ISL6112

Description

The ISL6112 targets the PCI-Express add-in card hot plug application. Together with two each of N-Channel and P-Channel MOSFETs, four current sense resistors and several external passive components the ISL6112 provides a compliant hot plug power control solution to any combination of two PCI-Express X1, X4, X8 or X16 slots. The ISL6112 features the ability to program a maximum current regulated level for each of the MAIN outputs for a common programmable duration so that both fault isolation protection and imperviousness to electrical transients (OC and soft-start protection) are provided to each system supply. For each 12VMAIN supply, the current regulated (CR) level is set by a resistor value dependant on the size of the PCI-Express connector (X1, X4/X8 or X16) to be powered. This resistor is a sub ohm standard value current sense resistor one each for each of the 3VMAIN and 12VMAIN supplies. The voltage across this resistor is compared to a 50mV reference providing a nominal CR protection level which would be set above the maximum specified slot limits. The 3.3V supply can use a 15m sense resistor compared to a 50mV reference to provide a nominal regulated current limit of 3.3A to all connector sizes. A shutdown without a CR duration delay is invoked if RSENSE voltage is >100mV. The VAUX is internally monitored and controlled to provide nominal limiting to 1A of load current. The ISL6112 is System Management Interface (SMI) capable with an integrated SMBus link for communication, control, monitoring and reporting of IC and slot conditions. Information such as UV, OC, STATUS, power level etc. are available. Additionally the IC has a minimum of I/O for implementations where Hot-Plug Hardware Interface (HPI) is implemented.