Abstract: A driving circuit for a solid state lighting apparatus includes a full wave rectifier configured to rectify an alternating current (AC) input voltage signal to generate a rectified input signal, a boost conversion circuit configured to receive the rectified input signal and responsively generate a direct current (DC) output voltage signal and to supply the output voltage signal to a solid state light source, and a boost control circuit coupled to the boost conversion circuit and configured to cause the boost conversion circuit to operate in a constant power mode.

Abstract: A gate-drive circuit (10) is an interface between a clock (12) and control circuit (14) and a circuit (16) comprising an isolated gate bipolar transistor (IGBT) devices. The clock (12) provides two complementary clock signals (CLK1, CLK2) to the gate-drive circuit (10); the control circuit provides a signal (ENABLE) for turning the gate-drive circuit on and off, and the gate-drive circuit outputs isolated supply voltages (+RAIL, -RAIL), a drive signal (GATE), and a common reference signal (EMITTER). The control signal is sent across an isolation boundary via a 2-MHz push-pull converter in the gate-drive circuit (10). A transformer (T1) in the gate-drive circuit provides the isolation boundary. The power required to switch the IGBT device (16) is sent through the same 2-MHz converter. The secondary of the 2-MHz push-pull transformer (T1) is referenced to the IGBT emitter.