Current/frequency conversion circuit linearity and symmetry digital compensation method

Abstract

The invention discloses a current / frequency conversion circuit linearity and symmetry digital compensation method. The current / frequency conversion circuit linearity and symmetry digital compensation method comprises the steps of measuring and recording D trigger output pulse number and subdivided pulse number when different current values are input into a current / frequency conversion circuit; confirming conversion circuit linearity compensation factors and performing compensation to a conversion circuit output in digital mode; measuring and obtaining symmetrical coefficient and zero coefficient of the current / frequency conversion circuit; and confirming symmetrical compensation coefficient of the conversion circuit and performing real-time compensation to the conversion circuit output in digital mode. By means of the current / frequency conversion circuit linearity and symmetry digital compensation method, the problems including complicated operation, effective accuracy, high demands on debugging persons and unsatisfied batch production demand in the current production debugging process is effectively solved.

Description

technical field [0001] The invention relates to the technical field of measurement of current-type devices, in particular to a digital compensation method for linearity and symmetry of a current / frequency conversion circuit. Background technique [0002] The measurement of current-mode devices usually uses a current / frequency conversion circuit, and its output pulse frequency is proportional to the input current. Affected by the actual parameters of the conversion circuit components, there is an error in the single charge and discharge of the switching circuit, which leads to the nonlinearity of the conversion circuit, and because the positive and negative channels are independent and asymmetrical, it is necessary to analyze the non-linearity of the current / frequency conversion circuit. Linearity and symmetry are compensated. [0003] In the current production process, the linearity of the conversion circuit is adjusted by changing the base saturation current of the switchi...

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Problems solved by technology

Affected by the actual parameters of the conversion circuit components, there is an error in the single charge and discharge of the switching circuit, which leads to the nonlinearity of the conversion circuit, and because the positive and negative channels are independent and asymmetrical, it is necessary to analyze the non-linearity of the current / frequency conversion circuit. Compensation for linearity and symmetry

[0003] In the current production process, the linearity of the conversion circuit is adjusted by changing the base saturation current of the switching transistor in the current / frequency conversion circuit, and the symmetry of the conversion circuit is adjusted by changing the positive and negative constant current source currents. Estimation and repeated trial and error adjustment, the operation process is complicated, the accuracy is limited, and the requirements for debugging personnel are high, which cannot meet the needs of mass production

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