STMicroelectronics L7824CV

Overview

L7824CV from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 24 V output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It operates with input voltages up to 40 V and maintains ±2 % output voltage tolerance over temperature, commonly used in industrial power supplies and local board-level regulation for 24 V control systems.

For engineers reviewing the L7824CV datasheet, L7824CV pinout, L7824CV application, or L7824CV equivalent, key selection criteria include dropout voltage (2 V @ 1 A), load regulation (≤100 mV), supply voltage rejection (54 dB @ 120 Hz), and thermal resistance (R_thJA = 50 °C/W in TO-220 package).

Technical Context

This IC implements a monolithic series pass transistor architecture with internal current limiting, thermal shutdown, and SOA protection-enabling robust operation without external protection circuitry. Its fixed-output design eliminates feedback network complexity while supporting adjustable configurations via external resistors and capacitors.

It requires minimum 5 mA load current for regulation stability and uses standard 0.33 µF input and 0.1 µF output ceramic capacitors per test conditions. Junction temperature range is 0 to 125 °C, with absolute maximum input voltage rated at 40 V for 24 V output variants.

Key Specifications

Pinout & Package

Supplied in TO-220 package (3-pin, vertical mounting, metal tab connected to ground), with industry-standard pinout: Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7824CT and MC7824CD2TR4G, the L7824CV offers superior thermal robustness (125 °C junction rating), lower quiescent current, and higher ripple rejection-making it optimal for industrial environments with wide ambient swings and noisy input sources.

Availability

L7824CV is available at Aetrix Electronics and suitable for industrial PLC power rails, 24 V sensor interface modules, legacy equipment retrofit, and DC motor control logic supply requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7824CV 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 power management applications.

The L78 series belongs to ST's legacy linear regulator product line, engineered for cost-effective, rugged local regulation in industrial and embedded systems where simplicity, reliability, and thermal resilience are prioritized over ultra-low quiescent current or ultra-high PSRR.

FAQ

What is the minimum input voltage required for stable 24 V output from the L7824CV?

The minimum input voltage is 27.3 V under full-load (1 A) and room-temperature conditions, based on its 2 V dropout specification. At higher temperatures or loads approaching 1.5 A, derating is required-consult thermal data (R_thJA = 50 °C/W) to ensure junction temperature remains ≤125 °C. Input below 27.3 V risks regulation loss and output sag.

Can the L7824CV be used without a heatsink?

At ≤500 mA load and ambient temperatures ≤40 °C, the TO-220 package may operate without an external heatsink-verified by thermal calculation: ΔT = P_D × R_thJA, where P_D ≈ (30 V − 24 V) × 0.5 A = 3 W → ΔT ≈ 150 °C (exceeds limit). In practice, even at 500 mA, a minimal heatsink is strongly recommended. Full 1.5 A operation always requires a heatsink.

Does the L7824CV require input and output capacitors, and what values are recommended?

Yes: a minimum 0.33 µF ceramic capacitor is required at the input (within 1 cm of Pin 1), and a minimum 0.1 µF ceramic capacitor at the output (within 1 cm of Pin 3), as specified in DS0422 Rev 38. These stabilize internal feedback and prevent oscillation. For high-noise environments, adding 10–100 µF bulk electrolytic capacitors in parallel improves transient response and ripple handling.

How does the L7824CV behave during short-circuit events?

Under sustained short-circuit, the L7824CV limits output current to approximately 0.2 A (I_sc) while maintaining thermal shutdown activation at ~165 °C junction temperature. It does not latch off-recovery occurs automatically once fault is removed and die cools. Peak short-circuit current reaches 2.2 A briefly (<100 ms), enabling safe handling of capacitive load inrush without damage.