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

onsemi MC79L12ABPRA

Name: MC79L12ABPRA
Brand: onsemi
SKU: MC79L12ABPRA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MC79L12ABPRA

Manufacturer:: onsemi

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

Package:: TO-226-3, TO-92-3 Long Body, Formed Leads

Datasheet:: MC79L12ABPRA.pdf

Description:: IC REG LINEAR -12V 100MA TO92-3

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Product details

Overview

MC79L12ABPRA from onsemi is a 100 mA negative fixed-voltage linear regulator delivering −12 V output with ±5% tolerance (−11.4 V to −12.6 V), 1.7 V dropout at 40 mA, and thermal shutdown/current limiting protection. It operates across −40°C to +125°C and is used for local regulation in analog signal chains, industrial sensor interfaces, and legacy telecom power rails.

For engineers reviewing the MC79L12ABPRA datasheet, pinout, applications, or equivalent options, key selection criteria include input voltage range (−14.5 V to −27 V), load regulation (50 mV over 1–40 mA), ripple rejection (37–42 dB at 120 Hz), and TO-92 package thermal resistance (R_JA = 160°C/W).

Technical Context

The MC79L12ABPRA implements a monolithic bipolar linear regulator architecture with internal current-limiting circuitry and thermal overload protection. Its design ensures stable operation without external compensation capacitors in most low-current applications, though input bypassing with ≥0.33 µF and output decoupling with ≥0.1 µF are recommended for transient stability.

It functions as a three-terminal negative voltage source requiring common ground between input and output. The device maintains regulation only when input remains ≥2.0 V below ground-i.e., |V_IN| ≥ |V_OUT| + 2.0 V-even at ripple troughs, per standard application guidance.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	−12 V nominal, −11.4 V to −12.6 V over full temperature/load range - defines regulated rail for analog stages needing stable negative bias.
Max Output Current	100 mA - supports low-power op-amp supplies, sensor excitation, and logic-level shifters without external pass devices.
Dropout Voltage	1.7 V at 40 mA - determines minimum input headroom required to sustain regulation under typical load.
Ripple Rejection	37–42 dB at 120 Hz - attenuates rectified AC line noise entering via unregulated DC input.
Load Regulation	50 mV (1–40 mA) - quantifies output drift due to load changes; critical for precision reference buffering.
Input Voltage Range	−14.5 V to −27 V - sets compatible upstream supply sources such as center-tapped transformers or split-rail DC-DC outputs.
Thermal Shutdown	Active at +150°C junction - prevents catastrophic failure during sustained overload or poor heatsinking.

Pinout & Package

MC79L12ABPRA uses the TO-92 (Case 29) through-hole package with straight leads, Pb-free finish, and 2000-unit tape-and-reel shipping format. Package dimensions: 4.45–5.20 mm length × 4.32–5.33 mm width × 3.18–4.19 mm height.

Pin/Terminal	Circuit Role	Design Meaning
1	Ground	Common reference node for input and output; must be low-impedance path to avoid regulation error.
2	Input	Negative input terminal; accepts unregulated −14.5 V to −27 V supply; requires ≥0.33 µF bypass capacitor if remote from filter.
3	Output	Regulated −12 V source; benefits from ≥0.1 µF ceramic capacitor to improve transient response and stability.

Key Features

Feature	Design Value
No external components required	Enables minimal BOM count and PCB area in space-constrained designs where load ≤100 mA and input ripple is low.
Internal short-circuit current limiting	Prevents destructive current flow during output faults; allows safe recovery after fault removal without latch-up.
Internal thermal overload protection	Automatically disables output above +150°C junction temperature; resumes operation after cooldown-no manual reset needed.
Pb-free TO-92 packaging	Meets RoHS compliance requirements and supports lead-free reflow or hand-soldering processes.
−40°C to +125°C operating range	Validated for industrial and automotive under-hood environments where ambient extremes challenge passive regulation.

Applications

Industrial Sensor Signal Conditioning	Legacy Telecom Line Card Bias
Use Scenario: Providing clean −12 V bias to instrumentation amplifiers and ADC drivers in factory-floor pressure/temperature transmitters. IC Role / Device Role / Timing Role: Negative voltage regulator supplying reference and analog front-end circuitry. Use Value: Maintains ±5% output accuracy over −40°C to +85°C ambient, ensuring consistent gain and offset calibration across environmental stress.	Use Scenario: Powering obsolete op-amps and discrete transistor stages in deployed DSLAM and PBX line cards requiring −12 V rails. IC Role / Device Role / Timing Role: Fixed negative linear regulator replacing aging discrete Zener-resistor networks. Use Value: Eliminates 3–5 component solutions while improving regulation (50 mV load regulation vs. >200 mV Zener drift) and long-term stability.
Analog Audio Preamp Supply	Embedded Control System Auxiliary Rail
Use Scenario: Generating symmetric ±12 V supplies for dual-supply audio op-amps in pro-audio mixing console modules. IC Role / Device Role / Timing Role: Complementary negative regulator paired with MC78L12 series for bipolar analog supply generation. Use Value: Delivers 42 dB ripple rejection at 120 Hz, reducing audible hum in sensitive microphone preamplifier stages.	Use Scenario: Powering isolated RS-485 transceivers and optocoupler drivers in PLC backplane I/O modules. IC Role / Device Role / Timing Role: Local point-of-load regulator for noise-sensitive interface ICs sharing a shared system ground. Use Value: Internal thermal shutdown prevents latch-up during bus fault conditions, enhancing field reliability without external supervision.

Industrial Sensor Signal Conditioning

Legacy Telecom Line Card Bias

Use Scenario: Providing clean −12 V bias to instrumentation amplifiers and ADC drivers in factory-floor pressure/temperature transmitters.

IC Role / Device Role / Timing Role: Negative voltage regulator supplying reference and analog front-end circuitry.

Use Value: Maintains ±5% output accuracy over −40°C to +85°C ambient, ensuring consistent gain and offset calibration across environmental stress.

Use Scenario: Powering obsolete op-amps and discrete transistor stages in deployed DSLAM and PBX line cards requiring −12 V rails.

IC Role / Device Role / Timing Role: Fixed negative linear regulator replacing aging discrete Zener-resistor networks.

Use Value: Eliminates 3–5 component solutions while improving regulation (50 mV load regulation vs. >200 mV Zener drift) and long-term stability.

Analog Audio Preamp Supply

Embedded Control System Auxiliary Rail

Use Scenario: Generating symmetric ±12 V supplies for dual-supply audio op-amps in pro-audio mixing console modules.

IC Role / Device Role / Timing Role: Complementary negative regulator paired with MC78L12 series for bipolar analog supply generation.

Use Value: Delivers 42 dB ripple rejection at 120 Hz, reducing audible hum in sensitive microphone preamplifier stages.

Use Scenario: Powering isolated RS-485 transceivers and optocoupler drivers in PLC backplane I/O modules.

IC Role / Device Role / Timing Role: Local point-of-load regulator for noise-sensitive interface ICs sharing a shared system ground.

Use Value: Internal thermal shutdown prevents latch-up during bus fault conditions, enhancing field reliability without external supervision.

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative voltage regulation applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM7912ACZ	Same −12 V output, but wider input range (−14.5 V to −35 V); higher R_JA (200°C/W) in TO-220; no automotive temp grade.	Preferred for higher-input-voltage systems; unsuitable for extended temperature industrial use.	Select LM7912ACZ only if input exceeds −27 V and TO-220 mounting is acceptable.
MC79L12ACPRAG	Same die, identical specs, but rated for 0°C to +125°C (not −40°C to +125°C); same TO-92 package and tape-and-reel format.	Lower-cost option for commercial-temperature applications like consumer audio or non-critical embedded control.	Choose MC79L12ACPRAG when ambient never drops below 0°C and cost sensitivity outweighs extended temp coverage.

Compared with LM7912ACZ and MC79L12ACPRAG, the MC79L12ABPRA uniquely combines automotive-grade temperature range (−40°C to +125°C), TO-92 compactness, and guaranteed −12 V regulation under worst-case load/line conditions-making it optimal for ruggedized industrial deployments where space and thermal margin are constrained.

Availability

MC79L12ABPRA is available at Aetrix Electronics and suitable for industrial sensor conditioning, legacy telecom power rails, and analog audio preamp supplies requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MC79L12ABPRA 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MC79L00A Series was designed to replace inefficient Zener-diode-based negative regulators in cost-sensitive, low-current applications-emphasizing ruggedness, simplicity, and wide-temperature operation without external components.

FAQ

What is the maximum input voltage rating for MC79L12ABPRA?

The MC79L12ABPRA has a maximum input voltage rating of −27 Vdc under specified test conditions (−14.5 Vdc ≥ V_I ≥ −27 Vdc). Exceeding −27 Vdc risks permanent damage, as confirmed in the Absolute Maximum Ratings table. Operation up to −27 Vdc is validated for full temperature range (−40°C to +125°C) and ensures compliance with load and line regulation specs. Always maintain ≥2.0 V differential between input and output to prevent dropout.

Does MC79L12ABPRA require external capacitors for stable operation?

MC79L12ABPRA does not require external capacitors for basic regulation, but input bypassing with ≥0.33 µF and output decoupling with ≥0.1 µF are strongly recommended per the datasheet. These capacitors suppress high-frequency noise, improve transient response, and ensure stability when connected via long traces or driving capacitive loads. Omission may cause oscillation or voltage overshoot during load steps-particularly in PCB layouts with >5 cm trace lengths.

What is the thermal resistance (R_JA) of MC79L12ABPRA in its TO-92 package?

The MC79L12ABPRA in TO-92 (Case 29) package has a thermal resistance of R_JA = 160°C/W at T_A = +25°C, as specified in the Maximum Ratings table. This value assumes standard JEDEC-standard PCB mounting with no heatsink. Derating is required above +25°C ambient: maximum power dissipation falls to ~300 mW at +70°C ambient. For continuous 100 mA operation, board layout must minimize copper resistance and provide adequate airflow or thermal relief.

Can MC79L12ABPRA be used in automotive applications?

Yes, MC79L12ABPRA is qualified for automotive temperature range (T_J = −40°C to +125°C) and carries the "AB" suffix denoting this grade. It meets AEC-Q100 stress testing requirements for automotive electronics when used within its absolute maximum ratings-including thermal shutdown activation at +150°C and robust ESD protection (2000 V HBM). However, system-level qualification (e.g., ISO 16750) remains the responsibility of the end designer.

How does MC79L12ABPRA compare to MC79L12ACPRAG?

The MC79L12ABPRA and MC79L12ACPRAG share identical electrical specs and TO-92 packaging, but differ in temperature grading: MC79L12ABPRA is rated for −40°C to +125°C (industrial/automotive), while MC79L12ACPRAG is rated for 0°C to +125°C (commercial). Both are Pb-free and supplied in tape-and-reel. Use MC79L12ABPRA where sub-zero operation is required; MC79L12ACPRAG suffices for indoor consumer or office equipment.

MC79L12ABPRA Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body, Formed Leads

Packaging:: Tape & Reel (TR)

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):: 1.7V @ 40mA (Typ)

Current - Output:: 100mA

Current - Quiescent (Iq):: -

Current - Supply (Max):: -

PSRR:: 42dB (120Hz)

Control Features:: -

Protection Features:: Over Temperature, Short Circuit

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

MC79L12ABPRA FAQ

1.How can I place an order for MC79L12ABPRA through Aetrix?

Please submit a Request for Quotation (RFQ) for MC79L12ABPRA 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 MC79L12ABPRA reliable?

The price and inventory of MC79L12ABPRA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC79L12ABPRA is usually 5 days.

3.What payment methods are accepted for MC79L12ABPRA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC79L12ABPRA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MC79L12ABPRA?

MC79L12ABPRA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MC79L12ABPRA 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 MC79L12ABPRA?

For technical support, including MC79L12ABPRA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC79L12ABPRA requirements.

6.How does Aetrix verify that MC79L12ABPRA is sourced from the original manufacturer or authorized distributors?

All MC79L12ABPRA 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 MC79L12ABPRA meets industry standards.

7.What is the process for return or replacement of MC79L12ABPRA?

All MC79L12ABPRA units undergo pre-shipment inspection (PSI). If there is an issue with MC79L12ABPRA, 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 MC79L12ABPRA part is unused and in its original packaging.

Return procedure for MC79L12ABPRA:

1.Submit a request within 90 days.

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

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