on October 29th 123

All You Need to Know About the 7815 Voltage Regulator

If you're looking to understand the 7815 voltage regulator, this article provides a complete overview of its purpose, features, and applications. It explains how this regulator maintains a stable 15V output, ideal for circuits and devices that need reliable voltage, along with usage tips and common questions answered for clear guidance.

Catalog

Overview of the 7815 Voltage Regulator

The 7815 voltage regulator is widely used in electronic circuits to provide a steady output voltage. This regulator, part of the 78xx series, has “78” to signify it’s designed for positive voltage output, while “15” indicates it delivers 15 volts. This design keeps the output voltage consistent even when the input voltage fluctuates, which makes it suitable for powering components sensitive to voltage changes. With a maximum output current of 1.5A, it’s efficient for many applications. However, it tends to produce heat, especially when handling high currents, so a heat sink is recommended to keep it cool. For instance, if the input voltage is 20V and it’s supplying 1A, the difference (20V - 15V) results in 15 watts of heat, which the device dissipates during operation.

7815 Voltage Regulator Pinout

Pin Number	Pin Name	Description
1	Input (V+)	Unregulated Input Voltage
2	Ground	Connected to Ground
3	Output (Vo)	Outputs Regulated +5V

7815 Voltage Regulator CAD Model

7815 Symbol

7815 Footprint

7815 3D Model

Key Features of the 7815 Voltage Regulator

15V Positive Voltage Output

The 7815 voltage regulator consistently provides a stable 15V output, making it suitable for circuits and devices that require a steady voltage. This feature ensures that your connected components receive a reliable voltage, helping them operate smoothly without interruptions due to fluctuations.

Minimum and Maximum Input Voltage Range

The 7815 operates with an input voltage that ranges between 17V and 35V. This range gives you some flexibility when choosing your power source, as long as the voltage falls within this limit, the 7815 will maintain its regulated 15V output.

Maximum Output Current

Capable of handling up to 1.5A of output current, the 7815 is powerful enough for many devices. This current capacity allows it to support a range of components without overloading. If your project requires consistent current, this regulator’s output capacity makes it a good choice.

Built-In Protection Features

The 7815 includes thermal overload protection and short-circuit protection, which help extend its lifespan and protect your components. Thermal overload protection prevents damage from overheating, while short-circuit protection safeguards against electrical faults, giving you added reliability in your projects.

Wide Temperature Range

This voltage regulator can operate in a range from -40°C to 125°C. With this broad range, you can use it in various environments, from cold settings to warmer conditions, without impacting performance.

Available Packages

The 7815 regulator is available in TO-220, TO-3, and KTE packages. These package options provide flexibility for different setups, allowing you to choose the best option for your circuit layout and thermal management needs.

Applications of the 7815 Voltage Regulator

Constant 15V Output for Powering Devices

The 7815 is commonly used to supply a constant 15V output for powering microcontrollers, sensors, and other devices. By providing stable power, it ensures that your components work as expected without being affected by voltage drops or spikes.

Adjustable Output Regulator

In certain circuits, the 7815 can be used alongside other components to create an adjustable output. This application can be helpful when you need varying voltage levels across different parts of a project, giving you more flexibility in power management.

Current Limiter

With its reliable current output, the 7815 can also function as a current limiter. This feature can help prevent excessive current from damaging sensitive components, providing an added layer of safety and helping extend the lifespan of your circuit.

Dual Supply Regulation

The 7815 can work in a dual supply configuration, where it provides a positive regulated voltage alongside a negative regulator (such as the 7915). This setup allows you to achieve dual supply voltages, which are often required in amplifier circuits and other specialized applications.

Output Polarity-Reversal Protection

The 7815 can be used in circuits designed to protect against accidental polarity reversal at the output. This feature can prevent potential damage to your components, adding more durability to your project setup.

Guide to Using the 7815 Voltage Regulator

Using the 7815 voltage regulator is straightforward and requires only a few additional components. To get optimal performance, you’ll typically include two capacitors in the setup—a 0.33uF ceramic capacitor at the input and a 0.1uF ceramic capacitor at the output. These capacitors help smooth out any input voltage fluctuations and enhance the circuit's stability, which makes the overall setup more reliable. Placing these capacitors close to the regulator terminals is essential, as it maximizes their effectiveness in stabilizing the voltage. Ceramic capacitors work well in this setup because they respond quickly to voltage changes compared to electrolytic capacitors.

Specifications of the ON Semiconductor LM7815CT

Technical specifications, attributes, parameters, and comparable parts for the ON Semiconductor LM7815CT.

Type	Parameter
Mount	Through Hole
Mounting Type	Through Hole
Package / Case	TO-220-3
Number of Pins	3
Weight	1.214g
Operating Temperature	-40°C ~ 125°C
Packaging	Tube
Published	2014
JESD-609 Code	e3
Pbfree Code	Yes
Part Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	3
ECCN Code	EAR99
Terminal Finish	Tin (Sn)
Packing Method	RAIL
Terminal Position	SINGLE
Number of Functions	1
Terminal Pitch	2.54mm
Base Part Number	LM7815
Number of Outputs	1
Voltage - Input (Max)	35V
Output Voltage	15V
Output Type	Fixed
Output Configuration	Positive
Quiescent Current	8mA
Accuracy	4%
Max Output Voltage	15V
Output Voltage 1	15V
Number of Regulators	1
Min Input Voltage	17.5V
Protection Features	Over Temperature, Short Circuit
Voltage Dropout (Max)	2V @ 1A Typ
PSRR	70dB (120Hz)
Dropout Voltage	2V
Dropout Voltage1-Nom	2V
Power Supply Rejection Ratio (PSRR)	70dB
Voltage Tolerance-Max	5%
Nominal Output Voltage	15V
Output Voltage Accuracy	4%
Height	20.4mm
Length	31.75mm
Width	6.35mm
REACH SVHC	No SVHC
Radiation Hardening	No
RoHS Status	RoHS Compliant
Lead Free	Lead Free

Comparable Parts for the 7815 Voltage Regulator

Part Number	LM7815CT	L78M15CV-DG	MC7812ABTG	KA7815ETU	LM7810CT
Manufacturer	ON Semiconductor	STMicroelectronics	ON Semiconductor	ON Semiconductor	ON Semiconductor
Package / Case	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3
Number of Pins	3	3	3	3	3
Number of Outputs	1	1	1	1	1
Min Input Voltage	17.5 V	12.5 V	14 V	17.5 V	17.5 V
Voltage - Input (Max)	35 V	35 V	35 V	35 V	35 V
Nominal Output Voltage	15 V	10 V	12 V	15 V	10 V
Output Voltage	15 V	10 V	12 V	15 V	15 V
Accuracy	4 %	4 %	4 %	4 %	4 %
Dropout Voltage	2 V	2 V	2 V	2 V	2 V
View Compare	LM7815CT VS L78M15CV-DG	LM7815CT VS MC7812ABTG	LM7815CT VS KA7815ETU	LM7815CT VS LM7810CT

7815 Package Options

Manufacturer Information for the 7815 Regulator

ON Semiconductor, a company known for energy-efficient technology, manufactures the 7815 regulator. With a strong focus on helping customers manage energy more effectively, ON Semiconductor provides an extensive selection of power management and signal solutions. These are valuable across various fields, from automotive to consumer electronics, where energy efficiency and reliability are priorities. The company’s global infrastructure includes manufacturing facilities and design centers that ensure consistent quality and availability. This reach enables engineers and designers to rely on ON Semiconductor components, such as the 7815 regulator, to handle diverse project needs across different regions.

Datasheet PDF

MC7812ABTG Datasheet:

MC7812ABTG.pdf

MC7812ABTG.pdf

KA7815ETU Datasheet:

KA7815ETU.pdf

KA7815ETU.pdf

LM7810CT Datasheet:

LM7810CT.pdf

Frequently Asked Questions [FAQ]

1. What is the 78xx series voltage regulator?

The 78xx series includes positive voltage regulators that output a steady positive voltage relative to a common ground. The 78xx models are used to supply positive voltages, while their 79xx counterparts provide negative voltages. Together, these can be combined in circuits that require both positive and negative power sources.

2. What is the LM7815?

The LM7815 is a fixed-voltage regulator that outputs a stable 15V, making it suitable for a wide variety of applications. This regulator is commonly used to power TTL components, providing a reliable 15V output. It is available in several package types, including TO-220, TO-220FP, TO-3, and D2PAK, which offer flexibility in circuit design.

3. What are the three main types of voltage regulators?

Voltage regulators come in three main types: Step-Up, Step-Down, and Inverter regulators. Step-Up regulators increase the input voltage to a higher output level, while Step-Down regulators lower the input voltage to a reduced output level. Inverter regulators, on the other hand, convert a positive input voltage into a negative output voltage.

4. Where are voltage regulators commonly used?

Voltage regulators are widely used in motor vehicles to match the generator's output voltage with the electrical load and maintain battery charge. They are also found in electronic devices where stable voltage is required, as variations can disrupt the performance or potentially damage sensitive components.