Micrel devices provide safe board insertion, removal

Micrel Semiconductors announced that its MIC2586 and MIC2586R are single-channel positive voltage hot swap controllers/sequencers that are designed to provide safe insertion and removal of boards for systems that require live (always-powered) backplanes.

According to the company, these devices use few external components and act as controllers for external N-channel power MOSFET devices to provide inrush current control and output voltage slew rate control. Overcurrent fault protection is provided via programmable analog foldback current limit circuitry equipped with a programmable overcurrent filter. These protection circuits combine to limit the power dissipation of the external MOSFET to insure that the MOSFET is in its SOA during fault conditions.

The MIC2586 provides a circuit breaker function that latches the output MOSFET off if the load current exceeds the current limit threshold for the duration of the programmable timer. Meanwhile, the MIC2586R will attempt to restart power after a load current fault with a low duty cycle to prevent the MOSFET from overheating. Each device provides either an active-HIGH (-1BM) or an active-LOW (-2BM) "Power-is-Good" signal. They both provide up to three, time-sequenced "Power-is-Good" outputs that can be used as a control for dc-dc converter circuits or power modules.

The new products operate from 10V to 80V with 100V ABS (max.) operation.