Integrated Circuits for Wide Vin Ranges

Bruce Schreiner posted 2014-07-08

Integrated circuit (IC) solutions in the industrial, automotive, and communications industries require a wide VIN range for their DC/DC power supply. The LM5000 series of high-voltage controllers and regulators from Texas Instruments (TI) is built to ensure that your architecture won't fry during a surge.  With over 35% of power management ICs rated above 20V, there are many designs that can be improved for safety, robustness, and every day high voltage uses.

Although power management ICs have been available for some time, the applications tended to be for lower input voltage requirements.  Existing high input voltage designs typically involve multiple low voltage rails each with integrated controllers, drivers, FETs, or even transformers.  Combining the features of the existing low input voltage ICs for high input voltage applications can reduce part counts, enhance reliability and encourages design reuse.

Advantages of the IC-based solutions for wide VIN DC/DC power solutions provided by TI include:

  • Robust operation for system reliability (eliminates added protection devices)
  • High performance and ease of use up to 100V (addresses popular high voltage bus voltages)
  • Broad portfolio in key topologies
  • Scalable, high-density devices

Systems that operate at high-input voltages (40V to 100), such as power over Ethernet (POE), require high-voltage ICs like the LM5017. In this setup, the chip can reduce your part count for the given implementation:

 

Automotive and industrial applications, however, typically operate at a lower voltage fixed rail between 12V to 24V. However, the occasional 60V high spikes means that protection is needed downstream for your circuit components. In this case, TI's LM5576 regulator might be a chip to look into for your solution.

 

For laptop consumer electronics, the TI LM5117 IC provides a buck converter design for a high current USB charging port application. The circuit can operate from a 12V/24V automotive power supply or a 19V laptop charger. Using the chip will allow for a smaller BOM and ensure the safety of the components at the higher voltages. 

Protection against the occasional spikes in low power circuits is provided by wide VIN IC solutions. These solutions give designers an extra wide margin of safety to create a robust design.  This will allow designers to reuse the architecture for different input/output rails without the need for design modifications.

The ability of the wide VIN ICs to provide inverting rails allows for multiple output supply rail designs. With the LM5007, designers can even produce negative voltages without using different multi-component circuit designs for each rail.

High-voltage semiconductor advancements have made integrated power management ICs for DC/DC controllers and regulators, such as the TI LM5000 series, an easy solution for wide VIN converter power circuits.  The use of these newer ICs provides design simplification, and added safety, for automotive, industrial, and network applications.  

Search the TI E2E Power Forum to find answers to VIN DC/DC questions and see what others are doing to update their resources with these tools.

Texas Instruments has sponsored promotion of their industrial communications solutions on ENGINEERING.com. They have no editorial input to this post - all opinions are mine.  Bruce Schreiner