Universal signal source compensation circuit module of MEMS pickup system

Abstract

The utility model discloses a general signal source compensation circuit module of an MEMS sound pickup system, which relates to the technical field of sound pickup environment calibration, and comprises a signal source circuit and a gain amplification circuit, the signal source circuit sends out signals, the gain amplification circuit amplifies the signals and drives a loudspeaker, the gain amplification circuit comprises a second operational amplifier, and the second operational amplifier is connected with the first operational amplifier. The IN + pin of the second operational amplifier is connected to a signal, the IN-pin of the second operational amplifier is connected to the first resistor, the other end of the first resistor is grounded, the IN-pin of the second operational amplifier is further connected to the fifth-zero resistor, the fifth-first resistor, the fifth-second resistor and the fifth-third resistor, the other ends of the four resistors are connected to the X0Y0, the X1Y1, the X2Y2 and the X3Y3 of the analog switch U18 respectively, the Y pin of the analog switch U18 is connected to the OUT pin of the second operational amplifier, and the Y pin of the analog switch U18 is connected to the OUT pin of the second operational amplifier. And the X pin of the analog switch U18 outputs a signal to drive a loudspeaker. Self-calibration is achieved, and the effect of providing compensation reference for normal work of the pickup is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of microphone environment calibration, in particular to a universal signal source compensation circuit module of a MEMS microphone system. Background Art

[0002] With the rapid popularization of intelligent products, MEMS pickups are widely used in consumer electronics. In particular, MEMS pickups are crucial in AI voice intelligent interaction. The performance of the sensor determines the performance of the product.

[0003] Currently, the sensitivity of most MEMS pickups on the market is basically determined when they leave the factory. In addition, many high-precision scenarios require very high signal sensitivity. Slight signal loss seriously affects product performance, requiring regular calibration with external equipment.

[0004] Therefore, there is an urgent need for a universal signal source compensation circuit module for MEMS pickup systems that can be adapted to many types of products, provide a convenient method for checking the stability of product pickup systems at any time, and compensate for the uncertainties caused by structural differences. Utility Model Content

[0005] The purpose of the utility model is to provide a universal signal source compensation circuit module for a MEMS pickup system. When checking the pickup, the signal source can be dynamically adjusted according to the specific application environment to achieve autonomous calibration, ensuring that the product is not damaged in an interference environment or due to aging during signal transmission, thereby providing a compensation reference for the normal operation of the MEMS pickup.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A universal signal source compensation circuit module for a MEMS pickup system includes a signal source circuit and a gain amplifier circuit. The signal source circuit sends a signal, and the gain amplifier circuit amplifies the signal and drives a speaker. The gain amplifier circuit includes a second op amp U2. The IN+ pin of the second op amp U2 receives the signal, and the IN- pin is connected to a first resistor R1. The other end of the first resistor R1 is grounded. The IN- pin of the second op amp U2 is also connected to four resistors. The other ends of the four resistors are respectively connected to X0Y0, X1Y1, X2Y2, and X3Y3 of an analog switch U18. The Y pin of the analog switch U18 is connected to the OUT pin of the second op amp U2. The X pin of the analog switch U18 outputs a ZOOM_OUT signal to drive the speaker.

[0008] Furthermore, the ZOOM_OUT signal is connected to an inverse proportional amplifier circuit, and the output signal of the inverse proportional amplifier circuit drives the speaker.

[0009] Furthermore, the output end of the reverse proportional amplifier circuit is connected to the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to drive the speaker.

[0010] Furthermore, the reverse proportional amplification circuit includes a fifth op amp U5A, the IN- pin of the fifth op amp U5A is connected to the seventh resistor R7 and the eighth resistor R8, the other end of the seventh resistor R7 is connected to the signal ZOOM_OUT, the other end of the eighth resistor R8 is connected to the OUT port of the fifth op amp U5A, the IN+ pin of the fifth op amp U5A is connected to the twelfth resistor R12, the other end of the twelfth resistor R12 is connected to GND, and the OUT port of the fifth op amp U5A is connected to the eleventh resistor R11.

[0011] Furthermore, the signal source circuit includes a crystal oscillator Y1, pin 4 VCC of the crystal oscillator Y1 is connected to the first inductor L1, the other end of the first inductor L1 is connected to a 5V power supply, pin 2 of the crystal oscillator Y1 is connected to GND, pin 3 is connected to the MCLK pin of the dds signal generator U1, and the FSYNC, SCLK, and SDATA pins control and drive the dds signal generator U1 to generate a signal source, and the signal source is output as an AD_OUT signal through the VOUT pin of the dds signal generator U1.

[0012] Furthermore, the signal emitted by the signal source circuit also passes through the signal source attenuation circuit, which controls the attenuation amplitude of the signal.

[0013] Furthermore, the signal source attenuation circuit includes a digital potentiometer U15, the PA0 pin of the digital potentiometer U15 is connected to the signal, the PB0 pin of the digital potentiometer U15 is connected to the attenuation resistor R5, the other end of the attenuation resistor R5 is connected to GND, and the timing signals of the CS, SCK, and SI pins of the digital potentiometer U15 are simultaneously controlled through the R5 attenuation resistor, thereby controlling the attenuation amplitude of the signal, and the PW0 pin of the digital potentiometer U15 outputs the signal ZOOM_IN.

[0014] Furthermore, the signal ZOOM_IN enters the IN+ pin of the second op amp U2.

[0015] In summary, the present invention has the following beneficial effects:

[0016] This application comes with its own signal source, which can be used to check the signal at the product's factory and application stages, including comparing it with the factory signal to correct the acquisition system;

[0017] The signal attenuation circuit makes the working range of the signal source wider and more products can be adapted;

[0018] Through the gain amplifier circuit, when the original signal source cannot be matched, the appropriate signal can be obtained through gain amplification, which is suitable for high-power acquisition systems;

[0019] The signal drives the speaker through the op amp, suppressing the common mode signal, thereby improving the signal-to-noise ratio and improving product quality;

[0020] In summary, the compensation module of this patent can provide a convenient inspection method for the acquisition system, greatly enhancing the controllability of the product; it has the functions of generating, attenuating, amplifying, and adapting the operational amplifier operation of the MEMS pickup signal source, thereby compensating for the loss of the transmission structure and the impact of interference on the actual use effect of the product. By using the compensation module of this patent, the working benchmark of the pickup can be adjusted more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the principle of the MEMS pickup signal acquisition system;

[0022] Figure 2 This is a schematic diagram of the connection between the gain amplifier circuit and the signal source attenuation circuit in a universal signal source compensation circuit module in a MEMS pickup system of the utility model;

[0023] Figure 3 This is a connection diagram of the gain amplifier circuit part of a MEMS pickup system of the utility model;

[0024] Figure 4 This is a connection diagram of the reverse proportional amplification circuit part in a MEMS pickup system of the utility model. DETAILED DESCRIPTION

[0025] The following is a further description of the specific embodiments of the present invention in conjunction with the accompanying drawings, which do not limit the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] A universal signal source compensation circuit module for a MEMS pickup system, such as Figure 1 As shown, it is applied to the MEMS pickup signal acquisition system. In the signal acquisition system, this compensation circuit module acts as a dynamic compensation unit to implement compensation to cope with errors such as aging and interference, and can also detect the stability of the sampling system.

[0027] like Figures 2 to 4As shown, the universal signal source compensation circuit module of the MEMS pickup system specifically includes a signal source circuit, a signal source attenuation circuit, and a gain amplifier circuit. The signal source circuit sends a signal through its own excitation source to ensure the relative stability of the calibration signal. The attenuation circuit unit controls the signal within a certain range, and then the gain amplifier circuit amplifies the signal. It amplifies the signal by selecting the gear of the op amp to adapt it to the speaker, and finally drives the speaker directly through the op amp.

[0028] Specifically,

[0029] like Figure 2 As shown, the signal source circuit includes a crystal oscillator Y1, pin 4 VCC of the crystal oscillator Y1 is connected to the first inductor L1 and the ninth capacitor C9, the other end of the first inductor L1 is connected to a 5V power supply, the ninth capacitor C9 is 100nF / 50V, and the other end of the ninth capacitor C9 is connected to GND; pin 2 of the crystal oscillator Y1 is connected to GND, pin 3 is connected to the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the MCLK pin of the DDS signal generator U1.

[0030] The model of the DDS signal generator U1 is AD9833BRMZ. The COMP pin of the DDS signal generator U1 is connected to the first capacitor C1, and the other end of the first capacitor C1 is connected to the +12V power supply. The VDD pin is respectively connected to the +12V power supply, the fourth capacitor C4 and the fifth capacitor C5, the CAP pin is respectively connected to the sixth capacitor C6 and the seventh capacitor C7, the DGND and AGND pins are connected to GND, and the other ends of the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor are connected to GND; the DDS signal generator U1 is driven to generate a signal source by controlling the FSYNC, SCLK and SDATA pins, and the signal source is output as the AD_OUT signal through the VOUT pin of the DDS signal generator U1.

[0031] like Figure 2 As shown, the signal source attenuation circuit controls the attenuation amplitude of the signal, including a digital potentiometer U15. The model of the digital potentiometer U15 is MCP41010T-I / SN. The PA0 pin of the digital potentiometer U15 is connected to the second resistor R2. The other end of the second resistor R2 is connected to the VOUT pin of the DDS signal generator U1 and the third capacitor C3, so that the digital potentiometer U15 is connected to the signal AD_OUT. The other end of the third capacitor C3 is connected to GND. The VSS pin of the digital potentiometer U15 is connected to GND, and the VDD pin is respectively connected to the +3.3V power supply and the 43 capacitor C43. The other end of the 43 capacitor C43 is connected to GND.

[0032] The PB0 pin of the digital potentiometer U15 is connected to the attenuation resistor R5, and the other end of the attenuation resistor R5 is connected to GND. Through the attenuation resistor R5, the timing signals of the CS, SCK, and SI pins of the digital potentiometer U15 are controlled at the same time, thereby controlling the attenuation amplitude of the signal. The PW0 pin of the digital potentiometer U15 outputs the signal ZOOM_IN.

[0033] like Figure 3 As shown, the gain amplifier circuit includes a second op amp U2, the signal ZOOM_IN enters the IN+ pin of the second op amp U2 (that is, connected to the PW0 pin of the digital potentiometer U15), the V+ of the second op amp U2 is connected to +12V and the eighth capacitor R8, and the other end of the eighth capacitor R8 is connected to GND; the V- of the second op amp U2 is connected to GND; the IN- pin of the second op amp U2 is connected to the first resistor R1, and the other end of the first resistor R1 is grounded.

[0034] The IN- pin of the second op amp U2 is also connected to the 50 resistor R50, the 51 resistor R51, the 52 resistor R52, and the 53 resistor R53 respectively. The other ends of the four resistors are connected to X0 and Y0, X1 and Y1, X2 and Y2, and X3 and Y3 of the analog switch U18 respectively (the analog switch U18 model is RS2252XTSS16). The Y pin of the analog switch U18 is connected to the OUT pin of the second op amp U2, the EN pin of the analog switch U18 is connected to GND, the VDD pin is connected to the +12V power supply, the 174 resistor R174 and the 46 resistor R46, the GND pin, the other end of the 174 resistor R174 and the other end of the 46 resistor R46 are grounded, and the X pin of the analog switch U18 outputs the ZOOM_OUT signal to drive the speaker.

[0035] like Figure 4 As shown, specifically, the ZOOM_OUT signal is connected to the reverse proportional amplifier circuit, the output end of the reverse proportional amplifier circuit is connected to the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to and drives the speaker;

[0036] Specifically, the reverse proportional amplification circuit includes a fifth operational amplifier U5A, the IN- pin of the fifth operational amplifier U5A is connected to the seventh resistor R7 (1K) and the eighth resistor R8 (1K), the other end of the seventh resistor R7 is connected to the signal ZOOM_OUT and the ninth resistor R9 (10K), the other end of the ninth resistor R9 is grounded, the other end of the eighth resistor R8 is connected to the OUT port of the fifth operational amplifier U5A, the IN+ pin of the fifth operational amplifier U5A is connected to the twelfth resistor R12 (100K), the other end of the twelfth resistor R12 is connected to GND, and the OUT port of the fifth operational amplifier U5A is connected to the eleventh resistor R11;

[0037] Among them, the V+ of the fifth op amp U5A is connected to +12V and the zero capacitor R10 and the five capacitor R15, and the other end of the zero capacitor R10 and the five capacitor R15 is connected to GND; the V- of the fifth op amp U5A is connected to -5V, the one-two capacitor C12 (10uF / 25V) and the one-nine capacitor C19 (100uF / 50V), and the other end of the one-two capacitor C12 and the one-nine capacitor C19 is connected to GND.

[0038] Working principle:

[0039] In the signal source circuit, a 5V power supply is connected to one end of the first inductor L1, and the other end of the first inductor L1 is connected to pin 4 VCC of the crystal oscillator Y1. Pin 2 of the crystal oscillator Y1 is connected to GND, and pin 3 is connected to pin 5 MCLK of the DDS signal generator U1. By controlling the FSYNC, SCLK, and SDATA pins, the DDS signal generator U1 is driven to generate a signal source, which is output through the AD_OUT pin.

[0040] In the signal source attenuation circuit, the AD_OUT signal is connected to the PA0 pin of the digital potentiometer U15, and attenuates through the R5 resistor, while controlling the timing signals of CS, SCK, and SI, thereby controlling the attenuation amplitude of the signal. The signal ZOOM_IN is output from the PW0 pin.

[0041] In the signal source gain circuit, ZOOM_IN enters the IN+ of the second op amp U2. The IN- of the op amp U2 is grounded through the first R1. At the same time, it is connected to the X0Y0, X1Y1, X2Y2, and X3Y3 of the analog switch U18 through four resistors. The Y pin of the analog switch U18 is connected to the OUT port of the second op amp U2, thus forming an adjustable gain amplifier circuit. The signal ZOOM_OUT is output through the X pin.

[0042] Finally, the signal ZOOM_OUT enters the IN- of the fifth op amp U5A through the seventh resistor R7. The IN- pin of the fifth op amp U5A passes through R8 to the OUT port. The IN+ of the fifth op amp U5A is connected to GND through R12, thus forming a reverse proportional amplifier circuit, which is connected to the eleventh resistor R11 to drive the speaker.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. A universal signal source compensation circuit module for a MEMS pickup system, characterized by: It includes a signal source circuit and a gain amplifier circuit. The signal source circuit sends a signal, the gain amplifier circuit amplifies the signal and drives the speaker. The gain amplifier circuit includes a second operational amplifier U2. The IN+ pin of the second operational amplifier U2 receives the signal, the IN- pin is connected to the first resistor R1, and the other end of the first resistor R1 is grounded. The IN- pin of the second operational amplifier U2 is also connected to four resistors respectively. The other ends of the four resistors are respectively connected to the X0 and Y0, X1 and Y1, X2 and Y2, and X3 and Y3 pins of the analog switch U18. The Y pin of the analog switch U18 is connected to the OUT pin of the second operational amplifier U2. The X pin of the analog switch U18 outputs the ZOOM_OUT signal to drive the speaker.

2. The universal signal source compensation circuit module of a MEMS pickup system according to claim 1, characterized in that: The ZOOM_OUT signal is connected to the reverse proportional amplifier circuit, and the reverse proportional amplifier circuit outputs a signal to drive the speaker.

3. The universal signal source compensation circuit module of a MEMS pickup system according to claim 2, characterized in that: The output end of the reverse proportional amplifier circuit is connected to the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to drive the speaker.

4. The universal signal source compensation circuit module of a MEMS pickup system according to claim 3, characterized in that: The reverse proportional amplification circuit includes a fifth op amp U5A, the IN- pin of the fifth op amp U5A is connected to the seventh resistor R7 and the eighth resistor R8, the other end of the seventh resistor R7 is connected to the signal ZOOM_OUT, the other end of the eighth resistor R8 is connected to the OUT port of the fifth op amp U5A, the IN+ pin of the fifth op amp U5A is connected to the twelfth resistor R12, the other end of the twelfth resistor R12 is connected to GND, and the OUT port of the fifth op amp U5A is connected to the eleventh resistor R11.

5. The universal signal source compensation circuit module of a MEMS pickup system according to claim 1, characterized in that: The signal source circuit includes a crystal oscillator Y1. Pin 4 VCC of the crystal oscillator Y1 is connected to the first inductor L1. The other end of the first inductor L1 is connected to a 5V power supply. Pin 2 of the crystal oscillator Y1 is connected to GND, and pin 3 is connected to the MCLK pin of the DDS signal generator U1. The FSYNC, SCLK, and SDATA pins control and drive the DDS signal generator U1 to generate a signal source. The signal source is output as an AD_OUT signal through the VOUT pin of the DDS signal generator U1.

6. The universal signal source compensation circuit module of a MEMS pickup system according to claim 1 or 5, characterized in that: The signal sent by the signal source circuit also passes through the signal source attenuation circuit, which controls the attenuation amplitude of the signal.

7. The universal signal source compensation circuit module of a MEMS pickup system according to claim 6, characterized in that: The signal source attenuation circuit includes a digital potentiometer U15. The PA0 pin of the digital potentiometer U15 is connected to the signal. The PB0 pin of the digital potentiometer U15 is connected to the attenuation resistor R5. The other end of the attenuation resistor R5 is connected to GND. The timing signals of the CS, SCK, and SI pins of the digital potentiometer U15 are simultaneously controlled through the attenuation resistor R5, thereby controlling the attenuation amplitude of the signal. The PW0 pin of the digital potentiometer U15 outputs the signal ZOOM_IN.

8. The universal signal source compensation circuit module of a MEMS pickup system according to claim 7, characterized in that: The signal ZOOM_IN enters the IN+ pin of the second op amp U2.

Images