NTSC Video Sync Separator and A Gm-C Anti-Aliasing Filter Design with Digitally Tunable Bandwidth for DVB-T Receivers

• Main Authors: Chien-Chih Hung, 洪健智
• Other Authors: Chua-Chin Wang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/31256874310655611712

碩士 === 國立中山大學 === 通訊工程研究所 === 93 === The first topic of this thesis is a novel NTSC video sync separator (NSS) with a high-PSR (power supply rejection) bias generation circuitry (BGC) comprising a temperature compensation circuitry. The proposed BGC is composed of step-down regulators and a bandgap-based bias with cascode current control. The clamping voltages required for sync separation from an NTSC signal are generated. The second topic is a temperature-compensated 6th order transconductance-C (Gm-C) anti-aliasing filter (AAF) with digitally tunable bandwidth which can be applied in the analog front-end circuit of DVB-T receivers. The proposed AAF is controlled by digital signals to provide three different baseband bandwidth (6, 7, 8 MHz) selection. A regulator with a bandgap circuitry supplies a stable voltage to suppress the variations of power and temperature. Moreover, a temperature -compensated circuitry is used to neutralize bandwidth drifting caused by the temperature variation. The bandwidth accuracy of the proposed design verified by HSPICE post-layout simulations is better than 3.28% at every PVT (process, supply voltage, temperature) corner. It is adequate for the DVB-T receivers’ baseband processing.