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STMicroelectronics L7809ACD2T-TR
- Part No.:
- L7809ACD2T-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
L7809ACD2T-TR.pdf
- Description:
- IC REG LINEAR 9V 1.5A D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:1,488
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Product details
Overview
L7809ACD2T-TR from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 9 V ±2% output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It operates across 0 to 125 °C junction temperature and is packaged in D²PAK for high-power local regulation in industrial power supplies and embedded control systems.
For engineers reviewing the L7809ACD2T-TR datasheet, L7809ACD2T-TR pinout, L7809ACD2T-TR application, or L7809ACD2T-TR equivalent, key selection considerations include dropout voltage (2 V @ 1 A), load regulation (≤100 mV), supply voltage rejection (61 dB), quiescent current (4.3–6 mA), and thermal resistance (RthJC = 3 °C/W).
Technical Context
This IC implements a monolithic series-pass linear regulator architecture with internal current limiting, thermal shutdown, and SOA protection-enabling robust operation without external protection circuitry. Its fixed 9 V output is trimmed during manufacturing to ±2% tolerance over temperature and load.
The device requires minimum 5 mA load current for regulation stability and supports input voltages up to 35 V (for VO = 9 V). Dropout voltage remains constant at 2 V under 1 A load at 25 °C, and output noise is specified at 10 µV/√Hz (10 Hz–100 kHz bandwidth).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 9 V ±2% (8.82–9.18 V at 25 °C); ensures stable logic/motor supply rail in cost-sensitive designs |
| Max Output Current | 1.5 A continuous; supports mid-power analog/digital subsystems without external pass transistors |
| Dropout Voltage | 2 V @ 1 A, 25 °C; defines minimum VI–VO margin required for regulation (e.g., VI ≥ 11 V) |
| Line Regulation | ≤45 mV (typ.) over VI = 11–17 V; limits output drift due to input ripple or supply variation |
| Load Regulation | ≤100 mV over IO = 5 mA–1 A; maintains voltage accuracy across dynamic load steps |
| Supply Rejection | 61 dB @ 120 Hz, 500 mA; attenuates low-frequency AC components on unregulated DC inputs |
| Thermal Resistance | RthJC = 3 °C/W (D²PAK); enables >1 A operation with modest heatsinking (e.g., 10 cm² copper) |
Pinout & Package
Package: D²PAK (TO-263), surface-mount, thermally enhanced with exposed drain pad for PCB heat transfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Input (IN) | Unregulated DC input terminal | Accepts 11.5–26 V DC; must be decoupled with ≥0.33 µF ceramic capacitor close to pin |
| Ground (GND) | Reference and return path | Common node for input/output capacitors and load; connects to exposed thermal pad |
| Output (OUT) | Regulated 9 V DC output | Delivers up to 1.5 A; requires ≥0.1 µF ceramic output capacitor for stability |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 9 V output with ±2% tolerance | Eliminates external resistor network; reduces BOM count and calibration effort |
| Integrated thermal shutdown | Automatically disables output above safe junction temperature (150 °C typical), preventing permanent damage |
| Internal current limiting | Clamps output current to ~2.2 A peak (Iscp), enabling safe short-circuit survival without fuse |
| SOA protection | Prevents transistor destruction during simultaneous high-voltage/high-current stress (e.g., startup into capacitive load) |
| Extended temperature range (0–125 °C) | Validated for industrial ambient environments without derating below 1.5 A |
Applications
| Industrial PLC Power Rail | Automotive Body Control Module |
|---|---|
Use Scenario: Local 9 V supply for microcontroller I/O buffers, sensor signal conditioning, and relay drivers in programmable logic controllers. IC Role / Device Role / Timing Role: Primary local regulator converting 24 V bus to clean 9 V rail; no timing function. Use Value: Delivers 1.2 A continuously with <100 mV load regulation, ensuring consistent ADC reference and digital logic levels despite varying module loads. | Use Scenario: Powering LIN transceivers, window lift motor drivers, and interior lighting controllers in 12 V automotive systems. IC Role / Device Role / Timing Role: Fixed-voltage post-regulator after DC-DC converter; provides ESD-robust 9 V for mixed-signal ICs. Use Value: Withstands 35 V transient input and delivers 61 dB ripple rejection, maintaining communication integrity during load dump events. |
| Medical Patient Monitor Auxiliary Supply | Point-of-Sale Terminal Logic Rail |
Use Scenario: Generating isolated 9 V for analog front-end amplifiers and display backlight drivers in portable diagnostic equipment. IC Role / Device Role / Timing Role: Low-noise local regulator (10 µV/√Hz); no clock/timing role. Use Value: Ultra-low output noise and <2% voltage tolerance ensure accurate biopotential signal acquisition without baseline shift. | Use Scenario: Powering barcode scanner ASICs, secure element ICs, and touch controller interfaces in retail terminals. IC Role / Device Role / Timing Role: Main 9 V logic supply; supports hot-plug USB peripherals via controlled enable sequencing. Use Value: Thermal shutdown and SOA protection prevent field failures during accidental short circuits on peripheral connectors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-voltage linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM7809CD2T | ±2% output tolerance, but only rated for 0–125 °C (no extended temp grade); RthJC = 5 °C/W (D²PAK) | Lower thermal performance; unsuitable for sustained 1.5 A operation without larger heatsink | Select when cost is prioritized over thermal margin and extended temperature validation is not required. |
| MC7809CD2TG | ±4% output tolerance (8.64–9.36 V); RthJC = 3.5 °C/W; no guaranteed SOA protection | Higher output variation impacts precision analog stages; reduced fault robustness | Choose only for non-critical digital-only rails where 9 V ±4% is acceptable and thermal load is light. |
Compared with LM7809CD2T and MC7809CD2TG, the L7809ACD2T-TR offers tighter output tolerance, lower thermal resistance, and verified SOA protection-making it the preferred choice for industrial and automotive applications demanding reliability under full-load thermal stress.
Availability
L7809ACD2T-TR is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control modules, medical patient monitors, and point-of-sale terminals requiring stable component supply and long-term manufacturability.
Supply support for L7809ACD2T-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets.
The L78 series belongs to ST's legacy positive voltage regulator product line, engineered for cost-effective, robust local DC-DC conversion in space-constrained industrial and automotive applications where simplicity and reliability outweigh efficiency requirements.
FAQ
What is the minimum input voltage required for regulation with L7809ACD2T-TR?
The minimum input voltage is 11.5 V under typical conditions (IO ≤ 1 A, TJ = 25 °C), based on the 2 V dropout specification. At full 1.5 A load or elevated temperature, VI should be ≥12 V to maintain regulation margin. Input below 11.5 V causes output to track input minus dropout loss.
Can L7809ACD2T-TR be used without an input capacitor?
No. A minimum 0.33 µF ceramic capacitor must be placed within 1 cm of the IN pin to prevent oscillation and ensure stability. Omitting it risks high-frequency instability, especially with long input traces or inductive sources, leading to erratic output or thermal shutdown.
Does L7809ACD2T-TR require a heatsink for 1.5 A operation?
Yes. With RthJC = 3 °C/W and power dissipation up to 13 W (at VI = 26 V, VO = 9 V, IO = 1.5 A), the junction temperature rise exceeds safe limits without heatsinking. A 10 cm² copper pour on 2 oz. PCB plus optional external heatsink is recommended for continuous 1.5 A operation at ambient >50 °C.
How does the L7809ACD2T-TR respond to a short-circuit event?
It immediately limits output current to ~0.2 A (Isc) and activates thermal shutdown if junction temperature exceeds ~150 °C. The device cycles on/off until the fault is removed, protecting itself and upstream circuitry. Peak short-circuit current reaches 2.2 A briefly before limiting engages, sufficient to blow a 1 A fast-blow fuse if used.
L7809ACD2T-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Packaging:
- Tape & Reel (TR)
- 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:
- 1.5A
- 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:
- Surface Mount
- Supplier Device Package:
- D2PAK
L7809ACD2T-TR FAQ
1.How can I place an order for L7809ACD2T-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L7809ACD2T-TR 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 L7809ACD2T-TR reliable?
The price and inventory of L7809ACD2T-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7809ACD2T-TR is usually 5 days.
3.What payment methods are accepted for L7809ACD2T-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7809ACD2T-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L7809ACD2T-TR?
L7809ACD2T-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L7809ACD2T-TR 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 L7809ACD2T-TR?
For technical support, including L7809ACD2T-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7809ACD2T-TR requirements.
6.How does Aetrix verify that L7809ACD2T-TR is sourced from the original manufacturer or authorized distributors?
All L7809ACD2T-TR 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 L7809ACD2T-TR meets industry standards.
7.What is the process for return or replacement of L7809ACD2T-TR?
All L7809ACD2T-TR units undergo pre-shipment inspection (PSI). If there is an issue with L7809ACD2T-TR, 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 L7809ACD2T-TR part is unused and in its original packaging.
Return procedure for L7809ACD2T-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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