Calibrating circuit and calibrating method

Abstract

The embodiment of the invention discloses a calibrating circuit. The calibrating circuit comprises a reference voltage generation circuit, a capacitor charging and discharging circuit, a voltage comparer and a digital control circuit, wherein the capacitor charging and discharging circuit and the voltage comparer are connected with the reference voltage generation circuit; the capacitor charging and discharging circuit is connected with the voltage comparer; the digital control circuit is connected with the voltage comparer; the digital control circuit is connected with the capacitor chargingand discharging circuit; the reference voltage generation circuit is used for generating a first reference voltage, a second reference voltage and a third reference voltage, and buffering the first reference voltage to obtain a first voltage; the capacitor charging and discharging circuit is used for generating a second voltage according to the first voltage, the second reference voltage and a received first clock signal; the voltage comparer is used for comparing the second voltage with the third reference voltage to obtain a voltage comparison output signal; and the digital control circuit is used for generating a first digital control signal, a second digital control signal and a third digital control signal according to the voltage comparison output signal. The embodiment of the invention further discloses a calibrating method.

Description

technical field [0001] The invention relates to a resistance-capacitance calibration technology in the field of active filters, in particular to a calibration circuit and a calibration method. Background technique [0002] In analog integrated circuits, active RC filters are widely used because of their good linearity. However, in modern semiconductor manufacturing processes, resistors and capacitors will vary greatly with the process, which will affect the performance of the filter. Therefore, the RC must be calibrated in the application. In the prior art, most of the RC calibration techniques have complicated circuits, requiring an accurate reference voltage or an accurate current source provided outside the circuit, and the calibration results obtained by most calibration methods are not suitable for active filters. Contents of the invention [0003] In order to solve the existing technical problems, the embodiments of the present invention provide a calibration circui...

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Problems solved by technology

[0002] In analog integrated circuits, active RC filters are widely used because of their good linearity. However, in modern semiconductor manufacturing processes, resistors and capacitors will vary greatly with the process, which will affect the performance of the filter. Therefore, the RC must b

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