Hot plug computer system protection circuit

摘要

A protection circuit 116 for a computer system 110 having PCI expansion cards 120 and PCI expansion slots 118 with multiple power rails 312,322;314,328;318,324;320,326 for supplying power to the PCI expansion cards is disclosed. The protection circuit includes a current monitor 212 that monitors the current levels drawn by the PCI expansion card at each power rail. An inrush current controller 330/332/334 controls the initial current applied to each of the power rails when an expansion card is initially inserted into an expansion slot. A voltage monitor 212 monitors the voltage levels applied to selected power rails and a disconnector 210 disconnects the power to the PCI expansion slot when either the current level drawn by the PCI expansion card at any of the power rails goes beyond a selected range or when the voltage levels at any of the selected monitored power rails are below a selected threshold, or when commanded to by the computer system. <IMAGE>