LM350T Adjustable 3-Terminal Positive Voltage Regulator

Overview

The LM350T is a member of the LM150 series of adjustable 3-terminal positive voltage regulators, designed to deliver a robust output current exceeding 3A across an adjustable output voltage range of 1.2V to 33V. This regulator is engineered for simplicity and reliability, requiring only two external resistors to configure the output voltage. The LM350T offers performance comparable to discrete regulator designs while providing superior ease of use and integration. Packaged in standard transistor packages, it is suitable for a wide range of applications demanding stable and adjustable voltage regulation.

Features

• High Output Current: Capable of supplying more than 3A of continuous output current.
• Adjustable Output Voltage: Output can be set from 1.2V to 33V using external resistors.
• Excellent Line and Load Regulation: Performance rivals that of discrete regulator designs.
• Thermal Overload Protection: Built-in safeguards prevent damage due to excessive heat.
• Short-Circuit Protection: Internal circuitry protects the regulator from damage in case of a short circuit.
• Standard Transistor Package: Easy to mount and integrate into existing designs.
• Low Dropout Voltage: Efficient operation with minimal voltage drop across the regulator.

Applications

The LM350T is versatile and can be employed in a variety of applications requiring stable and adjustable voltage regulation. Common uses include:

• Power Supplies: Ideal for use in adjustable bench power supplies and fixed-voltage applications.
• Battery Chargers: Suitable for charging circuits due to its adjustable output and current handling capabilities.
• Industrial Equipment: Used in machinery and control systems requiring reliable voltage regulation.
• Automotive Electronics: Can be integrated into vehicle electronics for stable voltage delivery.
• Consumer Electronics: Applicable in devices such as audio amplifiers and other portable electronics.
• LED Drivers: Provides consistent voltage for driving LED arrays and lighting systems.

Electrical Characteristics

The following table summarizes the key electrical specifications of the LM350T under typical operating conditions (unless otherwise noted):

Absolute Maximum Ratings

• Input-Output Voltage Differential: 35V
• Output Current: 3A (continuous)
• Power Dissipation: Internally limited
• Operating Junction Temperature Range: -40°C to +125°C
• Storage Temperature Range: -65°C to +150°C

Typical Performance Characteristics

• Output Voltage Range: 1.2V to 33V
• Line Regulation: 0.01% / V (typical)
• Load Regulation: 0.1% / A (typical)
• Dropout Voltage: 1.5V at 3A (typical)
• Ripple Rejection: 80dB (typical)
• Temperature Stability: 0.7mV/°C (typical)

Package Information

The LM350T is available in a standard TO-220 transistor package, which is widely used and easy to mount. The package dimensions and pin configuration are as follows:

TO-220 Package Dimensions

• Package Type: TO-220 (3-pin)
• Length: 10.4mm (max)
• Width: 4.6mm (max)
• Height: 8.8mm (max)
• Lead Pitch: 2.54mm

Pin Configuration

• Pin 1 (Input): Connects to the input voltage source.
• Pin 2 (Output): Provides the regulated output voltage.
• Pin 3 (Adjust): Used with external resistors to set the output voltage.

Conclusion

The LM350T is a highly reliable and versatile adjustable voltage regulator, offering exceptional performance for a wide range of applications. Its ability to deliver high current, combined with excellent regulation and protection features, makes it a preferred choice for engineers designing power supplies, battery chargers, and other electronic systems requiring stable voltage outputs. The standard TO-220 package ensures ease of integration, while the minimal external component count simplifies circuit design. Whether for industrial, automotive, or consumer applications, the LM350T provides a robust solution for adjustable voltage regulation.