| With the development of semiconductor process and circuits design technology,Analog integrated circuit improved greatly in recent years. There is a challenge to the performance of circuits. Also with the popular use of electronic system powered by battery,the request for the functions of the analog integrated circuit is much higher. The voltage reference circuit is an important part in the integrated circuit that used in many applications such as analogue circuits, hybrid circuit, sensor front circuit and system on chip. Thermal stability and Power Supply Rejection Ratio of the voltage reference circuit are the two major factors that influence the precision and stability of the whole system.Study and design an anti-technology and high-performance voltage reference circuit in this paper based on the importance of voltage reference. Using the SMIC 0.18μm, 1.8V technology. Firstly, the basis of the design of voltage reference was briefed, including the performance index and classification and basic principle and basic structure. Then, realization technique of the temperature compensation and zero temperature coefficient is explained this paper. After analyzed and compared with many structures of reference circuits, the traditional structure of the CMOS band-gap reference voltage circuit is chosen as the basis to design because of its good performance, and the design of the core of band-gap circuit based on high accuracy and low power supply is presented in this paper. For the former, using a higher-order temperature compensation method to carry out compensation; for the latter, using structure of current-mode band-gap reference circuit, and resistor voltage divider to reduce the op amp common-mode voltage, further reducing the power supply. Using Cadence spectre to simulate the overall circuit. The gain of op-amp can reach to 80dB, the temperature coefficient is 2ppm/℃, and the Power supply rejection ratio is -89.12dB, minimum working voltage is 1.0V. |
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