Several Novel Low Voltage Low Power CMOS Bandgap Reference Voltage Source

Design of Reference resource of low temperature coefficient, low voltage, low power and high PSRR is completely pivotal in IC design of ADC, DAC, Dynamic Memory, Flash Memory and so on. With the continuous development of Deep-Submicron technology, the voltage of power supply becomes lower and lower. It's very essential to study the design of low voltage and low power reference resource based on standard CMOS process.The performance of bandgap reference resource is the best in all of the present reference resource circuits because of its high PSRR and low temperature coefficient techniques. Hence, the work of this thesis is the design of a low voltage low power CMOS bandgap reference voltage source. It's first done to study the structure of conventional bandgap reference circuits. Then, analyze and compare the structures of first-order and second-order temperature compensation. After that, further study the main working principles of several kinds of low voltage bandgap reference voltage source circuits.Under analysis and compare of several low voltage bandgap reference sources, based on bulk-driven and resistive subdivision techniques, an ultra-low voltage CMOS bandgap reference using second-order temperature and current feedback techniques is realized. The bulk-driven op amp is applied as the negative feedback of the reference. Its output is used to bias its current sources, leading to a higher power supply rejection ratio (PSRR), that is -63.8dB. At last, based on TSMC 0.25μm 2P5M CMOS process, the bandgap reference is simulated by Hspice simulator. Under a 0.9V supply, the output voltage of the reference is 572.45mV, its temperature coefficient is 13.3ppm/oC. The results show that the circuit meets the design requirements, with good performance.