ON Semiconductor has introduced a new solution for world-class, high-density power adapters for notebooks, tablets and other portable devices that require compatibility with the USB Power Delivery (USB PD) or Qualcomm Quick Charge™ specifications. The solution, which includes multiple patents pending, comprises the NCP1568 active clamp flyback (ACF) controller and a corresponding high-speed, half-bridge driver – the NCP51530. This results in a 65W USB-PD compliant adapter with a 30W/in3 power density while operating at 94.5% peak efficiency.
The NCP1568 is a highly-integrated ac-dc pwm controller that implements an ACF topology, including zero voltage switching (ZVS) for high-frequency applications (up to 1MHz) that demand high levels of power density and efficiency. Furthermore, the NCP1568 controller can implement ACF topology with proven super junction (SJ) FETs or with high-performance GaN FETs.
Through the inclusion of high voltage start-up a solution based on the NCP1568 requires few external components, reducing standby power consumption. Additionally, high frequency of operation enables reduction in passive component sizes, dramatically increasing power density. Its ability to seamlessly transition to discontinuous conduction mode (DCM) further improves efficiency in light load conditions, resulting in standby power levels of less than 30mW.
This also allows power supply designers to pass worldwide efficiency regulatory standards. Adaptive ZVS frequency modulation provides a variable output voltage that optimizes USB-PD and Quick Charge implementation.
Housed in a small TSSOP-16 package, the NCP1568 includes a variety of protection features. The quiet skip feature eliminates audible noise during operation, an essential requirement for indoor power adapter applications.
The NCP51530A/B are 700V high-frequency high-side and low-side drivers for directly driving two N-channel power MOSFETs in high performance power applications. A particular feature is the fast dynamic response; a 30ns propagation delay is ideal for high frequency operation, while the 5ns propagation delay matching ensures market leading efficiency performance.
The device provides a very robust solution with high dv/dt immunity (up to 50V/ns) and negative transient immunity. It is available in an SOIC-8 or DFN-10 package, with the latter offering improved creepage distances and an exposed pad. An AEC-Q100 qualified version is available in an SO-8 package for demanding automotive applications.
Commenting on the new releases, Ryan Zahn, Director of Marketing and Applications for the AC-DC Business Group at ON Semiconductor, said: “This solution represents a significant step forward in design for modern power adapters and battery chargers. Advanced features and flexible operation in the NCP1568 ACF controller deliver excellent efficiency, while utilizing SJ FETs, and requiring few external components, thereby enabling high density designs to be realized for USB PD. The NCP51530 drivers are a high-speed, high-performance robust power solution that includes the option of AEC Q-100 qualification for automotive applications.”