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Diodes Incorporated AS7809ATF-E1
- Part No.:
- AS7809ATF-E1
- Manufacturer:
- Diodes Incorporated
- Package:
- TO-220-3
- Datasheet:
-
AS7809ATF-E1.pdf
- Description:
- IC REG LINEAR 9V 1A TO220-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,124
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Product details
Overview
AS7809ATF-E1 from Diodes Incorporated is a fixed-output +9V, 1A three-terminal positive linear voltage regulator in TO-220-3 package with internal current limiting, thermal shutdown, and safe-area protection. It delivers stable local regulation for microprocessor power supplies and post-regulation after switching converters, maintaining ±4% output accuracy over –40°C to +125°C junction temperature.
For engineers reviewing the AS7809ATF-E1 datasheet, AS7809ATF-E1 pinout, AS7809ATF-E1 application, or AS7809ATF-E1 equivalent, key selection criteria include dropout voltage (2 V at 1 A), line/load regulation (≤120 mV), PSRR (≥58 dB at 120 Hz), thermal resistance (θJA = 60°C/W), and RoHS-compliant lead-free construction.
Technical Context
The AS7809ATF-E1 implements a monolithic bipolar linear regulator architecture with built-in short-circuit current limiting, thermal overload protection, and output transistor safe-area compensation. Its internal circuitry ensures robust operation under sustained overload without external components.
It operates across an input voltage range of 11.8 V to 32 V (recommended) and supports output currents up to 1 A with adequate heatsinking. The device exhibits low quiescent current (3.4–6 mA) and stable performance at high ambient temperatures due to integrated thermal shutdown activation at +150°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | +9.0 V nominal, ±4% tolerance over full temperature range - ensures compatibility with 9 V logic rails and analog subsystems. |
| Max Output Current | 1 A continuous - sufficient for powering microcontrollers, FPGAs, and peripheral ICs on embedded boards. |
| Dropout Voltage | 2 V at 1 A, 25°C - defines minimum VIN–VOUT differential needed to sustain regulation; impacts efficiency in low-headroom designs. |
| Line Regulation | ≤120 mV (VIN = 11.8–32 V) - limits output variation due to input supply ripple or sag, critical for noise-sensitive analog circuits. |
| Load Regulation | ≤120 mV (IOUT = 5 mA–1 A) - maintains stable output despite dynamic load changes, e.g., CPU burst activity. |
| PSRR | ≥58 dB at 120 Hz - suppresses low-frequency switching noise from upstream DC/DC converters in hybrid power architectures. |
| Thermal Resistance θJA | 60°C/W (TO-220-3) - determines required heatsink size for continuous 1 A operation at elevated ambient temperatures. |
Pinout & Package
AS7809ATF-E1 is housed in a TO-220-3 plastic package with vertical mounting orientation and electrically isolated tab (pin 2). The case serves as the GND terminal and provides mechanical stability and thermal conduction path to heatsink.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | INPUT | Unregulated DC input supply; must exceed VOUT + VDROP (≥11 V) and remain ≤36 V absolute max. |
| 2 | GND | Ground reference and thermal interface; connects to PCB ground plane and heatsink; electrically tied to metal tab. |
| 3 | OUTPUT | Regulated +9 V output; requires 0.33 µF ceramic input and 0.1 µF ceramic output capacitors for stability per datasheet. |
Key Features
| Feature | Design Value |
|---|---|
| Internal Short-Circuit Protection | Limits output current to ~0.2 A during fault, preventing damage without external foldback circuitry. |
| Thermal Shutdown | Activates at +150°C junction temperature and resets automatically upon cooling - enables self-recovery in transient overloads. |
| Safe-Area Compensation | Prevents secondary breakdown of output transistor under simultaneous high voltage/current stress - improves reliability in unregulated input conditions. |
| ±4% Output Accuracy | Guaranteed over –40°C to +125°C - eliminates need for post-production trimming in industrial and telecom applications. |
| Lead-Free & Halogen-Free | RoHS 3 compliant, <900 ppm Br+Cl, <1000 ppm Sb - meets automotive and green electronics compliance requirements. |
Applications
| Microprocessor Power Supply | Post-Regulation for Switching Supplies |
|---|---|
|
Use Scenario: Providing clean, low-noise 9 V rail to ARM Cortex-M4 MCU and associated peripherals on a compact industrial controller board. IC Role / Device Role / Timing Role: Primary local voltage regulator delivering stable core I/O voltage independent of main DC/DC converter ripple. Use Value: Enables reliable MCU boot and real-time operation by suppressing 120 Hz ripple from upstream buck converter via 58 dB PSRR. |
Use Scenario: Final-stage regulation after a 12 V switching supply in a telecom line card requiring ultra-low noise for analog front-end circuitry. IC Role / Device Role / Timing Role: Low-noise linear post-regulator reducing switching artifacts before sensitive ADC drivers and op-amps. Use Value: Achieves <10 µV/VOUT broadband output noise, meeting SNR requirements for 16-bit data acquisition systems. |
| Motherboard Local Regulation | Telecommunication Equipment |
|
Use Scenario: Dedicated 9 V supply for USB hub controller and level-shifting buffers on a server motherboard with mixed-voltage domains. IC Role / Device Role / Timing Role: Point-of-load regulator isolating noisy digital domains from analog timing references and clock buffers. Use Value: Maintains ±120 mV load regulation during USB hot-plug transients, preventing communication glitches or enumeration failures. |
Use Scenario: Powering line interface ICs (e.g., SLICs) and isolation amplifiers in VoIP gateway hardware operating in extended temperature environments. IC Role / Device Role / Timing Role: High-reliability linear regulator supporting continuous operation from –40°C to +85°C ambient with thermal margin. Use Value: Delivers 1 A at +85°C ambient using standard TO-220 heatsink (60°C/W), eliminating need for derating or forced air cooling. |
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-TR | Same 9 V output, but higher quiescent current (6.5 mA typ), lower PSRR (45 dB), and no "Green" halogen-free certification. | Acceptable for cost-sensitive consumer designs where RoHS 3 and low noise are not mandatory. | Select if legacy footprint compatibility with STMicroelectronics' LM78xx series is required and thermal margin exceeds 10°C. |
| MC7809BD2TR4G | Higher output accuracy (±2%), lower dropout (1.7 V), but only rated to +125°C TJ (vs. +150°C) and lacks safe-area compensation. | Suitable for precision analog systems needing tighter voltage tolerance, but less robust under sustained overload. | Prefer when output stability under varying load is prioritized over fault resilience in harsh thermal environments. |
Compared with LM7809CDT-TR and MC7809BD2TR4G, AS7809ATF-E1 offers superior thermal robustness (+150°C shutdown), halogen-free compliance, and integrated safe-area protection-making it optimal for industrial and telecom applications demanding long-term reliability without external protection circuitry.
Availability
AS7809ATF-E1 is available at Aetrix Electronics and suitable for microprocessor power supplies, post-regulation for switching supplies, and telecommunication equipment requiring stable component supply, long-lifecycle support, and RoHS 3 compliance.
Supply support for AS7809ATF-E1 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
Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal devices, with manufacturing certified to IATF 16949 and quality systems aligned to AEC-Q200.
The AS78XXA series targets high-reliability linear regulation in industrial, telecom, and computing infrastructure, emphasizing thermal resilience, safety features, and environmental compliance over basic functionality.
FAQ
What is the maximum input voltage for AS7809ATF-E1?
The absolute maximum input voltage is 36 V. However, the recommended operating range is 11.8 V to 32 V to ensure proper regulation, thermal stability, and longevity. Exceeding 32 V increases power dissipation and risks triggering thermal shutdown under full load.
Does AS7809ATF-E1 require external capacitors?
Yes - a 0.33 µF ceramic capacitor on the INPUT pin and a 0.1 µF ceramic capacitor on the OUTPUT pin are mandatory for stability per the datasheet. Omitting either can cause oscillation or poor transient response, especially under fast load steps.
Is AS7809ATF-E1 pin-compatible with legacy 7809 regulators?
Yes - it uses standard TO-220-3 pinout (Input–Ground–Output) and matches electrical behavior of industry-standard 7809 devices. However, its improved PSRR, thermal shutdown threshold, and RoHS 3 compliance make it a direct upgrade without layout changes.
Can AS7809ATF-E1 deliver 1 A continuously without a heatsink?
No - at 1 A and 25°C ambient, power dissipation exceeds 2 W (e.g., VIN = 15 V → PD ≈ 6 W), requiring a heatsink with θJA ≤ 20°C/W for safe operation. Without heatsinking, continuous current must be limited to ~250 mA to stay within thermal limits.
AS7809ATF-E1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 29V
- 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:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-3
AS7809ATF-E1 FAQ
1.How can I place an order for AS7809ATF-E1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AS7809ATF-E1 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 AS7809ATF-E1 reliable?
The price and inventory of AS7809ATF-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS7809ATF-E1 is usually 5 days.
3.What payment methods are accepted for AS7809ATF-E1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS7809ATF-E1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AS7809ATF-E1?
AS7809ATF-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AS7809ATF-E1 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 AS7809ATF-E1?
For technical support, including AS7809ATF-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS7809ATF-E1 requirements.
6.How does Aetrix verify that AS7809ATF-E1 is sourced from the original manufacturer or authorized distributors?
All AS7809ATF-E1 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 AS7809ATF-E1 meets industry standards.
7.What is the process for return or replacement of AS7809ATF-E1?
All AS7809ATF-E1 units undergo pre-shipment inspection (PSI). If there is an issue with AS7809ATF-E1, 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 AS7809ATF-E1 part is unused and in its original packaging.
Return procedure for AS7809ATF-E1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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