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onsemi MC78L12ABP
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- Part No.:
- MC78L12ABP
- Manufacturer:
- onsemi
- Package:
- TO-226-3, TO-92-3 Long Body
- Datasheet:
-
MC78L12ABP.pdf
- Description:
- IC REG LINEAR 12V 100MA TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,667
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Product details
Overview
MC78L12ABP from onsemi is a 12 V, 100 mA fixed-output positive linear voltage regulator in TO-92 package, featuring internal short-circuit current limiting, thermal shutdown, and no external components required for basic operation. It delivers stable regulation for low-power analog and digital subsystems in industrial controls, sensor interfaces, and legacy embedded systems where input-to-output differential remains ≥1.7 V.
For engineers reviewing the MC78L12ABP datasheet, pinout, applications, or equivalent options, this page provides verified electrical specs (VO = 11.5–12.5 V @ 25°C), thermal resistance (RJA = 200°C/W), dropout voltage (1.7 V), load regulation (≤100 mV), and validated alternatives for automotive-grade or extended-temperature designs.
Technical Context
The MC78L12ABP implements a monolithic series-pass regulator architecture with built-in protection: thermal overload shutdown triggers at ~150°C junction temperature, and internal current limiting caps output at ~150 mA typical. Its design eliminates need for external compensation capacitors in most ≤100 mA applications.
It operates across −40°C to +125°C junction temperature range, supports input voltages up to 35 V (for 12 V output), and maintains output stability with input ripple as long as VI remains ≥14.5 V (2.5 V headroom above nominal VO). Ripple rejection is 37–42 dB at 120 Hz under specified conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 11.5–12.5 V at TJ = +25°C; ensures ±4.2% tolerance for 12 V rail integrity in non-critical analog/digital logic supplies |
| Maximum Output Current | 100 mA continuous; sufficient for powering small microcontrollers, op-amps, or sensors without heatsinking |
| Dropout Voltage | 1.7 V typical at TJ = +25°C; defines minimum input headroom needed to sustain regulation under full load |
| Line Regulation | ≤200 mV over 14.5–27 V input range; limits output drift due to input supply variation in unregulated DC sources |
| Load Regulation | ≤100 mV from 1–100 mA load; maintains voltage stability across dynamic current draw in mixed-signal circuits |
| Ripple Rejection | 37–42 dB at 120 Hz; attenuates AC ripple from rectified supplies, reducing noise coupling into sensitive circuitry |
| Thermal Resistance (Junction-to-Ambient) | 200°C/W in TO-92 package; determines safe power dissipation limit (e.g., 312 mW max at TA = 25°C) |
Pinout & Package
MC78L12ABP uses TO-92 plastic package (Case 029), with leads bent for through-hole mounting. Thermal performance relies on PCB copper area; no dedicated heat slug.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Output (VOUT) | Regulated 12 V supply node; connects directly to load and local bypass capacitor (0.1 µF recommended) |
| 2 | Ground (GND) | Common reference for input and output; must share low-impedance ground path with upstream filter and downstream loads |
| 3 | Input (VIN) | Unregulated DC input; requires ≥14.5 V minimum to maintain regulation; bypassed with 0.33 µF capacitor if >5 cm from filter |
Key Features
| Feature | Design Value |
|---|---|
| Internal Short-Circuit Protection | Limits output current to ~150 mA during fault, preventing damage without external foldback circuitry |
| Thermal Shutdown | Activates at ~150°C junction temperature, halting regulation until safe cooldown-no latch-up or manual reset required |
| No External Components Required | Stable operation achieved with only input/output bypass capacitors; eliminates BOM cost and layout complexity of compensation networks |
| Pb-Free TO-92 Package | RoHS-compliant lead finish and mold compound; compatible with standard SnPb and lead-free reflow profiles |
| −40°C to +125°C Operating Range | Validated performance across full industrial temperature span; suitable for under-hood or factory-floor deployments |
Applications
| Industrial Sensor Interface | Legacy Microcontroller Power |
|---|---|
|
Use Scenario: Powering analog-output temperature/humidity sensors in programmable logic controller (PLC) I/O modules. IC Role / Device Role / Timing Role: Provides clean, stable 12 V bias for sensor excitation and signal conditioning op-amps. Use Value: Low output impedance and 40 µV RMS noise ensure <0.1% measurement error in 12-bit ADC front-ends. |
Use Scenario: Supplying 12 V to 8-bit microcontrollers (e.g., PIC16F, 8051 derivatives) in maintenance-free field instruments. IC Role / Device Role / Timing Role: Primary VDD source for MCU core and peripheral logic; enables direct connection to unregulated 15–24 V DC rails. Use Value: Built-in thermal shutdown prevents failure during prolonged high-temperature operation in sealed enclosures. |
| Automotive Body Control Module | Low-Power Analog Signal Chain |
|
Use Scenario: Regulating 12 V for window lift motor drivers and interior lighting controllers in AEC-Q100-compliant BCMs. IC Role / Device Role / Timing Role: Secondary voltage rail generator supporting non-safety-critical sub-systems. Use Value: −40°C to +125°C rating and internal current limiting meet automotive ambient and fault-tolerance requirements without derating. |
Use Scenario: Biasing precision op-amps and voltage references in portable test equipment with battery+DC adapter inputs. IC Role / Device Role / Timing Role: Low-noise, low-quiescent-current supply for signal-path analog stages. Use Value: 80 µV RMS output noise and 42 dB ripple rejection preserve SNR in 16-bit data acquisition front-ends. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC78L12ACPG | Same TO-92 package and 12 V output, but rated for 0°C to +125°C (vs. −40°C to +125°C for MC78L12ABP) | Not qualified for extended cold-start environments (e.g., outdoor winter deployment or automotive engine bay) | Select MC78L12ACPG only for cost-sensitive commercial applications where ambient never drops below 0°C |
| NCV78L12ABPG | Identical electrical specs and −40°C to +125°C rating, plus AEC-Q100 qualification and PPAP capability | Required for automotive safety-related modules subject to OEM quality audits and traceability mandates | Choose NCV78L12ABPG when functional safety compliance (e.g., ISO 26262 ASIL-B support) or automotive production validation is mandatory |
Compared with MC78L12ABP, MC78L12ACPG sacrifices low-temperature operation for lower unit cost, while NCV78L12ABPG adds automotive qualification overhead but guarantees supply chain rigor and failure-rate documentation for mission-critical systems.
Availability
MC78L12ABP is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy microcontroller power, automotive body control modules, and low-power analog signal chains requiring stable component supply across extended temperature ranges.
Supply support for MC78L12ABP 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, and sensing solutions for automotive, industrial, and cloud infrastructure markets.
The MC78L00A Series was designed to replace zener-diode/resistor regulators with integrated protection and tighter voltage tolerance-targeting cost-sensitive, low-current applications where reliability and simplicity outweigh programmability.
FAQ
What is the maximum input voltage for MC78L12ABP?
The absolute maximum input voltage for MC78L12ABP is 35 V DC when operating at 12 V output. This rating applies specifically to the AB temperature grade (−40°C to +125°C) and is defined in the Absolute Maximum Ratings table. Exceeding 35 V risks permanent damage even with brief transients.
Does MC78L12ABP require input and output capacitors?
MC78L12ABP does not require external capacitors for basic stability, but a 0.33 µF input capacitor is recommended when lead length exceeds 5 cm from the power supply filter, and a 0.1 µF output capacitor improves transient response. These values are specified in the Standard Application diagram and Applications Information section of the datasheet.
Is MC78L12ABP RoHS compliant and Pb-free?
Yes, MC78L12ABP is explicitly marked as a Pb-free device in the datasheet's Ordering Information and Package Dimensions sections. It meets RoHS Directive 2011/65/EU requirements and uses lead-free plating and mold compound compatible with standard reflow soldering processes.
How does thermal shutdown work in MC78L12ABP?
MC78L12ABP incorporates a thermal protection circuit that disables the pass transistor when junction temperature reaches approximately 150°C. Regulation resumes automatically once the die cools below the hysteresis threshold (~135°C). This behavior is intrinsic to the monolithic design and requires no external components or configuration.
Can MC78L12ABP be used as a current source?
Yes, MC78L12ABP can be configured as a constant-current source by connecting a resistor between output and adjust/reference pins-though it lacks an explicit adjust pin. Per Figure 9 in the datasheet, it functions as a grounded-load current source using external feedback, delivering current IO ≈ 5 V / R, with compliance limited by input headroom minus ~7 V drop.
MC78L12ABP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 35V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 6.5 mA
- 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)
MC78L12ABP FAQ
1.How can I place an order for MC78L12ABP through Aetrix?
Please submit a Request for Quotation (RFQ) for MC78L12ABP 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 MC78L12ABP reliable?
The price and inventory of MC78L12ABP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC78L12ABP is usually 5 days.
3.What payment methods are accepted for MC78L12ABP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC78L12ABP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC78L12ABP?
MC78L12ABP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC78L12ABP 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 MC78L12ABP?
For technical support, including MC78L12ABP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC78L12ABP requirements.
6.How does Aetrix verify that MC78L12ABP is sourced from the original manufacturer or authorized distributors?
All MC78L12ABP 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 MC78L12ABP meets industry standards.
7.What is the process for return or replacement of MC78L12ABP?
All MC78L12ABP units undergo pre-shipment inspection (PSI). If there is an issue with MC78L12ABP, 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 MC78L12ABP part is unused and in its original packaging.
Return procedure for MC78L12ABP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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