A modular approach to the design of high-power DC-DC converters

Ripple current in the power filter capacitors of a DC-DC converter can be reduced with a multiphase power switching circuit. Ripple current reduction is easier to achieve in the output filter capacitor than in the input filter capacitor because a low-impedance interconnect is required to take advantage of the possible reduction in the input. Noise and reparability requirements may demand the use of a relatively high-impedance interconnect among the input capacitors. Reparability of a converter is improved if components that can cause each other to fail are contained in the same module. Reliability of a power switching module is improved if it contains a current limit based on an extension of the power transistor off-time. Testing is simplified if the number of interconnects between modules is minimized.