VOLTAGE SENSE METHOD AND CIRCUIT FOR START-UP OF PARALLEL SWITCHING CONVERTERS WITH OUTPUT CURRENT BI-DIRECTIONAL SWITCHES

摘要

The Voltage Sense Method is introduced and a number of its implementations using Voltage Sense Circuit are demonstrated to solve problems associated with the start-up of parallel switching converters, each converter having output synchronous rectifiers or more general Current Bi-directional Switches: prevention of the excessive reverse current, elimination of the excess voltage stress of the input switches and elimination of the voltage overshoot in the common output voltage. The Voltage Sense circuit added to each converter generates a Simulated Output Voltage, which predicts how would the output voltage of each particular unit rise during the start-up with enabled synchronous rectifiers if that particular unit were to operate alone. When the simulated output voltage of one converter reaches the actual common output voltage, synchronous rectifiers/CBS switches of that particular converter are all enabled so that their body-diodes, used up until that time to prevent reverse current flow, are by-passed eliminating all start-up problems.