US Patent 8723590 Power switch current estimator at gate driver

A power switch current estimator for a solid state power switch. The power switch includes a control terminal, an input current power terminal, and an output current power terminal. The power switch is further configured with at least one sense terminal. One or more parasitic elements define an electrical pathway between a power terminal and a corresponding sense terminal. A driver unit that selectively turns the power switch on and off is connected to the control terminal and a sense terminal. A current estimator generates an estimated level of current circulating through the solid state power switch in real time in response to one or more switching events of the power switch. The estimated level of current is based on values of at least one of the parasitic elements such that the estimated level of load current substantially corresponds to an actual level of load current circulating through the solid state power switch.