The invention relates to the technical field of analog integrated circuits, in particular to a high-precision temperature sensor temperature-sensing front-end circuit based on a chopping technology, and aims to solve the problems of low-frequency 1 / f
noise,
operational amplifier input offset voltage drift, band-gap reference temperature drift, limited output driving capability and the like existing at the front end of a traditional temperature sensor. The front-end circuit comprises a chopping band-gap reference source circuit, a chopping buffer circuit and a two-phase non-overlapping
clock generation circuit, wherein the chopping band-gap reference source circuit adopts a parasitic bipolar PNP
transistor with an emitter
junction area ratio of 8: 1 as a
temperature sensing device, and a high-
gain chopping folded
cascode operational amplifier is embedded in the chopping band-gap reference source circuit; and stable
positive temperature coefficient
voltage and low-temperature drift reference
voltage are generated.
Noise and maladjustment are inhibited from the
system architecture level, the
temperature measurement precision can reach the sub-degree centigrade level, the loading capacity is high, the method is achieved based on the standard
CMOS technology, a special technology and complex temperature calibration are not needed, and the method has the advantages of being low in cost, high in stability and large-scale integration.