LM350 Voltage Regulator: Features, Specifications, and Applications

The LM350 voltage regulator is a reliable, adjustable power regulator commonly used in electronics. Known for its stable performance and moderate current capacity, the LM350 is suitable for applications requiring a flexible output voltage and a robust current supply. This article provides a comprehensive guide to the LM350's features, specifications, applications, and benefits, making it an essential resource for electronics enthusiasts and professionals.

 Key Features of the LM350 Voltage Regulator

1. High Current Capacity: The LM350 can handle output currents up to 3 amps (3A), making it ideal for medium-power applications. 

2. Adjustable Output Voltage: The LM350 supports a voltage range from 1.25V to 33V, allowing flexibility for various electronic circuits.

3. Thermal Protection: Integrated thermal overload protection safeguards the regulator against overheating.

4. Short-Circuit Protection: Built-in current limiting ensures safety during short circuits.

5. Safe Operating Area (SOA) Protection: Prevents the regulator from operating outside safe conditions, enhancing durability.

6. Wide Input Voltage Range: Operates with an input voltage up to 35V, enabling compatibility with various power sources.

 

LM350 Specifications 

o   Output Voltage Range: 1.25V to 33V (adjustable)

o   Maximum Output Current: 3A

o   Input Voltage Range: Up to 35V

o   Line Regulation: Typically 0.01%/V

o   Load Regulation: Typically 0.3%

o   Dropout Voltage: 2V (at full load)

o   Operating Temperature Range: 0°C to 125°C

o   Package Options: TO-220 and TO-3 packages

 

These specifications make the LM350 an ideal choice for projects that require moderate power regulation and stable performance.

 

Applications of the LM350 Voltage Regulator

 

1. Adjustable Power Supplies: The LM350 is perfect for building variable power supplies. By adjusting the voltage, users can power different devices with a single regulator.

2. Battery Chargers: Its high current capability and adjustable voltage output make it suitable for charging batteries such as lead-acid or NiCd batteries.

3. DC-DC Converters: Converts a higher input voltage to a regulated lower output voltage, commonly used in industrial and DIY projects.

4. Bench Power Supplies: Popular for creating DIY bench power supplies, providing a reliable source of adjustable voltage for testing and prototyping.

5. LED Current Regulation: The LM350 can operate in a constant current mode, making it ideal for driving LEDs or other loads requiring precise current regulation.

6. Solar Power Applications: Regulates solar panel outputs to power devices or charge batteries effectively.

 

How to Use the LM350: Circuit Configuration

 

Setting up the LM350 is straightforward, requiring minimal external components. A basic adjustable voltage regulator circuit includes:

 

1. Input Capacitor: Use a 0.1 µF capacitor on the input to filter noise and stabilize the input voltage.

2. Resistor Divider Network: Two resistors, R1 and R2, are used to set the output voltage. The output voltage is calculated using the formula:

  

Vout = Vref ​(1+R2/​R1​​) + IADJ​*R2​

  

 Vref-Reference voltage (1.25V)  

IADJ​-Adjustment pin current (typically negligible)

 

3. Output Capacitor: A 10 µF capacitor stabilizes the output voltage under varying load conditions.

 

Benefits of Using the LM350

 

-        Ease of Use: Requires only a few components for basic operation.

-        Cost-Effective: Affordable and readily available for both hobbyists and professionals.

-        Built-in Protections: Thermal overload, short-circuit, and SOA protections ensure durability.

-        Versatile Applications: Supports a wide range of devices and use cases due to its adjustable voltage and moderate current capacity.

 

Why Choose the LM350 Voltage Regulator?

 

The LM350 is an excellent choice for projects requiring an adjustable, reliable power supply with moderate current capacity. Whether you’re building a DIY power supply, designing a battery charger, or working on a solar-powered application, the LM350 offers flexibility, safety, and performance.

 

Frequently Asked Questions (FAQs)

 

Q1: What is the maximum current output of the LM350? 

A1: The LM350 can deliver a maximum current of 3 amps.

 

Q2: Can the LM350 be used as a constant current source? 

A2: Yes, the LM350 can be configured to regulate current for applications like LED drivers or controlled charging circuits.

 

Q3: What is the input voltage range for the LM350? 

A3: The LM350 operates with input voltages up to 35V.

 

Q4: Is a heatsink necessary for the LM350? 

A4: A heatsink is recommended if the regulator operates at high current or under continuous load to prevent overheating. 

Watch the tutorial on Youtube