Summit Microelectronics Debuts SMH4812 Hot-Swap Controller

Summit Microelectronics (UK) premiered a new distributed power hot-swap controller for use in communications equipment add-in line cards. The new SMH4812 allows an add-in board to be inserted into a powered backplane and eliminates power supply disruption. On card insertion, the controller monitors the input voltage to ensure that it is within its valid range. It also checks the pin-detect inputs to confirm proper card insertion. At this point, the SMH4812 applies power to the dc/dc converters by driving an external FET with a programmable slew-rate controller to control in-rush current. Once the voltage input to the dc/dc converter has stabilized, the converters are enabled.

The controller also monitors card operation, turning the card off if a fault is detected on the primary side. The forced shutdown input also allows the card to be turned off in the event of a fault detection on the secondary side. In either case, the card will be isolated from the rest of the cards in the system. The hot-swap controller is fully programmable. Options include over-current filtering and response, pin detection intervals and power-on delay timers.

The SMH4812 is available in 16-pin SOIC and SSOP-16 packages.