阻抗轉換器應用於DC-DC功率轉換器回授補償電路之研究

Feasibility Study of Applying GIC to DC-DC Converter Feedback Compensation Circuit

潘添福(Tian-Fu Pan)

指導教授 ： 陳德玉

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.00984

摘要

由於目前大部分開關電源的回授補償電路都是採取外接方式，即採用離散型(discrete)的電阻電容元件兜在Control IC外側附近來實現的，往往佔去不少的電路板面積；在隨著低功率、體積小及可攜式消費性電子產品的應用需求日漸增加之下，現在的電源供應器切換頻率也愈來愈高了，這使得回授補償電路當中的電容值也愈來愈小了，但其值仍在nano-farad 級的範圍之內，這使得想以IC製程方式直接在Control IC裡頭做出nano-farad級的回授補償電容並不划算，因為超過這個數值目前所做出來的電容還太佔IC的面積了。
一源自於前人所提出的~Generalized Impendance Converter(簡稱GIC)的觀念，提供了我們一個或許是可以間接解決此一問題的方法，藉由GIC電路可以等效出許多阻抗類型的特性，我們就是想要利用當中它可以等效放大其電路當中的電容值這個特性，來取代外接回授補償電路當中的離散型(discrete)回授補償電容，如果可行，由於電阻已可以IC製程方式在IC內部實現，Control IC的外接回授補償電路即可以IC製程方式整合進Control IC內部，電源供應器電路板面積也就可以更為縮小，回授控制電路的設計及Layout上也將會更形簡化容易，對於大規模的生產製造上，成本也將可望伴隨降低，本篇論文主要即是在探討此一阻抗轉換器電路(GIC)應用於DC-DC功率轉換器回授補償電路當中的電源控制IC之可行性及問題之所在。

關鍵字

阻抗轉換器 ； 回授補償電路 ； 轉導放大器

並列摘要

Low- voltage low-power converters are used extensively in many battery-powered hand-held devices. In this type of application, the converter switching frequency is normally operated at frequencies higher than two to three hundred kilohertz. At such high frequencies, the converter feedback control compensation usually requires using capacitors of relatively small values. Integration of such capacitors into the converter controller chip becomes a viable option under such conditions, although these capacitors still occupy too much chip area.

In this thesis, investigation was conducted to evaluate the feasibility of using Generalized Impedance Converter (GIC) concept to reduce the chip area of a compensating capacitor for DC/DC converter applications. Several configurations of GIC were studied using simulations and discrete component experimentations. Under ideal component condition, the circuits perform as well as the theory predicts. However, when a non-idea operational amplifier was used in the simulations, characteristics of the GIC capacitors deviate from desirable features. Under certain conditions, GIC seems to work as a capacitor in low frequency area. This has been demonstrated by the discrete experimentation. But many questions are still unanswered. And warrant further investigation.

並列關鍵字

GIC (Generalized Impedance Converter) ； Feedback Compensation Circuit ； OTA(Operational Transconductance Amplifier)

參考文獻

[ 2 ] Sergio Franco,"Design with Operational amplifiers

and Analog Integrated Circuits",pp.176-179,McGraw

[ 5 ] Quirk,"Semiconductor Manufacturing Technology",

McGraw Hill,2001.

[ 6 ] "UA741 General-Purpose Operational Amplifiers