Texas Instruments LM5025A PWM Controller – High-Voltage PS Controller in SOIC

Texas Instruments LM5025A High-Voltage Current-Mode PWM Controller

The LM5025A from Texas Instruments (TI) is a high-performance, current-mode pulse-width modulation (PWM) controller specifically engineered for high-voltage applications. This device simplifies the design of isolated and non-isolated power supplies operating directly from rectified AC or high-voltage DC sources. It integrates key features such as an internal startup regulator, precision reference, slope compensation, and soft-start timing – all within a space-saving SOIC-16 package.

For engineers designing high-reliability switch-mode power supplies (SMPS), the LM5025A offers tight control, high efficiency, and thermal robustness. It supports both primary-side and secondary-side regulation topologies, such as forward converters and flyback configurations, making it a popular choice for telecom, industrial, and embedded power systems.

Core Functionality and Benefits for Power Supply Designers

This device excels in powering systems with high-voltage inputs up to 105 V, eliminating the need for external startup components and reducing design complexity. It features a current-mode control architecture, which offers improved load transient response and simplified loop compensation.

Its integrated oscillator allows adjustable switching frequencies, enabling designers to trade off between efficiency and component size. In addition, the programmable soft-start minimizes inrush current during startup, while comprehensive fault protection mechanisms help safeguard both the controller and the power stage.

Technical Parameters – LM5025A Controller Overview

Why Choose LM5025A Over General PWM Controllers?

Unlike basic PWM controllers, the LM5025A combines several high-voltage handling and control features into one compact IC. Its integrated startup regulator streamlines the high-side power path, reducing component count and boosting system reliability. The current-mode control simplifies loop compensation and makes it easier to stabilize isolated converters under dynamic loads.

Texas Instruments enhances this part with robust protection features, including thermal shutdown, undervoltage lockout (UVLO), and cycle-by-cycle current limiting, giving it an edge in mission-critical systems. Its flexibility across multiple power topologies also supports a wide design range without the need for multiple controller types.

Typical Applications

• Telecom Power Systems: Provides isolated power conversion in distributed base stations and fiber networks.
• Industrial AC-DC Power Supplies: Powers controllers and motors with consistent voltage and protective feedback mechanisms.
• Embedded Computing Systems: Supports system-level power conversion for servers and field equipment.
• High-Voltage LED Drivers: Manages efficient switching and fault protection in lighting applications.
• Forward and Flyback Converters: Designed for both isolated and non-isolated topologies in switch-mode power supplies.

Texas Instruments – Proven Innovation in Power Conversion

As a global leader in analog and mixed-signal technologies, Texas Instruments offers products like the LM5025A that embody innovation, quality, and field-tested reliability. TI’s power controllers are developed with attention to longevity, system efficiency, and global regulatory compliance – backed by extensive documentation, application notes, and technical support.

Choosing a TI device ensures access to robust online tools and reference designs that simplify development cycles and reduce time-to-market for OEMs and industrial integrators.

Frequently Asked Questions (FAQ)

1. What is the primary advantage of using LM5025A in SMPS designs?

Its high-voltage startup regulator allows direct connection to high-voltage sources without needing external components, simplifying the power path and improving overall reliability in industrial systems.

2. Does this controller support isolated power supply topologies?

Yes, it is suitable for both forward and flyback isolated topologies, making it versatile for various AC-DC and DC-DC converter designs with tight feedback requirements.

3. How does the programmable soft-start improve performance?

It allows designers to control the ramp-up time of the output voltage, preventing inrush currents and reducing stress on both the converter and the load during startup.

4. Is the device suitable for high-frequency operation?

Yes, the switching frequency can be set as high as 1 MHz, giving flexibility in component selection and supporting miniaturization in space-constrained applications.

5. What kind of protection features are integrated?

The LM5025A includes cycle-by-cycle current limit, undervoltage lockout, and thermal shutdown, ensuring safe operation even under overload or short-circuit conditions.