NEW CIRCUITS FOR ACCURATE CMOS SENSOR INTERFACES

摘要

Smart sensors require the integration of sensors and of electronic interfaces in the same chip; however, for many applications, standard CMOS processes must be used for low cost reasons As CMOS transistors typically show high input offset voltages and high input low frequency noise voltages, accurate CMOS amplifiers are only feasible by using dynamic techniques. All accurate CMOS amplifiers reported in literature may be grouped in two classes: autozero amplifiers and chopper amplifiers. In this paper we introduce a new class of accurate CMOS amplifiers. As a design example an accurate CMOS buffer is presented; this buffer may be very accurate even if very high gain op amps are not available, such as in low voltage low power applications.