iW676-32

iW676 Digital Synchronous Rectifier Controller Optimized for Wide Range Outputs with Optional Active Voltage Position Control 1 Description The iW676 is an advanced synchronous rectifier (SR) controller with an integrated MOSFET driver for discontinuous mode flyback converters. The device works with an external power MOSFET to replace the main rectifying diode on the secondary of a flyback converter, improving efficiency by reducing conduction losses on the secondary. The iW676 uses lossless sensing by monitoring the voltage across the synchronous MOSFET to determine when to switch the FET, further improving efficiency. Dialogs digital adaptive turn-off control technology minimizes turn-off deadtime, eliminating the need for an additional Schottky diode that is typically needed in parallel with the synchronous MOSFET in conventional synchronous rectifiers. The iW676 has the ability to work at output voltages as high as 25V and as low as 3V under all conditions to accommodate a wide array of power supplies. It can sense drain voltages up to 100V, eliminating the need for an external clamping circuit in applications with multi-level output voltage applications up to 12V. A unique internal regulator circuit enables the iW676 to operate down to very low voltages on the output of the power supply, optimizing the device for Direct Charging applications down to sub-3V levels. The iW676-3X/3XC integrates Dialogs unique Active Voltage Positioning (AVP) control for fast dynamic load response and very low no-load power consumption (non-rapid charge applications), without increasing the package size or pin count. 2 Features Supports system output voltages from 3V to 25V in 6-pin SOT23 package multi-level output voltage and current applications Digital adaptive turn-off control minimizes dead-time x Integrated pulse linear regulator (PLR) enables high and eliminates the parallel Schottky diode efficiency SR operation down to 3V under all load Lossless MOSFET V sensing for SR timing control DS conditions and below 2.4V under constant current (CC) mode condition Optimized 5V MOSFET gate driver x Supports Direct Charge down to sub-3V levels Intelligent low power management achieves ultra-low no- load operating current x Wide V pin operating voltage up to 25V IN Built-in Active Voltage Positioning (AVP) to provide High voltage Drain sensing up to 100V with no fast system output voltage transient detection with additional external clamping circuits required no additional pins or external components required. (iW676-3X/3XC options) 3 Applications Compact AC/DC adapters/chargers for media tablets and smart phones V OUT + RTN iW676 1 V 6 DRAIN IN 2 SOURCE V 5 CC + 3 OUT GND 4 Figure 3.1 : iW676 Typical Application Circuit 04-Oct-2019 Product Summary Rev. 1.4 www.dialog-semiconductor.com 1 of 7 2019 Dialog SemiconductoriW676 Digital Synchronous Rectifier Controller Optimized for Wide Range Outputs with Optional Active Voltage Position Control L V OUT + + N RTN U2 U1 iW676 iW1602 1 DRAIN V 6 IN 1 V OUTPUT 6 CC 2 V 5 SOURCE CC 2 5 V GND SENSE + R FS 3 4 CFG CS/FS 3 GND 4 OUT R ISNS Figure 3.2 : iW676 Typical Application Circuit Using iW1602 as the Primary-Side Controller (Achieving < 30mW No-Load Power Consumption in 5V, 2.5A Adapter Designs with Fast Dynamic Load Response, and Supporting Constant Current Operation at Low System Output) L V OUT + + N RTN U3 iW676 U1 DRAIN V 6 1 IN iW1782 1 8 V V SENSE CC + 2 SOURCE V 5 CC + 2 7 SD GND 3 4 OUT GND OUTPUT 3 DLNK 6 NTC 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 : iW676 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) 04-Oct-2019 Product Summary Rev. 1.4 www.dialog-semiconductor.com 2 of 7 2019 Dialog Semiconductor