Laser detection signal processing circuit and laser detection device

Abstract

The utility model discloses a laser detection signal processing circuit and a laser detection device, and relates to the technical field of laser detection, the laser detection signal processing circuit comprises an amplification circuit, a gain circuit and a feedback circuit, the amplifying circuit is used for amplifying and outputting the laser detection signal generated by the laser detection sensor; the gain circuit is connected with the amplification circuit, and the gain circuit is used for adjusting the amplification gain of the amplification output signal of the amplification circuit; and the feedback circuit is connected with the laser detection sensor and the amplification circuit, and the feedback circuit is used for suppressing the offset voltage of the amplification output signal of the amplification circuit. According to the laser detection signal processing circuit provided by the embodiment of the utility model, high broadband gain and low output offset voltage of an amplified output signal can be taken into consideration, the defect that the offset voltage of an amplifying circuit is relatively large is made up, and the working frequency band of the amplifying circuit is downwards expanded to direct current.

Description

Technical Field

[0001] This utility model relates to the field of laser detection technology, and in particular to a laser detection signal processing circuit and a laser detection device. Background Technology

[0002] Currently, the output signal pulse width of laser detection sensors is very narrow. In order to ensure that the subsequent amplifier circuit has sufficient amplification capability, a broadband operational amplifier with a sufficiently wide bandwidth and a sufficiently large slew rate is generally selected for amplification. However, the offset voltage parameter of the amplified output signal of this type of operational amplifier is poor.

[0003] In existing technologies, one approach is to use a high-bandwidth operational amplifier with relatively low offset voltage. However, due to the limitations of chip performance trade-offs, even if a high-bandwidth operational amplifier with relatively low offset voltage is used regardless of cost, the offset voltage of the final output signal after amplification by hundreds of times often approaches several hundred millivolts. Furthermore, the characteristics of the offset voltage can lead to significant inconsistencies. Another approach is to eliminate the offset voltage using DC blocking capacitors, but this cannot achieve high-bandwidth gain amplification from DC to high frequencies. Utility Model Content

[0004] This utility model provides a laser detection signal processing circuit and a laser detection device to solve the technical problem that existing laser detection signal processing circuits in the related art cannot simultaneously achieve high broadband gain and low output offset voltage of the amplified output signal.

[0005] In a first aspect, a laser detection signal processing circuit is provided, comprising:

[0006] An amplifier circuit is used to connect to a laser detection sensor, and the amplifier circuit is used to amplify and output the laser detection signal generated by the laser detection sensor;

[0007] A gain circuit, which is connected to the amplifier circuit, is used to adjust the amplification gain of the amplified output signal of the amplifier circuit;

[0008] A feedback circuit, connected to the laser detection sensor and the amplification circuit, is used to suppress the offset voltage of the amplified output signal of the amplification circuit.

[0009] In some embodiments, the amplification circuit includes a first operational amplifier, the non-inverting input of which is connected to the laser detection sensor, the inverting input of which is connected to the gain circuit and the feedback circuit, and the output of which is connected to the gain circuit and the feedback circuit.

[0010] In some embodiments, the feedback circuit includes a feedback unit and an adjustment unit. The feedback unit is connected to the laser detection sensor and to the inverting input of the first operational amplifier. The feedback unit is used to suppress the offset voltage of the amplified output signal of the first operational amplifier.

[0011] The adjustment unit is connected to the output terminal of the first operational amplifier and the feedback unit, and the adjustment unit is used to adjust the feedback depth of the feedback unit.

[0012] In some embodiments, the feedback unit includes a first resistor, a second resistor, a first capacitor, and a second operational amplifier;

[0013] The first end of the first resistor is connected to the laser detection sensor, the second end of the first resistor is connected to the inverting input of the second operational amplifier, the first end of the second resistor is connected to the output of the second operational amplifier, and the second end of the second resistor is connected to the inverting input of the first operational amplifier.

[0014] The first terminal of the first capacitor is connected to the inverting input terminal of the second operational amplifier, the second terminal of the first capacitor is connected to the output terminal of the second operational amplifier, and the non-inverting input terminal of the second operational amplifier is connected to the adjustment unit.

[0015] In some embodiments, the adjustment unit includes a third resistor and a fourth resistor, a first end of the third resistor is connected to the output terminal of the first operational amplifier, a second end of the first end of the third resistor is connected to the first end of the fourth resistor and the non-inverting input terminal of the second operational amplifier, and the second end of the fourth resistor is grounded.

[0016] In some embodiments, the gain circuit includes a fifth resistor and a sixth resistor, a first terminal of the fifth resistor is connected to the output terminal of the first operational amplifier, a second terminal of the first terminal of the fifth resistor is connected to the first terminal of the sixth resistor and the inverting input terminal of the first operational amplifier, and the second terminal of the sixth resistor is grounded.

[0017] In some embodiments, the third resistor and the fifth resistor have the same resistance value, and the fourth resistor and the sixth resistor have the same resistance value.

[0018] In some embodiments, the resistance of the first resistor is 100Ω to 1000Ω.

[0019] In some embodiments, the laser detection sensor is an avalanche photodiode.

[0020] Secondly, a laser detection device is provided, including the aforementioned laser detection signal processing circuit.

[0021] The beneficial effects of the technical solution provided by this utility model include:

[0022] This invention provides a laser detection signal processing circuit and a laser detection device. The laser detection signal processing circuit includes an amplification circuit, a gain circuit, and a feedback circuit. On the one hand, the amplification circuit and gain circuit achieve a high broadband gain for the amplified output signal, satisfying a wide operating range from DC to high frequency. On the other hand, the feedback circuit greatly suppresses the offset voltage of the amplified output signal, significantly reducing its offset voltage. Furthermore, the offset voltage of the amplified output signal in this invention is significantly reduced (approaching 0), allowing the final amplified output signal to vary over a larger dynamic range under the same power supply conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a laser detection signal processing circuit provided for an embodiment of this utility model;

[0025] Figure 2 A circuit diagram of a laser detection signal processing circuit provided for an embodiment of this utility model;

[0026] Figure 3 The simulation result of the amplified output signal of the existing laser detection signal processing circuit is shown in the figure.

[0027] Figure 4 The simulation result diagram of the amplified output signal of a laser detection signal processing circuit provided in this embodiment of the utility model is shown. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] This utility model provides a laser detection signal processing circuit that can solve the technical problem that existing laser detection signal processing circuits cannot simultaneously achieve high broadband gain and low output offset voltage in the amplified output signal.

[0030] See Figure 1 As shown in the figure, this utility model embodiment provides a laser detection signal processing circuit, including: an amplifier circuit, a gain circuit and a feedback circuit.

[0031] The amplifier circuit is used to connect to the laser detection sensor, and it amplifies and outputs the laser detection signal generated by the laser detection sensor.

[0032] The gain circuit is connected to the amplifier circuit and is used to adjust the gain of the amplified output signal of the amplifier circuit.

[0033] The feedback circuit is connected to the laser detection sensor and the amplifier circuit. The feedback circuit is used to suppress the offset voltage of the amplified output signal of the amplifier circuit.

[0034] See Figure 1 As shown, the laser detection signal generated by the laser detection sensor is amplified by the amplification circuit according to the gain configuration of the gain circuit, and then output as an amplified output signal, achieving high-bandwidth gain amplification of the laser detection signal. Simultaneously, the laser detection signal is fed into the feedback circuit, and the amplified output signal is fed back to the amplification circuit via the feedback circuit, suppressing the offset voltage of the amplified output signal and controlling the offset voltage within a few millivolts. Figure 3 The figure shows the simulation results of the amplified output signal of the existing laser detection signal processing circuit. Figure 4 The figure shows the simulation results of the amplified output signal of the laser detection signal processing circuit of this utility model embodiment. By comparison, it can be seen that the amplified output signal of the existing laser detection signal processing circuit has an offset voltage of about 400mV, while the offset voltage of the amplified output signal of the laser detection signal processing circuit of this utility model embodiment is close to 0.

[0035] This invention provides a laser detection signal processing circuit, which includes an amplification circuit, a gain circuit, and a feedback circuit. On one hand, the amplification and gain circuits achieve high broadband gain for the amplified output signal, satisfying a wide operating range from DC to high frequencies. On the other hand, the feedback circuit significantly suppresses the offset voltage of the amplified output signal, greatly reducing its offset voltage. Furthermore, the significantly reduced offset voltage (approaching 0) of the amplified output signal in this invention allows the final amplified output signal to vary over a wider dynamic range under the same power supply conditions.

[0036] As an optional implementation, in one embodiment of the utility model, participants Figure 2As shown, the amplifier circuit includes a first operational amplifier U1. The non-inverting input of the first operational amplifier U1 is connected to the laser detection sensor, the inverting input of the first operational amplifier U1 is connected to the gain circuit and the feedback circuit, and the output of the first operational amplifier U1 is connected to the gain circuit and the feedback circuit. The first operational amplifier U1 can be selected as an operational amplifier with a high gain-bandwidth product to achieve full-gain amplification of high-frequency signals.

[0037] As an optional implementation, in one embodiment of the utility model, participants Figure 2 As shown, the feedback circuit includes a feedback unit and an adjustment unit. The feedback unit is connected to the laser detection sensor and is also connected to the inverting input of the first operational amplifier U1. The feedback unit is used to suppress the offset voltage of the amplified output signal of the first operational amplifier U1. The adjustment unit is connected to the output of the first operational amplifier and the feedback unit, and is used to adjust the feedback depth of the feedback unit.

[0038] Furthermore, participate Figure 2 As shown, the feedback unit includes a first resistor R1, a second resistor R2, a first capacitor C1, and a second operational amplifier U2.

[0039] The first end of the first resistor R1 is connected to the laser detection sensor, the second end of the first resistor R1 is connected to the inverting input of the second operational amplifier U2, the first end of the second resistor R2 is connected to the output of the second operational amplifier U2, and the second end of the second resistor R2 is connected to the inverting input of the first operational amplifier U1.

[0040] The first terminal of the first capacitor C1 is connected to the inverting input terminal of the second operational amplifier U2, and the second terminal of the first capacitor C1 is connected to the output terminal of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the adjustment unit.

[0041] The adjustment unit includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the output terminal of the first operational amplifier U1, the second end of the first end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the non-inverting input terminal of the second operational amplifier U2, and the second end of the fourth resistor R4 is grounded.

[0042] The second operational amplifier U2 can be a low-speed operational amplifier with low offset voltage and small bias current to achieve the smallest possible output offset voltage. The value of the first resistor R1 should not be too large to avoid excessive DC unexpected voltage caused by bias current; a value of 100Ω to 1000Ω can be selected. The second resistor R2 couples the output of the second operational amplifier U2 to the inverting input of the first operational amplifier U1, forming a large negative feedback loop with the amplifier circuit.

[0043] The third resistor R3 and the fourth resistor R4 divide the amplified output signal and feed it back to the non-inverting input of the second operational amplifier U2 to control the feedback depth of the negative feedback loop, so as to ensure the gain of the final amplified output signal.

[0044] As an optional implementation, in one embodiment of the utility model, participants Figure 2 As shown, the gain circuit includes a fifth resistor R5 and a sixth resistor R6. The first terminal of the fifth resistor R5 is connected to the output terminal of the first operational amplifier U1. The second terminal of the first terminal of the fifth resistor R5 is connected to the first terminal of the sixth resistor R6 and the inverting input terminal of the first operational amplifier U1. The second terminal of the sixth resistor R6 is grounded. The fifth resistor R5, the sixth resistor R6, and the first operational amplifier U1 form a small loop to control the gain of the amplified output signal.

[0045] Furthermore, the gain circuit and feedback circuit need to select appropriate resistors to configure the resistance ratio to achieve the required amplification gain. Specifically, the resistance ratio for configuring the gain should be equal to the resistance ratio for configuring the feedback, ensuring that the final signal amplification gain is only related to the resistance ratio of the gain circuit. Therefore, the resistance values ​​of the third resistor R3 and the fifth resistor R5, and the resistance values ​​of the fourth resistor R4 and the sixth resistor R6 can be the same.

[0046] As an optional implementation, in one embodiment of the utility model, the laser detection sensor can be an avalanche photodiode, which is an optical sensor with internal amplification function. It can detect extremely weak light signals and convert them into corresponding electrical signals, and has the characteristics of high sensitivity, high gain and fast response.

[0047] This utility model provides a laser detector, including the aforementioned laser detection signal processing circuit.

[0048] In the description of this utility model, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0049] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A laser detection signal processing circuit, characterized by, include: An amplifier circuit is used to connect to a laser detection sensor, and the amplifier circuit is used to amplify and output the laser detection signal generated by the laser detection sensor; A gain circuit, which is connected to the amplifier circuit, is used to adjust the amplification gain of the amplified output signal of the amplifier circuit; A feedback circuit, connected to the laser detection sensor and the amplification circuit, is used to suppress the offset voltage of the amplified output signal of the amplification circuit.

2. The laser detection signal processing circuit according to claim 1, characterized in that: The amplification circuit includes a first operational amplifier, the non-inverting input of which is connected to the laser detection sensor, the inverting input of which is connected to the gain circuit and the feedback circuit, and the output of which is connected to the gain circuit and the feedback circuit.

3. The laser detection signal processing circuit according to claim 2, characterized in that: The feedback circuit includes a feedback unit and an adjustment unit. The feedback unit is connected to the laser detection sensor and to the inverting input terminal of the first operational amplifier. The feedback unit is used to suppress the offset voltage of the amplified output signal of the first operational amplifier. The adjustment unit is connected to the output terminal of the first operational amplifier and the feedback unit, and the adjustment unit is used to adjust the feedback depth of the feedback unit.

4. The laser detection signal processing circuit according to claim 3, characterized in that: The feedback unit includes a first resistor, a second resistor, a first capacitor, and a second operational amplifier; The first end of the first resistor is connected to the laser detection sensor, the second end of the first resistor is connected to the inverting input of the second operational amplifier, the first end of the second resistor is connected to the output of the second operational amplifier, and the second end of the second resistor is connected to the inverting input of the first operational amplifier. The first terminal of the first capacitor is connected to the inverting input terminal of the second operational amplifier, the second terminal of the first capacitor is connected to the output terminal of the second operational amplifier, and the non-inverting input terminal of the second operational amplifier is connected to the adjustment unit.

5. The laser detection signal processing circuit according to claim 4, characterized in that: The adjustment unit includes a third resistor and a fourth resistor. The first end of the third resistor is connected to the output terminal of the first operational amplifier. The second end of the first end of the third resistor is connected to the first end of the fourth resistor and the non-inverting input terminal of the second operational amplifier. The second end of the fourth resistor is grounded.

6. The laser detection signal processing circuit according to claim 5, characterized in that: The gain circuit includes a fifth resistor and a sixth resistor. The first end of the fifth resistor is connected to the output terminal of the first operational amplifier. The second end of the first end of the fifth resistor is connected to the first end of the sixth resistor and the inverting input terminal of the first operational amplifier. The second end of the sixth resistor is grounded.

7. The laser detection signal processing circuit according to claim 6, characterized in that: The third resistor and the fifth resistor have the same resistance value, and the fourth resistor and the sixth resistor have the same resistance value.

8. The laser ranging signal processing circuit of claim 4, wherein: The resistance of the first resistor is 100Ω to 1000Ω.

9. The laser ranging signal processing circuit of claim 1, wherein: The laser detection sensor is an avalanche photodiode.

10. A laser detection apparatus, characterized by, Includes the laser detection signal processing circuit as described in any one of claims 1-9.

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