High-Side Driver Supply With Reduced Coupling Capacitance

Abstract:
The parasitic capacitive coupling of high-side driver circuits is in the order of magnitude of the output capacitance of new semiconductors. To reduce the negative impact of the capacitive coupling, in particular common mode currents into the heatsink and the control circuit, a new gate drive supply circuit is presented, discussed and verified with laboratory measurements. In addition to a reduction of the capacitive coupling overall, the injected currents are differential mode, instead of common mode, enabling a much more effective filtering in common applications. Moreover, the impact on the inductor design is discussed, including a description of further optimization potentials.