Programmable slew rate power path switch with integrated super capacitor charging system

A switching circuit connectable between an input source voltage both an output load for controlling an inrush current to the output load upon turn-on and also a backup power capacitor that provides backup power, the switching circuit including:

• an integrated circuit, the integrated circuit including:
• a first power PMOS load switch including a first load switch gate, a first load switch source and a first load switch drain, the inrush current to an output load passing from the load switch source to the load switch drain and being controlled by a load switch control voltage on the load switch gate;
• a second power PMOS load switch including a second load switch gate, a second load switch source and a second load switch drain that is connected between the output load and the backup power capacitor;
• and
• a slew rate control circuit connected to the first and second load switch gates of the first and second power PMOS load switches, respectively, that provides load switch control voltages to each of the first and second power PMOS load switches, the slew rate control circuit providing a first set of control signals that provides for low current charging through the second power PMOS load switch while also supplying the inrush current through the first power PMOS load and further providing a second set of control signals that provides for a discharge path through the second power PMOS load switch to supply backup from the backup power capacitor to the output load upon detection of a loss of the input source voltage.