Correlator Output Processing Circuit for Array of Microwave Background Anistropy

• Main Authors: Wei Jui-Ming, 魏睿民
• Other Authors: Prof. Chiueh Tzi-Dar
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/54306392024475826958

碩士 === 國立臺灣大學 === 電機工程學研究所 === 89 === A correlator backend processing circuit is introduced. It is used in the CosPA subproject — AMiBA (Array of Microwave Background Anistropy). Two approaches of voltage-to-frequency converter are presented. One is master PLL with 17 slave VCO’s architecture. The PLL is to adjust the bias voltage of slave VCO’s, then their oscillating frequencies will change according to input voltage at the same reference value. The other approach is Charge-Balancing pulse period modulator. The output pulse period is determined by charging and discharging the same capacitor with current which is proportional to input voltage. The converted frequency signal is used to trigger the accumulator including phase-switching demodulation in order to complete the long-time integration. The accumulated result is then scanned out serially by readout circuit. These two approaches are designed and fabricated by 0.35μm CMOS technology. The chips are operated at 3.3V. For the first chip, the linear range of input voltage is 1.2V ~ 3.2V. Oscillating frequency range is 3.5MHz∼4.5MHz and the linearity error is less than 0.6%. For the second chip, input voltage range is full swing and the output pulse frequency range is 5MHz.