STMicroelectronics L78M10CV

Overview

L78M10CV 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 temperature, thermal overload and short-circuit protection, and 2 V dropout voltage - used for local on-card regulation in industrial power supplies and embedded control modules.

For engineers reviewing the L78M10CV datasheet, L78M10CV pinout, L78M10CV application, or L78M10CV equivalent, key selection considerations include guaranteed extended-temperature operation (−40 °C to 125 °C), SOA-protected pass transistor, input voltage range up to 35 V, and DPAK package thermal resistance of 8 °C/W junction-to-case.

Technical Context

The L78M10CV implements a monolithic bipolar pass transistor with internal current limiting, thermal shutdown, and safe-area compensation to prevent destruction under overload or fault conditions. Its architecture relies on a bandgap reference and error amplifier driving the series pass element, enabling stable regulation without external compensation in most applications.

It operates across an input voltage range of 12.5 V to 30 V for nominal 10 V output, maintains load regulation within 100 mV (5–200 mA) and line regulation within 30 mV (13–30 V), and delivers 56 dB supply voltage rejection at 120 Hz - confirming suitability for noisy DC bus environments.

Key Specifications

Pinout & Package

Supplied in DPAK (TO-252) surface-mount package with exposed thermal pad for enhanced heat dissipation. Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output - compatible with standard ST DPAK footprint (6.7 mm × 6.7 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78M10CDT-TR and MC78M10BDTG, the L78M10CV provides tighter initial accuracy and guaranteed performance across the full industrial temperature range - making it the preferred choice for applications where analog measurement integrity or thermal robustness cannot be compromised.

Availability

L78M10CV is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, medical diagnostic front-ends, and point-of-sale terminals requiring stable component supply with long-term lifecycle assurance.

Supply support for L78M10CV 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 belongs to ST's precision linear regulator product line, engineered specifically for robust local regulation in harsh environments where thermal resilience, fault tolerance, and parametric consistency are mandatory.

FAQ

What is the minimum input voltage required for stable 10 V output at 500 mA?

The L78M10CV requires a minimum input voltage of 12.5 V under full-load conditions (500 mA) and 25 °C junction temperature, based on its 2 V dropout specification. At elevated temperatures or higher load currents, VI must increase to maintain regulation - e.g., 13 V recommended for continuous 500 mA operation at 100 °C junction temperature.

Can the L78M10CV be used in adjustable configurations?

Yes - though designed as a fixed 10 V regulator, the L78M10CV can be configured as an adjustable regulator using external resistors per Figure 18 in the datasheet, enabling output voltages from 7.0 V to 20 V. The minimum input-to-output differential remains 2 V, and stability requires adherence to recommended input/output capacitor values.

Does the DPAK package require a thermal pad connection to PCB ground?

Yes - the DPAK package features an exposed thermal pad (Pin 2) that must be soldered to a large copper pour tied to the system ground plane. This connection is essential to achieve the specified 8 °C/W junction-to-case thermal resistance; omitting it degrades thermal performance by >50 % and risks thermal shutdown under moderate load.

How does short-circuit protection behave during sustained fault conditions?

Under sustained output short-circuit, the L78M10CV limits current to ~245 mA (typical) while simultaneously activating thermal shutdown if junction temperature exceeds ~165 °C. Once cooled below the hysteresis threshold (~145 °C), it automatically resumes regulation - providing self-recovering fault tolerance without external circuitry.