STMicroelectronics L4938ED013TR

Overview

L4938ED013TR from STMicroelectronics is a monolithic dual low-dropout voltage regulator IC designed for automotive microcomputer power supply systems. It delivers two regulated outputs: 5 V ±1% @ 100 mA (OUT1, standby) and 5 V ±2% @ 400 mA (OUT2, main), with programmable reset threshold (3.8–4.7 V), EN/SI inputs protected to −5 V, and quiescent current as low as 65 µA in standby mode.

For engineers reviewing the L4938ED013TR datasheet, L4938ED013TR pinout, L4938ED013TR application, or L4938ED013TR equivalent, this device is selected for automotive body control modules, engine control units, and infotainment subsystems requiring dual-rail regulation, robust transient immunity, and integrated power-on reset supervision.

Technical Context

The L4938ED013TR integrates two independent LDO regulators: OUT1 uses an isolated-collector vertical PNP transistor enabling dropout operation down to 3 V input while maintaining 5 V ±1% regulation up to 40 V transients; OUT2 employs identical topology rated for 400 mA with ADJ feedback allowing fixed or adjustable output configuration. Both outputs feature thermal shutdown with OUT2 disabling ~10 K before OUT1.

Its auxiliary circuitry includes a precision sense comparator (1.16 V typ threshold, ±30 mV hysteresis) for input voltage monitoring, a programmable reset generator (47 nF CT delay, 60–140 ms nominal pulse), and EN/SI inputs hardened against −5 V negative transients. The reference is supplied either from VS or VOUT1, reducing sensitivity to input transients during normal operation (VOUT1 > 4.5 V).

Key Specifications

Pinout & Package

Package: SO-20 (ECOPACK® compliant, surface-mount, 13.0 mm × 7.5 mm footprint). Thermal resistance R_thj-amb = 50 °C/W on 8 cm² copper ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70733PDPWR and TPS7B8150QDGNRQ1, the L4938ED013TR uniquely combines dual independent LDOs, programmable reset, and sense comparator in a single SO-20 package-enabling consolidated power supervision for complex automotive ECUs without external discrete support components.

Availability

L4938ED013TR is available at Aetrix Electronics and suitable for automotive body control modules, engine control units, and infotainment head units requiring stable component supply across extended temperature ranges (−40 °C to +125 °C junction).

Supply support for L4938ED013TR 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 AEC-Q100 qualification coverage.

The L4938ED013TR belongs to ST's automotive-grade linear regulator product line, engineered specifically for microcomputer power supply in harsh vehicle environments-emphasizing transient resilience, low IQ, and integrated system supervision functions.

FAQ

What is the maximum allowable input voltage for continuous operation?

The L4938ED013TR supports continuous DC supply voltage from 5 V to 28 V. Its absolute maximum DC rating is 28 V, and it tolerates transient inputs up to +40 V for durations ≤400 ms-covering standard automotive load-dump conditions per ISO 7637-2 Pulse 5a. Operation above 28 V DC is not permitted.

Can OUT2 be configured for an output voltage other than 5 V?

Yes. When the ADJ pin is connected to an external resistive divider between OUT2 and GND (not directly to OUT2), the output voltage is programmable using the formula V_OUT2 = V_OUT1 × (1 + R1E/R2E). The internal ADJ node reference is 5 V ±1%, and RADJ is specified 60–150 kΩ. Capacitive loading on ADJ must be avoided to preserve loop stability.

How does the sense comparator function in system diagnostics?

The SI input compares applied voltage against a 1.16 V internal reference. When SI falls below threshold, SO asserts low. Used with a resistor divider (e.g., 100 kΩ/10 kΩ from battery), it generates a precise low-battery warning signal. SO is open-drain and requires external pull-up; its 30 mV hysteresis prevents chatter during slow voltage transitions.

Is thermal shutdown coordinated between OUT1 and OUT2?

Yes. Thermal shutdown is staged: OUT2 disables approximately 10 K below the junction temperature that triggers OUT1 shutdown (T_JSD ≈ 165 °C). This staged response allows OUT1 (MCU supply) to remain active while OUT2 (peripheral supply) shuts down first-maintaining core functionality during thermal overload and enabling graceful system degradation.