TL783

TL783C High-Voltage Adjustable Linear Regulator

Overview

The TL783C is a high-performance, adjustable three-terminal linear voltage regulator designed for applications requiring high input voltages. With an input voltage range up to 125V, it provides a robust solution for power supply designs where standard regulators are insufficient. The device integrates critical protection features such as current limiting, thermal shutdown, and safe-operating-area (SOA) protection, ensuring reliable operation under demanding conditions.

This regulator is particularly suited for industrial, automotive, and telecommunications applications where stable voltage regulation is required despite wide input voltage fluctuations. Its adjustable output voltage (from 1.25V to 125V) and high output current capability (up to 700mA) make it a versatile choice for engineers.

Key Features

• Wide Input Voltage Range: Operates from 7V to 125V, making it suitable for high-voltage applications.
• Adjustable Output Voltage: Output can be set from 1.25V to 125V using external resistors.
• High Output Current: Delivers up to 700mA of continuous output current.
• Built-in Protections: Includes current limiting, thermal shutdown, and SOA protection for enhanced reliability.
• Stable Operation: Remains functional even if the ADJ (adjust) pin is disconnected accidentally.
• Low Dropout Voltage: Optimized for efficiency in high-voltage differential scenarios.

Applications

The TL783C is designed for a broad range of applications, particularly those requiring high-voltage regulation and robustness. Common uses include:

• Industrial Power Supplies: Provides stable voltage in motor control systems and factory automation equipment.
• Telecommunications: Used in base stations and networking hardware where input voltages can vary significantly.
• Automotive Electronics: Suitable for infotainment systems, sensors, and other automotive modules requiring reliable voltage regulation.
• Test and Measurement Equipment: Ensures precision voltage references in lab instruments.
• High-Voltage DC-DC Converters: Acts as a post-regulator in converter topologies.

Electrical Characteristics

The following table summarizes the key electrical specifications of the TL783C under typical operating conditions (unless otherwise noted):

• Input Voltage Range (V_IN): 7V to 125V
• Output Voltage Range (V_OUT): 1.25V to 125V (adjustable)
• Output Current (I_OUT): Up to 700mA
• Dropout Voltage: Typically 2V at full load (700mA)
• Line Regulation: 0.01%/V (typical)
• Load Regulation: 0.1% (typical)
• Quiescent Current: 10mA (typical)
• Operating Temperature Range: -40°C to +125°C

Package Information

The TL783C is available in a robust TO-220 package, which provides excellent thermal performance and mechanical durability. Key package details include:

• Package Type: TO-220 (3-pin)
• Pin Configuration:
  • Pin 1 (Input): Connects to the input voltage source.
  • Pin 2 (Ground/Adjust): Ground reference or adjustment pin for setting output voltage.
  • Pin 3 (Output): Regulated output voltage.
• Thermal Resistance (Junction-to-Ambient): 50°C/W (typical)
• Mounting: Through-hole, suitable for PCB or heatsink attachment.

Functional Description

The TL783C operates as an adjustable linear regulator, using an external resistor divider network to set the output voltage. The device maintains regulation by comparing a fraction of the output voltage (fed back via the ADJ pin) with an internal reference voltage. If the output voltage drifts, the regulator adjusts the pass transistor to correct the error.

Key functional aspects include:

• Current Limiting: Protects the device and load from excessive current by reducing output current if a threshold is exceeded.
• Thermal Shutdown: Disables the regulator if the junction temperature exceeds safe limits, preventing damage.
• Safe Operating Area (SOA) Protection: Ensures the device operates within voltage, current, and power dissipation limits.

Design Considerations

When implementing the TL783C, engineers should consider the following:

• Heatsinking: Due to potential high power dissipation, a heatsink may be required for high-current or high-input-voltage applications.
• Input/Output Capacitors: Use low-ESR capacitors at the input and output for stability and noise reduction.
• Adjustment Resistor Selection: Precision resistors are recommended for setting the output voltage accurately.
• PCB Layout: Minimize trace lengths for the ADJ pin to avoid noise pickup and instability.

Conclusion

The TL783C is a high-voltage, adjustable linear regulator offering robust performance and comprehensive protection features. Its ability to handle input voltages up to 125V and deliver a stable, adjustable output makes it ideal for demanding applications in industrial, automotive, and telecommunications systems. With proper design considerations, the TL783C provides a reliable and efficient solution for high-voltage regulation needs.