STMicroelectronics LM2931ADT50RY

Overview

LM2931ADT50RY from STMicroelectronics is a fixed 5.0 V, 100 mA low-dropout linear regulator in DPAK package, featuring 90 mV typical dropout at 10 mA, 2.5 mA quiescent current at full load, and AEC-Q100 qualification for automotive use. It integrates inhibit control, load dump protection up to 60 V, and reverse transient protection down to –50 V, enabling robust local power regulation in engine control units and body electronics.

For engineers reviewing the LM2931ADT50RY datasheet, LM2931ADT50RY pinout, LM2931ADT50RY application, or LM2931ADT50RY equivalent, key selection criteria include dropout voltage under 100 mA load, thermal resistance (R_thJC = 8 °C/W), shutdown logic compatibility with L78L-family footprints, and transient survivability in 12 V/24 V automotive battery systems.

Technical Context

This regulator uses a PNP pass transistor architecture to achieve ultra-low dropout and stable operation across –40 to 125 °C junction temperature. Its internal current and thermal limiting, combined with dedicated inhibit input (VINH), enables precise system-level power sequencing in multi-rail automotive ECUs.

The device implements dual-stage transient protection: clamping circuitry responds to 60 V load dumps (t < 100 ms) and –50 V reverse polarity events, while maintaining regulated output during fault conditions. Output noise is specified at 500 µV_RMS (10 Hz–100 kHz), supporting noise-sensitive analog sensors and microcontroller I/O rails.

Key Specifications

Pinout & Package

DPAK package (TO-252-3) with exposed thermal pad; thermally optimized for PCB copper pour mounting. Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN - matches standard DPAK footprint per DS1760 Rev 24 Figure 22 and 23.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout automotive regulator applications.

Compared with TLV73350PDBVR and TPS7B8750QKVURQ1, the LM2931ADT50RY uniquely balances AEC-Q100 qualification, integrated 60 V load dump protection, and logic-controlled inhibit - making it optimal for cost-sensitive, space-constrained automotive modules requiring self-contained fault resilience.

Availability

LM2931ADT50RY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS sensor nodes, and infotainment power domains requiring stable component supply across automotive production lifecycles.

Supply support for LM2931ADT50RY 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 consumer markets since 1987.

The LM2931 series belongs to ST's automotive-grade linear regulator product line, engineered specifically for fault-tolerant, low-noise local power delivery in harsh-temperature vehicle subsystems.

FAQ

What is the maximum input voltage the LM2931ADT50RY can withstand during transient events?

The LM2931ADT50RY sustains +60 V transient input voltage for durations under 100 ms, and –50 V reverse polarity transients for the same duration, per Table 1 and Table 3 of DS1760 Rev 24. This capability eliminates the need for external protection components in ISO 7637-2 compliant designs.

Does the LM2931ADT50RY require an external capacitor on the inhibit (VINH) pin?

No external capacitor is required on the VINH pin. The inhibit input draws only 22–50 µA and operates with standard CMOS logic levels (VIL < 1.2 V, VIH > 3.25 V). A simple pull-down resistor suffices for default-enable behavior; no filtering or decoupling is specified in the datasheet.

Can the LM2931ADT50RY be used without the output capacitor (CO)?

No. The device requires a minimum 100 µF output capacitor (CO) with appropriate ESR, as shown in Figure 3 of DS1760 Rev 24. Omitting CO causes instability and oscillation; ceramic capacitors alone are insufficient - aluminum or tantalum types meeting the stability zone in Figure 20 are mandatory.

Is the DPAK package of LM2931ADT50RY lead-free and RoHS-compliant?

Yes. Per Section 7 of DS1760 Rev 24, the DPAK variant is offered in ECOPACK®2-compliant packaging, meeting RoHS Directive 2011/65/EU and REACH SVHC requirements. The "Y" suffix in LM2931ADT50RY explicitly denotes lead-free, halogen-free, and green packaging per ST's ECOPACK specifications.