Digital controller targets fast-charging applications

By Gina Roos, editor-in-chief

Infineon Technologies AG is claiming the industry’s first flyback controller with zero-voltage switching (ZVS) on the primary side to achieve high efficiency. The XDP digital power XDPS21071 controller targets fast-charging applications such as USB-PD or QuickCharge.

The XDPS21071 digital flyback controller comes with an integrated dual-MOSFET gate driver and a 600-V depletion startup unit. The primary-side controller drives a high-voltage external MOSFET in a flyback topology and an external low-voltage MOSFET to create a pulse for achieving ZVS condition at the high-voltage MOSFET. ZVS operation enables the lowest switching losses.

In addition, the XDPS21071 supports fixed-frequency switching up to 140 kHz, and light-load efficiency is optimized for variable output application.

Infineon’s forced-frequency-resonant (FFR) switching scheme is implemented with a digital algorithm, which is configurable via parameter settings (UART port is included) to meet application requirements and the conversion efficiency of international regulatory standards (i.e., EU CoC version 5 Tier 2 and DoE Level VI).

Ease of design and system optimization are made possible thanks to the intelligent, self-adaptive, multi-mode operation that matches each line/load condition with the best-fit operational mode (i.e., FFR, CrCM, burst mode), said Infineon.

The controller comes with adaptive overcurrent protection. It is lead-free and RoHS-compliant. The XDPS21071 in a DSO-12 SMD package is now available. A 45-W USB-PD Type-C quick-charger reference design (REF_XDPS21071_45W1) will be available in March 2020, featuring the digital flyback controller, 700-V CoolMOS P7 Superjunction MOSFET  (IPD70R360P7S), OptiMOS PD synchronous-rectification MOSFET (BSC0805LS), and small-signal-MOSFET (BSL606SN).