Reference design supports Qualcomm Quick Charge 4 Class A

Diodes Incorporated and Weltrend Semiconductor Inc have announced a joint reference design for a 27W, Class A charger that is one of the industry’s first chargers to support Qualcomm Quick Charge 4 specification for the fast charging of mobile devices.

Quick Charge 4 is the latest fast-charging specification from Qualcomm Technologies, offering up to 20% faster charging, up to 30% greater efficiency, and running 5% cooler when compared to Quick Charge 3.0.



Quick Charge 4 also supports USB PD and PPS (programmable power supply), helping to standardise the capabilities of adaptors using these technologies, while being designed to deliver headline-making charging performance that provides five hours of talk time from just five minutes of charging, along with comprehensive safety features.

The reference design uses Diodes’ AP3302 peak-current control, quasi-resonant (QR) PWM controller, which is optimized for high performance, low standby power and cost-effective offline flyback conversion, and its APR345 secondary-side MOSFET synchronous rectification driver that directly supports CCM, DCM and QR flyback topologies.

Weltrend provides the highly integrated WT6615F programmable protocol decoder that supports the latest programmable power supply specification for Quick Charge protocols and USB PD, and consequently fully implements all the requirements of the Quick Charge 4 specification.

Weltrend’s WT6615F Qualcomm Quick Charge 4 Controller is certified by GRL. The reference design supports Quick Charge 4 Class A (18-27W) and also provides optional Quick Charge 2.0 and Quick Charge 3.0 compliance to support the Quick Charge 4+ program.

It provides support for USB PD 3.0 and PPS, including PDO at 5V and 9V, ADPO from 3V to 11V in 20mV steps, and current from 0A to 3A in 50mA steps.

Its safety management capability provides monitoring of voltage, current, and temperature, with reporting and protection features. The charger design supports low standby current consumption and meets Energy Star DOE VI and CoC Tier II efficiency requirements.