Sub 1V Crystal Less Clock Generator Circuit With Automatic Detection Process and Temperature Variation

• Main Authors: Ming-Hao Hong, 洪銘皓
• Other Authors: Wei-Bin Yang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/98310261904601765591

碩士 === 淡江大學 === 電機工程學系碩士班 === 102 === In the modern technology industry, many analog circuits are converted to digital, and digital circuits to sequential circuits as the main, however, the oscillator circuit in which plays a crucial role. 3C because of the booming industry, which is the maximum demands of light, thin , low power and cost savings, but to save space and under conditions to reduce power consumption , the system still must remain stable is the purpose of this study. From clock generated of the microprocessor to the mobile phone carrier synthesis which requires different oscillator circuit and performance parameters. Different forms of oscillators, quartz oscillator that on process and temperature is the most stable, design a tool to automatically detect the process, low temperature drift compensation supply voltage reference oscillator circuit that is this thesis target. Whole circuit is divided into three parts, the first part of the four differential voltage controlled delay units consisting ring oscillator, this voltage controlled ring oscillator due process and temperature variations caused by the control voltage at a fixed, the resulting output frequency will vary. The second part is the frequency of differential-ended to single-ended output circuit that aims to adjust the duty cycle of the output frequency of 50 %. The third part is a frequency-to-voltage converter circuit, the circuit will differ due to the input frequency converter output voltage, thus the voltage controlled oscillator as the correction process, and temperature changes under different. The combination of these three major overall circuit , since the frequency-to-voltage converter circuit can correct voltage controlled oscillator under different process and temperature variations generated output frequency ,and thus provide different output voltages to control the voltage-controll oscillator a control terminal device , since the relationship between the closed loop circuit is formed as a convergent state, and that the output can be stabilized at the target frequency of 25MHz, to achieve the compensation process and temperature variation .