EUP9290 ds9290 ver1.0 jan. 2017 1 synchronous rectifier controller description the EUP9290 is a high performance controller used t o secondary side synchronous rectifier (sr). the fundamental of EUP9290 is utilized n-channel mosfet power devices used for secondary side synchronous to emulate a near-ideal diode rectifier . this method not only directly reduces power dissipation of the rectifier but also reduces primary side losses as w ell. the EUP9290 is applied voltage-second balancing control method and not directly connected to the mosfet drain, so it is ideal for flyback power supp lies over the wide-output voltage range. the sr drive turn-off threshold is not related to the mosfet rds (on), which allows optimizing for maximum conduction time . the EUP9290 offers a frequency detector to automatically switch to standby mode during low pow er conditions and pin fault protections. it is compati ble with dcm, tm and ccm operation typical application circuit features secondary-side sr optimized controller for 5v to 24v flyback systems volt-second balance sr on-time control compatible with primary-side and second-side control ccm operation compatibility short pin fault protection available in sop-8 and sot23-6 packages rohs compliant and 100% lead (pb)-free halogen-free applications switching mode power supply(dcm, tm and ccm) chargers for smart phones and tablets high efficiency auxiliary power in server desktop and appliance application figure 1. sop-8 typical application
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