A front-end circuit and dynamic range improvement method based on gain adaptive adjustment

Abstract

The invention discloses a front-end circuit based on gain self-adaptive adjustment and a method for improving the dynamic range. The low-noise amplifier converts the bioelectrical signal input into the front-end circuit into a differential signal and amplifies the amplitude and then enters the programmable gain amplifier. The signal passes through the initial The programmable gain amplifier with a gain of 0dB is output to the ADC; the ADC quantizes the output and converts it into a digital value and outputs it to the gain self-adjusting logic circuit; the gain self-adjusting logic controls to change the gain of the programmable gain amplifier, and controls the ADC to change the gain again The output of the programmable gain amplifier is quantized, and then the second quantization result and the adjusted gain of the programmable gain amplifier are output to the subsequent circuit in the form of digital code values. The present invention adopts the working mode of two consecutive sampling conversions in one working cycle and real-time adjustment of the front-end gain, greatly reduces the area of ​​the circuit while improving the dynamic range of the front-end circuit, saves power consumption of the circuit, and is suitable for implantable and wearable application scenarios. .

Description

technical field [0001] The invention belongs to the technical field of low-power integrated circuits, and in particular relates to a front-end circuit and a dynamic range improvement method based on gain self-adaptive adjustment, and relates to wearable and implantable systems for biomedicine and consumer products for health care. Physiological signal detection product field. Background technique [0002] The advancement of low-power integrated circuit design technology is the technical guarantee for the vigorous development of medical electronics. There are more and more types of wearable or implantable medical electronic products and consumer electronic health care products. With the continuous development and complexity of functions of wearable and implantable medical electronic systems, the requirements of high dynamic range, small area, low voltage and low power consumption are also put forward for the analog front-end system. [0003] In the analog front-end used in i...

AI Technical Summary

Problems solved by technology

At the same time, nonlinear effects are introduced, which reduces the accuracy of analog-to-digital conversion

Improve the capacitor switching strategy to reduce the power consumption of the ADC. When the input signal changes relatively smoothly, the switching power consumption of the capacitor array can be saved, but the next input amplitude change cannot be predicted. Therefore, when the input changes greatly , will produce wrong conversion results

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