Research Of Key Technologies Of SiGe BiCMOS Ultra-high-speed A/D Converter

With the drastic development of computer science, digital communication and multimedia technology, especially high speed digital system, A/D converters(ADCs) are widely applied to digital signal processing, a great deal of data need to be converted by ADCs, and the speed of ADCs is becoming higher and higher.The whole design uses TSMC 0.35μm SiGe BiCMOS technology with 3 poly layers and 3 metal layers. In this thesis, a ultra-high speed 8-bit SiGe BiCMOS A/D Converter with 1 GS/S sample rate is presented. This design uses the 2-step flash architecture with analog switches, which has high conversion speed, high resolution as well as overcomes the shortcomings of conventional ADC such as difficulty of designing and fabricating. A fully differential ultra-high-speed comparator with full inputs and master-slave latches architecture is presented; a great number of high speed heterojunction bipolar transistors are used. 4 fully differential inputs architecture enhances the gain and bandwidth of preamplifier, and master-slave latches architecture improves the efficiency of clock; A high gain and high bandwidth THA using HBT is presented, fully differential inputs and high-gain input preamplifier ensures the circuit's speed and accuracy; A switch with two pseudo-MOSFETs which reduces clock-feedthrough is presented; a decoder circuit, a encoder circuit and a latch circuit are also designed, and parts of layout are realized.