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onsemi MC7809ACT
- Part No.:
- MC7809ACT
- Manufacturer:
- onsemi
- Package:
- TO-220-3
- Datasheet:
-
MC7809ACT.pdf
- Description:
- IC REG LINEAR 9V 1A TO220AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,118
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Product details
Overview
MC7809ACT from onsemi is a fixed-output +9.0 V, 1.0 A linear voltage regulator in TO-220 package with internal thermal shutdown, short-circuit current limiting, and safe-area compensation. It delivers stable output under input voltages from 11.5 V to 24 V, supports ≥2.2 A peak current, and maintains ±1.5% output tolerance (±0.135 V) at 25°C for industrial power rail regulation.
For engineers reviewing the MC7809ACT datasheet, pinout, applications, or equivalent options, this page provides verified electrical specs, thermal behavior, real-world load regulation performance, and validated alternatives for legacy 9 V supply designs requiring high reliability and no external compensation components.
Technical Context
The MC7809ACT employs a monolithic bipolar pass transistor with built-in safe-area compensation to dynamically reduce short-circuit current as VCE increases-preventing second breakdown during fault conditions. Its internal bandgap reference and error amplifier deliver 9.0 V output with −0.5 mV/°C temperature coefficient.
It operates with a fixed 2.0 V dropout (VIN − VOUT) at 1.0 A and 25°C, achieves 56–61 dB ripple rejection at 120 Hz, and sustains full 1.0 A continuous output with adequate heatsinking-verified across −40°C to +125°C junction temperature range per NCV-grade qualification baseline.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | +9.0 V nominal, ±1.5% tolerance (8.65–9.35 V at 25°C); ensures compatibility with 9 V logic rails and analog subsystems requiring tight DC accuracy. |
| Output Current | 1.0 A continuous, 2.2 A peak; supports motor drivers, relay coils, and multi-stage analog circuitry without external boost. |
| Input Voltage Range | 11.5 V to 24 V DC; enables use with unregulated 12 V wall adapters or automotive battery inputs after transient suppression. |
| Dropout Voltage | 2.0 V at 1.0 A and 25°C; mandates minimum 11 V input for stable 9 V output under full load-critical for thermal design margining. |
| Ripple Rejection | 56–61 dB at 120 Hz; suppresses line-frequency noise from AC/DC converters, reducing need for post-regulator filtering. |
| Quiescent Current | 3.3–6.0 mA typical; contributes <0.054 W standby loss at 9 V output-suitable for always-on industrial control modules. |
| Thermal Protection | Internal shutdown at +150°C junction temperature; prevents catastrophic failure during sustained overload or poor heatsink contact. |
Pinout & Package
MC7809ACT uses the standard TO-220-3 (Case 221AB) package with metal tab electrically connected to Pin 2 (Ground). The heatsink surface must be isolated or grounded via Pin 2 connection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Input | Unregulated DC input terminal; requires ≥0.33 µF low-ESR capacitor if located >2 cm from bulk filter to prevent oscillation. |
| 2 | Ground | Common reference for input and output; also connects to heatsink tab-must be tied to system ground plane for thermal and EMI control. |
| 3 | Output | Regulated +9.0 V supply; optional 0.1–1.0 µF ceramic capacitor improves transient response but is not required for stability. |
Key Features
| Feature | Design Value |
|---|---|
| No external components required | Operates stably with only input/output capacitors-reduces BOM count and layout area versus adjustable regulators. |
| Internal short-circuit current limiting | Limits output to ~0.2 A during hard shorts, enabling safe fault recovery without fuse replacement or PCB trace burnout. |
| Safe-area compensated pass transistor | Reduces short-circuit current as VCE rises-prevents thermal runaway and secondary breakdown during overvoltage transients. |
| Thermal overload protection | Shuts down output above +150°C junction temperature and auto-resumes when cooled-eliminates need for discrete thermal sensors. |
| Pb-free and RoHS-compliant | Meets EU Directive 2011/65/EU; suitable for consumer, industrial, and automotive applications without lead exemption requests. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
|
Use Scenario: Powers isolated 9 V analog sensor interfaces and digital level-shifters in modular PLC backplanes with shared 24 V DC input. IC Role / Device Role / Timing Role: Primary local 9 V regulator delivering clean, thermally robust supply to ADC front-ends and optocoupler drivers. Use Value: Maintains ±1.5% output accuracy across −40°C to +85°C ambient, eliminating need for calibration drift compensation in field-deployed units. |
Use Scenario: Supplies 9 V to microcontroller peripherals (CAN transceivers, EEPROM, LIN bus ICs) in vehicle body control modules. IC Role / Device Role / Timing Role: Fixed-voltage LDO replacement for legacy 78xx-based subsystems requiring AEC-Q100 alignment. Use Value: Withstands 35 V load-dump transients (per NCV7809B lineage), supports 12 V battery input with 2.0 V dropout headroom, and integrates thermal shutdown for under-hood reliability. |
| Legacy Equipment Power Retrofit | Test & Measurement Bench Supply |
|
Use Scenario: Replaces obsolete 9 V regulators in aging medical devices and factory automation controllers where redesign is cost-prohibitive. IC Role / Device Role / Timing Role: Drop-in compatible voltage source maintaining identical pinout, thermal profile, and electrical interface of original MC7809C. Use Value: Matches legacy 1.0 A current capability and 56 dB ripple rejection-ensures unchanged noise floor and load step response in certified systems. |
Use Scenario: Provides stable 9 V bias for precision op-amp test fixtures, signal generator outputs, and calibration reference circuits. IC Role / Device Role / Timing Role: Low-noise (10 µV/VOUT), low-drift (−0.5 mV/°C) DC source supporting sub-mV measurement accuracy. Use Value: Delivers <1.5 mV load regulation (5–1000 mA) and <6.2 mV line regulation-enabling repeatable bench validation without active feedback trimming. |
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 |
|---|---|---|---|
| LM7809CDT/NOPB | TI part with ±2% output tolerance (8.82–9.18 V), higher quiescent current (4.5–8.0 mA), and lower ripple rejection (45–50 dB at 120 Hz). | Less suitable for precision analog rails; acceptable for digital-only 9 V loads where tighter regulation is not required. | Select LM7809CDT/NOPB only when sourcing TI-qualified parts or when existing designs already use TI's thermal pad variant (DT package). |
| NCV7809BDTAR4G | onsemi automotive-grade version with AEC-Q100 Grade 1 (−40°C to +125°C), same 9.0 V ±1.5% spec, but rated for 35 V max input and enhanced ESD robustness (HBM 2000 V). | Required for new automotive designs; overqualified for industrial use but offers extended lifecycle assurance. | Choose NCV7809BDTAR4G for safety-critical or long-lifecycle deployments where PPAP documentation and automotive qualification are mandatory. |
Compared with LM7809CDT/NOPB, MC7809ACT offers tighter output tolerance and superior ripple rejection; versus NCV7809BDTAR4G, it provides identical regulation performance at lower cost and broader commercial availability-making it optimal for non-automotive industrial retrofits and general-purpose 9 V supplies.
Availability
MC7809ACT is available at Aetrix Electronics and suitable for industrial control systems, automotive aftermarket electronics, and legacy equipment repair requiring stable component supply with full traceability and long-term stocking support.
Supply support for MC7809ACT 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 MC7800 series was designed as a robust, drop-in-compatible family of fixed-output linear regulators targeting cost-sensitive, high-reliability applications where simplicity, thermal resilience, and long-term manufacturability are prioritized over programmability.
FAQ
What is the maximum input voltage rating for MC7809ACT?
The MC7809ACT has an absolute maximum input voltage of 35 V DC, as specified in the "Maximum Ratings" table. However, for reliable continuous operation at 1.0 A output, the recommended input range is 11.5 V to 24 V DC to maintain thermal safety margins and ensure dropout compliance. Exceeding 24 V significantly increases power dissipation and junction temperature.
Does MC7809ACT require input and output capacitors to operate stably?
MC7809ACT does not require output capacitance for stability, but a 0.1–1.0 µF ceramic capacitor is recommended to improve transient response. An input bypass capacitor (≥0.33 µF tantalum or low-ESR ceramic) is required if the regulator is located more than 2 cm from the main filter capacitor to prevent high-frequency oscillation and ensure robust line rejection.
How does thermal shutdown work in MC7809ACT?
MC7809ACT incorporates an internal thermal shutdown circuit that disables the output pass transistor when the junction temperature reaches +150°C. The device remains latched off until the die cools to approximately +130°C, then automatically resumes regulation. This protects against permanent damage during sustained overload, inadequate heatsinking, or ambient temperature excursions.
Can MC7809ACT be used in adjustable configurations?
Yes-MC7809ACT can be configured as an adjustable regulator using external resistors and a Zener diode, as shown in Figure 10 of the datasheet. However, doing so forfeits its factory-trimmed 9.0 V accuracy and introduces additional error sources; it is not recommended unless the design specifically requires non-standard output voltages and accepts reduced regulation performance.
What is the typical dropout voltage of MC7809ACT at full load?
The typical dropout voltage of MC7809ACT is 2.0 V at 1.0 A output current and 25°C junction temperature. This means the input must be at least 11.0 V to guarantee stable 9.0 V output under full continuous load. Dropout increases slightly with rising temperature and current, so thermal design must account for worst-case VIN(min) = VOUT + 2.0 V + margin.
MC7809ACT 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):
- 9V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 2V @ 1A (Typ)
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 6 mA
- Current - Supply (Max):
- -
- PSRR:
- 61dB (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
MC7809ACT FAQ
1.How can I place an order for MC7809ACT through Aetrix?
Please submit a Request for Quotation (RFQ) for MC7809ACT 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 MC7809ACT reliable?
The price and inventory of MC7809ACT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC7809ACT is usually 5 days.
3.What payment methods are accepted for MC7809ACT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC7809ACT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC7809ACT?
MC7809ACT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC7809ACT 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 MC7809ACT?
For technical support, including MC7809ACT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC7809ACT requirements.
6.How does Aetrix verify that MC7809ACT is sourced from the original manufacturer or authorized distributors?
All MC7809ACT 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 MC7809ACT meets industry standards.
7.What is the process for return or replacement of MC7809ACT?
All MC7809ACT units undergo pre-shipment inspection (PSI). If there is an issue with MC7809ACT, 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 MC7809ACT part is unused and in its original packaging.
Return procedure for MC7809ACT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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