STMicroelectronics LM2931BDT50

Overview

LM2931BDT50 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 typical quiescent current at full load, and integrated load dump protection up to 60 V - designed for automotive local power regulation in engine control units and body electronics.

For engineers reviewing the LM2931BDT50 datasheet, LM2931BDT50 pinout, LM2931BDT50 application, or LM2931BDT50 equivalent, key selection criteria include AEC-Q100 qualification (DPAK), reverse transient tolerance (−50 V), shutdown logic compatibility with L78L footprint, and thermal performance (R_thJA = 100 °C/W on standard PCB).

Technical Context

The LM2931BDT50 implements a PNP-based LDO architecture with internal current and thermal limiting, enabling stable operation under automotive transients including 60 V load dumps and −50 V reverse battery conditions. Its inhibit input (VINH) provides logic-level shutdown control, reducing quiescent current to ≤1 µA in OFF mode.

It operates across −40 °C to +125 °C junction temperature, supports input voltages from 6 V to 26 V (DC), and maintains output regulation within ±3% over full load (5–100 mA) and temperature range - verified per DS1760 Rev 24 electrical characteristics tables.

Key Specifications

Pinout & Package

DPAK (TO-252) package: surface-mount, 3-terminal, thermally enhanced plastic case with exposed drain pad for PCB heat sinking. Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN - matches industry-standard DPAK footprint per DS1760 Figure 22 and FP_0068772_25.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV73350PDBVR and NCP1117ST50T3G, the LM2931BDT50 uniquely combines AEC-Q100 Grade 1 qualification, integrated 60 V/−50 V transient hardening, and logic-controlled shutdown - making it the sole option for under-hood 5 V LDOs requiring zero external protection components.

Availability

LM2931BDT50 is available at Aetrix Electronics and suitable for automotive engine control, body electronics, and telematics systems requiring stable component supply with full AEC-Q100 compliance and long-term lifecycle support.

Supply support for LM2931BDT50 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 vertical manufacturing and AEC-Q100 validation infrastructure.

The LM2931 series belongs to ST's automotive-grade linear regulator product line, engineered specifically for robust local power delivery in harsh vehicle environments - emphasizing transient immunity, wide temperature operation, and functional safety readiness.

FAQ

What is the maximum input voltage the LM2931BDT50 can handle during transients?

The LM2931BDT50 withstands +60 V transient input voltage for durations under 100 ms per Table 1 of DS1760 Rev 24. During such events, the device automatically shuts down to protect internal circuitry and downstream loads - no external clamping required. Continuous DC operation remains limited to 26 V maximum.

Does the LM2931BDT50 require an external shutdown transistor or pull-down resistor on the inhibit pin?

No. The inhibit input (VINH) is internally biased and accepts direct logic-level signals: regulator enables when VINH < 1.2 V and disables when VINH > 3.25 V. No external components are needed - a microcontroller GPIO can drive VINH directly, drawing only 22–50 µA per Table 3.

Can the LM2931BDT50 be used with ceramic output capacitors instead of aluminum electrolytic?

Yes, but stability must be verified. Figure 20 (Stability vs CO) in DS1760 Rev 24 shows the stable region for CO ≥100 µF with ESR ≥10 mΩ. Ceramic capacitors typically have sub-mΩ ESR; adding a 10–22 mΩ series resistor restores phase margin. ST recommends using CO = 100 µF aluminum or tantalum unless compensated.

Is the DPAK package of LM2931BDT50 RoHS-compliant and halogen-free?

Yes. Per Section 7 of DS1760 Rev 24, the LM2931BDT50 is offered in ECOPACK®2-compliant DPAK packaging - fully RoHS-compliant, halogen-free, and compliant with ST's environmental specifications. The "BDT" order code suffix denotes this eco-friendly variant.