About Usonsemi Releases New Totem Pole Power Factor Controller
The NCP1681 can deliver solutions that operate at up to 99% efficiency
onsemi has introduced its latest mixed-signal controller dedicated to bridgeless totem pole PFC (TP PFC) topology. The new NCP1681 targets ultra-high density offline power supplies. Building upon the success of the 350W NCP1680 Power Factor Controller, the new controller extends the power capability into the kilowatt range.
Previously, TP PFC designs required the use of a microcontroller to control the operation, which added design complexity and the need for coding. However, with the onsemi NCP1681, only a few external components, no coding is needed for a fully-featured TP PFC solution, thereby saving time, cost and space.
“The new NCP1681 extends the benefits of code-free TP PFC design into higher power. This allows our customers to continue to enhance the efficiency of their design while reducing design time and cost, thereby delivering solutions to market quickly.” said Robert Tong, Senior Vice President & General Manager of Computing and Cloud Division for onsemi.
The onsemi NCP1681 can be configured to work in either fixed frequency continuous conduction mode (CCM) or multi-mode operation, where the PFC controller naturally transitions between CCM and critical conduction mode (CrM) for optimal performance across many power levels.
The new NCP1681 integrates established control algorithms with novel features to deliver a high performance and cost-effective TP PFC solution. Challenging efficiency standards such as ‘80Plus’ or ‘CoC Tier 2’, that require high efficiency over a wide load range, can also be met.
The NCP1681 is suited to higher-power power supplies from 350 W to several kilowatts range that operate on universal mains input (90 – 265 Vac), addressing a wide range of applications including server, high performance computing, telecom, industrial and OLED TV. At high power line, the NCP1681 TP PFC solutions will achieve close to 99% efficiency.
Features of the NCP1681 Power Factor Correction Controller include:
- Totem Pole PFC Topology Eliminates Input Diode Bridge
- Continuous Conduction Mode (CCM) Operation At High Power Level
- Optional Multi-mode Operation With CCM at High Power & CrM at Medium Power Level
- Frequency Foldback in DCM With 25 kHz Minimum Frequency
- Skip Mode in Very Light Load Condition
- Novel Current Sense Scheme
- Digital Voltage Loop Compensation
- AC Line Monitoring Circuit & AC Phase Detection
- Near Unity Power Factor in All Operating Modes
- PFC OK Indicator
More information on the NCP1681 Power Factor Correction Controller is available on the ONSEMI website at ONSEMI NCP1681 product page.
The onsemi website address is www.onsemi.com
[Reprinted with kind permission from onsemi - Release Date, 21st March, 2022]