切換式穩壓器會產生傳導性的電磁干擾,在國際無線電干擾特別委員會將規範其電 磁干擾量,故本論文提出一個輸入為1.8 V 輸出為1 V 的降壓轉換器、擁有兩種不同展 頻模式之多斜率展頻技術之低電磁干擾降壓轉換器。在此設計中,本設計使用含有多頻 率馳張震盪器,因此可在產生不同的頻率達到降低電磁干擾之功能。提出一個可切換斜 率的展頻控制希望可以讓電磁干擾抑制效果更佳。使用不同斜率的展頻模式會產生不同 的抑制效果,藉著比較不同的展頻模式得到一個良好的展頻效果。 本論文之具多斜率展頻技術之低電磁干擾降壓轉換器使用180 nm 1.8 V CMOS 製 程實現晶片,其操作頻率為1 MHz,並且擁有兩種展頻模式。電路在展頻範圍為1 MHz 時三角波調變展頻機制對於電磁干擾之抑制量為10.96 dB,而使用三斜率展頻之電磁干 擾抑制量為15.98 dB,展頻範圍為1.33 MHz 時三角波調變展頻機制對於電磁干擾之抑 制量為16.35 dB,而使用三斜率展頻之電磁干擾抑制量為24.63 dB,整體晶片面積為1200 × 1190 um2。;A Low EMI DC-DC Buck Converter with Multiple-Slopes Spread-spectrum Clock Technique with 1 voltage output has been presented in this thesis. A multi- frequency relaxation oscillator with switching capacitor has been used in this design and this circuit can be operating at difference frequency. The proposed spread-spectrum clock technique can switch slop and generate multi-frequency. The triple slop mode used in the spread-spectrum mechanism increases the more reduction of electromagnetic interference with comparison to other modulations. The proposed A Low EMI DC-DC Buck Converter with Multiple-Slopes Spread-spectrum Clock Technique has been fabricated in 180 nm 1.8 V CMOS process. The reduction of electromagnetic interference are 16.35 dB with the spread-spectrum mechanism modulated by triangular mode 24.63 dB with the spread-spectrum mechanism modulated by triple slop mode. The chip area is 1200 × 1190 um2 .