STMicroelectronics L4949EP013TR

Overview

L4949EP013TR from STMicroelectronics is a monolithic 5 V very low-dropout voltage regulator with integrated power-on reset, input voltage sense comparator, and preregulator functions. It delivers up to 100 mA output current with dropout voltage < 0.5 V at 100 mA, ±1% output accuracy (5 V ±1%), and supports automotive supply transients up to 40 V for microcontroller power domains in engine control units and body electronics.

For engineers reviewing the L4949EP013TR datasheet, L4949EP013TR pinout, L4949EP013TR application, or L4949EP013TR equivalent, key selection criteria include its 5 V ±1% regulated output, programmable reset delay via external capacitor, sense comparator with 1.23 V internal reference, and SO-20W package thermal resistance of 50 °C/W for sustained 100 mA operation in under-hood environments.

Technical Context

The device integrates a PNP-based linear regulator with foldback current limiting and thermal shutdown, enabling stable 5 V output down to 3 V input while maintaining regulation during 40 V/1 s transients. Its reset circuit monitors VOUT against a 4.5 V threshold with 100 mV hysteresis and uses an external CT capacitor to set delay (e.g., 100 ms typical with 100 nF).

The sense comparator accepts divided input voltage at SI pin, compares it to a 1.23 V internal reference, and drives open-collector SO with 0.4 V low-level output when triggered. The VZ pin provides a stabilized 5 V internal supply (≤10 µA sink) for improved transient immunity below 8 V input.

Key Specifications

Pinout & Package

Package: SO-20W (ECOPACK® compliant, 12+4+4 pin configuration, 7.4–7.6 mm width, 12.6–13 mm length).

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 TPS7B6750QDCYRQ1, the L4949EP013TR uniquely combines 100 mA regulation, programmable reset, and input sense in one SO-20W package - making it optimal for cost-sensitive, space-constrained automotive modules where discrete supervision would increase complexity and failure points.

Availability

L4949EP013TR is available at Aetrix Electronics and suitable for engine control units, body control modules, instrument clusters, and telematics control units requiring stable component supply across extended temperature ranges and automotive qualification lifecycles.

Supply support for L4949EP013TR 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 analog, microcontroller, power, and automotive-grade ICs since 1987.

The L4949E belongs to ST's automotive power management portfolio, engineered specifically for microcontroller power domains in harsh-temperature, high-transient automotive environments - emphasizing reliability, integration, and AEC-Q100 compliance.

FAQ

What is the maximum allowable input voltage for continuous operation?

The L4949EP013TR supports continuous DC input from 5 V to 28 V. Transient input up to 40 V is permitted for durations ≤1 second per ISO 7637-2 Pulse 5a, but sustained operation above 28 V risks exceeding absolute maximum ratings and triggering thermal shutdown.

Can the VZ pin be used as a secondary output supply?

No - VZ is an internal preregulator node rated for ≤10 µA load. Using it as a power source will destabilize the main regulator and degrade transient immunity. ST explicitly states VZ "should not be used as an output" and recommends leaving it open unless adding a noise-reduction capacitor.

How does the sense comparator function in a typical application?

The SI pin accepts a scaled version of VS via external resistor divider. When the divided voltage falls below 1.23 V, the open-collector SO pin pulls low. This allows early battery undervoltage warning (e.g., at 9 V VS) without affecting VOUT regulation - the SO signal can directly feed a microcontroller GPIO for diagnostics.

Is the L4949EP013TR pin-compatible with other variants in the L4949 family?

No - the SO-20W package (L4949EP/L4949EP013TR) has different pin count and layout than the SO-8 variant (L4949ED/L4949ED013TR). Pin functions are mapped differently across packages (e.g., VS is pin 19 in SO-20W but pin 1 in SO-8), requiring PCB redesign for substitution.