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. Dialog’s 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 Dialog’s 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

multi-level output voltage and current applications

x Integrated pulse linear regulator (PLR) enables high

efficiency SR operation down to 3V under all load

conditions and below 2.4V under constant current

(CC) mode condition

x Supports Direct Charge down to sub-3V levels

x Wide VIN pin operating voltage up to 25V

● High voltage Drain sensing up to 100V with no

additional external clamping circuits required

● 6-pin SOT23 package

● Digital adaptive turn-off control minimizes dead-time

and eliminates the parallel Schottky diode

● Lossless MOSFET VDS sensing for SR timing control

● Optimized 5V MOSFET gate driver

● Intelligent low power management achieves ultra-low noload

operating current

● Built-in Active Voltage Positioning (AVP) to provide

fast system output voltage transient detection with

no additional pins or external components required. (iW676-3X/3XC options)