時脈訊號產生器在大部分的電子系統中是必備的.應用於數位音頻放大器的時脈訊號產生器有三個功能.第一,為了簡化數位音頻放大器的複雜度它將所有的輸入頻率轉換成單一的輸出頻率,也因而使得數位音頻放大器可以操作在不同的頻率而可應用在像是DVD 撥放機,液晶電視或MP3 隨身聽等等應用.時脈訊號抖動是決定時脈訊號產生器優劣的準則而且直接影響數位音頻放大器的輸出品質.根據前言,第二個功能是抑制輸入的時脈抖動.由於脈波調變信號是音頻處理單元參考系統時脈訊號正負緣所產生的,所以時脈訊號產生器的第三個功能是恢復工作週期的回復. 建構在鎖相概念的時脈訊號產生電路藉由輸入與回授兩個除頻器對於輸入與輸出頻率做分數倍的轉換.為了操作在不同的系統上,可調整的頻寬是擁有較低的時脈抖動所必要的.此時脈產生器用0.35um 1P3M 邏輯製程製作.它的晶片面積是0.1mm2 而且在3.3 伏電壓下消耗6mW 的功率.量測結果顯示當輸出頻率50MHz 時,週期時脈抖動小於26ps.
　　數位音頻放大器是高功率積體電路.高操作溫度,錯誤的喇叭阻抗或是過高的操作電壓都會造成晶片內部溫度過高而造成破壞.因此數位音頻放大器往往內含溫度感測器去偵測內部溫度是否過高.論文中的溫度放大器利用能隙參考電壓的概念去偵測溫度並且為了抵制輸出級所造成的電壓抖動必須擁有較低的電源敏感度.電路架構疊接了兩級雙載子接面電晶體去達到較高的溫度曲線斜率.蒙地卡羅模擬結果與錯誤分析結果一致顯示在沒有修正的情況下溫度感測器的溫度錯誤小於 ±5°C.此溫度感測器用0.35um 1P3M 邏輯製程製作.它的晶片面積是0.075mm2 而且在3.3 伏電壓下消耗小於1mW 的功率.

　Clock generator is essential in mostly electronic systems. This clock generator for digital audio amplifier has three functions. First, it transforms all input frequencies into one and only one output frequency to reduce the complexity of digital audio amplifier, and therefore enables the digital audio amplifier to operate in different clock frequencies for multiple applications such as DVD player, LCD TV, and MP3 Player. Timing jitter is a criterion for judging the performance of a clock generator and directly influences the performance of digital audio amplifier consequently. According to the foregoing statement, the second function of the clock generator is input jitter suppression. Since pulse-width modulated signal is generated from audio signal processor by utilizing rising and falling edges of system clock, the thirdfunction of the clock generator is duty-cycle recovery. The circuit of this clock generator, based on phase-locked technique, multiplies input clock fractionally by placing two dividers in input and feedback paths. In order to operate in different systems, adjusting bandwidth is needed to reach the lower jitter. The clock generator is fabricated in 0.35um 1P3M Logic Process. Its chip area is 0.1mm2 and power consumption is 6mW under 3.3Volt supply voltage. Measurement result shows that the period jitter is under 26ps when output frequency is 50MHz.
　Digital audio amplifier is a high power IC. High ambient temperature, wrong speaker impedance, and over-high supply voltage can cause the whole IC to destroy itself by increasing the chip temperature to an unsafe value. Therefore a temperature sensor circuit is always included in an amplifier to detect whether the inner temperature is over-high or not. The temperature sensor circuit in this thesis utilizes the idea of bandgap voltage reference to detect temperature and needs lower Power Supply Sensitivity (PSS) to suppress the supply voltage ripple caused by output stage. The circuit architecture cascades two stages of bipolar junction transistors to attain to higher slope of temperature curve. Monte Carlo simulation result consistent with error analysis shows that temperature error of the temperature sensor without trimming is under ±5°C. The temperature sensor is fabricated in 0.35μm Logic 1P3M Logic Process. Its chip area is 0.075mm2 and power consumption is smaller than 1mW under 3.3Volt supply voltage.

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