VR transient improvement at high slew rate load--active transient voltage compensator

To meet the stringent transient response requirements of a voltage regulator (VR) at high slew rate load current while keeping high VR efficiency, this paper proposes a new topology: active transient voltage compensator (ATVC). ATVC only engages in transient periods operating at several MHZ to handle ac current and main VR operates at low switching frequency for better efficiency mainly providing dc current. ATVC injects a very high slew rate current in step up load and recovers energy in step down load. With introduction of a transformer, ATVC significantly reduces its conduction and switching losses due to the reduced current. Also, the new topology reduces the number of VR bulk capacitors while keeping the same output impedance. A built prototype and detailed experimental results verify the theoretical analysis. Index Terms--Active transient voltage compensator (ATVC), high slew rate, load line, synchronous buck converter, voltage regulator (VR).