The HIP1011 is the PCI Hot Plug voltage bus control IC for use in modern computer systems that facilitates hot plugging of adapter cards into and out of an active or passive back plane. Along with discrete power MOSFETs and a few passive components, the HIP1011 creates a small and simple yet complete power control solution. Four independent supplies are controlled, +5V, +3.3, +12V, and -12V. The +12V and -12V switches are integrated. For the +5V and +3.3V supplies, overcurrent protection is provided by sensing the voltage across external current-sense resistors. For the +12V and -12V supplies, overcurrent protection is provided internally. In addition, an on-chip reference is used to monitor the +5V, +3.3V and +12V outputs for undervoltage conditions. The PWRON input controls the state of the switches. During an overcurrent condition on any output, or an undervoltage condition on the +5V, +3.3V or +12V outputs, all MOSFETs are immediately latched-off and a LOW (0V) is asserted on the FLTN output. The FLTN latch is cleared when the PWRON input is toggled low again. During initial power-up of the main VCC supply (+12V), the PWRON input is inhibited from turning on the switches, and the latch is held in the Reset state until the VCC input is greater than 10V.