Hot-plug controller does more in one

The ISL6111 hot plug controller IC offers increased integration with the inclusion of overcurrent and timing features that improve system performance while reducing BOM cost and board space.

The ISL6111 hot plug controller IC offers increased integration with the inclusion of overcurrent and timing features that improve system performance while reducing bill-of-materials (BOM) cost and board space.

Targeted for servers, the ISL6111 is billed as the industry's most complete and highly integrated hot plug solution for PCI and PCI-X.

"Our new ISL6111 is a performance and value upgrade for server board designers who are still using multiple-IC solutions that take up precious board space and add to the BOM and manufacturing costs", said Cindy Drapcho, Vice President of Intersil's Power Products.

"No competing IC offers such an integrated solution that controls all four power rails with programmable current limiting and over-current duration timing in a near-chip-scale 5 x 5mm package".

A complete PCI slot power control solution is accomplished with one small ISL6111, two power MOSFETs and a few passive components.

It provides a maximum current regulation to the load for each supply.

Load current limiting begins when the load current on any of the four rails exceeds the user-programmed level and continues for the user-determined period of time.

The current-regulation level is set using a single resistor and the duration is set with a single capacitor.

The ISL6111 provides PCI or PCI-X slot power control for the four legacy supplies (-12, +12, +5 and +3.3V).

For the 3.3 and 5V supplies, current monitoring is accomplished by sensing the voltage across external current-sense resistors and current regulation is provided by active current modulation through external N-channel MOSFETs.

For the +12 and -12V supplies, both current monitoring and current regulation are provided internally.

Any overcurrent condition places the associated control switch in a linear mode to regulate current to the resistor-programmed level.

An overcurrent condition is defined as a current level, greater than the programmed setting, that transitions through the threshold with a quick ramp (better than 0.5us).

This current regulation mode is maintained until the overcurrent condition ceases or the regulation duration period, as determined by selected capacitor value, expires.

In the current-regulation mode the IC's timing pin charges the capacitor with a 20uA current until the capacitor voltage reaches 2.8V, at which time a turn-off latch is set on all four control switches.

This results in the open drain fault output going low, signalling a latched off state.

Cycling the enable pin low clears the open drain fault latch.

Back to top