Compensation Strategy And Circuit Realization Of High Precision BiCMOS Reference

Reference is the scale of analog circuits, the accuracy and performance of reference sources determine the functions and performances of the analog circuits. As the feature size of integrated circuits getting smaller in recent years, power supply voltage and power consumption of the chip is getting lower and lower, higher performances are required for reference sources. For a high-standard reference sources, low temperature coefficient is the most basic and important requirement.Several basic structures of the reference circuits and the development of reference design are described in this paper, the basic performances required in reference design are discussed. More attention is paid on the principles and methods of temperature compensation and several high-order temperature compensation strategies are analyzed and compared.A high-precision BiCMOS bandgap voltage reference is designed in this paper and the simulation based on ASMC 0.35um BiCMOS process is completed. Temperature coefficient of the first-order temperature compensation bandgap reference source is 35ppm /℃, PSRR is 98.8dB in low-frequency, and the reference source has a better PLR. Temperature coefficient of the high-order temperature compensation bandgap reference source is 14ppm/℃, its PSRR is 245dB in low-frequency. Bandgap reference source's temperature performances are improved obviously. The layout area of the reference source is 824~*322um~2. It is suitable for a variety of mixed-signal integrated systems.