STMicroelectronics LF50CPT

Overview

LF50CPT from STMicroelectronics is a 5.0 V fixed-output, very low-dropout linear voltage regulator in TO-220FP package with logic-controlled shutdown, 500 mA output current capability, 0.4 V typical dropout at 500 mA, ±2% output voltage accuracy at 25°C, and operation over –40 to +125°C junction temperature range-designed for local regulation in battery-powered industrial control modules.

For engineers reviewing the LF50CPT datasheet, LF50CPT pinout, LF50CPT application, or LF50CPT equivalent, this page delivers verified electrical specs, thermal performance data, shutdown interface behavior, stability requirements (2.2 µF ceramic), and real-world use cases in power-sensitive embedded systems where quiescent current (50 µA in OFF mode) and low-noise regulation (50 µV RMS noise) are critical selection criteria.

Technical Context

The LF50CPT implements a PNP pass transistor architecture enabling ultra-low dropout voltage (0.4 V typ. at 500 mA), internal current and thermal limiting, and TTL-compatible enable control (pin 2). Its feedback loop is optimized for stability with only 2.2 µF output capacitance (ESR 0.1–10 Ω), eliminating need for external compensation.

It operates across 6–16 V input range with 80 dB supply voltage rejection at 120 Hz, 71 dB at 1 kHz, and maintains 5.0 V ±2% output accuracy over –25 to +85°C ambient-supporting reliable local regulation in thermally constrained environments such as motor drive I/O modules and sensor signal conditioning stages.

Key Specifications

Pinout & Package

LF50CPT uses the TO-220FP (Full Pack) package: 3-pin, vertical mounting, isolated tab (no electrical connection), 50 °C/W junction-to-ambient thermal resistance, and 5 °C/W junction-to-case thermal resistance per STMicroelectronics package mechanical data.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDL115M50R and TPS7A2050PDBVR, LF50CPT uniquely balances high output current (500 mA), integrated shutdown control, TO-220FP thermal performance (5 °C/W R_thJC), and wide input range (6–16 V)-making it optimal for industrial and automotive applications demanding robust local regulation without external support circuitry.

Availability

LF50CPT is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, PLC I/O cards, and portable medical monitors requiring stable component supply, long-lifecycle availability, and guaranteed traceable sourcing.

Supply support for LF50CPT 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 LF00 series was developed specifically for low-noise, low-power local regulation in battery-operated and thermally constrained embedded systems-emphasizing minimal external components, wide input range, and integrated protection features.

FAQ

What is the minimum input voltage required for LF50CPT to maintain regulation at 500 mA?

The minimum input voltage is calculated as V_OUT + V_DROP = 5.0 V + 0.4 V = 5.4 V (typical). At worst-case 0.7 V dropout (per datasheet Table 19/20), 5.7 V is required. Input must remain ≥6 V per absolute maximum ratings to avoid shutdown mode activation above 18 V.

Can LF50CPT be used without the enable pin connected?

Yes-pin 2 (Enable) is TTL-compatible and internally pulled up. Leaving it open or connecting to V_IN places the device in permanent ON mode (500 µA I_Q). For shutdown functionality, drive pin 2 ≤0.8 V (e.g., via MCU GPIO) to enter 50 µA OFF mode.

Is a bypass capacitor required on the input pin?

A 0.1 µF ceramic capacitor is recommended at the input (per datasheet test circuits) to suppress high-frequency noise and improve transient response. While not strictly mandatory for stability, omission may degrade PSRR and cause oscillation under fast load steps.

Does LF50CPT require heatsinking in TO-220FP package at 500 mA?

At 500 mA with 10 V input (5 V dropout × 0.5 A = 2.5 W dissipation), junction temperature rise is ΔT = P × R_thJA = 2.5 W × 60 °C/W = 150°C above ambient. With T_JMAX = 125°C, heatsinking is mandatory for ambient > –25°C. Use of a small clip-on heatsink or copper pour is strongly advised.