Design Of 8 Bit Ultraspeed Track-and-Hold Circuit Based On 0.18μm CMOS Technology

In recent years, with the continuing development of digital communication technology, all kinds of high-speed digital communication systems have high demands upon Analog-to-Digital Converter (ADC), specially the speed, which has become the trend of the development of the ADC.The Track-and-Hold circuit, which is one of the key components of many analog and Mixed-signal IC circuits, is widely used in ADC, CMOS switch-capacitor filter, integrator and so on. In the ADC, as the first module in the whole signal processing chain, the Track-and-Hold circuit directly determines the performance of the entire ADC. Therefore, design a high-speed, high-precision Track-and-Hold circuit,which seems particularly important.The work of this thesis is the design of 8-Bit ultraspeed Track-and-Hold circuit based on 0.18μm CMOS process. Firstly, the thesis describes the development of ADC, performance, as well as several high-speed ADC's architecture and working principle. Then, analyzes the basic architecture and working principle of Track-and-Hold circuit, focuses on the sampling switch and the impact on the circuit that is caused by all kinds of nonideal factors. Under the guidance of the theory mentioned, designs a Track-and-Hold circuit of open-loop architecture, then analyzes the performance and simulates the circuit using the Cadence Spectre software. The results show that the circuit meets the design requirements, with good performance. Finally, designs the layout using the Virtuoso Layout software provided by Cadence in SMIC 0.18μm 1P6M CMOS process.