ADI’s iCoupler  isolated switching regulators use a secondary side controller architecture with isolated pulse-width modulation feedback and integrated transformer drivers. The secondary side controller senses the output voltage via a resistor divider and creates a PWM signal that is sent across the isolation barrier to the primary side controller. The primary side PWM converter varies the duty cycle of the X1 and X2 switches to modulate the oscillator circuit and control the power being sent to the secondary side. This feedback allows for high efficiency and better regulation and accuracy since the output voltage is directly sensed. The secondary-side controller replaces the optocoupler, shunt regulator, and compensation network in the traditional primary side controller approach. All loop compensation is integrated within the device, which significantly reduces design complexity, time to market, and cost. Fully tested reference designs using specific transformers are available in the device datasheets.