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

STMicroelectronics L7912ACV-DG

Name: L7912ACV-DG
Brand: STMicroelectronics
SKU: L7912ACV-DG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L7912ACV-DG

Manufacturer:: STMicroelectronics

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

Package:: TO-220-3

Datasheet:: L7912ACV-DG.pdf

Description:: IC REG LINEAR -12V 1.5A TO220

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Product details

Overview

L7912ACV-DG from STMicroelectronics is a fixed-output, three-terminal negative linear voltage regulator delivering -12 V at up to 1.5 A, featuring thermal overload, short-circuit, and safe operating area (SOA) protection. It operates with input voltages down to -35 V (for -12 V output), supports local on-card regulation in split-supply systems, and is commonly used in industrial power supplies and analog circuitry requiring stable negative bias.

For engineers reviewing the L7912ACV-DG datasheet, L7912ACV-DG pinout, L7912ACV-DG application, or L7912ACV-DG equivalent, key selection criteria include guaranteed -12 V output tolerance (±2.1% at 25°C), dropout voltage of 1.1 V at 1 A, junction temperature range of 0–125 °C, and compatibility with TO-220 package heatsinking for sustained 1.5 A operation.

Technical Context

This device implements a monolithic PNP pass transistor architecture with internal current limiting, thermal shutdown, and SOA protection-enabling robust operation under transient overloads and thermal stress. Its feedback loop maintains output regulation across line (VI = -15.5 V to -27 V) and load (IO = -5 mA to -1 A) variations while sustaining ≤120 mV load regulation and ≤120 mV line regulation within its specified operating window.

The regulator requires external input (CI ≥ 2.2 µF solid tantalum) and output (CO ≥ 1 µF) capacitors for stability and ripple rejection. It exhibits 200 µV RMS output noise (10 Hz–100 kHz), 54–60 dB supply voltage rejection at 120 Hz, and -0.8 mV/°C output voltage drift-making it suitable for precision analog subsystems where low-noise, thermally stable negative rails are critical.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	-12 V nominal, ±2.1% tolerance at 25°C ensures reliable biasing of op-amps and ADC references in dual-rail systems
Max Output Current	1.5 A continuous, limited by internal SOA protection-supports high-current analog stages without external current boost
Dropout Voltage	1.1 V at 1 A and 25°C-dictates minimum input headroom required for regulation (e.g., -13.1 V min for -12 V out)
Supply Rejection	54–60 dB at 120 Hz-attenuates ripple from upstream rectifier/filter stages in linear power supplies
Output Noise	200 µV RMS (10 Hz–100 kHz)-low enough for sensitive audio preamp or sensor signal conditioning circuits
Thermal Shutdown	Activates at ~150 °C junction temperature-prevents permanent damage during sustained overload or inadequate heatsinking
Quiescent Current	3 mA typical-minimizes no-load power loss in always-on subsystems

Pinout & Package

Supplied in TO-220 package (3-pin, vertical mounting, metal tab connected to GND), enabling direct heatsink attachment via the exposed backplate. Thermal resistance junction-to-case is 3 °C/W, supporting >1.5 A operation with appropriate heatsinking.

Pin/Terminal	Circuit Role	Design Meaning
Input (IN)	Negative DC input supply terminal	Accepts unregulated negative voltage (e.g., -15 V to -27 V); must be decoupled with ≥2.2 µF tantalum capacitor
Ground (GND)	Reference node and heat sink connection	Serves as common return path and electrically connects to metal tab-must be tied to system ground plane and heatsink
Output (OUT)	Regulated negative output terminal	Delivers stable -12 V; requires ≥1 µF output capacitor for stability and transient response

Key Features

Feature	Design Value
Fixed -12 V output with ±2% tolerance	Eliminates need for external feedback resistors-reduces BOM count and layout complexity in standard dual-rail designs
Integrated SOA protection	Prevents destructive second breakdown during output short-circuit or capacitive load transients without external foldback circuitry
Thermal overload shutdown	Auto-recovers after cooldown-avoids latch-up failure modes in enclosed industrial enclosures with limited airflow
Low output noise (200 µV RMS)	Enables use in low-noise instrumentation front-ends without additional post-regulation filtering
Split-supply compatibility	Matches L7812AC positive counterpart-simplifies design of symmetric ±12 V rails for op-amp and data converter applications

Applications

Industrial Power Supplies

Analog Signal Conditioning

Use Scenario: Local regulation of -12 V rail in programmable logic controller (PLC) I/O modules with isolated analog inputs.

IC Role / Device Role / Timing Role: Negative voltage regulator providing clean, stable bias for precision instrumentation amplifiers and 16-bit ADC reference buffers.

Use Value: Maintains <±0.5% output drift over 0–70 °C ambient, ensuring <0.1% gain error in 4–20 mA transmitter circuits.

Use Scenario: Dual-rail supply for audio preamplifier stage in broadcast mixing console channel strip.

IC Role / Device Role / Timing Role: Low-noise negative regulator paired with L7812AC to generate symmetric ±12 V rails for NE5532 op-amps.

Use Value: 200 µV RMS noise prevents audible hiss; 60 dB SVR suppresses 120 Hz rectifier ripple before amplification.

Test & Measurement Equipment

Legacy Industrial Control Systems

Use Scenario: Bias supply for photodiode transimpedance amplifier in portable spectrum analyzer front-end.

IC Role / Device Role / Timing Role: Stable -12 V source for ultra-low-input-bias-current op-amps (e.g., OPA128) in high-impedance current-to-voltage conversion.

Use Value: 3 mA quiescent current minimizes self-heating-induced offset drift in thermally sensitive measurement paths.

Use Scenario: Replacement regulator in aging CNC machine control cabinet requiring legacy -12 V logic and interface rail.

IC Role / Device Role / Timing Role: Direct-fit TO-220 drop-in replacement for obsolete discrete negative regulators in 1980s–90s industrial hardware.

Use Value: Pin-compatible with original footprint; thermal shutdown prevents field failures due to degraded heatsink compound over decades of operation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative fixed-voltage regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM337T/NOPB	Adjustable output (−1.25 V to −37 V); requires two external resistors; higher dropout (1.3 V @ 1.5 A); 80 µV noise	Used when variable output or tighter initial accuracy (±1%) is needed; less suitable for space-constrained fixed-rail designs	Select if adjustable output or lower noise is prioritized over simplicity and footprint
MC7912CT	Same -12 V fixed output; TO-220 package; slightly looser output tolerance (±4%); higher quiescent current (6 mA)	Common in cost-sensitive industrial controls where ±4% is acceptable; lacks SOA protection	Choose only for legacy redesigns where MC79xx footprint compatibility is mandatory and SOA protection is not required

Compared with LM337T/NOPB and MC7912CT, L7912ACV-DG offers superior built-in protection (SOA + thermal + short-circuit), tighter output tolerance (±2.1%), and lower quiescent current-making it optimal for new designs demanding reliability and precision in fixed -12 V applications.

Availability

L7912ACV-DG is available at Aetrix Electronics and suitable for industrial power supplies, analog signal conditioning, test & measurement equipment, and legacy industrial control systems requiring stable component supply and long-term lifecycle support.

Supply support for L7912ACV-DG 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 microcontrollers, power management ICs, analog chips, and discrete components for industrial, automotive, and consumer markets.

The L79xxAC series belongs to ST's legacy linear regulator product line, engineered specifically for robust, low-cost, fixed-output negative voltage regulation in industrial and instrumentation applications where reliability and thermal resilience are essential.

FAQ

What is the maximum input voltage for L7912ACV-DG?

The absolute maximum DC input voltage is -35 V for the -12 V output variant, as specified in Table 2 of the ST datasheet. Operation above this level risks permanent damage. For reliable long-term use, ST recommends keeping VI ≤ -27 V under full load to maintain thermal margin and ensure SOA compliance.

Can L7912ACV-DG be used in parallel for higher current?

No-L7912ACV-DG is not designed for parallel operation. Its output voltage tolerance (±2.1%) and lack of current-sharing features mean unequal current distribution would occur, risking thermal runaway in one device. For >1.5 A, use a single higher-current regulator or an external pass transistor configuration per Figure 7 in the datasheet.

Is a heat sink mandatory for 1.5 A operation?

Yes. With R_thJA = 50 °C/W (TO-220), dissipating 1.65 W (1.5 A × 1.1 V dropout) raises junction temperature by 82.5 °C above ambient. At 25 °C ambient, T_J reaches ~108 °C-within spec but near thermal shutdown threshold. A heatsink reducing R_thJA to ≤20 °C/W is strongly recommended for continuous 1.5 A operation.

Does L7912ACV-DG require input and output capacitors?

Yes-both are mandatory. CI ≥ 2.2 µF solid tantalum (or ≥22 µF aluminum electrolytic) is required for stability and transient response; CO ≥ 1 µF is needed to prevent oscillation and improve load-step immunity. Omitting either capacitor risks instability, overshoot, or thermal shutdown under dynamic loads.

L7912ACV-DG Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Output Configuration:: Negative

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: -35V

Voltage - Output (Min/Fixed):: -12V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 1.1V @ 1A (Typ)

Current - Output:: 1.5A

Current - Quiescent (Iq):: 3 mA

Current - Supply (Max):: -

PSRR:: 60dB (120Hz)

Control Features:: -

Protection Features:: Over Temperature, Short Circuit

Operating Temperature:: 0°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

L7912ACV-DG FAQ

1.How can I place an order for L7912ACV-DG through Aetrix?

Please submit a Request for Quotation (RFQ) for L7912ACV-DG 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 L7912ACV-DG reliable?

The price and inventory of L7912ACV-DG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7912ACV-DG is usually 5 days.

3.What payment methods are accepted for L7912ACV-DG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7912ACV-DG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L7912ACV-DG?

L7912ACV-DG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L7912ACV-DG 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 L7912ACV-DG?

For technical support, including L7912ACV-DG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7912ACV-DG requirements.

6.How does Aetrix verify that L7912ACV-DG is sourced from the original manufacturer or authorized distributors?

All L7912ACV-DG 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 L7912ACV-DG meets industry standards.

7.What is the process for return or replacement of L7912ACV-DG?

All L7912ACV-DG units undergo pre-shipment inspection (PSI). If there is an issue with L7912ACV-DG, 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 L7912ACV-DG part is unused and in its original packaging.

Return procedure for L7912ACV-DG:

1.Submit a request within 90 days.

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

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