Built-In Test of Switched-Mode Power Converters: Avoiding DUT Damage Using Alternative Safe Measurements

This paper proposes a novel test method for the line and load regulation specifications of switched mode power converters (SMPCs) using alternative safe measurements. These specifications are not tested for many power converters because they cause voltage spikes under full load conditions on the tester that can damage the converter circuitry. To prevent damage to the DUT during manufacturing test, we propose a modification of the power converter load during test application. Optimized low cost tests are applied to the converter under low load current conditions, allowing accurate prediction of the closed-loop load and line regulation specifications (that require high load current) from the modified test procedure without the possibility of any damage to the DUT. The test approach is facilitated by the use of two sensors that allow the line and load regulation specifications of the converter to be predicted accurately from the proposed alternative test measurements. Simulation data and measurements from a hardware prototype are used to demonstrate the viability of the proposed safe testing approach.