With the popularization of gallium nitride fast charging, the gallium nitride device and the controller and driver are packaged in the same chip, and gradually become the mainstream efficient solution. By integrating two to three chips in the traditional Gallium nitride power supply, it not only simplifies the power supply design, but also greatly reduces the PCB footprint, meeting the pursuit of easy production and high cost performance of fast charging chargers.
Biyiwei has launched two closed gallium nitride chips using DFN8*8 packages, of which KP22066 has a built-in 165mΩ gallium nitride switch tube, and a single chip supports 100W power output. A large-area heat dissipation PAD is used at the bottom of the chip, which effectively reduces the temperature rise of the device. High-voltage start-up and X-capacitor discharge are also integrated, and the standby power consumption is less than 30mW, meeting increasingly stringent energy efficiency requirements.
Gallium nitride and controller, driver after all sealed, can reduce the impact of parasitic parameters on high-frequency applications, compared with the traditional multi-chip fast charging solution, the closure can greatly reduce the parasitic parameters caused by the ringing and overshoot, to avoid parasitic parameters caused by false opening, improve the stability of the charger, to meet the high-frequency switch applications.
First, Biyi micro 65W combined gaN fast charging reference design appearance
The Biyiwei 65W closed Gallium Nitride fast charge reference design uses two small boards to solder the input EMI filter circuit and the USB-C output mother. The output board also solders protocol chips to simplify circuit design and improve space utilization.
Since this reference design uses a Biyi micro-sealing Gallium Nitride chip, the primary side circuit is very streamlined, with only a rectifier bridge and KP22066 Gallium nitride sealing chip.
The length of the power reference design measured using a vernier caliper is 51.7mm.
The width is 30mm.
The height is 23.7mm and the power density is 1.766W/cm according to the size.
Second, Biyi micro 65W combined ganide fast charging reference design analysis
Thanks to the application of highly integrated gaN, this 65W fast charge design circuit is very streamlined, not only has a streamlined circuit, improved efficiency, but also has a very high power density.
The input board has a front soldered fuse, X capacitor, common mode inductor, and a diode and current-limiting resistor for high-voltage start-up on the back.
The input filter capacitor adopts Yongming KCX series high voltage capacitor, 400V 33μF, a total of three. The output voltage is fed back by an optocoupler.
The output uses two NMING's NPX solid capacitor filters, 25V 470μF, two in parallel.
From the side space, it can be seen that there is still a lot of room for reduction in the volume of the biyi micro 65W combined ganium nitride reference design.
The input rectifier adopts the Wald WRLSB60M rectifier bridge.
The Biyi Micro KP22066 is the core element of this fast charging reference design. The KP22066 integrates a 165mΩ conductivity-resisted Gallium nitride switch, a flyback controller, and reliable drive circuitry. The chip integrates a high-voltage start-up circuit to reduce start-up time and standby power consumption. An X-capacitor discharge function is also integrated to further reduce standby power consumption. At the same time, it has a highly reliable gallium nitride drive and provides a stable 6.2V gate drive voltage.
KP22066 adopts negative voltage current sampling technology, there is no sampling resistor in the drive loop, and the drive voltage is not affected by the current sampling resistor voltage drop when turned on, making it more efficient. The sealing technique further reduces the influence of parasitic parameters on high-frequency switches and improves overall stability. The KP22066 has three operating frequencies that can be configured via pins, supports 140kHz, 300kHz, 500kHz, supports 9-112V supply voltage, and is suitable for wide voltage output applications.
KP2206X built-in peak current jitter function to optimize EMI, support green mode and hiccup mode operation, integrated power supply undervoltage, overvoltage protection, integrated input undervoltage, overvoltage protection, integrated output overvoltage protection, cycle-by-cycle current limiting, overload protection, overcurrent protection, overtemperature protection, current sampling resistor open circuit protection and other protective measures.
It is worth mentioning that the KP2206X combination chip also supports dual windings to power the chip, with two power supply pins, which can switch the power supply winding tap according to the output voltage. When the output voltage range is wide and the output voltage is high, the chip can automatically switch to a low-voltage winding power supply, reducing the chip's own losses. KP22066 adopts The proprietary DFN8*8 package of BiyiWei separates the power trace and the control trace, and adopts a large-area heat dissipation PAD, which effectively reduces the temperature rise and has excellent heat dissipation performance.
The SMT Y capacitor comes from Terry Xiang.
The synchronous rectifier controller is also from BW, model KP4060, in a space-saving SOT23-6 package. The KP4060 supports operation frequencies up to 600kHz for KP22066 high frequency switching applications.
KP4060 supports DCM, BCM, CCM, QR operating mode and active clamp Flyback topology, supports 600kHz operating frequency, integrated high voltage detection circuit and high voltage power supply circuit, integrated intelligent dual LDO, no auxiliary winding power supply, support output short circuit SR operation.
The KP4060 supports a wide range of output voltage applications (0 to 20V), especially suitable for fast charging applications that support QC, PD and other protocols. And supports high-side or low-side configurations.
Synchronous rectifiers from Infineon, BSC0805LS, NMOS, withstand voltage 100V, conductivity resistance 8.5mΩ.
The output protocol chip comes from Huinengtai HUSB350, which is a single C-port protocol chip that has passed USB PD3.0 and PPS certification.
Third, Biyi micro 65W combined gaN fast charging reference design test
The following is the test information provided by Biyiwei on this gallium nitride fast charge, Biyiwei has carried out a detailed test of this scheme, and the test results are for reference.
According to the test data provided by Biyiwei, the conversion efficiency of the 9, 12, and 15V3A outputs of this 65W combined ganium nitride fast charge is higher than 92% at 230Vac input, of which the conversion efficiency of the 20V3.25A full-load output is about 93.5%, which is significantly improved compared with the traditional silicon MOS solution.
Next is the no-load standby power consumption test, the no-load input power consumption is 19.7mW at 110Vac input, and 26mW at 230Vac input, and the standby power consumption is eye-catching.
The KP22066 has excellent overload consistency protection, with a maximum output current of 7A at 5,9V output and a maximum output current of less than 5A at 12, 15, and 20V outputs, which meets the requirements of safety LPS.
This is followed by a conduction test of KP22066.
220Vac (L)-20V/3.25A
220Vac(n)-20V/3.25A
110Vac (L)-20V/3.25A
110Vac(n)-20V/3.25A
It can be seen through the test that the conduction test of KP22066 meets the standard and has a large margin.
Biyiwei has launched a variety of complete gallium nitride fast charging solutions, including KP2801 PFC controller for high-power applications, KP2206/2202 for direct drive gallium nitride switch tubes, KP22064/22066 for gallium nitride chips and KP4060 high-frequency synchronous rectifier controllers. In addition, the 120W fast charging scheme using PFC + gallium nitride sealing form is now available, and the charging head network will bring you detailed analysis and testing in the near future.
Charging head net summary
Through the demonstration of the reference design of Biyiwei 65W combined ganide fast charging, we fully felt the volume advantages of ganide sealing. The chip can significantly reduce the number of components and simplify charger design. The reduction in the number of devices can reduce the cost of mass production of chargers and speed up production, thereby accelerating market capture.
Through the test of conversion efficiency and standby power consumption, the performance advantages of the integrated gaN chip integrating the controller, driver, and gallium nitride device can be clearly seen. The increase in efficiency and the reduction of standby power consumption meet the increasingly stringent energy efficiency standards, which is more environmentally friendly and helps to save energy and reduce emissions.