For Digital Power Supply Based On The Research And Design Of Ad Converter Of Time

Switching mode power supply (SMPS) is taking a large part in the power management applications nowadays. In this thesis the development of power supply circuits is reviewed in brief. The classification of power supply is presented, as well as the comparison of advantages and disadvantages between them. Some fundamental of SMPS is introduced in details. SMPS can now be mainly divided into two types by the means of the controller implementation. One is analog power supply while the other is digital power supply. The former one is now the mainstream of the current generation of SMPS. But the later one is enjoying big research interests and is believed to be prospective enough to become the next generation of SMPS as it has some important advantages over analog power supply. The ADC in this thesis is used in the digital power supply. The function of ADC in digital power supply and ADC’s effect at system level is analyzed. Thus some system level constraints on ADC in digital power supply are summarized. Combining the time mode signal processing technique, a time based ADC structure is designed based on the analysis.As for ADC in digital power supply, universal theories of ADC are introduced. And the difference between ADC in digital power supply and ADC in other system like communication is also analyzed in this thesis. As the control loop of power management is a close loop system, the nonlinearity caused by quantization of ADC may results in an unstable loop. Constraints on ADC to avoid such unstable factor are summarized through small signal system analysis. Digital power supply system also has different requirements on ADC. This thesis summarized the structures and working principles of the wide-used ADCs in digital power supply. Comparison between them is done and their character in common is drawn.From the view of time mode signal processing (TMSP), this thesis introduces the principles of this technique. TMSP circuit design used in ADC implementation includes mainly two steps:voltage to time convert (VTC) and time to digital convert (TDC). Techniques used in these two steps like edge comparison and pulse width comparison and so on are introduced. An example of ADC via TMSP is given to illuminate the design flow of using TSMP in ADC design. The advantages and prospect of TSMP circuit are summarized.From the view of circuit design, the characteristic of the power system which is using the ADC is presented, especially the characteristic of DPWM module. A time-based ADC structure is proposed based on the combination of DPWM topology and TMSP technique. Behavior level validation of this structure is verified using MATLAB/Simulink tool. The building blocks of the ADC:ramp generator, comparator and encoder are analyzed theoretically. The guiding design rule of this ADC is to use DLL as a time quantizer to quantize pulse width. This can extend to other design tasks. For example, when a multichannel ADC is required, it could be done by simply add some comparator and encoder, while employing only one time quantizer and only one ramp generator. This can save much silicon area and power dissipation.After circuit designing and layout designing, the chip has been taped out using SMIC0.13um CMOS process. The test results show that it fulfills the application requirement. Test environment and test results are presented. Analysis of the test results is also presented.