Various current-sharing controllers for current-sharing interface circuits

Current-sharing (CS) interface circuits are developed by applying the current-sensing, current-programming and current control techniques into the traditional ORing-MOSFET protection circuits. Using a CS interface circuit instead of a traditional ORing-MOSFET protection circuit in a high-availability parallel power module system can make the load current distribution problem among the non-identical paralleled power modules solved in an “add-in” way with relatively low cost. The applications of the various current-sensing, current-programming and current control techniques can produce many kinds of the CS controllers suitable for the CS interface circuits. The CS interface circuits controlled by different CS controllers will possess different operation characteristics. In this paper, eight kinds of the CS controllers are proposed. Two of them, as examples, are designed, simulated, implemented and tested with the power stages of the CS interface circuits. The data about the switch-mode characteristics and the steady-state CS performance of the CS interface circuits obtained from simulations and experiments are in good agreement with those obtained from theoretical estimations. Based on these data, the features of the CS interface circuits controlled by the proposed CS controllers are summarized.