A temperature compensation method for i/f conversion circuit board

Abstract

The invention discloses a temperature compensation method for an I / F conversion circuit board, so that the input current of the I / F conversion circuit board enters a piece of high-precision A / D chip to collect and convert it into a digital quantity after passing through a current / voltage conversion and a filter circuit. , this digital quantity corresponds to the current input current value; the digital quantity enters the error correction circuit, combines the current module temperature information to obtain the corrected value, eliminates zero offset, temperature drift and nonlinear error, and then sends it to direct frequency synthesis pulse generation The circuit generates the required frequency pulses, and the A / D chip adopts successive approximation or Σ-Δ type architecture, and the number of quantization bits reaches more than 16 bits. The invention has the advantage that it does not need to rely on external thermostats to improve temperature stability.

Description

technical field [0001] The invention relates to the field of conversion circuits, in particular to a temperature compensation method for an I / F conversion circuit board. Background technique [0002] At present, in the high-precision inertial integrated navigation system, the acceleration measurement sensor generally uses a quartz accelerometer, and the output of the quartz accelerometer is a current signal. In the high-precision inertial integrated navigation system, the current signal must be converted into a digital signal for navigation and other processing; In order to convert the current signal into a digital signal, the temperature compensation method of the I / F conversion circuit board is generally used in the high-precision analog-to-digital conversion to realize the analog-to-digital conversion from current to frequency. [0003] Such as figure 1 As shown, the traditional I / F conversion circuit is a pure hardware circuit. The input current enters the integrator co...

AI Technical Summary

Problems solved by technology

[0004] For the above-mentioned traditional structure, its stability, precision, especially temperature stability, completely depend on the characteristics of the hardware circuit itself, any temperature compensation measures can only be inserted reluctantly in the form of hardware circuits, or even rely on external constant temperature measures, It does not meet the strict requirements of this product on temperature stability (scaling factor temperature coefficient) and volume power consumption; other indicators, such as zero bias and second-order linearity, also have the same problem

Images