard applications.

Designed for fixed-output use, it supports adjustable configurations via external resistors (e.g., current regulation or boosted output), but requires minimum input-to-output differential of 2 V and input bypass capacitance (≥0.33 µF) for stability under high-frequency load transients or long PCB trace feeds.

Key Specifications

Pinout & Package

Supplied in DPAK (TO-252) surface-mount package with exposed thermal pad for enhanced heat dissipation; footprint matches STD-ST mechanical dimensions (6.0–6.2 mm width, 6.4–6.6 mm length, 2.2–2.4 mm height).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2940CT-10 and TL78L10ACDR, L78M10ABDT-TR delivers optimal balance of 500 mA capability, 56 dB ripple rejection, and integrated thermal/short-circuit protection in a thermally efficient DPAK package-making it preferred for industrial analog power domains where reliability and noise immunity outweigh raw current or size metrics.

Availability

L78M10ABDT-TR is available at Aetrix Electronics and suitable for industrial sensor interfaces, motor drive auxiliary supplies, programmable logic controller (PLC) I/O modules, and automotive body control units requiring stable component supply with guaranteed long-term manufacturability.

Supply support for L78M10ABDT-TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The L78MxxA series was developed to provide rugged, pin-compatible fixed-voltage regulators for harsh-environment embedded systems-emphasizing thermal resilience, fault tolerance, and extended temperature operation without external protection circuitry.

FAQ

What is the minimum input voltage required for stable 10 V output?

The L78M10ABDT-TR requires a minimum input-to-output differential of 2 V to maintain regulation. With a nominal 10 V output, the absolute minimum input voltage is 12 V under all load and temperature conditions. At light loads (<50 mA), regulation may hold down to 11.5 V, but design margins should retain 12 V minimum to ensure stability across temperature and line variations.

Can this regulator be used without input or output capacitors?

No. The datasheet mandates a minimum 0.33 µF input capacitor (tantalum, ceramic, or film) placed directly across IN–GND to prevent oscillation under high-frequency transients. An output capacitor ≥0.1 µF is also required for load transient stability and noise reduction. Omission risks instability, overshoot, or thermal runaway under dynamic loads.

How does thermal performance differ between DPAK and TO-220 packages?

In DPAK (L78M10ABDT-TR), R_thJA is 100 °C/W versus 50 °C/W for TO-220 (L78M10AB). This means the DPAK version reaches thermal shutdown ~50 °C faster at the same power dissipation. For 500 mA output at 12 V input (2 V dropout → 1 W dissipation), DPAK junction temperature rises ~100 °C above ambient-requiring PCB copper pour or thermal vias. TO-220 allows higher ambient operation without heatsink.

Is the L78M10ABDT-TR qualified for automotive applications?

The AB grade (−40 °C to +125 °C) meets temperature requirements for under-hood and cabin automotive modules, but ST does not certify this part as AEC-Q100 qualified. It is approved for non-safety-critical automotive functions like interior lighting control or HVAC fan drivers-never for airbag, braking, or ADAS systems. Customers must perform full system-level qualification per ISO 26262 if deploying in ASIL-B or higher domains.