The Application Design And Feature Study Of Graphic Card Power

The graphics card is an important part of the personal computer and mainly includes the Graphic Process Unit(GPU)and the memory unit Graphic Double Data Rate version 5(GDDR5),the graphic card is used as graphics processing and parallel computing.With the development of computer technology,the miniaturization of GPU and GDDR5 has gradually become a new trend,this requires the power supply circuit to be able to provide better power quality.Today's graphics card power supplies mainly use DC-DC buck solutions.Because there are different voltage requirements for different modules in the graphics card,the power supply scheme with different voltage regions is mainly adopted and different voltage standards are used for different modules.For example,the GDDR5 adopts 1.5V standard.The single-phase buck circuit is generally applied;the GPU based on a 14 nm Fin FET process mainly uses 0.9-1.2V standard,and the multi-phase buck circuit is generally applied.The work of this thesis mainly includes two parts.The first part designs the power supply application of GDDR5 in AMD graphics card.The scheme converts the 12 V of external input into the 1.5V required by GDDR5,and the application can provide the maximum 20 A output current for GDDR5.The application scheme uses GS-XXXX power chip,according to the requirements of the power supply parameters of GDDR5,the parameters of the components in the application circuit are determined,and the specific power supply application circuit is obtained.Through experimental validation of the output voltage ripple,bandwidth,duty cycle,dead time and other parameters of the application circuit,it is verified that the power supply application meets the basic requirements of GDDR5 for power quality.Since the power required by the GPU of the graphics card is much greater than the power of the GDDR5,the single-phase buck circuit cannot meet the power requirement,and therefore the power supply to the GPU needs to introduce a multiphase buck circuit.The second part of this article is mainly based on a voltage regulator IR-XXX(Voltage Regulator,VR)chip designed 6-phase buck circuit application.This scheme needs to meet the GPU's basic requirements for output current,bandwidth,ripple voltage,and phase margin.Under this premise,board-level external circuits suitable for voltage regulators are designed.It mainly includes current sampling circuit,VR enable circuit,load line regulation circuit,SVI2 protocol circuit,PWORK circuit,loop digital compensation,and peak current protection circuit.After the design of the scheme is completed,the 6-phase buck circuit of the GPU is verified.The test result shows that the six-phase buck circuit can meet the GPU's requirements for power quality.