Technology collaboration between Dialog Semiconductor and Qualcomm Technologies, Inc. has delivered a high efficiency AC/DC adapter interface IC for Qualcomm Quick Charge 2.0 power supplies. The new iW620 rapid charge interface IC is said to be found on the secondary side of the AC/DC charger power supply and works with Dialog’s iW1760 PrimAccurate primary-side digital pulse width modulation (PWM) controller.

The companies claim efficiency as high as 88 percent enables the higher power density needed for smaller form-factor fast charging adapters. Quick Charge 2.0 is a protocol from Qualcomm Technlogies, Inc., part of Qualcomm Incorporated, for charging smartphones, tablets and other mobile devices thought to be up to 75 percent faster than conventional USB charging technology.

Dialog’s Quick Charge 2.0 rapid charge AC/DC adapter solution is claimed to deliver high efficiency up to 83 percent without the need for a synchronous rectifier. This rapid charge solution can be used with a synchronous rectifier to provide even higher efficiency up to some 88 percent.

The rapid charge interface IC is said to detect commands from the Quick Charge 2.0-enabled mobile device via the USB cable, then communicates with the iW1760 PWM primary-side controller and configures the power adapter output voltage.

The company highlights that current sensing is performed by the iW1760 on the primary side, eliminating the need for a secondary-side current sense resistor for an inherently more efficient solution than similar Quick Charge 2.0 wall charger approaches. Primary-side current control is also said to enable low cost implementation of different constant current thresholds for each output voltage.

The iW620 is claimed to ensure safe operation with programmable, patented active fast output voltage discharge from 9V or 12V down to 5V. So, when the USB cable is unplugged from a Quick Charge 2.0 phone and then used with a non-Quick Charge 2.0 phone, the iW620 rapidly discharges the output voltage down to 5V, to protect the phone from damage.

Reducing battery charge time is one of the most compelling trends today in smartphones,” said Mark Tyndall, Senior VP Corporate Development & Strategy, GM Power Conversion Business Group at Dialog Semiconductor.

“Dialog is excited to debut the first primary-side regulation solution for Quick Charge 2.0, delivering on our goal to be an early provider of  high power density rapid charge solutions.”

The iW620 supports Quick Charge 2.0 High Voltage Dedicated Charging Port (HVDCP) Class A (5V, 9V, 12V output) applications and, with the iW1760 primary-side digital PWM controller, it is claimed to provide fast voltage transition and low no-load power consumption of under 100mW. The iW620+iW1760 rapid charge solution is claimed to provide comprehensive protection features: adjacent pin-to-pin short circuit and floating pin protection; built-in fault protections against output short-circuit, output over-voltage, output over-current, and current-sense resistor short; output current limit and over-load protection; and a dedicated pin for external over-temperature and over-voltage protection.

Dialog Semiconductor