My Inquiry
My Account
onsemi MC7812ECT
- Part No.:
- MC7812ECT
- Manufacturer:
- onsemi
- Package:
- TO-220-3
- Datasheet:
-
MC7812ECT.pdf
- Description:
- IC REG LINEAR 12V 1A TO220-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,885
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MC7812ECT from Fairchild Semiconductor is a three-terminal fixed-output +12 V positive voltage regulator in TO-220 package, delivering up to 1 A output current with ±4% output voltage tolerance, thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It is used in industrial power supplies, embedded control systems, and analog instrumentation requiring stable, low-noise DC voltage.
For engineers reviewing the MC7812ECT datasheet, pinout, applications, or equivalent options, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific use cases, and two confirmed alternative parts with documented functional and application differences.
Technical Context
The MC7812ECT employs an internal series pass transistor with error amplifier, reference voltage, current generator, thermal shutdown circuitry, and SOA protection - all integrated into a monolithic silicon structure. Its regulation relies on feedback-controlled emitter-follower topology with built-in current limiting and junction temperature monitoring.
It operates across 0°C to +125°C ambient range, requires minimum 2 V input-to-output differential (dropout), and achieves typical ripple rejection of 71 dB at 120 Hz with 15 V–25 V input. Output noise is 76 μV/VO (10 Hz–100 kHz), and load regulation is ≤120 mV over 5 mA–1.5 A output current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 12 V nominal, ±4% tolerance (11.4–12.6 V at 5 mA–1 A, 14.5–27 V input); ensures compatibility with 12 V logic and analog rails. |
| Output Current | Up to 1 A continuous (with adequate heatsinking); supports medium-power loads like relays, op-amp stages, and microcontroller peripherals. |
| Dropout Voltage | 2 V typical at 1 A and +25°C; mandates ≥14 V unregulated input for reliable 12 V output under full load. |
| Ripple Rejection | 71 dB typical at 120 Hz (15–25 V input); suppresses rectified AC ripple without external filtering beyond standard 0.33 μF/0.1 μF caps. |
| Thermal Resistance (Junction-to-Case) | 5 °C/W (TO-220); enables ~20 W dissipation with 100°C case-to-ambient ΔT, critical for high-current linear regulation. |
| Quiescent Current | 5.1–8.0 mA; contributes <100 mW no-load loss at 12 V input, supporting low-standby-power designs. |
| Short-Circuit Current | 230 mA typical (VI = 35 V, TA = +25°C); limits fault energy during output shorts while preserving device integrity. |
Pinout & Package
MC7812ECT uses the industry-standard TO-220 package (15.90 mm × 10.08 mm × 4.50 mm, tab-connected to Pin 2). Mounting tab is electrically connected to Ground (Pin 2) and serves as primary thermal path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Input) | Unregulated DC input supply | Accepts 14.5–27 V DC; must exceed output by ≥2 V under worst-case load and ripple. |
| 2 (GND) | Common reference and thermal tab | System ground return; tab must be thermally coupled to heatsink; electrically tied to PCB ground plane. |
| 3 (Output) | Regulated +12 V output | Delivers stable 12 V to load; requires 0.1 μF ceramic capacitor (CO) within 1 cm for transient stability. |
Key Features
| Feature | Design Value |
|---|---|
| Internal SOA Protection | Prevents destruction during simultaneous high-voltage/high-current stress (e.g., startup into capacitive load), eliminating need for external foldback circuitry. |
| Thermal Shutdown | Activates at ~170°C junction temperature, latching off until cooldown; enables robust operation in sealed enclosures without active cooling. |
| Short-Circuit Protection | Limits output current to ~230 mA during hard shorts, allowing safe indefinite fault condition without damage or fire hazard. |
| Fixed +12 V Output | Eliminates external resistor network; reduces BOM count and layout sensitivity versus adjustable regulators like LM317. |
| Low Output Noise | 76 μV/VO (10 Hz–100 kHz) enables clean biasing for precision op-amps and ADC references without added filtering. |
Applications
| Industrial Power Supply | Embedded Control System |
|---|---|
Use Scenario: Converts rectified 18 V AC–DC adapter output to stable 12 V for PLC I/O modules and sensor signal conditioning. IC Role / Device Role / Timing Role: Primary DC-DC conversion stage providing isolated, regulated rail for analog front-ends and digital logic. Use Value: Maintains 12 V ±5% across 10–1000 mA load steps and 120 Hz ripple, enabling consistent ADC reference and relay coil actuation. |
Use Scenario: Powers microcontroller core, CAN transceiver, and EEPROM in automotive body control module. IC Role / Device Role / Timing Role: Secondary regulated supply derived from vehicle battery (13.8 V nominal), rejecting alternator noise. Use Value: Delivers 12 V with 71 dB ripple rejection at 120 Hz, preventing CAN bus bit errors caused by supply modulation. |
| Analog Instrumentation | Legacy Equipment Retrofit |
Use Scenario: Supplies dual ±12 V rails (paired with MC7912ECT) for op-amp-based data acquisition front-ends. IC Role / Device Role / Timing Role: Positive rail generator in split-supply configuration; referenced to common ground with matched thermal behavior. Use Value: Low 76 μV/VO noise and <120 mV load regulation ensure <0.01% gain error in 16-bit precision amplifiers. |
Use Scenario: Replaces obsolete 7812 variants in aging test equipment power boards where footprint and pinout must match. IC Role / Device Role / Timing Role: Drop-in replacement for legacy TO-220 12 V regulators with identical mechanical and electrical interface. Use Value: Same 3-pin layout, ±4% tolerance, and thermal characteristics enable zero-layout-change field upgrades. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM7812CT | Same TO-220 package, ±4% output tolerance, but higher quiescent current (7–10 mA vs. 5.1–8.0 mA) and lower ripple rejection (62 dB typical). | Less suitable for low-noise analog circuits; acceptable for digital-only loads with relaxed PSRR requirements. | Select LM7812CT only when cross-manufacturer second sourcing is required and noise/PSRR margins are >10 dB above system needs. |
| MC7812CD2TR4 | D2PAK (TO-263) package, same ±4% tolerance and 1 A rating, but lower RθJA (40 °C/W vs. 65 °C/W) and higher cost. | Better thermal performance in high-density SMT layouts; not compatible with through-hole TO-220 footprints. | Choose MC7812CD2TR4 for surface-mount designs needing >1 W dissipation without external heatsink; avoid for through-hole retrofits. |
Compared with LM7812CT, MC7812ECT offers superior ripple rejection and lower quiescent current for noise-sensitive analog rails; compared with MC7812CD2TR4, it provides identical electrical performance in a lower-cost through-hole package but requires mechanical heatsinking for >0.8 A continuous operation.
Availability
MC7812ECT is available at Aetrix Electronics and suitable for industrial power supplies, embedded control systems, and analog instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for MC7812ECT 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete ICs before its acquisition by ON Semiconductor in 2016; its legacy linear regulator portfolio remains widely deployed.
The MC78XXE series was designed for cost-effective, robust fixed-voltage regulation in industrial, automotive, and consumer equipment where simplicity, reliability, and thermal resilience are prioritized over ultra-low dropout or switching efficiency.
FAQ
What is the maximum input voltage for the MC7812ECT?
The absolute maximum input voltage for the MC7812ECT is 35 V. However, for reliable operation with 1 A output, the recommended input range is 14.5 V to 27 V - ensuring ≥2 V headroom for dropout while staying within safe power dissipation limits. Exceeding 27 V increases thermal stress and reduces reliability, especially without forced-air cooling.
Does the MC7812ECT require input and output capacitors?
Yes, the MC7812ECT requires a 0.33 μF ceramic capacitor (CI) on the input and a 0.1 μF ceramic capacitor (CO) on the output, placed as close as possible to the device pins. These capacitors stabilize regulation, suppress high-frequency oscillation, and improve transient response. Omitting them risks instability or output overshoot during load steps.
Can the MC7812ECT be used in parallel for higher current?
No, the MC7812ECT is not designed for direct parallel operation due to mismatched output voltages causing current hogging. To achieve >1 A, use external pass transistors (e.g., Figure 12 in the datasheet) with current-sharing resistors, or select a higher-current regulator like the LM338. Parallel connection without ballasting will damage one or both devices.
What is the thermal shutdown threshold of the MC7812ECT?
The MC7812ECT activates thermal shutdown at approximately 170°C junction temperature. Once triggered, it disables the output until the die cools by ~20–30°C, then automatically recovers. This protects against permanent damage during sustained overload or inadequate heatsinking, but repeated cycling indicates undersized thermal design.
Is the MC7812ECT RoHS compliant?
Yes, the MC7812ECT manufactured after 2006 complies with RoHS Directive 2011/65/EU. Lead-free TO-220 packaging and halogen-free molding compound meet exemption 7a (lead in high-melting-temperature type solders). Always verify compliance via Aetrix's certified material declarations for your specific lot.
MC7812ECT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- 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):
- 2V @ 1A (Typ)
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 8 mA
- Current - Supply (Max):
- -
- PSRR:
- 71dB (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-220-3
MC7812ECT FAQ
1.How can I place an order for MC7812ECT through Aetrix?
Please submit a Request for Quotation (RFQ) for MC7812ECT 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 MC7812ECT reliable?
The price and inventory of MC7812ECT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC7812ECT is usually 5 days.
3.What payment methods are accepted for MC7812ECT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC7812ECT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC7812ECT?
MC7812ECT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC7812ECT 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 MC7812ECT?
For technical support, including MC7812ECT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC7812ECT requirements.
6.How does Aetrix verify that MC7812ECT is sourced from the original manufacturer or authorized distributors?
All MC7812ECT 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 MC7812ECT meets industry standards.
7.What is the process for return or replacement of MC7812ECT?
All MC7812ECT units undergo pre-shipment inspection (PSI). If there is an issue with MC7812ECT, 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 MC7812ECT part is unused and in its original packaging.
Return procedure for MC7812ECT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC7812ECT Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
