Signal conditioning circuit and communication equipment

Abstract

The utility model provides a signal conditioning circuit which comprises a crystal oscillator, and the signal conditioning circuit comprises a sampling circuit which is used for sampling the temperature of the environment where the crystal oscillator is located; the adjusting circuit is coupled with the sampling circuit, and the adjusting circuit is used for receiving a temperature signal, sampled by the sampling circuit, of the environment where the crystal oscillator is located, converting the temperature signal into an adjusting signal matched with the crystal oscillator and sending the adjusting signal to the crystal oscillator; therefore, the output frequency of the crystal oscillator is adjusted. By means of the mode, the situation that the output frequency of the crystal oscillator shifts in the high and low temperature environment is effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and in particular to a signal adjusting circuit and a communication device. BACKGROUND

[0002] Currently, the mainstream modulation methods of DMR intercom include single-point modulation and two-point modulation. The single-point modulation scheme mainly modulates the crystal oscillator of the PLL (Phase-Locked Loop). The two-point modulation scheme mainly includes the following two schemes: scheme one, one route modulates the crystal oscillator, and the other route modulates the VCO (Voltage Controlled Oscillator); scheme two, one route directly modulates the PLL, and the other route modulates the VCO. The above three modulation schemes are widely used in different products in combination with different platforms and different product requirements.

[0003] However, in the prior art, when the crystal oscillator is adjusted, the crystal oscillator is easily affected by high and low temperatures. In a high and low temperature environment, the frequency generated by the crystal oscillator will be offset. The frequency offset is an important factor affecting the signal quality. Unstable frequency offset will seriously affect the user experience. CONTENT OF THE INVENTION

[0004] The present application provides a signal adjusting circuit to solve the problem of unstable frequency offset of the communication device in the prior art in high and low temperature environments.

[0005] To solve the above technical problems, the present application provides a signal adjusting circuit, comprising a crystal oscillator, comprising: a sampling circuit, the sampling circuit is used for sampling the temperature of the environment where the crystal oscillator is located; an adjusting circuit, the adjusting circuit is coupled with the sampling circuit, the adjusting circuit is used for receiving the temperature signal of the environment where the crystal oscillator is located sampled by the sampling circuit, and converting the temperature signal into an adjusting signal suitable for the crystal oscillator to the crystal oscillator, so as to adjust the output frequency of the crystal oscillator.

[0006] Among them, the sampling circuit includes a temperature detection circuit and a control circuit, the temperature detection circuit is coupled with the control circuit, and the control circuit is coupled with the adjusting circuit.

[0007] Among them, the temperature detection circuit includes a thermistor, the thermistor is coupled with the control circuit, and the thermistor is used for detecting the environmental temperature where the crystal oscillator is located.

[0008] Among them, the control circuit includes a digital processor, the input end of the digital processor is coupled with the temperature detection circuit, and the output end is coupled with the adjusting circuit.

[0009] Among them, the adjusting circuit includes a digital-to-analog converter, the input end of the digital-to-analog converter is coupled with the control circuit, and the output end is coupled with the crystal oscillator.

[0010] The signal conditioning circuit further comprises an amplification circuit, an input end of the amplification circuit is coupled with the digital-to-analog converter, and an output end of the amplification circuit is coupled with the crystal oscillator.

[0011] The amplification circuit comprises an operational amplifier, an input end of the operational amplifier is coupled with the digital-to-analog converter, and an output end of the operational amplifier is coupled with the crystal oscillator.

[0012] The crystal oscillator comprises at least a first interface and a second interface, the first interface is externally connected with a direct current power supply, and the second interface is coupled with the conditioning circuit.

[0013] The crystal oscillator is externally connected with a direct current power supply and is configured with a filter circuit.

[0014] To solve the above problems, the application further provides a communication device, comprising: a signal conditioning circuit, the signal conditioning circuit being any one of the above signal conditioning circuits.

[0015] The application has the following beneficial effects: different from the prior art, the application samples the temperature of the current environment of the crystal oscillator through a sampling circuit and analyzes the sampled temperature signal through the sampling circuit. If the sampled temperature signal exceeds a temperature threshold, the temperature signal is transmitted to the conditioning circuit, the conditioning circuit converts the received temperature signal into an adjustment signal suitable for the crystal oscillator, adjusts the output frequency of the crystal oscillator, and effectively avoids the situation that the output frequency of the crystal oscillator deviates in a high or low temperature environment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural block diagram of an embodiment of the signal conditioning circuit of the application;

[0017] Figure 2 is a structural block diagram of another embodiment of the signal conditioning circuit of the application;

[0018] Figure 3 is a structural block diagram of the connection between the amplification circuit and the conditioning circuit of the application;

[0019] Figure 4 is a structural block diagram of the connection between the signal conditioning circuit and the phase-locked loop circuit of the application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0021] It should be noted that if the embodiments of the present application involve directionality indication (such as up, down, left, right, front, back, …), the directionality indication is only used to explain the relative position relationship, motion condition, etc. between components in a certain posture (as shown in the drawings), if the certain posture changes, the directionality indication also changes accordingly.

[0022] In addition, if the embodiments of the present application involve "first", "second" and the like, the "first", "second" and the like are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection claimed by the present application.

[0023] Please refer to Figure 1 , Figure 1 is a structural block diagram of an embodiment of the signal conditioning circuit provided by the present application.

[0024] The present application provides a signal conditioning circuit, which comprises a crystal oscillator 10, as Figure 1 shown, a signal conditioning circuit of the present embodiment comprises a sampling circuit 20 and a conditioning circuit 30. The conditioning circuit 30 is coupled with the sampling circuit 20, and the conditioning circuit 30 is used to receive the temperature signal sampled by the sampling circuit 20 from the environment where the crystal oscillator 10 is located, and convert the temperature signal into an adjustment signal suitable for the crystal oscillator 10 to the crystal oscillator 10, so as to adjust the output frequency of the crystal oscillator 10. Wherein, the temperature threshold is set in the sampling circuit 20, the temperature in the current environment where the crystal oscillator 10 is located is obtained through the sampling circuit 20, so as to judge whether the signal needs to be sent to the conditioning circuit 30, if it is judged that the signal needs to be sent to the conditioning circuit 30, the conditioning circuit 30 sends the adjustment signal to the crystal oscillator 10, so as to adjust the output frequency of the crystal oscillator 10.

[0025] In an optional embodiment, the sampling circuit 20 samples the temperature of the current environment of the crystal oscillator 10, and analyzes the collected environmental temperature by the sampling circuit 20, so as to determine whether the current environmental temperature is within the range of the temperature threshold. If the collected temperature is within the range of the temperature threshold, the sampling circuit 20 does not send a signal to the adjusting circuit 30. If the collected temperature is not within the range of the temperature threshold, the sampling circuit 20 sends the collected temperature signal to the adjusting circuit 30. After the adjusting circuit 30 receives the environmental temperature signal of the crystal oscillator 10, the adjusting circuit 30 converts the temperature signal into an adjusting signal suitable for the crystal oscillator 10, so as to adjust the output frequency of the crystal oscillator 10. Specifically, the crystal oscillator 10 is connected to a direct current power supply and an alternating current power supply, so that the crystal oscillator 10 outputs a corresponding frequency. After the sampling circuit 20 collects the environmental temperature of the crystal oscillator 10, if the sampling circuit 20 determines that the environmental temperature of the crystal oscillator 10 exceeds the range of the temperature threshold, the sampling circuit 20 transmits a signal to the adjusting circuit 30. After the adjusting circuit 30 receives the temperature signal and converts it into an adjusting signal suitable for the crystal oscillator 10, the adjusting circuit 30 adjusts the alternating current power supply connected to the crystal oscillator 10, thereby adjusting the output frequency of the crystal oscillator 10. This effectively avoids the situation that the output frequency of the crystal oscillator 10 deviates in a high or low temperature environment.

[0026] In a specific application scenario, the signal adjusting circuit is arranged in a intercom. If the intercom is in a low or high temperature environment, the output frequency of the crystal oscillator 10 will deviate according to the temperature. The sampling circuit 20 collects the environmental temperature of the crystal oscillator 10. If the sampling circuit 20 analyzes that the environmental temperature of the crystal oscillator 10 is within the range of the temperature threshold, the sampling circuit 20 does not send an adjusting signal to the adjusting circuit 30. If the sampling circuit 20 analyzes that the environmental temperature of the crystal oscillator 10 exceeds the temperature threshold, the sampling circuit 20 transmits the analyzed temperature signal to the adjusting circuit 30. The adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10. The adjusting signal adjusts the alternating current signal outside the crystal oscillator 10, thereby adjusting the output frequency of the crystal oscillator 10.

[0027] In the above embodiment, the sampling circuit 20 samples the environmental temperature of the current crystal oscillator 10, and analyzes the collected temperature signal by the sampling circuit 20. If the sampled temperature signal exceeds the temperature threshold, the temperature signal is transmitted to the adjusting circuit 30. The adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10, thereby adjusting the output frequency of the crystal oscillator 10. This effectively avoids the situation that the output frequency of the crystal oscillator 10 deviates in a high or low temperature environment.

[0028] In an optional embodiment, as shown in FIG. 4, the sampling circuit 20 is connected to the crystal oscillator 10, and the adjusting circuit 30 is connected to the sampling circuit 20. The sampling circuit 20 collects the environmental temperature of the crystal oscillator 10, and analyzes the collected temperature signal. If the sampled temperature signal exceeds the temperature threshold, the sampling circuit 20 transmits the temperature signal to the adjusting circuit 30. The adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10, thereby adjusting the output frequency of the crystal oscillator 10. Figure 2As shown, the sampling circuit 20 comprises a temperature detection circuit 201 and a control circuit 202, the temperature detection circuit 201 is coupled with the control circuit 202, and the control circuit 202 is coupled with the adjusting circuit 30. The temperature detection circuit 201 is arranged close to the crystal oscillator 10, so that the temperature detection circuit 201 can accurately detect the temperature of the environment where the crystal oscillator 10 is located, thereby facilitating the subsequent accurate adjustment of the alternating current signal input into the crystal oscillator 10, so that the crystal oscillator 10 outputs a preset frequency. Specifically, the temperature detection circuit 201 detects the ambient temperature of the crystal oscillator 10, and transmits the detected temperature signal to the control circuit 202. The control circuit 202 receives the temperature signal transmitted by the temperature detection circuit 201 and analyzes the temperature signal. If the temperature signal exceeds the temperature threshold range set by the control circuit 202, the control circuit 202 transmits the analyzed temperature signal to the adjusting circuit 30. The adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10, and transmits the adjusting signal to the crystal oscillator 10, thereby adjusting the alternating current signal input to the crystal oscillator 10, so that the crystal oscillator 10 outputs a corresponding frequency. If the temperature signal transmitted by the temperature detection circuit 201 is within the temperature threshold range set by the control circuit 202, the control circuit 202 does not transmit the temperature signal to the adjusting circuit 30. That is, the adjusting circuit 30 no longer outputs a corresponding adjusting signal, and the crystal oscillator 10 outputs a corresponding frequency.

[0029] In this embodiment, the temperature detection circuit 201 can be provided with a plug terminal, and the control circuit 202 can be provided with an interface matched with the plug terminal. When the temperature detection circuit 201 is connected with the control circuit 202, the plug terminal of the temperature detection circuit 201 is plugged into the interface of the control circuit 202. After the temperature detection circuit 201 detects the ambient temperature of the crystal oscillator 10, the temperature signal is transmitted to the control circuit 202 through the plug terminal. In other embodiments, the temperature detection circuit 201 and the control circuit 202 can be connected by wire harness or other means, which are not limited in this application. The control circuit 202 can be provided with a temperature threshold, and the temperature signal collected by the temperature detection circuit 201 can be analyzed, that is, the temperature signal collected by the temperature detection circuit 201 is compared with the temperature threshold, so as to determine whether the temperature signal needs to be output to the adjusting circuit 30.

[0030] In an optional embodiment, as shown in FIG. 2B, the sampling circuit 20 comprises a temperature detection circuit 201 and a control circuit 202, the temperature detection circuit 201 is coupled with the control circuit 202, and the control circuit 202 is coupled with the adjusting circuit 30. The temperature detection circuit 201 is arranged close to the crystal oscillator 10, so that the temperature detection circuit 201 can accurately detect the temperature of the environment where the crystal oscillator 10 is located, thereby facilitating the subsequent accurate adjustment of the alternating current signal input into the crystal oscillator 10, so that the crystal oscillator 10 outputs a preset frequency. Specifically, the temperature detection circuit 201 detects the ambient temperature of the crystal oscillator 10, and transmits the detected temperature signal to the control circuit 202. The control circuit 202 receives the temperature signal transmitted by the temperature detection circuit 201 and analyzes the temperature signal. If the temperature signal exceeds the temperature threshold range set by the control circuit 202, the control circuit 202 transmits the analyzed temperature signal to the adjusting circuit 30. The adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10, and transmits the adjusting signal to the crystal oscillator 10, thereby adjusting the alternating current signal input to the crystal oscillator 10, so that the crystal oscillator 10 outputs a corresponding frequency. If the temperature signal transmitted by the temperature detection circuit 201 is within the temperature threshold range set by the control circuit 202, the control circuit 202 does not transmit the temperature signal to the adjusting circuit 30. That is, the adjusting circuit 30 no longer outputs a corresponding adjusting signal, and the crystal oscillator 10 outputs a corresponding frequency. Figure 2As shown, the temperature detection circuit 201 includes a thermistor 203 coupled with the control circuit 202, and the thermistor 203 is configured to detect the ambient temperature of the crystal oscillator 10. The thermistor 203 can be arranged close to the crystal oscillator 10. After the thermistor 203 detects the ambient temperature of the crystal oscillator 10, the thermistor 203 changes its resistance with the change of the temperature. The control circuit 202 can detect the resistance of the thermistor 203, and analyze the ambient temperature of the crystal oscillator 10 according to the resistance of the thermistor 203. That is, the control circuit 202 can determine whether the ambient temperature of the crystal oscillator 10 is within the temperature threshold according to the resistance of the thermistor 203. If the crystal oscillator 10 is determined to be within the temperature threshold, the control circuit 202 does not send the adjustment signal to the adjustment circuit 30. If the control circuit 202 determines that the ambient temperature of the crystal oscillator 10 is out of the temperature threshold set by the control circuit 202, the control circuit 202 transmits the temperature signal to the adjustment circuit 30. The adjustment circuit 30 receives the temperature signal and converts it into the adjustment signal suitable for the crystal oscillator 10, so as to adjust the AC signal input into the crystal oscillator 10, and make the crystal oscillator 10 transmit the preset frequency.

[0031] In this embodiment, the thermistor 203 can be a positive temperature coefficient thermistor 203. The resistance of the thermistor 203 increases with the increase of the ambient temperature of the crystal oscillator 10. That is, the resistance of the thermistor 203 increases when the temperature detected by the thermistor 203 increases. The control circuit 202 detects the resistance of the thermistor 203, and determines whether the crystal oscillator 10 is within the temperature threshold according to the resistance. In this embodiment, the thermistor 203 controls the temperature. Specifically, the thermistor 203 detects the ambient temperature of the crystal oscillator 10. When the temperature increases, the resistance of the thermistor 203 increases, so that the current transmitted by the thermistor 203 decreases, and the current received by the control circuit 202 decreases. The control circuit 202 receives the current value, and determines whether the ambient temperature of the crystal oscillator 10 is within the preset range.

[0032] In other embodiments, the thermistor 203 can be a negative temperature coefficient thermistor 203. That is, the resistance of the thermistor 203 decreases with the increase of the ambient temperature of the crystal oscillator 10. The control circuit 202 detects the resistance of the thermistor 203 or the current increased by the decrease of the resistance of the thermistor 203, and determines whether the ambient temperature of the crystal oscillator 10 is out of the temperature threshold, so as to determine whether the AC signal input into the crystal oscillator 10 needs to be adjusted. The present application does not make specific limitation here.

[0033] In an optional embodiment, the control circuit 202 comprises a digital processor 204, an input end of the digital processor 204 is coupled with the temperature detection circuit 201, and an output end of the digital processor 204 is coupled with the adjusting circuit 30. The digital processor 204 is configured to receive the temperature signal transmitted by the temperature detection circuit 201, process the temperature signal, and transmit the temperature signal to the adjusting circuit 30 if the temperature signal exceeds the set temperature threshold range, and not transmit the temperature signal to the adjusting circuit 30 if the temperature signal does not exceed the set temperature threshold range. In this embodiment, the thermistor 203 detects the ambient temperature of the crystal oscillator 10, the thermistor 203 changes its resistance value according to the ambient temperature, the digital processor 204 receives the resistance value of the thermistor 203, and compares and analyzes the resistance value with the temperature threshold set in the digital processor 204, and transmits the digital signal of the resistance value of the thermistor 203 to the adjusting circuit 30 if the ambient temperature of the crystal oscillator 10 exceeds the temperature threshold. In other embodiments, the digital processor 204 can receive the resistance value changed by the thermistor 203 to change the size of the current signal output by the digital processor 204, and the digital processor 204 can analyze and determine whether the temperature threshold is exceeded according to the size of the current signal transmitted by the thermistor 203.

[0034] In an optional embodiment, the adjusting circuit 30 comprises a digital-to-analog converter 301, an input end of the digital-to-analog converter 301 is coupled with the control circuit 202, and an output end of the digital-to-analog converter 301 is coupled with the crystal oscillator 10. That is, the input end of the digital-to-analog converter 301 is configured to receive the temperature signal transmitted by the control circuit 202, and the output end of the digital-to-analog converter 301 is coupled with the crystal oscillator 10. Specifically, after the temperature detection circuit 201 detects the ambient temperature of the crystal oscillator 10, the temperature detection circuit 201 transmits the detected temperature signal to the control circuit 202, the control circuit 202 receives the temperature signal and analyzes the temperature signal to determine whether the temperature signal exceeds the temperature threshold range, and transmits the temperature signal to the adjusting circuit 30 if the temperature signal exceeds the temperature threshold range. The temperature signal transmitted by the control circuit 202 is a digital signal, the digital signal is converted into an analog signal by the digital-to-analog converter 301 after being transmitted to the digital-to-analog converter 301, and the analog signal is transmitted to the crystal oscillator 10, so as to adjust the alternating current signal input by the crystal oscillator 10.

[0035] In other embodiments, the temperature detection circuit 201 can change its resistance value to change the current signal output by the temperature detection circuit 201 after collecting the current ambient temperature of the crystal oscillator 10, and transmit the current signal to the control circuit 202, the control circuit 202 analyzes the current signal, and transmits the current signal directly to the adjusting circuit 30 if the current signal exceeds the temperature threshold, the adjusting circuit 30 transmits the current signal to the crystal oscillator 10 and adjusts the alternating current signal of the crystal oscillator 10.

[0036] In an optional embodiment, the signal conditioning circuit further includes an amplifier circuit 40. The input terminal of the amplifier circuit 40 is coupled to the digital-to-analog converter 301, and the output terminal is coupled to the crystal oscillator 10. The input terminal of the amplifier circuit 40 is coupled to the digital-to-analog converter 301. After the digital-to-analog converter 301 receives the temperature signal output by the control circuit 202, it converts the temperature signal into a conditioning signal adapted to the crystal oscillator 10. The conditioning signal is transmitted to the amplifier circuit 40, which amplifies the current signal after the AC signal is conditioned, thereby completing the frequency adjustment of the crystal oscillator 10. The amplifier circuit 40 can be a voltage amplifier circuit; that is, after the conditioning circuit 30 transmits the conditioning signal to the amplifier circuit 40, the amplifier circuit 40 amplifies the voltage and transmits it to the crystal oscillator 10 to condition the external AC signal, causing the crystal oscillator 10 to output a preset frequency signal. In other embodiments, the amplifier circuit 40 can also be a current amplifier circuit; this application does not specifically limit its application.

[0037] In this embodiment, the amplification circuit 40 includes an operational amplifier 401. The input terminal of the operational amplifier 401 is coupled to the adjustment circuit 30, and the output terminal is coupled to the crystal oscillator 10. That is, the temperature detection circuit 201 detects the temperature of the environment where the crystal oscillator 10 is located and transmits the temperature signal to the control circuit 202. The control circuit 202 transmits the temperature signal to the digital-to-analog converter 301. The digital-to-analog converter 301 converts the temperature signal into an adjustment signal and transmits it to the operational amplifier 401. The operational amplifier 401 amplifies the converted adjustment signal, thereby compensating for the output frequency of the crystal oscillator 10, so that the crystal oscillator 10 outputs a preset frequency.

[0038] In an optional embodiment, such as Figure 3 As shown, the crystal oscillator 10 includes at least a first interface 701 and a second interface 702. The first interface 701 is connected to an external DC power supply, and the second interface 702 is coupled to an adjustment circuit 30. That is, the crystal oscillator 10 can output a frequency after being connected to a DC power supply. The second interface 702 is connected to the adjustment circuit 30, thereby adjusting the output frequency of the crystal oscillator 10 based on the adjustment signal output by the adjustment circuit 30. Specifically, the first interface 701 is connected to an external DC power supply, and the second interface 702 is coupled to the output of the operational amplifier 401. That is, after the digital-to-analog converter 301 converts the temperature signal transmitted by the control circuit 202 into an adjustment signal, the adjustment signal is transmitted to the operational amplifier 401. The operational amplifier 401 amplifies the adjustment signal, thereby adjusting the output frequency of the crystal oscillator 10, causing the crystal oscillator 10 to output a preset frequency.

[0039] In this embodiment, a filter circuit 50 is configured before the crystal oscillator 10 is connected to an external DC power supply. That is, the filter circuit 50 can filter the DC signal transmitted by the DC power supply, thereby enabling the crystal oscillator 10 to output a preset frequency.

[0040] In other embodiments, such as Figure 3 As shown, the output terminal of the operational amplifier 401 is provided with a delay circuit 60 to delay the transmitted adjustment signal. A filter circuit can also be provided at the output terminal of the operational amplifier 401, but this application does not make specific limitations here.

[0041] In a specific application scenario, when the crystal oscillator 10 is in a high or low temperature condition, the temperature detection circuit 201 samples the temperature of the environment in which the crystal oscillator 10 is located. Specifically, the thermistor 203 detects the temperature of the environment and changes its resistance value based on the collected temperature. The control circuit 202 determines whether the ambient temperature of the crystal oscillator 10 exceeds a set temperature threshold range based on the resistance value of the thermistor 203. If the temperature of the environment in which the crystal oscillator 10 is located exceeds the temperature threshold range, the temperature signal is transmitted to the digital-to-analog converter circuit. The digital-to-analog converter circuit converts the temperature signal into an adjustment signal adapted to the crystal oscillator 10 and transmits the adjustment signal to the amplifier circuit 40, specifically to the operational amplifier 401, where the adjustment signal is amplified. This completes the adjustment of the AC signal connected to the crystal oscillator 10, compensating for the output frequency of the crystal oscillator 10, so that the crystal oscillator 10 outputs a preset frequency. If the control circuit 202 detects that the ambient temperature of the crystal oscillator 10 does not exceed the set temperature threshold based on the resistance value of the thermistor 203, then the control circuit 202 will not output a temperature signal to the adjustment circuit 30, and the crystal adjustment circuit 30 will output the preset frequency normally.

[0042] In an optional embodiment, such as Figure 4As shown, the signal adjusting circuit further comprises a phase-locked loop circuit 90, an analog circuit 802, and a feedback circuit 801, the output end of the crystal oscillator 10 is connected to the phase-locked loop circuit 90, the output end of the phase-locked loop circuit 90 is connected to the analog circuit 802, the output end of the analog circuit 802 is used to output a frequency, and the output end of the analog circuit 802 is connected to the feedback circuit 801, so as to transmit the frequency signal output by the analog circuit 802 to the phase-locked loop circuit 90, so as to judge whether the output frequency signal is a preset frequency through the phase-locked loop circuit 90. Specifically, the temperature of the environment where the crystal oscillator 10 is located is collected through the sampling circuit 20, and if the temperature of the environment where the crystal oscillator 10 is located exceeds a temperature threshold, the temperature signal is transmitted to the adjusting circuit 30, so that the adjusting signal is output through the adjusting circuit 30, the alternating current signal input to the crystal oscillator 10 is adjusted, so that the crystal oscillator 10 outputs a preset frequency, and the preset frequency is transmitted to the phase-locked loop circuit 90 and output through the analog circuit 802, and the output frequency is fed back to the phase-locked loop circuit 90 through the feedback circuit 801.

[0043] In the embodiment, when the frequency signal output by the signal adjusting circuit is adjusted, the crystal oscillator 10 and the analog circuit 802 can be adjusted at the same time, so as to complete the regulation and control of the frequency output by the signal adjusting circuit. Specifically, the temperature environment temperature where the crystal oscillator 10 is located can be detected through the temperature detection circuit 201 and the temperature signal is transmitted to the control circuit 202, the control circuit analyzes the temperature signal, and if the temperature signal exceeds a temperature threshold, the temperature signal is transmitted to the adjusting circuit 30, the adjusting circuit 30 converts the temperature signal into an adjusting signal suitable for the crystal oscillator 10, and transmits the adjusting signal to the operational amplifier 401, so as to adjust the alternating current signal connected to the crystal oscillator 10 through the operational amplifier 401, so that the crystal oscillator 10 outputs a preset frequency. And the input voltage of the analog circuit 802 is adjusted, so as to adjust the output frequency of the analog circuit 802, so that the signal adjusting circuit outputs a preset frequency. The feedback circuit 801 feeds back the output frequency to the phase-locked loop circuit 90, so as to analyze the output frequency and judge whether the frequency signal output by the signal adjusting circuit is a preset frequency.

[0044] By the above manner, the application can sample the ambient temperature of the crystal oscillator 10 by the sampling circuit 20, and if the sampled temperature signal exceeds the temperature threshold, the temperature signal is transmitted to the adjusting circuit 30, and the adjusting circuit 30 converts the received temperature signal into an adjusting signal suitable for the crystal oscillator 10, so as to adjust the AC power source connected to the crystal oscillator 10, complete the adjustment of the output frequency of the crystal oscillator 10, and effectively avoid the output frequency deviation of the crystal oscillator 10 in high and low temperature environment. By setting the temperature detection circuit 201 and the control circuit 202 in the sampling circuit 20, the temperature of the environment where the crystal oscillator 10 is located can be detected by the temperature detection circuit 201, and the temperature detected by the temperature detection circuit 201 can be analyzed by the control circuit 202, so as to accurately adjust the output frequency of the crystal oscillator 10. By setting the temperature detection circuit 201 as a thermistor 203, the temperature of the environment where the crystal oscillator 10 is located can be detected by the thermistor 203, so as to convert the temperature signal into the resistance value of the thermistor 203, and the control circuit 202 can accurately analyze the ambient temperature of the crystal oscillator 10. By setting the control circuit 202 as a digital processor 204, the temperature signal transmitted by the thermistor 203 can be processed, so as to accurately determine whether the output frequency of the crystal oscillator 10 needs to be compensated. By setting the adjusting circuit 30 as a digital-to-analog converter 301, the digital signal transmitted by the digital processor 204 can be converted into an analog signal, so as to complete the adjustment of the AC signal connected to the crystal oscillator 10. By setting the amplification circuit 40, the adjusted AC signal can be amplified. By configuring the filter circuit 50 before the DC power supply connected to the crystal oscillator 10, the DC signal can be filtered, so that the crystal oscillator 10 outputs a preset frequency.

[0045] The application also provides a communication device, which comprises a signal adjusting circuit, wherein the signal adjusting circuit is arranged in the communication device, and the signal adjusting circuit is any one of the signal adjusting circuits.

[0046] The above is only an embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent process transformation by using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A signal conditioning circuit comprising a crystal oscillator, characterized by, The signal adjusting circuit comprises: a sampling circuit for sampling the temperature of the environment where the crystal oscillator is located; an adjusting circuit coupled with the sampling circuit, the adjusting circuit being configured to receive the temperature signal sampled by the sampling circuit and convert the temperature signal into an adjusting signal suitable for the crystal oscillator to the crystal oscillator to adjust the output frequency of the crystal oscillator; The crystal oscillator comprises at least a first interface and a second interface, the first interface being connected to a DC power supply, and the second interface being coupled with the adjusting circuit to output the adjusting signal from the adjusting circuit to adjust the AC signal input to the crystal oscillator, so that the crystal oscillator outputs a preset frequency.

2. The signal conditioning circuit of claim 1, wherein, The sampling circuit comprises a temperature detection circuit and a control circuit, the temperature detection circuit being coupled with the control circuit, and the control circuit being coupled with the adjusting circuit.

3. The signal conditioning circuit of claim 2, wherein, The temperature detection circuit comprises a thermistor, the thermistor being coupled with the control circuit, and the thermistor being configured to detect the ambient temperature of the crystal oscillator.

4. The signal conditioning circuit of claim 2, wherein, The control circuit comprises a digital processor, the input of the digital processor being coupled with the temperature detection circuit, and the output of the digital processor being coupled with the adjusting circuit.

5. The signal conditioning circuit of claim 2, wherein, The adjusting circuit comprises a digital-to-analog converter, the input of the digital-to-analog converter being coupled with the control circuit, and the output of the digital-to-analog converter being coupled with the crystal oscillator.

6. The signal conditioning circuit of claim 5, wherein, The signal adjusting circuit further comprises an amplification circuit, the input of the amplification circuit being coupled with the digital-to-analog converter, and the output of the amplification circuit being coupled with the crystal oscillator.

7. The signal conditioning circuit of claim 6, wherein, The amplification circuit comprises an operational amplifier, the input of the operational amplifier being coupled with the digital-to-analog converter, and the output of the operational amplifier being coupled with the crystal oscillator.

8. The signal conditioning circuit of claim 1, wherein, The crystal oscillator is provided with a filter circuit before being connected to a DC power supply.

9. A communication device, characterized by The communication device comprises: a signal adjusting circuit, the signal adjusting circuit being any one of the signal adjusting circuits according to claims 1-8.

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