Efficient and powerful Dual-phase interleaved CCM PFC chip for high power AC-DC power supplies

The dual-phase interleaved power factor correction (PFC) technology reduces the input current ripple through a parallel structure, improves EMI performance, reduces the current stress on the switching device, distributes heat evenly, and thus improves system reliability and lifespan. Therefore, it is widely used in medium to large power applications, especially in high power density, flat design applications with stringent requirements. The mainstream dual-phase interleaved CCM mode PFC chips on the market, such as UCC28070,FAN9672, R2A20114BFP, STNRGPF02, etc., are mainly analog chips. For the ever-changing various application scenarios, it is becoming more and more restrictive. Hynetek HP1011 and HP1013 are interleaved Boost PFC converters with Continuous Conduction Mode (CCM) of inductor current. The main difference between these two chips is in the degree of integration, HP1013 built-in dual drive, further simplifying the peripheral circuit. Compared to the previous generation of analog solutions, the two Hynetek HyCtrl® chips have two major advantages: flexible configuration and intelligence.

Figure 1: Typical application of dual-phase interleaved PFC, HP1011 (left) externally driving HP3000, HP1013 (right)

Simple And Flexible Configuration

HP1011 and HP1013 integrated complete protection functions and intelligent communication and many other excellent performance, can help customers easily design a high-performance, highly reliable switching power supply products. At the same time, the digital core of HP1011 and HP1013 ensures the flexible configuration of key parameters to meet the different specifications of various applications. Customers can use HP1011 or HP1013 to replace similar products from friends, such as UCC28070, FAN9672, R2A20114BFP, etc., at a lower replacement cost and better performance.

Dynamic equalization of phase currents

The parallel structure of two-phase interleaved PFC inevitably needs to solve the problem of current asymmetry caused by the difference between the two branches. Usually, the differences mainly come from the layout of the circuit version of the alignment differences in the circuit device itself. These differences can lead to distortion of the feedback signal, resulting in the asymmetry of the two currents. hp1011 supports dynamic equalization of phase current. The GUI software can be configured to enable dynamic equalization of inductor currents between the two channels, and the average current RMS deviation of inductor currents between the two phases is less than 5%. As shown in Figure 2, current equalization (IBAL GAIN) has four stops to choose from. If the specific degree of difference between the two branches is very small, you can select the coefficient 1; Conversely, if the difference is large, the coefficient of 4. Obviously, this simple and flexible choice, than the optimization of the placement of the circuit, as well as the elimination of errors in the design, the efficiency of the work is much higher. Moreover, in a limited space and system environment, absolute symmetry is impractical. Dynamic current equalization is even more important in this case. A true increase in design flexibility.

Figure 2: Configuration interface (GUI) for two-phase interleaved PFC, phase-slicing and equalization

Figure 3: Enable dynamic current sharing of phase current. Current sharing can still be achieved even when there are obvious differences in two-phase parameters.

Intellectualize

Equipment intelligence is the inevitable result of complying with the policy and market. First of all, according to the National Development [2024] No. 7 document, “Promoting Large-scale Equipment Renewal and Consumer Goods Replacement Action Program”, the Ministry of Finance and the State Administration of Taxation issued Announcement No. 9 of 2024, which gives enterprise income tax inclination to the digitalization and intelligent transformation of energy-saving and water-saving, environmental protection, and special equipment for safe production. Secondly, driven by the catalytic commercialization of AI in various industries, more and more scenarios require information transfer for further intelligent processing. For example, the back-end system of electric vehicle charging station needs to communicate with the charging vehicle to control the charging process, monitor the charging status and billing; smart home and IoT devices need efficient power management to extend the life of the devices and optimize energy use. If the PFC controller can communicate with the home energy management system to coordinate device power management, power quality optimization and efficient energy consumption can be achieved. For these application requirements, the HP1011 specifically supports power metering and communication interfaces.

Power Metering For The HP1011

The HP1011 provides information on 5 parameters: input voltage, current average, input power, input voltage frequency, and input voltage average. In addition, the monitored power range and monitoring update rate can be adjusted through four configuration options to meet the actual needs of the design application. The figure below shows the actual power metering curves measured on the HP1011 600W evaluation board. 200W and above, the accuracy is basically within 2%. For loads above 50%, 1% accuracy can be achieved.

Figure 6: Power metering accuracy curve (HP1011 600W measured waveform)

I2C & UART Communication Interface

Applications that communicate with PFC controllers often involve complex power management and intelligent optimization requirements that require real-time monitoring, remote control, and data exchange to ensure efficient, stable, and reliable system operation. With the communication function, PFC controllers can provide critical power quality data and receive optimized control commands to improve the overall system performance. hp1011 provides two common communication interfaces, I2C and UART. The data transfer rate of UART has 4 kinds of options.

Figure 7: UART, I2C Communication Interface

In summary, the HP1011 and HP1013 are the latest digital controllers for Hynetek dual-phase interleaved CCM-mode PFCs with average current control. Their digital architecture is based on a high-speed digital state machine architecture and integrates a high-performance analog front-end as well as a high-speed comparator to ensure high-performance real-time control of the PFC. The digital core gives engineers a very flexible and differentiated design and a simple and fast design experience. In addition, the rich protection functions of these two chips protect the new generation of intelligent scenes.

Figure 8: HP1011 (left), HP1013 (right) Pin Definition and Package Diagrams

Hynetek has synchronized the HP1011 1000W evaluation board. The basic parameters of this evaluation board are as follows:

Input voltage range: 90 VAC ~ 265 VAC

Output Voltage: 400 VDC

Output Power: 1000 W

Typical Efficiency: 98.5%

Figure 9: 1000W evaluation board using HP1011