STMicroelectronics L7824CP

Overview

L7824CP from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 24 V output with up to 1.5 A continuous current, thermal overload and short-circuit protection, and ±2 % output voltage tolerance (A-grade). It operates across an input range of 27.3–38 V, features 2 V dropout at 1 A, and is used in industrial power supplies, motor control logic rails, and embedded system auxiliary regulation.

For engineers reviewing the L7824CP datasheet, L7824CP pinout, L7824CP application, or L7824CP equivalent, key selection criteria include guaranteed 24 V output stability over temperature (−40 °C to 125 °C), junction-to-case thermal resistance of 5 °C/W in TO-220 package, load regulation ≤100 mV (5 mA–1 A), and supply voltage rejection of 54 dB at 120 Hz.

Technical Context

The L7824CP implements a monolithic series-pass transistor architecture with internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry-enabling robust operation without external protection components. Its feedback loop maintains regulation via internal bandgap reference and error amplifier, with minimum 5 mA load required for stable output.

Designed for local on-card regulation, it eliminates centralized supply distribution issues and supports adjustable configurations using external resistors or pass transistors. Input-to-output differential must remain ≥2 V under full load to sustain regulation, and capacitor requirements are CI = 0.33 µF (input) and CO = 0.1 µF (output) per test circuits.

Key Specifications

Pinout & Package

Supplied in TO-220 package (3-pin, vertical mounting, metal tab connected to ground), with standard pinout: Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output. The metal tab is electrically tied to Pin 2 and serves as primary thermal path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7824CT, L7824CP offers tighter output tolerance and superior ripple rejection-critical for noise-sensitive analog sections-while MC7824ACT extends cold-temperature capability at no performance trade-off, making it ideal for harsh-environment deployments where L7824CP's −40 °C lower limit is insufficient.

Availability

L7824CP is available at Aetrix Electronics and suitable for industrial power supplies, motor control logic rails, and embedded system auxiliary regulation requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7824CP 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The L78 series belongs to ST's legacy linear regulator product line, designed specifically for cost-effective, robust local voltage regulation in space-constrained industrial and embedded systems where simplicity and reliability are prioritized over ultra-low quiescent current or switching efficiency.

FAQ

What is the minimum input voltage required for L7824CP to maintain regulation?

The minimum input voltage is VO + V_d = 24 V + 2 V = 26 V under 1 A load at 25 °C. Per datasheet Table 9, the specified minimum VI for regulation is 27.3 V across the full temperature and load range (5 mA–1 A), accounting for worst-case dropout and line/load regulation effects.

Can L7824CP be used without a heatsink?

Yes, at ambient temperatures ≤50 °C and output currents ≤500 mA, the TO-220 package's R_thJA = 50 °C/W allows sufficient self-cooling. Above 500 mA or in enclosed/high-ambient environments, a heatsink is mandatory to keep junction temperature below 125 °C-calculated as T_J = T_A + (P_D × R_thJA).

Does L7824CP require input and output capacitors?

Yes-per Figure 4 and test conditions in DS0422, a 0.33 µF ceramic capacitor must be placed ≤10 mm from Pin 1 (Input), and a 0.1 µF ceramic capacitor must be placed directly at Pin 3 (Output). These prevent oscillation and improve transient response; omitting them risks instability or excessive output ripple.

Is L7824CP pin-compatible with older L7824C variants?

Yes-L7824CP shares identical TO-220 pinout (Input-Ground-Output), same footprint, and compatible electrical behavior with L7824C. However, L7824CP (A-grade) improves output tolerance (±2 % vs. ±4 %), lowers quiescent current (4.6–6 mA vs. 8 mA), and extends temperature range (−40 °C to +125 °C vs. 0 °C to +125 °C), enabling drop-in upgrades in most designs.