應用於交流-直流複合晶片之變頻節能脈衝寬度
調變系統

雖然目前的交換式電源供應器已經比早期的線性式電源供應器輕巧許多，但是交換式電源供應器內部仍然含有許多的控制功能，以及各個控制電路所需要的外加被動元件，因此仍具有一定的體積與重量；若是將這些控制電路以及被動元件皆整合成為一個複合式控制晶片，將使得電源供應器的體積與重量能夠有效的縮減，同時產品的製造成本也能降低。因此本論文旨在提出一個結合功率因數校正電路、脈衝寬度調變系統以及啟動時序電路之交直流複合式控制器以應用於交流對直流電源供應系統。在現今能源短缺的時代，如何有效提昇電力設備的轉換效率便更顯得重要，因此在交直流轉換的過程中，利用功率因數校正電路降低電路上所產生不必要的虛功與諧波以提昇轉換效率；而在脈衝寬度調變系統的設計上，則具有變頻節能的功能，在轉換器產生額定輸出功率之使用率低於20%時，系統會切換至低頻操作，整體操作頻率降低為正常模式之操作頻率的1/3，是為節能模式，此時額定輸出功率降低為原本的1/3；當系統進入節能模式後，負載使用率必須高於額定輸出功率之25%，操作頻率才會切換回正常模式。節能模式以及正常模式之功率使用率切換點之不同，主要是為了防止相同切換點可能較容易產生振盪情形，因此將系統之切換點設定為具有5%之遲滯區間。由於脈衝寬度調變系統具有節能模式，因此轉換器能夠避免產生多餘的輸出功率，而達到使用上效率的提昇。最後，整體轉換系統的啟動、關閉以及內部晶片的時序管理則由啟動電路來控制。　　本交直流複合晶片採用TSMC 0.5um 5V/40V CMOS 製程實現。經由模擬顯示脈衝寬度調變系統將分別控制兩組不同的轉換器使其產生兩組不同輸出功率的直流電壓，以提供不同需求之應用負載使用；為了符合目前一般市面上普遍之交換式電源供應器操作頻率，因此調變系統之操作頻率訂為79kHz，而於此操作頻率下，整體脈衝寬度調變系統之功率消耗包含驅動電路僅為6mW。

關鍵字

交流/直流；脈衝寬度調變；馳返式；順向式；節能模式；最大週期鉗制

並列摘要

Though the present switching power supply has been already much lighter and handier than the early linear power supply. But the switching power supply interior still contains a lot of control functions and each control circuit needs some external passive devices, so it still has certain volume and weight. If we combine all the control circuits and the passive devices with whole combo control IC, it will efficiently reduce the volume and weight of the power supply, and the manufacturing cost of the products can be reduced, too. The thesis aims to combine the power factor correction circuit, the pulse width modulation system and the start-up controller to the AC/DC combo IC for the AC to DC power supply system. Nowadays, we are in an era of energy shortage, how to promote the conversion efficiency to the electric equipment seems more important. Therefore, during the process of handing in AC to DC transformation, in order to promote the conversion efficiency, we use the power factor correction circuit to reduce unnecessary busywork and harmonic components. In the design of the pulse width modulation system, the green-mode function is introduced to the PWM system to change the operation frequency which can save the power consumption. When the converter produces the normal rated power (NRP) whose utility rate is lower than 20%, the system will change to the low frequency operation which will decrease to one third of the normal mode. This is called green-mode. Meanwhile, the NRP will also decrease to one third of the original power. When the system changes to the green-mode, the utility rate has to 25% higher than the NRP, and then the system will change to the normal mode as well. The difference of the switching point between the green-mode and the normal mode is primarily to prevent the oscillation of the system. Because the green-mode is introduced to the PWM system, the converter can avoid extra power consumption to increase the efficiency while using. Finally, the start, close and the inside IC time sequence of the converting system are all controlled by the start-up controller. The whole chip is presented and fabricated in TSMC 0.5um 5V/40V CMOS process. It was displayed by the simulation result, the PWM system will respectively control two kinds of converters to produce two output dc voltages with different output power for different applications. Under the operation frequency of 79kHz, the whole PWM system including the drive circuit is only 6mW.

並列關鍵字

AC/DC ； Pulse Width Modulation(PWM) ； Flyback ； Forward ； Green-mode ； Duty Clamp

參考文獻

[1] J. H. Huijsing and D. Linebarger, “Low-Voltage Operational Amplifier with Rail-to-Rail Input and Output Ranges,” IEEE J. Solid-state Circuits, vol. SC-20, no. 6, pp.1144-1150, Dec. 1985.

[2] R. Hogervorst, J. P. Tero, R. G. H. Eschauzier, and J. H. Huijsing, “A Compact Power-Efficient 3V CMOS Rail-to-Rail Input/Output Operational Amplifier for VLSI Cell Libraries,” IEEE J. Solid-state Circuits, vol. 29, no.12, pp.1505-1513, Dec. 1994.

[3] R. J. Baker, CMOS, Circuit Design, Layout, and Simulation, 2nd ed., John Wiley & Sons, INC, 2005.

[4] W. Jin and Q. Yulin, “Analysis and design of fully differential gain-boosted telescopic cascode opamp,” ICSICT, vol. 2, pp. 1457-1460, Oct. 2004.

[5] K. Bult, and G. J. G. M. Geelen, “A Fast-Settling CMOS Op Amp for SC Circuits with 90-dB DC Gain, ” IEEE J. Solid-state Circuits, vol. 25, no. 6, pp. 1379-1384, Dec. 1990.

國際替代計量

應用於交流-直流複合晶片之變頻節能脈衝寬度調變系統

全文下載

主題瀏覽