Dual Slot Hot Swap Controller for PCI Express

The LTC4242 Hot Swap™ controller allows safe board insertion and removal for two independent slots on a PCI Express backplane. External N-channel transistors control the 12V and 3.3V supplies while integrated switches control the 3.3V auxiliary supplies. Both 12V and 3.3V supplies can be ramped up at an adjustable rate. Dual level circuit breakers and fast active current limiting protect all supplies against overcurrent faults.

A supply filter at the VCC pin allows the LTC4242 to endure supply transients. The EN input detects the presence of a card in the PCI Express slot. The FAULT and AUXFAULT outputs alert the system of overcurrent conditions on the main and auxiliary supplies, respectively. PGOOD and AUXPGOOD outputs indicate proper main and auxiliary supply outputs.

Applications

* PCI Express-Based PC and Servers

* Hot Swap Application for Triple Supply Systems

* Allows Live Insertion into PCI Express® Backplane

* Controls Two Independent PCI Express Slots

* Independent Control of Main and Auxiliary Supplies

* 20V Rating for 12V Supply Input Pins

* Integrated 0.25Ω AUX Switches

* Limits Fault Current in ≤1µs

* Force On Test Mode

* Adjustable Supply Voltage Power-Up Rate

* High Side Drivers for N-Channel MOSFETs

* Thermal Shutdown Protection

* Available in 38-Lead QFN and 36-Lead SSOP Packages