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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics LM2931AZ50

Name: LM2931AZ50
Brand: STMicroelectronics
SKU: LM2931AZ50
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM2931AZ50

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: TO-226-3, TO-92-3 (TO-226AA)

Datasheet:: LM2931AZ50.pdf

Description:: IC REG LINEAR 5V 100MA TO92-3

Quantity:: RFQ Add To RFQ list

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Inventory:3,578

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Product details

Overview

LM2931AZ50 from STMicroelectronics is a fixed 5.0 V, 100 mA low-dropout linear regulator in TO-92 package, featuring 90 mV typical dropout at 10 mA, ±2% output voltage accuracy over -40 to 125 °C, and integrated load dump protection up to 60 V - designed for automotive body electronics, battery-powered sensors, and engine control module local regulation.

For engineers reviewing the LM2931AZ50 datasheet, LM2931AZ50 pinout, LM2931AZ50 application, or LM2931AZ50 equivalent, key selection criteria include dropout voltage under light/heavy load, reverse transient immunity (-50 V), quiescent current in ON/OFF modes, thermal resistance (R_thJA = 200 °C/W), and compatibility with standard 0.1 µF input / 100 µF output capacitor networks.

Technical Context

The LM2931AZ50 employs a PNP pass transistor architecture enabling ultra-low dropout operation while maintaining stability with minimal external capacitance. Its internal current and thermal limiting functions operate autonomously without external sensing components.

Unlike standard 78L-series regulators, it integrates dedicated reverse polarity protection (-50 V transient) and load dump shutdown (60 V transient), with inhibit logic disabled in TO-92 variant - confirming its role as a robust, standalone 5 V supply for harsh automotive environments where input transients exceed 26 V maximum operating voltage.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	5.0 V ±2% (4.75–5.25 V) across full temperature and load range - ensures stable MCU I/O rail compliance.
Dropout voltage	90 mV typ. at 10 mA; 250–600 mV at 100 mA - enables regulation from 5.1 V input in battery-depleted conditions.
Quiescent current	2.5 mA typ. at 100 mA load; ≤1 mA in OFF mode - minimizes standby power in always-on vehicle modules.
Input transient rating	+60 V / -50 V (100 ms) - survives ISO 7637-2 pulse 5a load dump and reverse battery connection.
Operating temperature	-40 to +125 °C junction - qualified for under-hood automotive placement per AEC-Q100 (DPAK variant).
Noise voltage	500 µV_RMS (10 Hz–100 kHz) - suitable for analog sensor signal chains without additional filtering.
Line regulation	4–30 mV over VI = 6–26 V - maintains tight output during alternator voltage fluctuations.

Pinout & Package

LM2931AZ50 uses TO-92 package (3-pin, through-hole), with pin 1 = V_OUT, pin 2 = GND, pin 3 = V_IN (bottom view). Thermal resistance is R_thJA = 200 °C/W on standard PCB - requires minimal copper area for automotive ambient conditions.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (V_OUT)	Regulated output terminal	Delivers stable 5.0 V; requires 100 µF ceramic or tantalum output capacitor for transient stability.
Pin 2 (GND)	Ground reference	Low-impedance return path; must be routed directly to power plane to minimize noise coupling.
Pin 3 (V_IN)	Unregulated input supply	Accepts 6–26 V DC; withstands +60 V/-50 V transients without latch-up or damage.

Key Features

Feature	Design Value
Load dump protection	Automatic shutdown during +60 V transients - prevents downstream component damage without external TVS.
Reverse polarity immunity	Withstands -50 V input for 100 ms - eliminates need for series diode in battery-reversal-prone installations.
Thermal & current limiting	Fully internal foldback current limit and thermal shutdown - no external sense resistor or shutdown circuit required.
Low-noise regulation	500 µV_RMS output noise - avoids interference with precision ADCs or RF receivers sharing same 5 V rail.
Wide temperature operation	Specified performance from -40 to +125 °C - supports direct mounting on ECU PCBs near heat sources.

Applications

Automotive Body Control Module

Industrial Sensor Node

Use Scenario: Powering door lock actuators, mirror controls, and interior lighting drivers in 12 V vehicle systems.

IC Role / Device Role / Timing Role: Local 5 V LDO supplying microcontroller peripherals and CAN transceiver VCC.

Use Value: Survives load dump pulses without brownout, eliminating system resets during alternator regulation faults.

Use Scenario: Regulating power for wireless temperature/humidity sensors deployed in factory machinery enclosures.

IC Role / Device Role / Timing Role: Primary 5 V supply for ultra-low-power MCU and analog front-end ICs.

Use Value: 2.5 mA quiescent current extends battery life beyond 5 years in sleep-dominated duty cycles.

Engine Control Unit Auxiliary Rail

Telematics GPS/Cellular Module

Use Scenario: Generating clean 5 V for fuel injector driver logic and crankshaft position sensor interface circuits.

IC Role / Device Role / Timing Role: Secondary regulated rail isolated from noisy main 5 V domain.

Use Value: 500 µV_RMS noise floor prevents timing jitter in high-resolution position decoding.

Use Scenario: Supplying 5 V to GNSS receiver and LTE modem in vehicle tracking units exposed to wide ambient swings.

IC Role / Device Role / Timing Role: Input-tolerant LDO bridging unregulated 9–16 V vehicle bus to digital subsystem.

Use Value: -40 to +125 °C operation ensures continuous connectivity even during extreme under-hood thermal cycling.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM2931CD50	SO-8 package with enable (inhibit) pin; higher R_thJA (55 °C/W); 3.3 V version also available.	Requires PCB space for 8-pin footprint and control logic routing; suited for board-level power sequencing.	Select when system-level shutdown coordination is needed; not drop-in for TO-92 layout.
TLV73350PDQNR	200 mA output; 170 mV dropout at 300 mA; 25 µA quiescent current; SOT-23-5 package.	Lower IQ benefits battery longevity but lacks -50 V reverse protection and load dump shutdown.	Prefer for portable industrial devices; avoid in automotive where transients dominate reliability requirements.

Compared with LM2931AZ50, LM2931CD50 adds controllable enable functionality at the cost of larger footprint and reduced thermal margin, while TLV73350PDQNR trades transient robustness for ultra-low IQ and higher current - making LM2931AZ50 uniquely balanced for cost-sensitive, high-reliability automotive point-of-load use.

Availability

LM2931AZ50 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, and telematics modules requiring stable component supply across extended temperature and transient-voltage conditions.

Supply support for LM2931AZ50 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 LM2931 series belongs to ST's automotive-qualified linear regulator portfolio, engineered specifically for harsh-environment voltage regulation where transient immunity and thermal resilience outweigh raw efficiency metrics.

FAQ

What is the maximum input voltage the LM2931AZ50 can withstand during transients?

The LM2931AZ50 sustains +60 V for up to 100 ms and -50 V for up to 100 ms without damage or functional interruption. This exceeds ISO 7637-2 Pulse 5a requirements and eliminates need for external TVS diodes in most automotive designs.

Does the LM2931AZ50 have an enable/inhibit pin?

No. The TO-92 variant (LM2931AZ50) lacks the inhibit function present in SO-8 versions (e.g., LM2931CD50). It operates continuously when powered within its absolute maximum ratings - simplifying design for always-on applications like sensor biasing.

What output capacitor value is required for stability?

A minimum 100 µF output capacitor (tantalum or low-ESR aluminum electrolytic) is required per the datasheet application circuit. Ceramic capacitors alone are insufficient due to ESR dependency; adding 1–10 Ω series resistance may stabilize ceramic-only configurations.

How does the LM2931AZ50 behave during a 60 V load dump event?

During a +60 V transient, the device automatically enters shutdown mode, halting output conduction while protecting internal circuitry and downstream loads. Regulation resumes within microseconds after input returns to safe operating range, with no latch-up or manual reset required.

LM2931AZ50 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA)

Packaging:: Bulk

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 26V

Voltage - Output (Min/Fixed):: 5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.6V @ 100mA

Current - Output:: 100mA

Current - Quiescent (Iq):: 1 mA

Current - Supply (Max):: 30 mA

PSRR:: 75dB (120Hz)

Control Features:: -

Protection Features:: Current Limit, Thermal Shutdown

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

LM2931AZ50 FAQ

1.How can I place an order for LM2931AZ50 through Aetrix?

Please submit a Request for Quotation (RFQ) for LM2931AZ50 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LM2931AZ50 reliable?

The price and inventory of LM2931AZ50 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2931AZ50 is usually 5 days.

3.What payment methods are accepted for LM2931AZ50?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2931AZ50 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM2931AZ50?

LM2931AZ50 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM2931AZ50 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LM2931AZ50?

For technical support, including LM2931AZ50 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2931AZ50 requirements.

6.How does Aetrix verify that LM2931AZ50 is sourced from the original manufacturer or authorized distributors?

All LM2931AZ50 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM2931AZ50 meets industry standards.

7.What is the process for return or replacement of LM2931AZ50?

All LM2931AZ50 units undergo pre-shipment inspection (PSI). If there is an issue with LM2931AZ50, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LM2931AZ50 part is unused and in its original packaging.

Return procedure for LM2931AZ50:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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