STMicroelectronics L4936EH

Overview

L4936EH from STMicroelectronics is a monolithic dual-output automotive voltage regulator IC with 100mA and 400mA low-dropout outputs, integrated power-on reset, sense comparator, enable control, and transient-protected EN/SI inputs. It delivers precise 5V ±1% (OUT1) and 5V ±2% (OUT2) outputs across 5–28V DC supply, supports 40V transients, and operates from −40°C to +150°C - deployed in engine control units and body electronics.

For engineers reviewing the L4936EH datasheet, L4936EH pinout, L4936EH application, or L4936EH equivalent, key selection criteria include dual-output current capability (100mA/400mA), adjustable reset threshold (3.8–4.7V), standby quiescent current ≤90μA, negative transient tolerance down to −5V on EN/SI, and Multiwatt-15 thermal performance (R_{th j-case} = 3°C/W).

Technical Context

The L4936EH integrates two independent LDO regulators: OUT1 uses an isolated-collector vertical PNP for ultra-low dropout (0.2V @ 100mA) and maintains regulation down to 3V input; OUT2 employs the same topology rated for 400mA with ADJ feedback enabling fixed 5V or externally adjustable output via resistor divider. Both outputs feature thermal shutdown with OUT2 disabling ~10K before OUT1.

Its auxiliary functions include a precision reset circuit (programmable 3.8–4.7V threshold, 40–140ms delay via CT), a sense comparator referenced to 1.23V (±30mV hysteresis), and ESD-protected EN/SI inputs tolerant of −5V transients. The reference is dual-supplied (VS or VOUT1), reducing sensitivity to input transients during normal operation (VOUT > 4.5V).

Key Specifications

Pinout & Package

Package: Multiwatt-15 (vertical mounting, tab connected to Pin 6/GND), R_{th j-case} = 3°C/W, suitable for high-power dissipation in constrained automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLF49412GS and MAX16910ATP+, the L4936EH uniquely combines dual independent LDOs, programmable reset, and a dedicated sense comparator in one Multiwatt-15 package - enabling compact, self-contained power supervision for cost-sensitive automotive ECUs without microcontroller overhead.

Availability

L4936EH is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera ECUs, and infotainment power management requiring stable component supply across extended temperature and automotive transient conditions.

Supply support for L4936EH 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 scale and AEC-Q100 qualification expertise.

The L4936EH belongs to ST's automotive-grade linear regulator product line, designed specifically for microcomputer-controlled systems in harsh environments where reliability, transient immunity, and integrated supervision functions are mandatory.

FAQ

What is the maximum allowable transient voltage on VS1 and VS2 pins?

The L4936EH supports transient supply voltages up to +40V and down to −14V for durations under 400ms on both VS1 and VS2 pins, per absolute maximum ratings. This enables robust operation during automotive load-dump and reverse-battery events without external protection circuitry.

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

Yes - when the ADJ pin is disconnected from OUT2 and connected to an external resistor divider between OUT2 and GND, OUT2 voltage becomes adjustable using the formula VOUT2 = VOUT1 × (1 + R1E(R2E + RADJ)/(R2E × RADJ)), where RADJ is internal (60–150kΩ). Typical configurations yield 3.3V or adjustable ranges.

How does the sense comparator function differ from the reset circuit?

The sense comparator (SI/SO) operates independently of the reset circuit: it compares SI voltage against a 1.23V reference and asserts SO for early warning, while the reset circuit monitors VOUT1 directly and asserts RES only when VOUT1 falls below the programmed VRT threshold - enabling layered fault detection.

Is thermal shutdown coordinated between OUT1 and OUT2?

Yes - thermal shutdown is staged: OUT2 disables approximately 10°C before OUT1 reaches its 165°C junction limit. This allows continued MCU operation (powered by OUT1) while shedding non-critical load (OUT2), improving system fault tolerance and graceful degradation behavior.