Broadening reset high-precision current/frequency conversion circuit

Abstract

The invention relates to a broadening reset high-precision current / frequency conversion circuit. The circuit comprises an integrator, a threshold level generation circuit, a crystal oscillator, a frequency division circuit, a constant current source, a comparator, a reset switch and an output circuit. The input end of the integrator is connected with input current. The circuit comprises a shapingcircuit, a pre-stage D trigger, a monostable trigger and a post-stage D trigger. The integrator and the output end of the threshold level generating circuit are connected with the input end of the comparator. The input end of the preceding-stage D trigger is connected with the output end of the comparator. The output end of the preceding-stage D trigger is connected with the input end of the backward-stage D trigger through the monostable trigger. The output end of the backward-stage D trigger is connected with the output circuit. The crystal oscillator is connected with the input end of the shaping circuit through the frequency dividing circuit. The output end of the shaping circuit is respectively connected with the CLK ends of the front-stage D trigger and the rear-stage D trigger. According to the invention, the horizontal offset and overshoot of the output waveform of the integrator can be reduced. The linear error is reduced in mechanism, and the circuit conversion precision is improved.

Description

Technical field [0001] The invention belongs to the field of current / frequency conversion, and specifically relates to a widening reset high-precision current / frequency conversion circuit. Background technique [0002] The current / frequency conversion circuit is one of the important components of the inertial navigation system. It is used together with the accelerometer in the inertial navigation system to convert the output current of the accelerometer into a digital pulse signal proportional to it. At present, the current / frequency conversion circuit adopting the principle of charge balance is widely used. Currently, it mainly includes several methods of widening, equal width, widening and widening. Among them, the extended reset method is widely used due to its simple topology, theoretically can balance the error of the switching transition process, use a constant current source with high efficiency and effectively expand the measurement range. However, the traditional single...

AI Technical Summary

Problems solved by technology

[0004] In addition, when the circuit is integrated, the constant current source is usually designed to be connected to the ground through a diode, which will cause a large overshoot of the integration wavelength and affect the conversion accuracy of the circuit.

Images