SC4250

Negative Voltage Hot Swap Controller POWER MANAGEMENT Description The SC4250 is a negative voltage hotswap controller that allows the insertion of line cards into a live backplane. The inrush current is programmable, and the closed loop operation limits the maximum current even under short circuit conditions. A built-in timing circuit prevents false shutdown. The signal from the drain voltage is fed to the timer, providing safety for the MOSFET when in linear mode. The SC4250 latches off under abnormal conditions The power has to be recycled in order to resume operation. The device comes in two options, PWRGD (SC4250H) and PWRGD (SC4250L). These high or low signals can be directly used to enable power modules. SC4250 Features ‹ Programmable slew of the inrush current when ‹ ‹ ‹ ‹ ‹ ‹ ‹ used for hot insertion in the negative 24V and 48V backplane Closed loop operation limits the maximum current even in short circuit condition Built in timer prevents false shutdown when the closed loop operation limits the current Sensing the drain voltage allows for immediate shutdown in short circuit conditions where current spikes and noise are ignored Power good signal Input UVLO and OVLO sensing Circuit breaker and retry SO-8 package Applications ‹ Central office switching ‹ -48V Distributed power systems ‹ Power supply hotswap & inrush control Typical Application Circuit GND C1 0.1 8 PWRGD/PWRGD 1 U1 SC4250 PWRGD /PWRGD VCC GND(remote) R1 562k 2 OV DRAIN 7 Vee VEE R6 18k 3 UV GA...