An Autonomous Control to Realize the AVP Scheme for a Switching-Mode DC-DC Converter
| Autor: | Chih-WeiLiu, 劉智偉 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 A digitally controlled Buck converter for adaptive voltage positioning (AVP) scheme is proposed in this thesis. Compare to the traditional Buck converter, AVP scheme can reduce almost half numbers of the output capacitor for the same design specification and thus save more cost and circuit area. In addition, AVP scheme can perform optimal fast transient response if the resistive output impedance could be achieved by tuning the current sensing parameter (Ri) to be equal to the value of the output capacitor equivalent series resistor (Rc). Practically, Rc value is not constant and would varies with circuit components and operating environment. Therefore, an auto-tuning algorithm is beneficial to tuning the Ri value in accordance with the operating status. Compare to the analog control approach, digital control is programmable, which enables a possibility of integrating the auto-tuning algorithm into the controller. Furthermore, Hall Sensor as well as the analog to digital converter(ADC) are the traditional way to obtain the inductor current for digital current control. Both of two components seize most of cost and circuit area. This research also adopts a self-tuning inductor current estimator. The estimator uses the available circuit parameters to derive the inductor current by a current sensing algorithm. The whole digital controller with two algorithms is realized by a FPGA board for the implementation of a PCB-layout 12V-to-1.2V switching Buck converter. Simulated and experimental results show that the digitally controlled AVP scheme is able to automatically tune the parameters of the controller for giving out optimal output voltage response. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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