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

STMicroelectronics L7818CV-DG

Name: L7818CV-DG
Brand: STMicroelectronics
SKU: L7818CV-DG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L7818CV-DG

Manufacturer:: STMicroelectronics

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

Package:: TO-220-3

Datasheet:: L7818CV-DG.pdf

Description:: IC REG LINEAR 18V 1.5A TO220

Quantity:: RFQ Add To RFQ list

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Inventory:4,930

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Product details

Overview

L7818CV-DG from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 18 V output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection in a TO-220FP package. It operates across 0 to 125 °C junction temperature, supports input voltages up to 40 V for 18 V output, and maintains ±2 % output voltage tolerance over load and temperature - ideal for industrial power rails and local on-card regulation in embedded control systems.

For engineers reviewing the L7818CV-DG datasheet, L7818CV-DG pinout, L7818CV-DG application, or L7818CV-DG equivalent, key selection criteria include dropout voltage (2 V @ 1 A), quiescent current (≤6 mA), line/load regulation performance (≤240 mV), thermal resistance (R_thJC = 5 °C/W), and compatibility with standard 0.33 µF input / 0.1 µF output capacitor configurations.

Technical Context

The L7818CV-DG implements a monolithic series pass transistor architecture with internal current limiting, thermal shutdown, and SOA protection - eliminating external protection circuitry. Its fixed-output design uses precision bandgap reference and error amplifier feedback to maintain regulation under varying line (VI = 20–38 V) and load (IO = 5 mA–1.5 A) conditions.

It requires no external components for basic operation but supports adjustable output via external resistors; minimum load current is 5 mA. Input-to-output differential must remain ≥2 V for regulation, and stability is ensured with CI ≥ 0.33 µF (tantalum or aluminum electrolytic) and CO ≥ 0.1 µF (ceramic).

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 18 V ±2 % at TJ = 25 °C; ensures stable MCU/ASIC supply rail without trimming
Max Output Current	1.5 A continuous; supports motor drivers, sensors, and analog front-ends requiring robust local regulation
Input Voltage Range	20 V to 38 V DC; compatible with unregulated 24 V industrial bus after rectification/filtering
Dropout Voltage	2 V @ IO = 1 A, TJ = 25 °C; defines minimum headroom needed between input and regulated output
Line Regulation	≤240 mV (VI = 20–38 V); limits output drift due to input ripple or supply variation
Load Regulation	≤240 mV (IO = 5 mA–1.5 A); ensures consistent voltage across dynamic load steps
Quiescent Current	≤6 mA; enables low-power standby modes without significant idle loss
Thermal Resistance	R_thJC = 5 °C/W (TO-220FP); determines heatsink requirement for 1.5 A continuous operation

Pinout & Package

Supplied in TO-220FP package - a full-packaged, insulated variant of TO-220 with integrated mounting flange and creepage-enhanced body for industrial safety compliance. Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output (top view, tab facing down).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Left)	Input (VI)	Unregulated DC input; must be ≥20 V and ≤38 V; requires ≥0.33 µF bypass capacitor
Pin 2 (Center)	Ground (GND)	Common reference for input and output; low-impedance return path critical for noise rejection
Pin 3 (Right)	Output (VO)	Regulated 18 V supply; requires ≥0.1 µF ceramic capacitor for high-frequency stability

Key Features

Feature	Design Value
Internal Thermal Shutdown	Activates at ~165 °C junction temperature, latching off until cooldown - prevents permanent damage during overload
Short-Circuit Current Limit	0.35 A typical (L7818C spec); protects against sustained output shorts without external fusing
SOA Protection	Monitors V_CE × I_C in real time to prevent transistor destruction during transient overloads
Low Output Noise	75 µV/V RMS (10 Hz–100 kHz); suitable for analog signal chains and precision ADC references
Extended Temp Range	0 to 125 °C operating junction range (C version); validated for industrial ambient environments

Applications

Industrial PLC Power Supply

Automotive Body Control Module

Use Scenario: Local 18 V rail generation for I/O expansion cards in programmable logic controllers with wide-input 24 V bus.

IC Role / Device Role / Timing Role: Primary linear regulator providing clean, protected 18 V for digital isolators, relay drivers, and CAN transceivers.

Use Value: Eliminates single-point regulation distribution losses; thermal and short-circuit protection reduces field failure risk.

Use Scenario: Powering microcontroller peripherals (LIN transceivers, sensor interfaces) in non-safety-critical automotive zones.

IC Role / Device Role / Timing Role: Fixed-voltage post-regulator downstream of switching pre-regulator, ensuring EMI-clean 18 V for analog subsystems.

Use Value: R_thJC = 5 °C/W enables compact heatsinking; ±2 % tolerance meets AEC-Q100 Class 2 voltage accuracy requirements.

Test & Measurement Equipment

Medical Diagnostic Interface

Use Scenario: Bias supply for op-amp rails and DAC reference buffers in portable benchtop analyzers.

IC Role / Device Role / Timing Role: Low-noise (75 µV/V), low-drift (−1 mV/°C) linear regulator stabilizing analog signal paths.

Use Value: Output noise specification directly supports <12-bit ENOB in precision data acquisition stages.

Use Scenario: Isolated auxiliary power for patient-connected sensor signal conditioning circuits in diagnostic ultrasound front-ends.

IC Role / Device Role / Timing Role: Safety-isolated 18 V source feeding isolated ADC drivers and anti-alias filters.

Use Value: TO-220FP package provides reinforced creepage (>5 mm) meeting IEC 60601-1 2×MOPP requirements.

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
LM7818CDT/NOPB	Higher quiescent current (8 mA vs. ≤6 mA); lower SVR (55 dB vs. 55 dB typical); same TO-220 package	No extended temp grade; rated only to 70 °C ambient (not junction), limiting industrial use	Prefer L7818CV-DG where extended temperature operation or lower IQ is required
MC7818BD2TR4	Tighter initial tolerance (±1 % vs. ±2 %); higher dropout (2.5 V vs. 2 V); D2PAK package with R_thJC = 3 °C/W	Optimized for high-current, high-thermal-demand applications with forced-air cooling	Choose MC7818BD2TR4 only when tighter initial accuracy and superior thermal performance outweigh TO-220FP's insulation benefits

Compared with LM7818CDT/NOPB, L7818CV-DG offers wider temperature range and lower IQ; versus MC7818BD2TR4, it trades 1 % tolerance and 0.5 V higher dropout for creepage-safe packaging and broader industrial qualification.

Availability

L7818CV-DG is available at Aetrix Electronics and suitable for industrial PLC power supplies, automotive body control modules, test equipment bias rails, and medical diagnostic interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7818CV-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 smart driving, power management, and industrial control applications.

L7818CV-DG belongs to the L78 positive voltage regulator IC family - engineered for cost-effective, robust local regulation in industrial, automotive, and medical systems where simplicity, reliability, and safety-certifiable packaging are prioritized over ultra-low dropout or ultra-low noise.

FAQ

What is the maximum allowable input voltage for L7818CV-DG?

The absolute maximum DC input voltage is 40 V when regulating 18 V output, per Table 1 of DS0422 Rev 38. Operation above 38 V risks exceeding safe SOA limits even with thermal protection engaged. For reliable long-term use, keep VI ≤ 35 V with adequate heatsinking and derate output current above 125 °C junction temperature.

Does L7818CV-DG require external capacitors, and what values are recommended?

Yes - a minimum 0.33 µF aluminum or tantalum capacitor is required at the input pin, and a minimum 0.1 µF ceramic capacitor at the output pin. These values ensure stability across all operating conditions; larger values improve ripple rejection but do not affect basic regulation. Electrolytic input caps must have ESR < 1 Ω; ceramic output caps must be X7R or better.

Can L7818CV-DG be used in parallel to increase output current?

No - the L7818CV-DG lacks built-in current-sharing capability. Parallel connection without external ballast resistors causes unequal current distribution and thermal runaway. For >1.5 A, use a single higher-current regulator (e.g., L78xxCD2T series) or switch to a switching controller with current-mode feedback.

Is L7818CV-DG compliant with RoHS and REACH regulations?

Yes - L7818CV-DG is RoHS-compliant (Pb-free lead finish, halogen-free molding compound) and REACH-conformant, as confirmed in STMicroelectronics' official product change notifications (PCN 19-0127) and material declarations. Full compliance documentation is available upon request through Aetrix Electronics' technical support portal.

L7818CV-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):: 18V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 2V @ 1A (Typ)

Current - Output:: 1.5A

Current - Quiescent (Iq):: 8 mA

Current - Supply (Max):: -

PSRR:: 53dB (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

L7818CV-DG FAQ

1.How can I place an order for L7818CV-DG through Aetrix?

Please submit a Request for Quotation (RFQ) for L7818CV-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 L7818CV-DG reliable?

The price and inventory of L7818CV-DG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7818CV-DG is usually 5 days.

3.What payment methods are accepted for L7818CV-DG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7818CV-DG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L7818CV-DG?

L7818CV-DG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L7818CV-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 L7818CV-DG?

For technical support, including L7818CV-DG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7818CV-DG requirements.

6.How does Aetrix verify that L7818CV-DG is sourced from the original manufacturer or authorized distributors?

All L7818CV-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 L7818CV-DG meets industry standards.

7.What is the process for return or replacement of L7818CV-DG?

All L7818CV-DG units undergo pre-shipment inspection (PSI). If there is an issue with L7818CV-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 L7818CV-DG part is unused and in its original packaging.

Return procedure for L7818CV-DG:

1.Submit a request within 90 days.

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

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