Linear ultralow temperature coefficient reference source adopting operational amplifier negative feedback

Abstract

The invention relates to the field of electronics, in particular to a low-temperature-coefficient reference source adopting operational amplifier negative feedback, which is characterized in that a fully differential operational amplifier A1 amplifies negative temperature coefficient voltage and positive temperature coefficient voltage and then adds the negative temperature coefficient voltage andthe positive temperature coefficient voltage to output a low-temperature-coefficient voltage to an inverting input end of an operational amplifier A2; the reference voltage Vout output by the operational amplifier A2 is subtracted by positive temperature coefficient voltage output after being amplified by the fully differential amplifier circuit through the operational amplifier A3, then is inputto the positive phase input end of the operational amplifier A2, and is subtracted by low temperature coefficient voltage at the reverse phase input end of the operational amplifier A2 to form a negative feedback loop. A reference voltage Vout with a linear ultralow temperature coefficient is generated through automatic adjustment. A positive temperature coefficient voltage and a negative temperature coefficient voltage are generated by the voltage generation circuit and output to the operational amplifier feedback circuit, and then the voltages are output through the buffer output circuit toform a final reference voltage which is not affected by temperature change, has a linear ultralow temperature coefficient and is high in drive.

Description

technical field [0001] The invention relates to the field of electronics, in particular to a linear ultra-low temperature coefficient reference source adopting negative feedback of an operational amplifier. Background technique [0002] As a voltage output circuit, the reference source is mainly used to provide voltage reference and bias for the integrated circuit; to reduce the temperature drift effect of the integrated circuit. With the improvement of circuit precision, the requirements for the reference source are also increasing. However, the temperature coefficient of the current reference source output voltage is relatively high. Contents of the invention [0003] In order to solve the above problems, the present invention proposes a linear ultra-low temperature coefficient reference source using negative feedback of an operational amplifier. [0004] A linear ultra-low temperature coefficient reference source using negative feedback from an operational amplifier, ...

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Problems solved by technology

However, the temperature coefficient of the current reference source output voltage is relatively high

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