Alternative “safe” test of hysteretic power converters

This paper presents a novel alternative “safe” test method for line and load regulation specifications of hysteretic controlled switching power converters. These specifications have not been tested in production before because the conventional measurement techniques lead to huge voltage spikes during switching transients. Those voltage spikes are caused by energy accumulation from parasitic inductances of ATE interface board to input capacitance of the device under test (DUT) and can damage DUT´s internal circuitries. The proposed alternative test approach offers a “safe” manufacturing test of load/line regulation specifications of hysteretic controlled switching power converters through a carefully altered feedback circuit and a current-limited load. Through injecting the altered feedback circuit with a carefully crafted stimulus, the load and line regulation specifications of DUT are accurately predicted. This test approach is facilitated by the use of a DAC for stimulus generation and ADC for DUT response capturing. Both simulated data and hardware measurements are used to demonstrate the viability of the proposed ”safe”testing method.