On November 26, the 2021 (autumn) USB PD&Type-C Asia Exhibition was successfully held in Shenzhen, and the 2021 (autumn) USB PD&Type-C Asia Conference was also held during the exhibition, and 20 industry leaders were invited to discuss the present and future of USB PD&Type-C with everyone, and share the latest semiconductor technology and fast charging source solutions for everyone.
Mr. Zhang Bo, Vice President of Biyi Micro and General Manager of AC-DC Product Line of Power Management, delivered a speech on the theme of "Introduction of Biyi Micro High Performance, High Reliability Gallium Nitride Fast Charging Solution", based on the analysis of the characteristics of Gallium Nitride devices, detailed the advantages of Biyi Micro in gallium nitride direct drive and sealing scheme, and highlighted the reliability of the program.
As a professional power management chip design company, Biyiwei has the responsibility and obligation to promote the development of the gallium nitride industry, while providing customers with more reliable and cost-effective power chip solutions.
Founded in May 2014, Biyiwei is one of the few chip design companies in China that can provide a complete power management chip solution, covering consumer electronics, industrial and communication applications.
With its high-quality products and services, Biyiwei has won the recognition of more well-known customers in the industry.
Gallium nitride has changed the volume of traditional fast charging, Philips launched a GaN design LED bulb, lidar is also using gallium nitride inside, so gallium nitride properties have natural advantages over silicon, gallium nitride has a wide range of application prospects.
Gallium nitride is divided into D-mode and E-mode, D-mode depletion type is normally open type, and it is necessary to use series low-voltage silicon MOS in fast charging. The E-mode enhanced type is a normal-off type, which is used in a manner similar to traditional silicon MOS, and the device structure is simple, suitable for high-frequency applications. Today's speech revolves around E-mode gallium nitride.
Before using gallium nitride, the characterization of the gallium nitride device is performed. From the specification book of Innosyco INN650D02, it can be seen that the higher the drive voltage, the smaller the internal resistance; at room temperature, the drive voltage of 4-5V can be fully turned on; in the case of high temperature, a driving voltage of 6V is required to ensure that the device is fully opened after the junction temperature rises. If 5V drive is used, the internal resistance will be increased and the temperature rise will be increased. In addition, the drive voltage limit value cannot exceed 7V.
This is another specification for a GaN Systems device, which also requires the use of a 6V voltage to drive the Gallium Nitride switch, the use of 6V drive can obtain full on and optimal efficiency, and the 5V drive voltage can be used but will reduce the efficiency. It proves once again that for gallium nitride to be stable and reliable to use, the design of the drive circuit is very important.
Gallium nitride sealing solves the effect of parasitic parameters on performance of traditional discrete devices in high-frequency applications, and can avoid false opening caused by parasitic parameters. Because the sealing can reduce the parasitic resistance and parasitic inductance in the drive loop, improve the stability at high dv/dt and high di/dt, and truly meet the needs of 200-500KHz applications.
The KP2206 microcontroller has a built-in driver and a very simple peripheral circuit. The chip uses negative voltage sampling to ensure that the drive voltage remains stable during any turn-on and shutdown process, and reliability is fully guaranteed. As can be seen from the waveform graph, the drive voltage is very stable during the turn-on process.
Biyi micro KP2206 controller adopts direct drive design ideas, and the built-in LDO of the chip ensures the stability of the 6V drive voltage and improves the consistency of the product. The shutdown loop adopts ultra-low internal resistance downtube, which can effectively suppress oscillation in high-frequency applications and ensure stable shutdown.
Biyi micro-sealing gallium nitride chip minimizes the drive control loop through the sealing, and supports 6V drive voltage, the external drive voltage can be adjusted for driving speed, integrated current negative voltage sampling, reliability and ease of use are greatly improved. At the same time, the sealing scheme reduces the area by 50% compared with the traditional independent controller plus gallium nitride switch tube.
Biyiwei introduced the E-mode Gallium Nitride Direct Drive Control KP2206 and the KP2202 compatible with silicon MOS and nano-e-mode Gallium Nitride. Biyiwei has realized the mass production of Gallium Nitride controllers, which can be freely selected for different types of devices.
KP22064 and KP22066 are the latest gallium nitride sealing chips from Biyiwei, both of which are packaged in DFN8X8 packages and have a thermal PAD with a 90% area on the bottom. The KP22066 has an internal resistance of 0.2Ω and supports a 100W power output. The KP22064 has an internal resistance of 0.4Ω and supports a 45W power output. The operating frequency can reach up to 500KHz.
Biyiwei also introduced the KP2801 PFC controller for high-power PD fast charging applications, without auxiliary windings, and the periphery is simple. Supports single-stage self-starting, ideal for LLC applications.
Biyi micro 30W gallium nitride sealing scheme, using KP22064 gallium nitride chip + KP4060 synchronous rectifier controller, using ATQ1715 transformer, power density reached 25W / per cubic inch, efficiency reached 92.8%, 30W constant power output one hour temperature rise to 64 °C. Standby power consumption is less than 30mW and ripple is less than 120mV.
Biyi micro 65W gallium nitride sealing reference design, at room temperature, no external copper heat dissipation measures, full load output one hour temperature rise less than 80 °C, 30mW lower than standby power consumption and less than 120mV ripple, full load efficiency of 93.9%, to meet the LPS primary side current limiting needs.
The 100W reference design of Biyi micro adopts KP2801+KP2202+KP4060 Biyi micro complete solution, with an efficiency of 92.7%, no-load standby power consumption of less than 75mW, output full load ripple of less than 120mV, harmonics far below the standard.
Biyi micro-fast charging product series is complete, synchronous rectification products are divided into built-in MOS tube version and controller version, KP4050 for low frequency, KP4060 for high frequency, KP40511 suitable for 30W cost-effective applications. The high-frequency SSR master control is divided into a combination chip with integrated gallium nitride and a separate controller scheme. Biyiwei will also launch a protocol chip next year to achieve a full set of fast charging one-stop services, so stay tuned.
Charging head net summary
At the 2021 (Fall) USB PD&Type-C Asia Show, Biyi Microelectronics mainly shared the impact of the drive voltage of gallium nitride on performance, as well as negative voltage current sampling technology, which can eliminate the effect of sampling resistance voltage drop on the drive voltage of gallium nitride devices. At the same time, it also introduces Biyiwei's gallium nitride sealing chip and PFC chip.
The two gaN nitride chips launched by Biyiwei for USB PD fast charging are KP22066 integrated chips with built-in 0.2Ω conductive resistance gallium nitride switch transistor, which support 100W power output. The other clamping chip contains a 0.4Ω conductive-resistance Gallium nitride switch, KP22064, which supports 45W power output. Operates at frequencies up to 500KHz. The KP2801 PFC chip was introduced for high-power applications to meet the power factor correction of high-power fast charging.