STMicroelectronics L4925PD

Overview

L4925PD from STMicroelectronics is a monolithic 5 V low-dropout linear voltage regulator with integrated power-on reset and programmable reset delay, designed for microcomputer-controlled automotive systems. It operates from 6–28 V DC input, delivers up to 500 mA output current, maintains dropout voltage <0.6 V at 500 mA, and includes thermal shutdown, short-circuit protection, and transient tolerance up to 40 V for ≤1 s.

For engineers reviewing the L4925PD datasheet, L4925PD pinout, L4925PD application, or L4925PD equivalent, key selection criteria include its 4.9–5.1 V output precision over load/temperature, programmable reset delay via external capacitor (e.g., 100 nF → 60–140 ms), and PowerSO-20 package compatibility with high-thermal-demand automotive ECUs.

Technical Context

The L4925PD implements a PNP-based pass transistor architecture enabling ultra-low dropout (0.2–0.6 V) across 1–500 mA load range while sustaining regulation down to 3 V input. Its internal 1.23 V reference and precision divider set nominal 5 V output with ±2% tolerance (4.9–5.1 V) under full operating conditions (–40°C to +125°C).

The integrated reset circuit monitors regulated output voltage against a 4.2–4.8 V threshold and generates a clean active-low reset pulse with user-defined delay (t_RD = CT × 2 V / 2 µA); reaction time is 5–30 µs, ensuring noise immunity without compromising startup timing integrity in engine control units.

Key Specifications

Pinout & Package

Supplied in PowerSO-20 package: thermally enhanced surface-mount package with exposed die pad, 15.8 mm × 14.5 mm footprint, 3.6 mm height, and R_th(j-c) = 3.5 °C/W for efficient heat transfer to PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 5 V automotive LDO regulator applications.

Compared with TLV73350PDBVR and TLE42754G, the L4925PD uniquely combines 500 mA output, <0.6 V dropout, programmable reset delay, and PowerSO-20 thermal performance - making it optimal for high-reliability, thermally demanding automotive ECUs where integrated supervision and headroom are critical.

Availability

L4925PD is available at Aetrix Electronics and suitable for engine control units, body control modules, transmission control units, and ADAS camera ECUs requiring stable component supply across automotive production lifecycles.

Supply support for L4925PD 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, specializing in automotive, industrial, and power management ICs with broad manufacturing and quality certifications.

The L4925PD belongs to ST's automotive-grade linear regulator product line, engineered specifically for microcontroller power delivery in harsh-temperature, high-transient automotive environments - emphasizing reliability, integrated supervision, and thermal resilience.

FAQ

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

The L4925PD maintains 5 V regulation down to 3 V input in dropout mode, but for guaranteed 500 mA output with specified dropout voltage (<0.6 V), the minimum input is 5.6 V (5 V + 0.6 V). Below this, output current capability degrades progressively per the foldback characteristic shown in Figure 3 of the datasheet.

Can the reset output drive a 3.3 V logic input directly?

Yes - the RES pin is an open-collector NPN output rated for 5 mA sink current and 0.4 V max low-level voltage with 10 kΩ pull-up to VO (5 V). When pulled up to 3.3 V via external resistor, it remains compatible; verify pull-up resistor value ensures sufficient base drive for the internal transistor while meeting 3.3 V logic thresholds.

How does the L4925PD handle load dump transients above 28 V?

The device tolerates up to 40 V for ≤1 second per absolute maximum ratings, but sustained operation above 28 V DC is prohibited. For ISO 7637-2 Pulse 5a (load dump), external clamping (e.g., TVS diode) is recommended per ST's application note guidance - the 40 V rating reflects survival capability, not functional operation.

Is the PowerSO-20 package RoHS and REACH compliant?

Yes - the L4925PD PowerSO-20 package conforms to RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, with lead-free terminations and halogen-free molding compound, as confirmed in ST's official material declarations and packaging data sheet (Doc ID 1770 Rev 8, Section 5).