本論文採用三角波隨機跳頻機制，實現低切換突波與低諧波量降壓型轉換器電路。除了分析鋸齒波和三角波與電感電流的關係外，並將兩者整合在電路裡面，比較輸出電壓的變化量。利用隨機跳頻的機制來降低諧波量，並比較八個頻率與單一頻率的輸出電壓頻譜。此低諧波量降壓型轉換器電路將功率電晶體也一併整合於晶片之中，以減少PCB面積與成本。
本論文晶片以TSMC 0.35 μm Mixed-Signal 2P4M Polycide 3.3/5 V製程實現。規格如下：輸入電壓為5 V，輸出電壓為2.5 V，操作頻率範圍為1.5 MHz ~ 3.25 MHz，輸出最大負載電流為500 mA。根據模擬結果，使用本論文所提出的三角波跳頻機制電路，直流-直流轉換器的輸出電壓諧波量在八個跳頻頻率的情況下比單一頻率降低約27 dB。使用鋸齒波從低頻跳到高頻的輸出電壓變化量和回復時間為42 mV和70 μs，而高頻跳到低頻分別為45 mV和92 μs。三角波從低頻跳到高頻的輸出電壓變化量和回復時間為28 mV和47 μs，而高頻跳到低頻分別為36 mV和30 μs。三角波的輸出電壓變化量與回復時間都優於鋸齒波的數值。

This thesis introduces a random frequency hopping with triangle-wave control to implement a buck converter with spur and harmonic reduction. The sawtooth-wave and triangle-wave are analyzed the relation with the inductor current, and are integrated into the converter to compare the variation of output voltage further. A random frequency hopping scheme is used to reduce harmonics, and the frequency spectrum of the output voltage is compared with eight and single switching frequencies. The power MOSFET are integrated into the chip of spur reduction design of a buck converter for decreasing the PCB area and cost.
The chip is implemented with TSMC 0.35 μm 2P4M CMOS process. The specifications are as follows: the input voltage is 5 V, output voltage is 2.5 V, the operating frequency is from 1.5 MHz to 3.25 MHz, and the maximum output current is 500 mA. To compare with eight and single switching frequencies, the proposed frequency hopping circuit can suppress the output harmonics by 27 dB from simulation results.
When switching frequency is from low to high with the sawtooth wave, the variation of the output voltage is 42 mV and the recovery time is 70 μs. The variation of the output voltage is 45 mV and the recovery time is 92 μs when switching frequency hops from 3.25 MHz to 1.5 MHz. Similarly, when switching frequency is from low to high with the triangle wave, the variation of the output voltage is 28 mV and recovery time is 47 μs. The variation of the output voltage is 36 mV and the recovery time is 30 μs when switching frequency hops from 3.25 MHz to 1.5 MHz. The output voltage variation and recovery time with the triangle wave are better than those of the sawtooth wave.

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