This is a 65W gallium nitride (1A1C) PD fast charging power supply scheme, which adopts CX75GD015E+CX7539F, and achieves better power supply performance through the design of the scheme and PCB wiring. This 65W integrated GaN PD fast charging scheme has the advantages of small volume, low temperature rise, high efficiency and multi-protocol fast charging support, and is suitable for digital products such as chargers, power adapters, notebook computers and docking stations.

Characteristics of 65W GaN fast charger

1. The input voltage range is 90VAC~264VAC

2. The input standby power consumption is lower than 75mW @230VAC.

3. Output port C (5VDC/3A, 9VDC/3A, 12VDC/3A, 15VDC/3A, 20VDC/3.25A)

4. The total output power is 65W.

5. The ripple of output port C is 134mV.

6. It has the functions of output over-current protection, short-circuit protection and over-temperature protection.

7. Comply with "DOE&COC" level 6 energy efficiency standard.

8. passed the EMI test standard of EN55022 ClassB.

9. Pass EFT and Surge 4KV test standards.

USB-A port supports FCP, SCP, AFC, QC3+, DCP and Apple2.4A charging protocols.

USB-C port supports FCP, SCP, AFC, QC3+/5, PD3.0, PPS and DCP charging protocols. The USB-C port also has five 

groups of fixed voltage gears: 5V3A, 9V3A, 12V3A, 15V3A and 20V3.25A, and two groups of PPS voltage gears: 

3.3-11VF3A and 3.3-16V3A.

The whole power supply scheme is composed of CX75GD015E and synchronous rectifier CX7539F, which has high 

power density design, high integration, better loop stability and can greatly reduce the overall cost. This fast charging 

scheme supports a wide input voltage of 90~264V, and the output supports 5V/3A, 9V/3A, 12V/3A, 15V/3A and 20V/3.25A. 

This 65W fast charge reference design of gallium nitride adopts two small boards, and the protocol chip is welded on the 

output board, which simplifies the circuit design and improves the space utilization.

CX75GD015E is a high-frequency and high-performance quasi-resonant AC-DC conversion power switch with integrated 

high-voltage GaNFET power device, which is applied to isolated flyback switching power supply with high performance, 

low standby power, low cost and high efficiency within 65W.

CX75GD015E integrates complete protection functions, including: Vcc undervoltage protection (UVLO),Vcc overvoltage protection (Vcc_OVP), input undervoltage protection (Brown in), input overvoltage protection (Brown out), output overvoltage protection (VO_OVP), FB open and short circuit protection, secondary side SR short circuit protection, CS open and short circuit protection, etc. The scheme adopts "multi-protocol" design, is compatible with multiple PD protocols, and supports the output of 5V, 9V, 12V, 15V and 20V voltages, which can meet the charging requirements of various 3C digital products.

CX7539F is a high-performance synchronous rectification control circuit for the secondary side of switching power supply. In the application of low-voltage and high-current switching power supply, it can easily meet the energy efficiency of class 6, and is an ideal solution for ultra-low conduction voltage drop rectifier devices. The chip can support switching frequency applications as high as 150kHz, as well as switching power mode applications such as CCM/QR/DCM. The loss caused by its extremely low turn-on voltage drop is far less than the turn-on loss of Schottky diode, which greatly improves the conversion efficiency of the system and greatly reduces the temperature of the rectifier device.

CX7539F is a synchronous rectifier switch with built-in high voltage NMOSFET, and it has extremely low internal resistance, which can provide the application output of the system up to 5 years. IC determines the switching state of integrated MOSFET by detecting its source-drain voltage, which is compatible with flyback converters in continuous mode, discontinuous mode and quasi-resonant mode.

CX75GD015E sealed chip can significantly reduce the number of devices and simplify the design of charger. Reducing the number of devices can reduce the cost of mass production and speed up the production of chargers, thus accelerating the market capture. Thanks to the application of highly integrated and sealed gallium nitride, this 65W fast charge design circuit is very simple, which not only has a simplified circuit, but also has a very high power density. At present, Chengxin Micro has launched a number of complete gallium nitride fast charging solutions, covering 25W, 35W, 45W, 65W and other multi-power segments. A sealed gallium nitride chip can easily replace the functions of two or three chips on the primary side. A compact and efficient gallium nitride charger is designed through a highly integrated sealed chip, which can effectively simplify the charger design and production process, thus helping industry customers to seize the market quickly.

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