US Patent 10574229 System and device for high-side supply

An electrical circuit includes a ground-referenced transistor and a non-ground-referenced transistor configured in a half-bridge topology. The non-ground-referenced power transistor has a first conducting electrode coupled to a high voltage power supply, a control electrode coupled to a high-side pre-driver, and a second conducting electrode coupled to a switch node. The electrical circuit further includes a boot-strapped capacitor having a bottom plate coupled to the second conducting electrode and a top plate coupled to the high-side pre-driver, and an interface coupled to a first sense device for sensing a voltage at the top plate, a second sense device for sensing a voltage at the bottom plate, and a charging device for selectively increasing the voltage at the top plate. The interface controls the charging device based on the voltage at the top plate and the voltage at the bottom plate.