Fairchild Semiconductor used its PowerTrench process in building the new FDMS7650 30V MOSFET. The company guarantees the device for a 0.99mΩ maximum on-resistance at 36A with a 10V gate drive; resistance rises to a maximum of 1.7mΩ at 125°C. The FET has a pulse current of 450A and a junction-to-case thermal resistance of 1.2°C/W. With proper heat sinking, the device provides a power rating of 104W, and it features 15-nF maximum input capacitance and 209nC maximum gate charge with a gate-to-source voltage of 10V. Other features include 45ns and 133ns maximum turn-on and turn-off delays, respectively; maximum rise and fall times are 38ns and 34ns, respectively.
The device is useful as the ORing diode in server-farm power supplies. The parts provide an OR-diode function on the output of a single supply so that you can strap together multiple supplies for redundancy and reliability. The FETs are always on, so their efficiency affects the overall efficiency of these server farms. The low on-resistance also makes these parts useful as synchronous FETs in switching power supplies.
The FDMS7650 comes in an eight-pin-SOIC-derivative power-56 package with a large thermal bond pad. It operates in the -55°C to 150°C temperature range.
Fairchild Semiconductor
www.fairchildsemi.comCaption
You can use the FDMS7650 FET as an OR-function diode in server-farm intermediate-bus-power supplies or as the synchronous FET in switching power supplies.
