3-Amp buck regulators claimed as most-efficient available

June 10, 2014 // By Graham Prophet
Intersil’s highly integrated ISL85003/3A support the auxiliary rails on the latest FPGA platforms for the most demanding infrastructure and industrial applications.

ISL85003 and ISL85003A 3A synchronous buck regulators have integrated high side and low side MOSFETs. They have an input voltage range of 4.5V to 18V while delivering very efficient and continuous 3A and are, Intersil says, the most efficient regulators of their kind, improving reliability and extending the life of end products. The regulators are designed to deliver a very low resistance in a triode region RDS(ON) with an optimised current mode controller to further improve efficiency and reduce die temperatures, keeping complex systems cooler and preventing product failures.

Many 12V infrastructure and industrial applications need a buck regulator solution to step the system voltage down to 3.3V and lower while delivering a continuous 3A current. These applications require a high level of reliability and low power loss to extend product life and reduce risk of system failure. Existing 3A solutions have failed to meet the needs of these applications because they frequently hit their temperature limits, which reduces power management efficiency and product reliability.

Intersil specifically designed the new 3A synchronous buck regulators to operate at the highest efficiency. Based on a proprietary high-performance power FET, the ISL85003/3A's high side MOSFET runs at 65 mΩ and the low side RDS(ON) runs at 45mΩ. This makes them the lowest RDS(ON) buck regulator solutions, with up to 95% efficiency. The high efficient MOSFETs also enable the ISL85003/3A buck regulators to work in applications that do not have expensive cooling systems.

They have a light load mode that allows systems to go into sleep mode when power requirements drop, effectively consuming less power. MCUs or FPGAs are put into sleep mode during down time. For applications in which the load can vary from full operation to low power state, having a light load mode feature improves the overall system efficiency. In applications that do not require light load mode, designers can easily disable the feature, reducing the switching frequencies and simplifying design.