Proposal of an External Remote Sensing Circuitry for Switching-Mode Power Supplies

Abstract

This work proposes a low-cost and easy-to-implement solution for a remote voltage-sensing circuitry that can be used to ensure stability and good voltage regulation in applications with power supplies driving currents over long paths. The circuitry is implemented with general-purpose electronic components and is provided as an external feature to be attached to power supplies without remote sensing. To demonstrate its capabilities, a test bench was put together alongside a power supply module which has local sensing only. With the test bench, the output voltage from the power supply was delivered in various scenarios to an electronic load. Multiple parameters were monitored in order to assess the power supply performance to which the proposed remote voltage-sensing circuitry is attached. The measurements include stability and transient response tests, and the results were compared with the ones obtained with the standard local sensing. The tests reveal that the power supply module kept its output voltage stable with less than +/−10% voltage variation, and the average transient recovery time was less than 100 µs. The results are given for two different output voltage values of 1.2 V and 3.3 V and at high current capabilities of 3.5 A.