MOSFET Controller from Diodes Incorporated Enables PSUs to Exceed Energy Star Efficiency Goals



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Enabling flyback power supply designers to replace inefficient Schottky rectifiers with a MOSFET driven as an ideal diode, the ZXGD3105N8 synchronous MOSFET controller from Diodes Incorporated can achieve a standby power consumption for set-top boxes of less than 100mW and full-load efficiencies greater than 87%. Drawing a quiescent current of less than 1mA, and with its ability to operate from supply voltages as low as 4.5V, the controller outperforms competing solutions and delivers flyback power supplies capable of exceeding the Energy Star standby ratings. Of interest to makers of AC-DC and DC-DC internal and external power supplies used in both industrial and consumer product sectors, the SO8 packaged ZXGD3105N8 can also operate at switching frequencies as high as 500kHz, affecting a reduction in transformer size leading to slimmer form factor design. To help maximize power supply circuit efficiency, the MOSFET controller functions as a proportional gate drive, which both protects against unnecessary MOSFET turn-off and reduces MOSFET turn-off propagation delay down to 15ns, thereby minimizing reverse current flow. The ZXGD3105N8 synchronous MOSFET controller is priced at $0.5 USD each in 10,000 piece quantities. Further information can be found at