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

STMicroelectronics L7809CV-DG

Name: L7809CV-DG
Brand: STMicroelectronics
SKU: L7809CV-DG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L7809CV-DG

Manufacturer:: STMicroelectronics

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

Package:: TO-220-3

Datasheet:: L7809CV-DG.pdf

Description:: IC REG LINEAR 9V 1.5A TO220

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Inventory:2,965

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Product details

Overview

L7809CV-DG from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 9 V output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It operates with input voltages up to 35 V (for VO = 9 V), maintains ±4% output tolerance over temperature and load, and is commonly used for local regulation in industrial power supplies and embedded control boards.

For engineers reviewing the L7809CV-DG datasheet, L7809CV-DG pinout, L7809CV-DG application, or L7809CV-DG equivalent, key selection considerations include dropout voltage (2 V @ 1 A), quiescent current (8 mA), supply voltage rejection (55 dB @ 120 Hz), output noise (70 µV/VO), and thermal resistance (R_thJA = 50 °C/W in TO-220).

Technical Context

This IC implements a monolithic series pass transistor 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 meet ±4% tolerance across the 0–125 °C junction temperature range.

The device requires only two external capacitors (0.33 µF input, 0.1 µF output) for stability and exhibits 2 V dropout at 1 A load, making it suitable for moderate-input-voltage applications where simplicity and reliability outweigh efficiency demands.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 9 V, ±4% tolerance (8.55–9.45 V) over IO = 5 mA to 1 A and TJ = 0–125 °C
Max Output Current	1.5 A continuous, internally current-limited with foldback behavior under overload
Input Voltage Range	11.5 V to 26 V for stable 9 V regulation; absolute max VI = 35 V
Dropout Voltage	2 V at 1 A and TJ = 25 °C - defines minimum headroom needed between input and output
Supply Rejection	55 dB at 120 Hz, VI = 12–23 V - suppresses low-frequency ripple from unregulated DC sources
Quiescent Current	8 mA typical - contributes directly to no-load power loss in battery-backed or standby systems
Output Noise	70 µV/VO (10 Hz–100 kHz) - impacts analog sensor signal integrity when powering precision circuits
Thermal Resistance	R_thJA = 50 °C/W (TO-220 package) - determines heatsink requirement for 1 A continuous operation

Pinout & Package

Supplied in TO-220 package with standard 3-pin configuration: Input (Pin 1), Ground (Pin 2), Output (Pin 3). Requires minimal PCB footprint and supports mechanical mounting via tab (connected to Pin 2/GND).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Input)	Unregulated DC input connection	Accepts 11.5–26 V DC; must be decoupled with ≥0.33 µF ceramic capacitor close to pin
Pin 2 (Ground)	Common reference and heat sink interface	Internally connected to metal tab; electrically tied to system GND and provides primary thermal path
Pin 3 (Output)	Regulated +9 V output node	Delivers up to 1.5 A; requires ≥0.1 µF ceramic capacitor at pin for high-frequency stability

Key Features

Feature	Design Value
Integrated protection	Thermal shutdown, short-circuit current limiting, and SOA protection eliminate need for external fault-handling components
Low external component count	Stable operation with only two capacitors - reduces BOM cost and layout complexity
Wide operating temperature	Rated for 0 to 125 °C junction temperature - suitable for industrial ambient environments without derating
Precision output tolerance	±4% over full load/temperature range - enables direct use in 9 V logic and analog subsystems without post-regulation trimming
Robust ESD immunity	Qualified to HBM ±4 kV - enhances manufacturability and field reliability in handling-sensitive environments

Applications

Industrial PLC I/O Module

Automotive Body Control Unit

Use Scenario: Powering digital isolators and level-shifters in 24 V-powered programmable logic controller backplanes.

IC Role / Device Role / Timing Role: Local +9 V rail generator for optocoupler biasing and microcontroller peripheral interfaces.

Use Value: Eliminates centralized 9 V distribution losses; thermal protection prevents latch-up during transient overloads on field wiring.

Use Scenario: Supplying 9 V to LIN transceivers and window motor drivers in door module ECUs.

IC Role / Device Role / Timing Role: Primary regulated supply for communication PHY layers requiring stable voltage under battery voltage fluctuations (9–16 V).

Use Value: Maintains 9 V output down to 11.5 V input - compatible with cold-crank conditions while rejecting alternator ripple via 55 dB SVR.

Medical Patient Monitor Front-End

Point-of-Sale Terminal Power Management

Use Scenario: Providing clean 9 V bias to analog front-end amplifiers and ADC reference buffers in portable diagnostic devices.

IC Role / Device Role / Timing Role: Low-noise local regulator for signal-chain subrailing, decoupled from noisy digital domains.

Use Value: 70 µV/VO output noise ensures <1 LSB error in 12-bit medical-grade ADCs operating at 9 V reference.

Use Scenario: Generating 9 V for thermal print head drivers and smart card readers in retail terminals.

IC Role / Device Role / Timing Role: High-current, fault-tolerant supply enabling rapid print activation pulses up to 1.2 A peak.

Use Value: SOA protection sustains repeated 1.5 A print-head current surges without shutdown, ensuring transaction continuity.

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 identical 9 V output, but ±2% tolerance (tighter), higher quiescent current (6.5 mA typ), and R_thJA = 65 °C/W (DPAK)	Lower output drift (−0.5 mV/°C vs −1 mV/°C) suits temperature-stable references; DPAK limits thermal performance at >1 A	Select when tighter initial accuracy is critical and heatsinking is constrained; verify SOA margin for pulsed loads
MC7809BD2TR4G	ON Semiconductor part with same 9 V output, ±4% tolerance, but lower short-circuit current (0.35 A vs 0.4 A) and higher dropout (2.2 V @ 1 A)	Reduced fault energy during sustained shorts; slightly higher dropout increases minimum input requirement	Prefer in safety-critical designs where lower fault current reduces fire risk; confirm input headroom availability

Compared with LM7809CDT/NOPB and MC7809BD2TR4G, L7809CV-DG offers superior thermal performance in TO-220 (R_thJA = 50 °C/W), higher short-circuit current capability (0.4 A), and optimized supply rejection for 120 Hz line-derived inputs - making it ideal for industrial mains-powered systems requiring ruggedness and thermal headroom.

Availability

L7809CV-DG is available at Aetrix Electronics and suitable for industrial PLCs, automotive body controllers, medical front-ends, and point-of-sale terminals requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7809CV-DG 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 power management applications.

L7809CV-DG belongs to the L78 positive voltage regulator IC family, engineered for cost-effective, robust local DC-DC conversion in space-constrained industrial and automotive control systems where simplicity and fault resilience are prioritized over switching efficiency.

FAQ

What is the minimum input voltage required for regulation at full 1.5 A load?

The L7809CV-DG requires a minimum input voltage of 11.5 V to maintain 9 V output regulation at 1 A, and 13.5 V is recommended for reliable 1.5 A operation considering worst-case dropout (2 V) and line/load regulation margins. Below this, output voltage sags or regulation is lost.

Can L7809CV-DG be used in parallel for higher current?

No - L7809CV-DG lacks built-in current-sharing features and has mismatched output voltages (±4% tolerance), causing unequal load division and potential thermal runaway. For >1.5 A, use a single higher-current regulator or a discrete pass transistor configuration with external current sensing.

Is an input capacitor mandatory, and what value is recommended?

Yes - a minimum 0.33 µF ceramic capacitor placed within 1 cm of Pin 1 (Input) is mandatory for stability per ST's DS0422. Larger values (e.g., 10 µF aluminum electrolytic + 0.33 µF ceramic) improve transient response and low-frequency ripple suppression, especially with long input traces.

Does L7809CV-DG require a heatsink for 1 A continuous operation?

Yes - at 1 A with 20 °C ambient and R_thJA = 50 °C/W, junction temperature rises ~100 °C above ambient (P_D ≈ 2 W × 50 °C/W), exceeding the 125 °C limit. A heatsink reducing R_thJA to ≤25 °C/W (e.g., 15 cm² aluminum finned) is required for safe continuous 1 A operation.

L7809CV-DG 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):: 8 mA

Current - Supply (Max):: -

PSRR:: 55dB (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

L7809CV-DG FAQ

1.How can I place an order for L7809CV-DG through Aetrix?

Please submit a Request for Quotation (RFQ) for L7809CV-DG 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 L7809CV-DG reliable?

The price and inventory of L7809CV-DG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7809CV-DG is usually 5 days.

3.What payment methods are accepted for L7809CV-DG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7809CV-DG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L7809CV-DG?

L7809CV-DG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L7809CV-DG 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 L7809CV-DG?

For technical support, including L7809CV-DG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7809CV-DG requirements.

6.How does Aetrix verify that L7809CV-DG is sourced from the original manufacturer or authorized distributors?

All L7809CV-DG 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 L7809CV-DG meets industry standards.

7.What is the process for return or replacement of L7809CV-DG?

All L7809CV-DG units undergo pre-shipment inspection (PSI). If there is an issue with L7809CV-DG, 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 L7809CV-DG part is unused and in its original packaging.

Return procedure for L7809CV-DG:

1.Submit a request within 90 days.

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

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