Dual MOSFET driver controller requires minimal external components for LLC topologies

ON Semiconductor has introduced an advanced SR controller optimised for LLC resonant converter topologies. The FAN6248 requires minimal additional components, delivers high efficiency, eases thermal management, improves overall system reliability, and simplifies the design of LLC power supplies. The device is an ideal solution for modern, high-performance, PSU where high levels of reliability and efficiency are required in a small space. Typical applications include server and desktop computing, gaming, large screen LCD TV and OLED TV, networking, telecom and LED lighting applications. The device incorporates an advanced, mixed, SR control methodology combining instantaneous drain voltage detection with previous switching cycle information. The separate 100V rated sense inputs accurately sense the drain and source voltages across the two SR MOSFETs, allowing for any asymmetries or poor coupling in the secondary winding. With this advanced control approach, the device prevents current inversion and avoids SR mis-triggering due to capacitive current spikes, giving highly reliable operation. The anti-shoot-through control within the controller enhances the reliability of the PSU and prevents potentially destructive simultaneous turn on of the two SR MOSFETs. "The FAN6248 comprehensively addresses the needs of modern LLC PSU designers. Innovations such as the mixed control methodology and adaptive parasitic inductance compensation ensure reliable and highly efficient operation." said Shane Chilton, general manager of the Power Conversion Solutions at ON Semiconductor. "With only two resistors and MOSFETs required to realise an advanced state-of-the-art LLC converter the controller will prove popular with all engineers that are designing for applications that require high levels of performance."