A signal processing circuit powered by a single power supply

Abstract

The present invention discloses a signal processing circuit powered by a single power supply, belonging to the technical field of signal processing circuits. An APD receives a signal as a signal, and converts the current signal output by the APD into a voltage signal through a resistor R10. The signal is passed through a differential amplifier U3A to amplify the received signal accordingly. The power supply voltage in the circuit is +VCC-GND. R21 and R22 are connected in parallel, and have the functions of matching the differential circuit and the high reference value. R22 and R21 raise the reference voltage of the U3A output signal from GND to VCC / 2, and then a part of the useless high-frequency signal is filtered out through a high-pass filter, and the useful signal is amplified again. In this way, the functions of improving signal quality and reducing signal noise can be achieved.

Description

Technical Field

[0001] The invention relates to a signal processing circuit, in particular to a signal processing circuit powered by a single power supply, and belongs to the technical field of signal processing circuits. Background Art

[0002] APD is a device that can receive laser signals. At present, APD devices have been widely used in various fields, such as: APD temperature control equipment, APD dual power automatic switching equipment, APD receiving equipment for laser radar, etc.

[0003] APD is a photoelectric avalanche diode. APD devices have high sensitivity, fast response speed and wide bandwidth. Therefore, the signals received by the APD need to be processed accordingly to meet the needs.

[0004] However, the APD signal processing in the current market all adopts dual power supply. Since the power supply noise will be amplified by the operational amplifier, when dual power supply amplification is used, the final signal noise is larger and the signal quality is poorer than when single power supply is used. Therefore, a single power supply signal processing circuit is designed to optimize the above problem. Summary of the invention

[0005] The main purpose of the present invention is to provide a signal processing circuit powered by a single power supply. The APD receives the signal as a signal, and the current signal output by the APD is converted into a voltage signal through the resistor R10. The signal passes through the differential amplifier U3A to amplify the received signal accordingly. The power supply voltage in the circuit is +VCC-GND. R21 and R22 are connected in parallel, and have the functions of matching the differential circuit and the too high reference value. R22 and R21 raise the reference voltage of the U3A output signal from GND to VCC / 2, and then a part of the useless high-frequency signal is filtered out through a high-pass filter, and then the useful signal is amplified. In this way, the functions of improving signal quality and reducing signal noise can be achieved.

[0006] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] A single-power-supply signal processing circuit comprises an APD signal acquisition circuit, a differential amplifier circuit, a second-order high-pass filter amplifier circuit and a low-pass filter amplifier circuit;

[0008] The APD signal acquisition circuit is used to collect the APD signal;

[0009] The differential amplifier circuit differentially amplifies the signal input by the APD signal acquisition circuit;

[0010] The second-order high-pass filter amplifier circuit obtains the differentially amplified signal and performs high-pass filtering before further amplification;

[0011] The low-pass filter amplifier circuit obtains the amplified signal after high-pass filtering and further performs low-pass filtering and amplifies it again before outputting the signal;

[0012] The APD signal acquisition circuit is electrically connected to a differential amplifier circuit, the differential amplifier circuit is electrically connected to a second-order high-pass filter amplifier circuit, and the second-order high-pass filter amplifier circuit is electrically connected to a low-pass filter amplifier circuit.

[0013] Preferably, the APD signal acquisition circuit includes a light-emitting diode D3 and a resistor R10, the cathode of the light-emitting diode D3 is electrically connected to one end of the resistor R10, the other end of the resistor R10 is electrically connected to the anode of the light-emitting diode D3, and the anode of the light-emitting diode D3 is also grounded.

[0014] Preferably, the differential amplifier circuit includes an operational amplifier U3A, the +INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R11, one end of a resistor R12 and one end of a capacitor CB1, the other end of the resistor R12 is electrically connected to the other end of the capacitor CB1 and is electrically connected to the OUT1 terminal of the operational amplifier U3A, the other end of the resistor R11 is electrically connected to one end of a resistor R10, and the -INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R19, one end of a resistor R21, one end of a resistor R22 and one end of a capacitor CB5.

[0015] Preferably, the other end of the capacitor CB5 is electrically connected to the other end of the resistor R22 and grounded, the other end of the resistor R21 is electrically connected to the power supply +VCC, the other end of the resistor R19 is electrically connected to the other end of the resistor R10, the 4-wire disconnect wire of the operational amplifier U3A is connected to the other end of the resistor R22, and the 8-wire terminal of the operational amplifier U3A is electrically connected to the power supply +VCC.

[0016] Preferably, the second-order high-pass filter amplifier circuit includes an operational amplifier U4A, the +INA terminal of the operational amplifier U4A is electrically connected to one end of the capacitor CB3, the other end of the capacitor CB3 is electrically connected to one end of the capacitor CB4 and one end of the resistor R, and the other end of the capacitor CB4 is electrically connected to the OUT1 terminal of the operational amplifier U3A.

[0017] Preferably, the -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R18 and one end of a resistor R17, the other end of the resistor R18 is grounded, the other end of the resistor R17 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to the power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the resistor R is also electrically connected to the OUT1 terminal of the operational amplifier U4A.

[0018] Preferably, the low-pass filter amplifier circuit includes a +INA terminal of an operational amplifier U5A electrically connected to one end of a resistor R14, the other end of the resistor R14 electrically connected to one end of a capacitor CB2 and one end of a resistor R13, and the other end of the resistor R13 electrically connected to the OUT1 terminal of the operational amplifier U4A.

[0019] Preferably, the -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R16 and one end of a resistor R15, the other end of the resistor R16 is grounded, the other end of the resistor R15 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to a power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the capacitor CB2 is electrically connected to the OUT terminal of the operational amplifier U4A.

[0020] Beneficial technical effects of the present invention:

[0021] The present invention provides a signal processing circuit powered by a single power supply. An APD receives a signal as a signal. A resistor R10 converts the current signal output by the APD into a voltage signal. The signal passes through a differential amplifier U3A to amplify the received signal accordingly. The power supply voltage in the circuit is +VCC-GND. R21 and R22 are connected in parallel, and have the functions of matching the differential circuit and the high reference value. R22 and R21 raise the reference voltage of the U3A output signal from GND to VCC / 2, and then a part of the useless high-frequency signal is filtered out through a high-pass filter, and the useful signal is amplified again. In this way, the functions of improving signal quality and reducing signal noise can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. 1 is a circuit diagram of a preferred embodiment of a single-power-supply signal processing circuit according to the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0024] like Figure 1 As shown, a single-power-supply signal processing circuit provided in this embodiment includes an APD signal acquisition circuit, a differential amplifier circuit, a second-order high-pass filter amplifier circuit and a low-pass filter amplifier circuit;

[0025] The APD signal acquisition circuit is used to collect the APD signal;

[0026] The differential amplifier circuit differentially amplifies the signal input by the APD signal acquisition circuit;

[0027] The second-order high-pass filter amplifier circuit obtains the differentially amplified signal and performs high-pass filtering before further amplification;

[0028] The low-pass filter amplifier circuit obtains the amplified signal after high-pass filtering and further performs low-pass filtering and amplifies it again before outputting the signal;

[0029] The APD signal acquisition circuit is electrically connected to a differential amplifier circuit, the differential amplifier circuit is electrically connected to a second-order high-pass filter amplifier circuit, and the second-order high-pass filter amplifier circuit is electrically connected to a low-pass filter amplifier circuit.

[0030] APD receives the signal as a signal, and converts the current signal output by APD into a voltage signal through resistor R10. The signal passes through the differential amplifier U3A to amplify the received signal accordingly. The power supply voltage in the circuit is +VCC-GND. R21 and R22 are connected in parallel, which have the function of matching the differential circuit and the too high reference value. R22 and R21 raise the reference voltage of U3A output signal from GND to VCC / 2, and then pass through the high-pass filter to filter out part of the useless high-frequency signal, and then amplify the useful signal. In this way, the signal quality can be improved and the signal noise can be reduced.

[0031] In this embodiment, the APD signal acquisition circuit includes a light-emitting diode D3 and a resistor R10, the cathode of the light-emitting diode D3 is electrically connected to one end of the resistor R10, the other end of the resistor R10 is electrically connected to the anode of the light-emitting diode D3, and the anode of the light-emitting diode D3 is also grounded.

[0032] In this embodiment, the differential amplifier circuit includes an operational amplifier U3A, the +INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R11, one end of a resistor R12 and one end of a capacitor CB1, the other end of the resistor R12 is electrically connected to the other end of the capacitor CB1 and is electrically connected to the OUT1 terminal of the operational amplifier U3A, the other end of the resistor R11 is electrically connected to one end of a resistor R10, and the -INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R19, one end of a resistor R21, one end of a resistor R22 and one end of a capacitor CB5.

[0033] In this embodiment, the other end of the capacitor CB5 is electrically connected to the other end of the resistor R22 and grounded, the other end of the resistor R21 is electrically connected to the power supply +VCC, the other end of the resistor R19 is electrically connected to the other end of the resistor R10, the 4-wire disconnect wire of the operational amplifier U3A is connected to the other end of the resistor R22, and the 8-wire terminal of the operational amplifier U3A is electrically connected to the power supply +VCC.

[0034] In this embodiment, the second-order high-pass filter amplifier circuit includes an operational amplifier U4A, the +INA terminal of the operational amplifier U4A is electrically connected to one end of the capacitor CB3, the other end of the capacitor CB3 is electrically connected to one end of the capacitor CB4 and one end of the resistor R, and the other end of the capacitor CB4 is electrically connected to the OUT1 terminal of the operational amplifier U3A.

[0035] In this embodiment, the -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R18 and one end of a resistor R17, the other end of the resistor R18 is grounded, the other end of the resistor R17 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to the power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the resistor R is also electrically connected to the OUT1 terminal of the operational amplifier U4A.

[0036] In this embodiment, the low-pass filter amplifier circuit includes a +INA terminal of an operational amplifier U5A electrically connected to one end of a resistor R14, the other end of the resistor R14 electrically connected to one end of a capacitor CB2 and one end of a resistor R13, and the other end of the resistor R13 electrically connected to the OUT1 terminal of the operational amplifier U4A.

[0037] In this embodiment, the -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R16 and one end of a resistor R15, the other end of the resistor R16 is grounded, the other end of the resistor R15 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to a power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the capacitor CB2 is electrically connected to the OUT terminal of the operational amplifier U4A.

[0038] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A signal processing circuit powered by a single power supply, characterized in that: It includes an APD signal acquisition circuit, a differential amplifier circuit, a second-order high-pass filter amplifier circuit and a low-pass filter amplifier circuit; The APD signal acquisition circuit is used to collect the APD signal; The differential amplifier circuit differentially amplifies the signal input by the APD signal acquisition circuit; The second-order high-pass filter amplifier circuit obtains the differentially amplified signal and performs high-pass filtering before further amplification; The low-pass filter amplifier circuit obtains the amplified signal after high-pass filtering and further performs low-pass filtering and amplifies it again before outputting the signal; The APD signal acquisition circuit is electrically connected to the differential amplifier circuit, the differential amplifier circuit is electrically connected to the second-order high-pass filter amplifier circuit, and the second-order high-pass filter amplifier circuit is electrically connected to the low-pass filter amplifier circuit; The APD signal acquisition circuit includes a light emitting diode D3 and a resistor R10, wherein the cathode of the light emitting diode D3 is electrically connected to one end of the resistor R10, and the other end of the resistor R10 is electrically connected to the anode of the light emitting diode D3, and the anode of the light emitting diode D3 is also grounded; The differential amplifier circuit includes an operational amplifier U3A, a +INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R11, one end of a resistor R12 and one end of a capacitor CB1, the other end of the resistor R12 is electrically connected to the other end of the capacitor CB1 and to the OUT1 terminal of the operational amplifier U3A, the other end of the resistor R11 is electrically connected to one end of a resistor R10, and a -INA terminal of the operational amplifier U3A is electrically connected to one end of a resistor R19, one end of a resistor R21, one end of a resistor R22 and one end of a capacitor CB5; The other end of the capacitor CB5 is electrically connected to the other end of the resistor R22 and grounded, the other end of the resistor R21 is electrically connected to the power supply +VCC, the other end of the resistor R19 is electrically connected to the other end of the resistor R10, the 4-wire disconnect wire of the operational amplifier U3A is connected to the other end of the resistor R22, and the 8-wire terminal of the operational amplifier U3A is electrically connected to the power supply +VCC.

2. The single-power-supply signal processing circuit according to claim 1, characterized in that: The second-order high-pass filter amplifier circuit includes an operational amplifier U4A, the +INA terminal of the operational amplifier U4A is electrically connected to one end of the capacitor CB3, the other end of the capacitor CB3 is electrically connected to one end of the capacitor CB4 and one end of the resistor R, and the other end of the capacitor CB4 is electrically connected to the OUT1 terminal of the operational amplifier U3A.

3. The single-power-supply signal processing circuit according to claim 2, characterized in that: The -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R18 and one end of a resistor R17, the other end of the resistor R18 is grounded, the other end of the resistor R17 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to the power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the resistor R is also electrically connected to the OUT1 terminal of the operational amplifier U4A.

4. The single-power-supply signal processing circuit according to claim 3, characterized in that: The low-pass filter amplifier circuit includes a +INA terminal of an operational amplifier U5A electrically connected to one end of a resistor R14, the other end of the resistor R14 electrically connected to one end of a capacitor CB2 and one end of a resistor R13, and the other end of the resistor R13 electrically connected to the OUT1 terminal of the operational amplifier U4A.

5. The single-power-supply signal processing circuit according to claim 4, characterized in that: The -INA terminal of the operational amplifier U4A is electrically connected to one end of a resistor R16 and one end of a resistor R15, the other end of the resistor R16 is grounded, the other end of the resistor R15 is electrically connected to the OUT1 terminal of the operational amplifier U4A, the 8 terminal of the operational amplifier U4A is electrically connected to a power supply +VCC, the 4 terminal of the operational amplifier U4A is grounded, and the other end of the capacitor CB2 is electrically connected to the OUT terminal of the operational amplifier U4A.

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