Apparatus and method for distributing power-up power dissipation

A circuit for energizing a load comprising:

• a control circuit including:
• a first switch control output configured to control a first switch by providing a first control signal varying between establishing a cut-off state and a fully-on-state of the first switch;
• and
• a second switch control output configured to control a second switch by providing a second control signal varying between establishing a cut-off state and a fully-on state of the second switch;
• wherein the first and second switch control outputs of the control circuit are configured to respectively provide the first and second control signals to establish a load current to control a rate of change of a voltage across the load to energize the load using the first and second switches in a parallel configuration;
• first and second current monitor inputs;
• a supply voltage input;
• a load voltage input;
• and
• wherein the control circuit is configured to provide a signal at the first switch control output to place the first switch in the fully on state for a first period;
• to provide a signal at the second switch control output to place the second switch in the cut-off state, to receive a representation of the load current using the first and second current monitor inputs, to receive a representation of a voltage across the first switch using the supply voltage input and the load voltage input, to determine thermal stress information of the first switch using the load current and the representation of the voltage across the first switch, and to modify a length of the first period of the first switch using the thermal stress information.

A method for energizing a load comprising:

• providing a first signal at a first switch control output to place a first switch in a fully on state for a first period using a first control output of a control circuit
• providing a second signal at a second switch control output to place a second switch in a cut-off state using a second control output of the control circuit;
• receiving a representation of a load current of the load using first and second current monitor inputs of the control circuit;
• receiving a representation of a voltage across the first switch using a supply voltage input of the control circuit and a load voltage input of the control circuit;
• determining thermal stress information of the first switch using the load current and the representation of the voltage across the first switch;
• modifying a length of the first period of the first switch using the thermal stress information;
• and
• providing first and second switch control signals to establish a specified load current to control a rate of change of a voltage across the load to energize the load using the first and second switches in a parallel configuration.