POINT OF LOAD CONVERTERS - The Topologies, Converters and Switching Devices Required For Efficient Conversion

摘要

Point of load (POL) or point of use (POU) converters are emerging as the popular solution for applications where circuits require low voltages of 3.3V and below. The demand for these types of voltage levels stems from the requirement for lower core voltages, and it is obvious that the current capability for these converters will increase even if the power capability stays the same. This has several implications on the power supply circuitry including the need to route low voltage, high current round a PCB board, leading to relatively large voltage drops, higher power consumption, large PCB tracks, and could result in poor output regulation. Also converting the voltage from 48V to 0.9V requires a very low duty cycle, which in turn results in a low efficiency. Typically there will be several voltage levels required across a PCB card and these could range from 5V down to 0.9V, resulting in the need for multi-output converters or several POL converters.