SC4250 Negative Voltage Hot Swap Controller POWER MANAGEMENT Description Features u Programmable slew of the inrush current when The SC4250 is a negative voltage hotswap controller that allows the insertion of line cards into a live backplane. used for hot insertion in the negative 24V and 48V backplane The inrush current is programmable, and the closed loop u Closed loop operation limits the maximum current operation limits the maximum current even under short even in short circuit condition circuit conditions. A built-in timing circuit prevents false u Built in timer prevents false shutdown when the shutdown. The signal from the drain voltage is fed to the closed loop operation limits the current timer, providing safety for the MOSFET when in linear u Sensing the drain voltage allows for immediate mode. The SC4250 latches off under abnormal condi- shutdown in short circuit conditions where current tions The power has to be recycled in order to resume spikes and noise are ignored operation. u Power good signal u Input UVLO and OVLO sensing The device comes in two options, PWRGD (SC4250H) u Circuit breaker and retry and PWRGD (SC4250L). These high or low signals can u SO-8 package be directly used to enable power modules. Applications u Central office switching u -48V Distributed power systems u Power supply hotswap & inrush control Typical Application Circuit GND GND C1 U1 0 .1 PW RGD/ PW RGD SC4 2 5 0 1 8 PWRGD /PWRGD VCC VVEEee GND(remote) 2 7 R1 OV DRAIN 5 6 2 k R6 C4 1 8 k 3 .3 nF C5 3 6 UV GATE 1 5 0 R2 4 5 VEE SENSE 9 .3 1 k R5 1 0 R3 C2 1 0 .2 k C3 0 .0 0 1 0 .3 3 R4 Q1 0 .0 1 -- 4 8 V -- 4 8 V Figure 1 Revision 2.0 1SC4250 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Symbol Maximum Units Supply Voltage V -0.3 to 100 V CC DRAIN, PWRGD/ PWRGD -0.3 to 100 V SENSE, GATE -0.3 to 20 V UV, OV -0.3 to 60 V Thermal Resistance Junction to Ambient 168 C JA Thermal Resistance Junction to Case 38.8 C JC Operating Junction Temperature Range T -40 to 125 C J Storage Temperature Range T -65 to 150 C STG Lead Temperature (Soldering) 10 sec T 300 C LEAD Electrical Characteristics Unless specified: T = 25C, V = 48V, V = 0V. A CC EE Values in bold apply over full operating temperature range. Parameter Symbol Test Conditions Min Typ Max Units DC Characteristics Supply Operating Range V 10 80 V CC Supply Current I UV = 3V, 0V = V , SENSE = V 3 5 mA CC EE EE Circuit Breaker Trip Voltage V V = (V - V ) 50 60 70 mV CB CB SENSE EE Gate Pin Pull-up Current I Gate drive ON, V = V -50 A PU GATE EE Gate Pin Pull-down Current I Any fault condition 40 mA PD Sense Pin Current I V = 50mV -0.05 A SENSE SENSE External Gate Drive (V -V ), 20V < V 80V 9 13 16 V V GATE GATE EE DD (V -V ), 10V V 20V 8 GATE EE DD UV Pin High Threshold Voltage V UV Low to High transition 1.241 1.273 1.305 V UVH UV Pin Low Threshold Voltage V UV High to Low transition 1.192 1.223 1.253 V UVL UV Pin Hystersis V 50 mV UVHY UV Pin Input Current I V = V -0.1 A INUV UV EE OV Pin High Threshold Voltage V OV Low to High transition 1.192 1.223 1.253 V OVH OV Pin Low Threshold Voltage V OV High to Low transition 1.153 1.188 1.223 V OVL OV Pin Hystersis V 35 mV OVHY OV Pin Input Current I V 1.5V -0.05 A INOV OV 2