iW673-88 Dialog Semiconductor

iW673 Digital Green-Mode Synchronous Rectifier Controller 1 Description The iW673 is a high performance synchronous rectifier controller with an integrated MOSFET driver for flyback converters operating at discontinuous conduction mode. Combined with the MOSFET, the iW673 can emulate the diode rectifier at the secondary side of the flyback to reduce conduction loss. The iW673 determines the timing of the driver by sensing the voltage across the R to achieve lossless sensing. The iW673 uses proprietary digital adaptive turn- DS(ON) off control technology to minimize the turn-off deadtime of the synchronous rectifier so that the parallel Schottky diode required by conventional synchronous rectifiers can be eliminated. The integrated driver has strong driving capability for high efficiency. The operating power consumption of the controller excluding the driver is less than 4mW at no load to achieve the ultra-low no-load power consumption at 5V output. The iW673 integrates a pulse linear regulator to maintain the operation of the synchronous rectifier at low system output voltage when the system is operating in constant current (CC) mode. 2 Features Digital adaptive turn-off control minimizes dead-time Optimized 5V MOSFET gate driver Intelligent low power and eliminates the parallel Schottky diode management achieves ultra-low no-load operating current Integrated pulse linear regulator (PLR) enables SR operation at down to 2.4V system output when system Lossless MOSFET V sensing for SR timing control DS is in constant current (CC) mode with iW673-00, 6-pin SOT23 package iW673-01, or iW673-20 Wide V pin operating voltage up to 25V (16V for IN iW673-00) 3 Applications Compact AC/DC adapters/chargers for media tablets and smart phones V OUT + RTN iW673 1 V 6 DRAIN IN 2 5 SOURCE V CC + 3 4 OUT GND Figure 3.1 : iW673 Typical Application Circuit 12-Mar-2018 Product Summary Rev. 1.5 www.dialog-semiconductor.com 1 of 6 2018 Dialog SemiconductoriW673 Digital Green-Mode Synchronous Rectifier Controller L V OUT + + N RTN U2 U1 iW673 iW1602 1 DRAIN V 6 IN 1 6 V OUTPUT CC 5 2 SOURCE V CC + 2 5 V GND SENSE R 3 4 OUT GND FS 3 4 CFG CS/FS R ISNS Figure 3.2 : iW673 Typical Application Circuit Using iW1602 as the Primary-Side Controller (Achieving <75mW No-Load Power Consumption in 5V, 2.5A Adapter Designs with Fast Dynamic Load Response, and Supporting Constant Current Operation down to 2.4V System Output) L V OUT + + N RTN U3 iW673 U1 1 DRAIN V 6 IN iW1782 2 SOURCE V 5 1 8 V V CC + SENSE CC + 3 OUT GND 4 2 SD GND 7 OUTPUT NTC 3 DLNK 6 4 CS/CDC 5 ASU R CDC 3 2 1 V DRV DIS CC U2 iW636 D- GND D+ 4 5 6 D+ D- Figure 3.3 : iW673 Typical Application Circuit for Multi-Level Output Voltage and Current TM (Using iW1782 as Primary-Side Controller and iW636 as Secondary-Side Controller) for Qualcomm Quick Charge 3.0 (Achieving <20mW No-Load Power Consumption) Note: The DFET clamping circuit at the DRAIN pin of iW673 is not needed if the maximum voltage on the drain of the SR MOSFET is lower 60V. 12-Mar-2018 Product Summary Rev. 1.5 www.dialog-semiconductor.com 2 of 6 2018 Dialog Semiconductor