1 Description
The iW709 is an AC/DC secondary-side controller for USB Power Delivery (PD) 3.0 with Programmable Power Supply
(PPS) and Qualcomm® Quick ChargeTM QC4+ (QC2.0/QC3.0/QC4) support which integrates a secondary-side regulation
controller, interface protocol controller, USB VBUS driver and synchronous rectifier controller into a single IC.
The iW709 allows rapid charge of USB PD PPS or QC-enabled mobile devices (MDs). It resides on the secondary
side of an AC/DC travel adapter (TA) and allows the TA to be configured for multi-level output voltage and current.
The iW709 measures the output voltage and load current and sends the results to a digital compensator for closed-loop
control of flyback converter. The digital control signal generated by the compensator is converted to an analog signal
and transferred to primary controller via an optocoupler.
The iW709 is also an advanced synchronous rectifier (SR) controller with an integrated MOSFET driver. The device
works with an external power MOSFET to replace the main rectifying diode on the secondary of a flyback converter.
The SR control block optimizes the SR on/off timing and also uses proprietary technologies for timing control of ZVS
or active clamp flyback topologies to achieve best efficiency when coupled with Dialog’s ZVS-enabled primary-side
controllers.
The iW709 can be paired with one of Dialog’s high-performance flyback controllers that support either quasi-resonant
(QR) control or QR and Zero Voltage Switching (ZVS) technology to achieve high efficiency, low no-load power
consumption, accuracy voltage/current control and fast dynamic load response.

2 Features
● USB-IF certified: USB PD 3.0 with PPS
x Supports 3.3V to 21V in 20mV steps and output
current in 50mA steps
● Optionally supports Qualcomm QC4+
(QC2.0/QC3.0/QC4)
● High resolution accuracy multi-level output voltage and
current control
● Built-in digital loop compensation to minimize the
external component count
● Built-in synchronous rectification controller with
integrated driver
● Optimized VDS-based SR timing and driving control for
ZVS or active clamp flyback with wide output range
● NFET driver for VBUS switch
● Programmable active fast discharge from a high
voltage to 5V at MD unplug or from a high voltage level
to a lower level upon request with built-in switch or
external switch
● Intelligent low power mode enables very low no-load
power consumption when paired with one of Dialog’s
primary-side controllers, the iW9801 or iW9809
● Supports DCM and CCM operation
● PD-based power derating feature
● Wide VVIN operating range from 2.6V to 25V
● 16-Lead QFN package