US Patent 9595949 Control of a clamp circuit during transient conditions

According to example configurations herein, a clamp circuit includes: i) a power dissipation circuit disposed between a first node and a second node of the clamp circuit, and ii) a capacitive element disposed in a control path between the first node and a control input of the power dissipation circuit. During operation, when a voltage spike occurs at the first node, such as caused by opening of a respective switch, the capacitive element in the control path conveys a portion of energy from the first node to control activation of the power dissipation circuit. That is, during the voltage spike, based on conveyance of the energy over the control path, the power dissipation circuit turns ON to dissipate the transient voltage, protecting a main power switch.