Multifunctional analog signal output circuit

Abstract

The utility model relates to a multifunctional analog signal output circuit, and relates to the technical field of analog signal circuits. The circuit comprises a first conversion unit, a second conversion unit, a selection output unit and a controller, a digital input signal is respectively input to the input ends of the first conversion unit and the second conversion unit, and the first conversion unit is used for converting the digital input signal into an analog quantity current signal; the second conversion unit is used for converting the digital input signal into an analog quantity voltage signal; the output end of the first conversion unit is electrically connected to the first input end of the selection output unit, the output end of the second conversion unit is electrically connected to the second input end of the selection output unit, the control end of the selection output unit is electrically connected to the output end of the controller, and the selection output unit is used for outputting analog quantity current signals or analog quantity voltage signals. According to the invention, the output of the analog current signal and the analog voltage signal can be flexibly switched.

Description

Technical Field

[0001] The present application relates to the technical field of analog signal circuits, and in particular to a multifunctional analog signal output circuit. Background Art

[0002] Analog signal output circuits are widely used in industrial automation control systems to process digital input signals and output analog current signals or analog voltage signals to drive or control other devices. However, existing analog signal output circuits can usually only output a single type of analog signal (such as current signal or voltage signal), which cannot meet diverse control requirements.

[0003] To solve the above problems, the prior art generally adopts multiple independent analog signal output circuits to output different types of analog signals. However, this solution cannot achieve flexible switching between analog current signals and analog voltage signals, and needs to select output analog current signals and analog voltage signals according to needs by setting switches or other methods. Utility Model Content

[0004] In order to achieve flexible switching between analog current signal and analog voltage signal output, the present application provides a multifunctional analog signal output circuit.

[0005] The present application provides a multifunctional analog signal output circuit adopting the following technical solution:

[0006] A multifunctional analog signal output circuit comprises a first conversion unit, a second conversion unit, a selection output unit and a controller, wherein a digital input signal is input to the input ends of the first conversion unit and the second conversion unit respectively, the first conversion unit is used to convert the digital input signal into an analog current signal, and the second conversion unit is used to convert the digital input signal into an analog voltage signal; the output end of the first conversion unit is electrically connected to the first input end of the selection output unit, the output end of the second conversion unit is electrically connected to the second input end of the selection output unit, the control end of the selection output unit is electrically connected to the output end of the controller, and the selection output unit is used to output the analog current signal or the analog voltage signal.

[0007] By adopting the above technical solution, the digital input signal is amplified by the first conversion unit and then outputs an analog current signal; the digital input signal is amplified by the second conversion unit and then outputs an analog current signal. The selection output unit selectively outputs an analog current signal or an analog current signal according to the control signal sent by the first output terminal and the second output terminal of the controller, so that the entire circuit can realize flexible switching of different analog signal types through the controller.

[0008] Preferably, the selection output unit includes a switch chip U3 and peripheral components thereof, the first input terminal of the switch chip U3 is electrically connected to the output terminal of the first conversion unit, and the second input terminal of the switch chip U3 is electrically connected to the output terminal of the second conversion unit; the selection control terminal of the switch chip U3 is electrically connected to the first output terminal of the controller, and the enable control terminal of the switch chip U3 is electrically connected to the second output terminal of the controller.

[0009] By adopting the above technical solution, when the second output terminal outputs a low level, the output unit is selected not to output a signal; when the second output terminal outputs a high level and the first output terminal outputs a low level, the output unit is selected to output an analog current signal; when the second output terminal outputs a high level and the first output terminal outputs a high level, the output unit is selected to output an analog voltage signal, thereby enabling the output switching of the analog current signal and the analog voltage signal to be more flexibly realized through the controller.

[0010] Preferably, the first conversion unit includes a first op amp U1, a feedback resistor R4, a push-pull module and a reference power supply, the output end of the digital input signal is electrically connected to the non-inverting input end of the first op amp U1, and the reference power supply output end is electrically connected to the inverting input end of the first op amp U1; the output end of the first op amp U1 is electrically connected to the input end of the push-pull module, the output end of the push-pull module is electrically connected to the inverting input end of the first op amp U1 through the feedback resistor R4, the output end of the push-pull module is also electrically connected to the non-inverting input end of the first op amp U1 through the resistor R6 and the resistor R2 in sequence, and the connection between the resistor R6 and the resistor R2 is the output end OUT1 of the first conversion unit.

[0011] By adopting the above technical solution, the first operational amplifier U1 and peripheral devices can realize differential amplification of the input signal, and by setting a push-pull module, the current push amplification function can be achieved, and current negative feedback is formed by resistors R6 and R2, so that the first conversion unit can output a stable analog current signal.

[0012] Preferably, the push-pull module includes: the output end of the first op amp U1 is electrically connected to the base of the transistor Q1 and the transistor Q2, the collector of the transistor Q1 is electrically connected to a positive power supply, the collector of the transistor Q2 is electrically connected to a negative power supply, and the emitter of the transistor Q1 is electrically connected to the emitter of the transistor Q2.

[0013] By adopting the above technical solution, complementary transistors Q1 and Q2 are provided to play a push-pull role, thereby further amplifying the signal at the output end of the first operational amplifier U1; and because only one of the two complementary transistors is turned on at a time, it also has the effects of small conduction loss and high efficiency.

[0014] Preferably, the push-pull module further includes a resistor R3, one end of the resistor R3 is electrically connected to the output end of the first operational amplifier U1, and the other end of the resistor R3 is electrically connected to the collector of the transistor Q1.

[0015] By adopting the above technical solution, the resistor R3 can achieve dead zone compensation to a certain extent.

[0016] Preferably, the first conversion unit further includes a capacitor C1, one end of the capacitor C1 is electrically connected to the inverting input end of the first operational amplifier U1, and the other end of the capacitor C1 is electrically connected to the output end of the first operational amplifier U1.

[0017] By adopting the above technical solution, the capacitor C1 is used to play the role of filtering and stabilizing voltage, thereby improving the stability of the first conversion unit.

[0018] Preferably, the second conversion unit includes a second op amp U2 and a reference power supply, the output end of the digital input signal is electrically connected to the non-inverting input end of the second op amp U2, the reference power supply output end is electrically connected to the inverting input end of the second op amp U2, the output end of the second op amp U2 is also electrically connected to the inverting input end of the second op amp U2 through a resistor R9 and a feedback resistor R10 in sequence, and the connection between the resistor R9 and the feedback resistor R10 is the output end OUT2 of the second conversion unit.

[0019] By adopting the above technical solution, the second operational amplifier U2 and peripheral devices can realize differential amplification of the input signal, so that the second conversion unit can output a stable analog voltage signal.

[0020] Preferably, the inverting input terminal of the second operational amplifier U2 is also electrically connected to a capacitor C2, and the other end of the capacitor C2 is electrically connected to the output terminal of the second operational amplifier U2.

[0021] By adopting the above technical solution, the capacitor C2 is used to play the role of filtering and stabilizing voltage, thereby improving the stability of the overall second conversion unit.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: the digital input signal is amplified, converted and processed by the first conversion unit to output an analog current signal; the digital input signal is amplified, converted and processed by the second conversion unit to output an analog current signal; the output unit can select whether to output an analog signal under the control of the controller, and select the output analog signal to be a current signal or a voltage signal, thereby realizing flexible switching of different analog signal type outputs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of an embodiment of the present application;

[0024] Figure 2 is a circuit diagram of a first conversion unit in an embodiment of the present application;

[0025] Figure 3 is a circuit diagram of a second conversion unit in an embodiment of the present application;

[0026] Figure 4 It is a circuit diagram of selecting an output unit in an embodiment of the present application.

[0027] Figure numerals: 1. first conversion unit; 11. push-pull module; 2. second conversion unit; 3. selection output unit; 4. controller. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-4 This application is described in further detail.

[0029] The embodiment of the present application discloses a multifunctional analog signal output circuit.

[0030] Reference Figure 1 A multifunctional analog signal output circuit includes a first conversion unit 1, a second conversion unit 2, a selection output unit 3 and a controller 4. The first conversion unit 1 is used to convert a digital input signal into an analog current signal, and the second conversion unit 2 is used to convert a digital input signal into an analog voltage signal. The digital input signal is input to the input ends of the first conversion unit 1 and the second conversion unit 2 respectively. The output end of the first conversion unit 1 is electrically connected to the first input end of the selection output unit 3, and the output end of the second conversion unit 2 is electrically connected to the second input end of the selection output unit 3. The control end of the selection output unit 3 is electrically connected to the output end of the controller 4, and the selection output unit 3 is used to output an analog output signal. The analog output signal can be controlled to be an analog current signal or an analog voltage signal through the controller 4, so that the output analog current signal or analog voltage signal can be more conveniently controlled.

[0031] refer to Figure 2, the first conversion unit 1 includes a first operational amplifier U1, a feedback resistor R4, and a push-pull module 11. The output terminal of the digital input signal is set as the input signal terminal DAC2, and the input signal terminal DAC2 is electrically connected to the non-inverting input terminal of the first operational amplifier U1 through a resistor R1; the embodiment of the present application further includes a reference power supply, and the output terminal VREF+ of the reference power supply is electrically connected to the inverting input terminal of the first operational amplifier U1 through a resistor R5. The output terminal of the first operational amplifier U1 is electrically connected to the input terminal of the push-pull module 11, and the output terminal of the push-pull module 11 is electrically connected to the inverting input terminal of the first operational amplifier U1 through a feedback resistor R4. The output terminal of the push-pull module 11 is also sequentially electrically connected to the non-inverting input terminal of the first operational amplifier U1 through a resistor R6 and a resistor R2, so as to be able to form a current negative feedback and convert the voltage signal into a current signal. The connection point between the resistor R6 and the resistor R2 is the output terminal OUT1 of the first conversion unit 1, and the output terminal OUT1 is used to output an analog current signal.

[0032] The push-pull module 11 includes a triode Q1 and a triode Q2, where the triode Q1 is set as an NPN-type triode, the triode Q2 is set as a PNP-type triode, and a positive power supply and a negative power supply are also included in this embodiment. The output terminal of the first operational amplifier U1 is electrically connected to the bases of the triode Q1 and the triode Q2, the collector of the triode Q1 is electrically connected to the positive power supply output terminal VCC, the collector of the triode Q2 is electrically connected to the negative power supply output terminal VEE, and the emitter of the triode Q1 is electrically connected to the emitter of the triode Q2. The push-pull module 11 plays a role in current push amplification. Since only one of the two complementary triodes conducts each time, it also has the effects of small conduction loss and high efficiency.

[0033] When the voltage value of the input signal terminal DAC2 is greater than the reference power supply voltage value, at this time, the first conversion unit 1 outputs a positive current signal; when the voltage value of the input signal terminal DAC2 is less than the reference power supply voltage value, at this time, the first conversion unit 1 outputs a negative current signal.

[0034] Preferably, the push-pull module 11 further includes a resistor R3, one end of the resistor R3 is electrically connected to the output terminal of the first operational amplifier U1, and the other end of the resistor R3 is electrically connected to the collector of the triode Q1. By setting the resistor R3, dead zone compensation can be achieved to a certain extent.

[0035] Moreover, the first conversion unit 1 further includes a capacitor C1, one end of the capacitor C1 is electrically connected to the inverting input terminal of the first operational amplifier U1, and the other end of the capacitor C1 is electrically connected to the output terminal of the first operational amplifier U1. The capacitor C1 is used to filter and stabilize the voltage, improving the stability of the first conversion unit 1.

[0036] Reference Figure 3The second conversion unit 2 includes a second amplifier U2, the input signal terminal DAC2 is electrically connected to the non-inverting input terminal of the second amplifier U2 through a resistor R7, and the non-inverting input terminal of the second amplifier U2 is also grounded through a resistor R8. The reference power supply output terminal VREF+ is electrically connected to the inverting input terminal of the second amplifier U2 through a resistor R11, and the output terminal of the second amplifier U2 is also electrically connected to the inverting input terminal of the second amplifier U2 through a resistor R9 and a feedback resistor R10 in sequence. The connection between the resistor R9 and the feedback resistor R10 is the output terminal OUT2 of the second conversion unit 2, and the output terminal OUT2 is used to output an analog voltage signal.

[0037] When the voltage value of the input signal terminal DAC2 is greater than the reference power supply voltage value, the second conversion unit 2 outputs a positive voltage signal; when the voltage value of the input signal terminal DAC2 is less than the reference power supply voltage value, the second conversion unit 2 outputs a negative voltage signal.

[0038] On this basis, the inverting input terminal of the second amplifier U2 is also electrically connected to a capacitor C2, and the other end of the capacitor C2 is electrically connected to the output terminal of the second amplifier U2. The capacitor C2 plays a role in filtering and stabilizing voltage, thereby improving the stability of the overall second conversion unit 2.

[0039] refer to Figure 4 , the selection output unit 3 includes a switch chip U3, the first power supply terminal 4 pin of the switch chip U3 is electrically connected to the positive power supply output terminal VCC, the second power supply terminal 7 pin of the switch chip U3 is electrically connected to the negative power supply output terminal VEE, and the ground terminal 3 pin of the switch chip U3 is grounded. The output terminal OUT1 of the first conversion unit 1 is electrically connected to the first input terminal 8 pin of the switch chip U3, and the output terminal OUT2 of the second conversion unit 2 is electrically connected to the second input terminal 2 pin of the switch chip U3. The first output terminal CT6 of the controller 4 is electrically connected to the selection control terminal 6 pin of the switch chip U3, and the first output terminal CT6 is also grounded through a resistor R13. The second output terminal CT7 of the controller 4 is electrically connected to the enable control terminal 5 pin of the switch chip U3, and the second output terminal CT7 is also grounded through a resistor R12. The output terminal 1 pin of the switch chip is set to the output terminal AO2 of the selection output unit 3.

[0040] When the second output terminal CT7 outputs a low level, the output unit 3 is selected not to output a signal; when the second output terminal CT7 outputs a high level and the first output terminal CT6 outputs a low level, the output signal of the output terminal AO2 is the analog current signal output by the output terminal OUT1; when the second output terminal CT7 outputs a high level and the first output terminal CT6 outputs a high level, the output signal of the output terminal AO2 is the analog voltage signal output by the output terminal OUT2, so that the analog current signal or the analog voltage signal can be output more conveniently through the controller 4 according to needs.

[0041] The implementation principle of a multifunctional analog signal output circuit in an embodiment of the present application is: a digital input signal is amplified, converted and processed by a first conversion unit 1, and then an analog current signal is output; a digital input signal is amplified, converted and processed by a second conversion unit 2, and then an analog current signal is output; then, according to the control signal sent by the first output terminal and the second output terminal of the controller 4, the output unit 3 is selected to selectively output the analog current signal or the analog current signal through the switch chip U3, so that the entire circuit can realize flexible switching of different analog signal type outputs through the controller 4.

[0042] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A multifunctional analog signal output circuit, characterized in that: The invention comprises a first conversion unit (1), a second conversion unit (2), a selection output unit (3) and a controller (4), wherein a digital input signal is input to the input ends of the first conversion unit (1) and the second conversion unit (2), respectively; the first conversion unit (1) is used to convert the digital input signal into an analog current signal, and the second conversion unit (2) is used to convert the digital input signal into an analog voltage signal; the output end of the first conversion unit (1) is electrically connected to the first input end of the selection output unit (3), the output end of the second conversion unit (2) is electrically connected to the second input end of the selection output unit (3), the control end of the selection output unit (3) is electrically connected to the output end of the controller (4), and the selection output unit (3) is used to output the analog current signal or the analog voltage signal.

2. A multifunctional analog signal output circuit according to claim 1, characterized in that: The selection output unit (3) comprises a switch chip U3 and peripheral components thereof; a first input terminal of the switch chip U3 is electrically connected to an output terminal of the first conversion unit (1); a second input terminal of the switch chip U3 is electrically connected to an output terminal of the second conversion unit (2); a selection control terminal of the switch chip U3 is electrically connected to a first output terminal of the controller (4); and an enable control terminal of the switch chip U3 is electrically connected to a second output terminal of the controller (4).

3. The multifunctional analog signal output circuit according to claim 1, characterized in that: The first conversion unit (1) comprises a first operational amplifier U1, a feedback resistor R4, a push-pull module (11) and a reference power supply, the output end of the digital input signal is electrically connected to the non-inverting input end of the first operational amplifier U1, and the reference power supply output end is electrically connected to the inverting input end of the first operational amplifier U1; the output end of the first operational amplifier U1 is electrically connected to the input end of the push-pull module (11), the output end of the push-pull module (11) is electrically connected to the inverting input end of the first operational amplifier U1 through the feedback resistor R4, the output end of the push-pull module (11) is also electrically connected to the non-inverting input end of the first operational amplifier U1 through the resistor R6 and the resistor R2 in sequence, and the connection between the resistor R6 and the resistor R2 is the output end OUT1 of the first conversion unit (1).

4. The multifunctional analog signal output circuit according to claim 3, characterized in that: The push-pull module (11) comprises a transistor Q1 and a transistor Q2, the output end of the first operational amplifier U1 is electrically connected to the bases of the transistor Q1 and the transistor Q2, the collector of the transistor Q1 is electrically connected to a positive power supply, the collector of the transistor Q2 is electrically connected to a negative power supply, and the emitter of the transistor Q1 is electrically connected to the emitter of the transistor Q2.

5. The multifunctional analog signal output circuit according to claim 4, characterized in that: The push-pull module (11) further comprises a resistor R3, one end of which is electrically connected to the output end of the first operational amplifier U1, and the other end of which is electrically connected to the collector of the transistor Q1.

6. The multifunctional analog signal output circuit according to claim 4, characterized in that: The first conversion unit (1) further comprises a capacitor C1, one end of the capacitor C1 is electrically connected to the inverting input end of the first operational amplifier U1, and the other end of the capacitor C1 is electrically connected to the output end of the first operational amplifier U1.

7. The multifunctional analog signal output circuit according to claim 1, characterized in that: The second conversion unit (2) comprises a second operational amplifier U2 and a reference power supply, the output end of the digital input signal is electrically connected to the non-inverting input end of the second operational amplifier U2, the reference power supply output end is electrically connected to the inverting input end of the second operational amplifier U2, the output end of the second operational amplifier U2 is also electrically connected to the inverting input end of the second operational amplifier U2 via a resistor R9 and a feedback resistor R10 in sequence, and the connection point between the resistor R9 and the feedback resistor R10 is the output end OUT2 of the second conversion unit (2).

8. The multifunctional analog signal output circuit according to claim 7, characterized in that: The inverting input terminal of the second operational amplifier U2 is also electrically connected to a capacitor C2, and the other end of the capacitor C2 is electrically connected to the output terminal of the second operational amplifier U2.

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