Detection of low-frequency signal processing chip and low-frequency signal processing circuit

Abstract

The invention relates to detection of low-frequency signal processing chip and low-frequency signal processing circuit. The detection of low-frequency signal processing chip comprises a VDD pin, a VCCpin, an OUT pin, a TXC pin, a VSS pin, an LS pin, an OPO pin and an INN pin; the VCC pin is electrically connected with the band-gap reference circuit through a low-dropout linear regulator LDO circuit; the INN pin is connected with the negative electrode of an operational amplifier OPA, the OPO pin is connected with the output end of the operational amplifier OPA, a fixed gain amplifier AMP is connected between the OPO pin and the output end of the operational amplifier OPA, the output of the fixed gain amplifier AMP is connected to the positive electrode of a comparator COMP1 and the negative electrode of a comparator COMP2. The chip integration level is high, the peripheral circuit is simple, the peripheral components are small, the miniaturization is convenient, the system is low in cost, the anti-interference capability is strong, the error is not triggered, and the installation and debugging are convenient.

Description

technical field [0001] The invention belongs to the field of integrated circuits, and in particular relates to a detecting low-frequency signal processing chip and a low-frequency signal processing circuit. Background technique [0002] The early human body sensing chips had many pins and low integration, and more components such as resistors and capacitors were needed around the chip to cooperate with the chip to realize signal processing and control functions. [0003] In recent years, more integrated human body sensing chips have appeared on the market, with simple peripheral circuits and fewer components. This type of chip retains the second-stage band-pass amplifier of the early chip circuit system as the first-stage amplifier, while the second stage amplifier is fully integrated into the chip. Since the frequency of human body motion signals is very low, generally 0.3Hz to 3Hz, the peripheral capacitors required by the bandpass filter are usually large-capacity electr...

AI Technical Summary

Problems solved by technology

This patent solves the problem of false triggering caused by the common-mode voltage of the operational amplifier inside the traditional chip changing rapidly with the high-frequency noise of the power supply voltage. The circuit adds a voltage divider node to the resistor divider that generates the common-mode voltage of the operational amplifier The filter capacitor is used to stabilize the common-mode voltage of the internal operational amplifier, but this circuit adds a chip pin and an external capacitor, and the capacitor and the chip's internal voltage division resistor form a low-pass filter, a low-pass filter It can effectively filter out high-frequency noise and interference, but it cannot effectively suppress low-frequency fluctuations on the power supply voltage

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