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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics L7809ACV

Name: L7809ACV
Brand: STMicroelectronics
SKU: L7809ACV
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L7809ACV

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: TO-220-3

Datasheet:: L7809ACV.pdf

Description:: IC REG LINEAR 9V 1.5A TO220AB

Quantity:: RFQ Add To RFQ list

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Inventory:371

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Product details

Overview

L7809ACV from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 9 V output with ±2 % tolerance (A-grade), 1.5 A maximum output current, thermal overload and short-circuit protection, and operation across 0 to 125 °C junction temperature. It serves as a local on-card power supply in industrial control modules, automotive body electronics, and embedded sensor interfaces requiring stable low-noise DC power.

For engineers reviewing the L7809ACV datasheet, L7809ACV pinout, L7809ACV application, or L7809ACV equivalent, key selection considerations include dropout voltage (2 V at 1 A), load regulation (≤30 mV over 5 mA–1.5 A), supply voltage rejection (61 dB at 120 Hz), output noise (10 µV/√Hz), and TO-220FP package thermal resistance (R_thJC = 5 °C/W).

Technical Context

The L7809ACV implements a monolithic bipolar linear regulator architecture with internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry-enabling robust operation without external protection components. Its fixed 9 V output is trimmed during manufacturing to meet ±2 % accuracy over temperature and load.

Designed for use with minimal external capacitance (0.33 µF input, 0.1 µF output), it maintains regulation under line variations from 11.5 V to 23 V input and load steps up to 1.5 A, with output voltage drift of −0.8 mV/°C and output resistance of 18 mΩ at 1 kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	9 V ±2 % (min 8.82 V, max 9.18 V at 25 °C); ensures precise rail generation for 9 V logic or analog circuits
Max Output Current	1.5 A continuous; supports mid-power subsystems like motor drivers or multi-sensor nodes
Dropout Voltage	2 V at 1 A and 25 °C; requires ≥11 V input for regulated 9 V output under full load
Line Regulation	≤45 mV (typical 5 mV) over VI = 11–17 V; minimizes output shift from input ripple or supply sag
Load Regulation	≤30 mV over IO = 5 mA–1.5 A; maintains stable voltage across dynamic load changes
Supply Rejection	61 dB at 120 Hz; effectively attenuates AC mains-derived ripple in offline power supplies
Thermal Range	0 to 125 °C operating junction temperature; qualified for industrial ambient environments

Pinout & Package

Supplied in TO-220FP package (3-pin, vertical mounting, isolated tab), featuring integrated heat sink interface and creepage/clearance compliant with industrial safety standards.

Pin/Terminal	Circuit Role	Design Meaning
1 (Input)	Unregulated DC input	Accepts 11.5–23 V DC; must be decoupled with ≥0.33 µF ceramic capacitor near pin
2 (Ground)	Reference and return path	Common node for input/output capacitors and load ground; low-inductance layout critical for stability
3 (Output)	Regulated 9 V output	Delivers up to 1.5 A; requires ≥0.1 µF ceramic capacitor directly at pin for transient response

Key Features

Feature	Design Value
Fixed-output precision	±2 % tolerance over temperature and load ensures compatibility with 9 V-tolerant ICs without post-regulation trimming
Integrated protection	Thermal shutdown + short-circuit current limiting + SOA protection eliminate need for external fuses or foldback circuits
Low output noise	10 µV/√Hz (10 Hz–100 kHz) enables clean power for analog front-ends and ADC references
High PSRR	61 dB supply rejection at 120 Hz suppresses rectified AC ripple in unregulated DC inputs
Robust thermal design	R_thJC = 5 °C/W (TO-220FP) allows >1 A continuous output with moderate heatsinking in enclosed enclosures

Applications

Industrial PLC I/O Module

Automotive Body Control Unit

Use Scenario: Powering isolated digital I/O channels and analog sensor signal conditioning circuitry in DIN-rail mounted controllers.

IC Role / Device Role / Timing Role: Local 9 V rail generator providing stable bias for optocouplers, level shifters, and op-amps.

Use Value: Eliminates single-point regulation distribution losses and improves noise immunity via on-board regulation.

Use Scenario: Supplying 9 V to interior lighting drivers, window lift motor controllers, and door module microcontrollers.

IC Role / Device Role / Timing Role: Primary 9 V power source for non-safety-critical sub-systems with wide input voltage transients (e.g., load dump).

Use Value: Withstands 35 V absolute max input and includes thermal shutdown-critical for under-hood reliability.

Embedded Sensor Hub

Legacy RS-232 Interface Adapter

Use Scenario: Powering multi-sensor fusion boards (temperature, humidity, motion) in smart building nodes.

IC Role / Device Role / Timing Role: Low-noise 9 V supply for precision ADCs and analog sensor excitation circuits.

Use Value: 10 µV/√Hz noise and <18 mΩ output impedance preserve signal integrity in high-resolution measurements.

Use Scenario: Generating +9 V for RS-232 line drivers in industrial serial gateways and protocol converters.

IC Role / Device Role / Timing Role: Fixed-voltage source meeting TIA-232-E ±5 V tolerance requirements for driver bias rails.

Use Value: ±2 % output accuracy and 61 dB ripple rejection ensure compliant voltage levels despite noisy 12/24 V field bus inputs.

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	±4 % output tolerance (C-grade), higher quiescent current (8 mA vs. 4.3–6 mA), R_thJC = 4.5 °C/W (TO-220)	Lower accuracy limits use in precision analog; higher I_q reduces efficiency in battery-backed systems	Select when cost sensitivity outweighs accuracy or thermal margin requirements
MC7809BDTG	±4 % tolerance, −40 to 125 °C extended temp range (B-grade), R_thJC = 5.5 °C/W (DPAK)	Wider temp range suits automotive under-hood use; DPAK package offers smaller footprint but lower thermal performance than TO-220FP	Prefer for space-constrained automotive designs where extended temperature rating is mandatory

Compared with LM7809CDT/NOPB and MC7809BDTG, the L7809ACV provides tighter output tolerance (±2 %), lower quiescent current, and superior thermal resistance in TO-220FP-making it optimal for industrial applications demanding accuracy, efficiency, and thermal headroom.

Availability

L7809ACV is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, embedded sensor hubs, and legacy RS-232 interface adapters requiring stable component supply with long-term lifecycle support.

Supply support for L7809ACV 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 analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The L78 series belongs to ST's legacy linear regulator product line, engineered for ruggedness, ease of use, and broad compatibility in fixed-voltage local regulation applications across industrial and automotive domains.

FAQ

What is the minimum input voltage required for stable 9 V output at 1.5 A?

The L7809ACV requires a minimum input voltage of 11.5 V to maintain regulation at full 1.5 A load and 25 °C junction temperature, based on its 2 V dropout specification. At elevated temperatures or with reduced heatsinking, input voltage should be increased to maintain margin against thermal shutdown.

Can L7809ACV be used without an input bypass capacitor?

No-STMicroelectronics specifies a minimum 0.33 µF ceramic capacitor between input and ground, placed as close as possible to the input pin. Omitting it risks instability, oscillation, or failure to reject high-frequency noise, especially with long input traces or switching upstream supplies.

Does L7809ACV support adjustable output voltage configurations?

Yes-though designed as a fixed 9 V regulator, the L7809ACV can be configured as an adjustable regulator using external resistors per ST's Application Note AN2817. This requires connecting the ground pin to a resistor divider network and adds complexity versus dedicated adjustable regulators like LM317.

How does thermal performance differ between TO-220FP and standard TO-220 packages?

The TO-220FP package used in L7809ACV features an isolated metal tab and optimized internal die attach, yielding R_thJC = 5 °C/W-identical to standard TO-220 but with enhanced creepage/clearance. Its key advantage is electrical isolation of the tab, enabling direct heatsink mounting without insulating washers in grounded-chassis systems.

L7809ACV Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

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:: 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:: Through Hole

Supplier Device Package:: TO-220

L7809ACV FAQ

1.How can I place an order for L7809ACV through Aetrix?

Please submit a Request for Quotation (RFQ) for L7809ACV 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 L7809ACV reliable?

The price and inventory of L7809ACV are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7809ACV is usually 5 days.

3.What payment methods are accepted for L7809ACV?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7809ACV transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L7809ACV?

L7809ACV orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L7809ACV 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 L7809ACV?

For technical support, including L7809ACV datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7809ACV requirements.

6.How does Aetrix verify that L7809ACV is sourced from the original manufacturer or authorized distributors?

All L7809ACV 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 L7809ACV meets industry standards.

7.What is the process for return or replacement of L7809ACV?

All L7809ACV units undergo pre-shipment inspection (PSI). If there is an issue with L7809ACV, 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 L7809ACV part is unused and in its original packaging.

Return procedure for L7809ACV:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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