A Linearity Improved and Digitally Programmable Operational Transconductance Amplifier for Gm-C Filter

• Main Authors: Hung-chang Chen, 陳弘昌
• Other Authors: Bin-da Liu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/63599032971070667902

碩士 === 國立成功大學 === 電機工程學系碩博士班 === 95 === In this thesis, a linearity improved and digitally programmable operational transconductance amplifiers (OTA) for Gm-C filter has been designed and implemented in a 0.35-µm 2P4M CMOS process. In order to improve the linearity of OTA, we used an adaptive biasing technique. In addition, the transconductance of OTA can be controlled by our proposed digitally programmable current mirror technique. A second-order bandpass filter was designed to verify the linearity and transconductance of OTA by using our proposed techniques. The digitally programmable OTA has been simulated by circuit simulator, HSPICE. While the sampling frequency and input frequency are 50 MHz and 10 MHz respectively, the signal-to-noise and distortion ratio (SNDR) of the digitally programmable OTA is 61 dB. In our bandpass filter, the specification of 56-dB third-order intermodulation (IM3) was also achieved with input frequency mixed 9 MHz and 10 MHz.