Research And Design Of High Precision Reference Source Based On CMOS Technology

The voltage reference is used as a basic module for analog integrated circuits and widely used in several circuits and systems to provide accurate voltage and current reference. Under DC and AC conditions, the stability of the voltage reference plays an important role in the entire system. Its stability includes insensitivity to the system's environment (supply voltage, temperature, output load) and process. If the stability does not meet the requirements, the performance of the overall circuit or system is directly limited, and even the predetermined function may not be performed correctly and efficiently. Therefore, it is of great significance to design a reference source to meet the design requirements.In this paper, the basic principle and important parameters of the reference source are analyzed in detail, and several kinds of high-order temperature compensation circuits are introduced. The third chapter analyzes and designs the conventional first-order temperature compensated bandgap reference circuit and the new one. Then,the voltage regulator is introduced and applied to the first-order temperature compensated bandgap reference circuit. Core circuit, operational amplifier and start circuit module were designed, and finally the main simulation results were showed.The fourth chapter analyzes IPTAT2 current and the sub-threshold current high-order temperature compensation theory, which are applied to the first-order temperature compensation bandgap reference. And then a low temperature coefficient and high power supply rejection ratio Bandgap reference is proposed. The design of this paper is under SMIC40nm standard CMOS process and completes the circuit and layout design in the Cadence software environment. The normal operating voltage range is 2.1V ?3.5V, and the typical working voltage is 2.5V. At typical voltage, when the operating frequency is within 80kHz, the power supply rejection ratio is higher than 80dB; when operating frequency is higher than 10M Hz, the power supply rejection ratio is not less than 30dB. When the temperature ranges from -20? to 120?, the temperature coefficient working in TT, SS, FF technology corners ,were 3.06 ppm/?, 4.78 ppm/?,8.15 ppm/?.