STMicroelectronics LF50CPT-TRY

Overview

LF50CPT-TRY from STMicroelectronics is a 5.0 V, ±2% tolerance automotive-grade low-dropout linear regulator in PPAK-5 package with 500 mA output current capability, 0.45 V dropout at 200 mA, and logic-controlled shutdown (TTL-compatible enable pin). It operates from -40 °C to 125 °C and requires only 2.2 µF output capacitance for stability-designed for local power regulation in engine control units and ADAS domain controllers.

For engineers reviewing the LF50CPT-TRY datasheet, LF50CPT-TRY pinout, LF50CPT-TRY application, or LF50CPT-TRY equivalent, key selection criteria include its AEC-Q100 qualification, 50 µA shutdown quiescent current, 76 dB supply voltage rejection at 120 Hz, and PPAK thermal resistance of 8 °C/W junction-to-case-critical for under-hood thermal design and battery-backed standby operation.

Technical Context

The LF50CPT-TRY implements a fixed-output, NPN-based LDO architecture with internal current and thermal limiting. Its 5-pin PPAK configuration integrates a TTL-compatible enable input (Pin 2) that drives the regulator into sub-100 µA OFF mode, enabling system-level power gating.

It achieves 0.45 V dropout at 200 mA load and maintains ±2% output accuracy over temperature (–40 °C to 125 °C) and line/load variations, with 50 µV RMS output noise (10 Hz–100 kHz) and stable operation using ceramic capacitors as low as 2.2 µF (ESR 0.1–10 Ω).

Key Specifications

Pinout & Package

LF50CPT-TRY is housed in a thermally enhanced PPAK-5 surface-mount package (4.5 mm × 3.5 mm × 1.0 mm), with exposed thermal pad electrically connected to GND for optimal heat transfer to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDL112PU50R and TLV73350PDBVR, LF50CPT-TRY uniquely balances 500 mA output, 50 µA shutdown IQ, AEC-Q100 qualification, and PPAK thermal performance-making it the only option for demanding automotive local regulation where all four attributes are mandatory.

Availability

LF50CPT-TRY is available at Aetrix Electronics and suitable for engine control units, ADAS domain controllers, body control modules, and infotainment head units requiring stable component supply across automotive production lifecycles.

Supply support for LF50CPT-TRY 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 LFXX series was developed specifically for automotive power management-delivering robust, low-noise, enable-controlled LDO regulation in thermally demanding under-hood and cabin environments.

FAQ

What is the minimum input voltage required for regulation at full 500 mA load?

The LF50CPT-TRY requires a minimum input voltage of 5.45 V to maintain 5.0 V output at 500 mA load, based on its maximum dropout voltage of 0.45 V at 200 mA and 0.7 V at 500 mA (per Table 17). At 500 mA, worst-case dropout is 0.7 V, so VI(min) = 5.0 V + 0.7 V = 5.7 V. This ensures regulation during cold-crank conditions down to 6.5 V battery voltage.

Can the EN pin be left floating, or does it require a pull-up/down resistor?

The EN pin must not be left floating. It has no internal pull-up or pull-down. To ensure reliable startup, connect EN to IN via a 100 kΩ resistor for default-ON operation. For microcontroller control, drive it actively between GND (OFF) and IN (ON); leakage current is <10 µA, so standard GPIO outputs suffice without additional buffering.

Is the exposed thermal pad (Pin 5) electrically isolated or connected internally?

The exposed thermal pad (Pin 5) is electrically connected to Pin 3 (GND) internally, as confirmed in Figure 2 (pin connections) and Section 6.6 (PPAK package information). It must be soldered to a PCB GND plane with ≥4 thermal vias to achieve rated R_thJA = 100 °C/W; isolation would compromise thermal performance and violate safe operating area limits.

Does LF50CPT-TRY support ceramic output capacitors, and what ESR range is acceptable?

Yes, LF50CPT-TRY is optimized for ceramic output capacitors with ESR between 0.1 Ω and 10 Ω, as specified in Table 3–17 for CO parameter. A 2.2 µF X7R 0805 ceramic capacitor (typical ESR ≈ 10 mΩ) meets stability requirements and eliminates need for higher-ESR tantalum or aluminum electrolytics-reducing size, cost, and aging-related drift.