Triple oscillation feedback weak signal processing circuit

Abstract

The invention relates to a triple oscillation feedback weak signal processing circuit which including an offset voltage self-calibration front end current mode amplification circuit, a current mode phase subtraction integrator, a current mode oscillator, a digital differential circuit, a self-calibration feedback loop, a filter feedback loop and an oscillation feedback loop, wherein the offset voltage self-calibration front end current mode amplification circuit determines low-pass filtering of the signal processing circuit to a signal and a self-calibration function to sensor offset voltage; the current mode phase subtraction integrator determines integration of the signal processing circuit to signal errors and a high-pass filtering function to the signal; and the oscillation feedback circuit loop improves the accuracy for processing a weak signal. The triple oscillation feedback weak signal processing circuit is used for a subsequent signal processing chip circuit of a small signal sensor, and a signal processing function of low energy consumption and high accuracy of sensor chip integration is realized.

Description

technical field [0001] The invention relates to the technical field of weak signal processing circuit design, in particular to an integrated low power consumption and high precision triple oscillation feedback weak signal processing circuit. Background technique [0002] As the sensor chip system has higher and higher requirements for the accuracy, power consumption and integration index of the weak signal processing circuit chip, the weak signal processing chip has become a hot spot in the research of the industry. [0003] Resolution, harmonic distortion, power consumption and integration are the most important performance indicators of weak signal processing chip systems. The resolution characterizes the minimum value of the input signal that the chip system can distinguish, that is, the signal resolution capability of the chip system, which is mainly limited by the flicker noise and thermal noise of the chip system circuit, and high-end sensor applications require the ch...

AI Technical Summary

Problems solved by technology

Since the frequency of the pulse width modulation signal is a modulation signal with a higher fixed frequency, and the device with simple passive filtering function can only filter out part of its energy, the output signal will generate electromagnetic interference in the circuit system. Make the power consumption of the whole system circuit increase and affect the accuracy at the same time

In order to eliminate the influence of electromagnetic interference on the circuit, an active filter with higher filtering performance can be designed in the subsequent circuit to suppress it, but it will not be used due to the limitation of the system's low power consumption.

In order to solve the problem that the traditional analog signal processing method has a great influence on the accuracy of the output signal, the Delta-Sigma analog-to-digital / digital-to-analog conversion method is currently mainly used to eliminate the influence of pulse width modulation driving on the system circuit accuracy and power consumption performance.

However, in order to reduce the quantization noise in the low frequency band, it is necessary to increase the order of the quantization noise modulation of the Delta-Sigma A / D converter, that is, it is necessary to increase the integrator module, and the addition of the integrator module will inevitably lead to an increase in system power consumption

Therefore, the above factors pose challenges to the design of integrated low-power high-precision system circuits

Images