TW202002504A - Operational amplifier device with enhanced output voltage response capable of making output voltage more rapidly achieving stable voltage value to enhance output voltage response - Google Patents

Abstract

An operational amplifier device comprises an amplifying unit, a current compensation unit, and an operational amplifying unit. The amplifying unit receives an output voltage and amplifies the output voltage to generate an amplified voltage. The current compensation unit receives an input voltage and is electrically connected with the amplifying unit to receive the amplified voltage, and may adjust and generate a compensation current according to the amplified voltage and the input voltage. The operational amplifying unit receives the input voltage and is electrically connected to the amplifying unit and the current compensation unit, and receives the compensation current from the current compensation unit, and adjusts and generates the output voltage according to the input voltage and the compensation current, and outputs the output voltage to the amplifying unit. The rising speed of the output voltage is related to the current value of the compensation current.

Description

Operational amplification device with improved output voltage response

The invention relates to an operational amplifier device, in particular to an operational amplifier device with improved output voltage response.

Referring to FIG. 1, the conventional operational amplifier 1 is used to amplify an input voltage vi to generate an output voltage vo. However, the output voltage vo is affected by a time constant τ of a resistor 11 and a capacitor 12, and a voltage value of the output voltage vo will reach a stable voltage value after a delay time.

For example, when a resistance value of each of the resistors 11 and 13 is 10 k ohms and a capacitance value of the capacitor 12 is 0.01 u farad, the simulation result obtained by the operational amplifier 1 is shown in FIG. 2. It can be seen from FIG. 2 that when the input voltage vi rises from 0V to 5V, the output voltage vo will delay about 500us before rising from 0V to 5V (that is, the delay time is about 500us, and the stable voltage value is 5V) . Therefore, how to design an operational amplifying device that can shorten the delay time to increase the response of the output voltage vo is one of the goals of the related industry.

Therefore, the object of the present invention is to provide an operational amplifier device that can improve the output voltage response.

Therefore, the operational amplification device of the present invention includes an amplification unit, a current compensation unit, and an operational amplification unit.

The amplifier unit receives an output voltage and amplifies the output voltage to generate an amplified voltage.

The current compensation unit is used to receive an input voltage, and is electrically connected to the amplification unit to receive the amplified voltage, and adjusts and generates a compensation current according to the amplified voltage and the input voltage.

The operational amplifier unit is used to receive the input voltage, and is electrically connected to the amplifier unit and the current compensation unit, receives the compensation current from the current compensation unit, and adjusts and generates the output voltage according to the input voltage and the compensation current, And the output voltage is output to the amplifying unit, and the rising speed of the output voltage is related to a current value of the compensation current.

The effect of the present invention is that the compensation current is generated by the current compensation unit and transmitted to the operational amplifier unit for compensation, so that the output voltage can reach a stable voltage value faster, and then the output voltage of the operational amplifier device can be improved The purpose of the response.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same number.

Referring to FIGS. 3 and 4, a first embodiment of the operational amplification device of the present invention includes an amplification unit 2, a current compensation unit 3, and an operational amplification unit 4.

The amplifying unit 2 has a non-inverting input terminal 201 and an inverting input terminal 202 that cooperate with each other to receive an output voltage Vo, and amplifies the output voltage Vo to generate an amplified voltage Va. In this embodiment, the amplifying unit 2 includes first to third operational amplifiers 20, 21, 22, first and second resistors 23, 24, a gain resistor 25, and third to sixth resistors 26 , 27, 28, 29. The amplifying unit 2 is an instrument amplifying unit, but it is not limited thereto.

The first operational amplifier 20 has a first non-inverting input terminal electrically connected to the non-inverting input terminal 201 of the amplification unit 2, a first inverting input terminal, and a first output terminal. The first resistor 23 is electrically connected between the first inverting input terminal and the first output terminal of the first operational amplifier 20. The second operational amplifier 21 has a second non-inverting input terminal electrically connected to the inverting input terminal 202 of the amplifying unit 2, a second inverting input terminal, and a second output terminal. The second resistor 24 is electrically connected between the second inverting input terminal and the second output terminal of the second operational amplifier 21. The gain resistor 25 is electrically connected between the first inverting input terminal of the first operational amplifier 20 and the second inverting input terminal of the second operational amplifier 21. In this embodiment, the gain resistor 25 is a variable resistor, but it is not limited thereto. The third resistor 26 has a first terminal electrically connected to the first output terminal of the first operational amplifier 20, and a second terminal. The fourth resistor 27 is electrically connected between the second end of the third resistor 26 and ground. The fifth resistor 28 has a first terminal electrically connected to the second output terminal of the second operational amplifier 21, and a second terminal. The third operational amplifier 22 has a third non-inverting input terminal electrically connected to the second terminal of the third resistor 26, and a third inverting input terminal electrically connected to the second terminal of the fifth resistor 28, And a third output terminal that outputs the amplified voltage Va. The sixth resistor 29 is electrically connected between the third inverting input terminal and the third output terminal of the third operational amplifier 22.

The current compensation unit 3 is used to receive an input voltage Vi, and is electrically connected to the third output terminal of the third operational amplifier 22 of the amplification unit 2 to receive the amplified voltage Va, and according to the amplified voltage Va and the input voltage Vi adjusts and generates a compensation current Ic. In this embodiment, the current compensation unit 3 includes an operational amplifier circuit 31 and a voltage-current conversion circuit 32.

The operational amplifier circuit 31 is used to receive the input voltage Vi, and is electrically connected to the third output terminal of the third operational amplifier 22 to receive the amplified voltage Va, and subtracts the input voltage Vi from the amplified voltage Va to generate an error Voltage Ve. In this embodiment, the operational amplifier circuit 31 includes first to fourth resistors 311 to 314, and an operational amplifier 315.

The first resistor 311 has a first terminal for receiving the input voltage Vi, and a second terminal. The second resistor 312 has a first terminal electrically connected to the third output terminal of the third operational amplifier 22 to receive the amplified voltage Va, and a second terminal. The third resistor 313 is electrically connected between the second end of the second resistor 312 and ground. The operational amplifier 315 has an inverting input terminal electrically connected to the second terminal of the first resistor 311, a non-inverting input terminal electrically connected to the second terminal of the second resistor 312, and an output of the error voltage Ve output. The fourth resistor 314 is electrically connected between the inverting input terminal and the output terminal of the operational amplifier 315.

The voltage-current conversion circuit 32 is electrically connected to the output terminal of the operational amplifier 315 of the operational amplifier circuit 31 to receive the error voltage Ve, and generates the compensation current Ic according to the error voltage Ve. In this embodiment, the voltage-current conversion circuit 32 includes first to fourth resistors 321, 322, 323, 324, and an operational amplifier 325.

The first resistor 321 has a grounded first end and a second end. The second resistor 322 has a first terminal electrically connected to the output terminal of the operational amplifier 315 to receive the error voltage Ve, and a second terminal. The operational amplifier 325 has an inverting input terminal electrically connected to the second terminal of the first resistor 321, a non-inverting input terminal electrically connected to the second terminal of the second resistor 322, and an output terminal. The third resistor 323 is electrically connected between the inverting input terminal and the output terminal of the operational amplifier 325. The fourth resistor 324 is electrically connected between the non-inverting input terminal and the output terminal of the operational amplifier 325. A common contact N1 between the fourth resistor 324, the non-inverting input terminal of the operational amplifier 325 and the second terminal of the second resistor 322 provides the compensation current Ic.

The operational amplifier unit 4 is used to receive the input voltage Vi, and is electrically connected to the non-inverting input terminal 201 and the inverting input terminal 202 of the amplifying unit 2, and is electrically connected to the common contact N1 of the current compensation unit 3 to This compensation current Ic is received. The operational amplifier unit 4 adjusts and generates the output voltage Vo according to the input voltage Vi and the compensation current Ic, and outputs the output voltage Vo to the non-inverting input terminal 201 and the inverting input terminal 202 of the amplifier unit 2. In this embodiment, the operational amplifier unit 4 includes an operational amplifier 41, first and second resistors 42, 43, and a capacitor 44.

The operational amplifier 41 has a non-inverting input terminal for receiving the input voltage Vi, an inverting input terminal, and an output terminal. The first resistor 42 is electrically connected between the inverting input terminal and the output terminal of the operational amplifier 41. The second resistor 43 is electrically connected between the inverting input terminal of the operational amplifier 41 and ground. The capacitor 44 has a first terminal electrically connecting the output terminal of the operational amplifier 41 and the non-inverting input terminal 201 of the amplifying unit 2 and a second terminal. The second terminal of the capacitor 44 is electrically connected to the common contact N1 of the current compensation unit 3 to receive the compensation current Ic, and is electrically connected to the inverting input terminal of the operational amplifier 41 and the inversion of the amplifying unit 2 Input terminal 202. A voltage across the capacitor 44 is used as the output voltage Vo.

It should be noted that, in this embodiment, the operational amplifier device generates the compensation current Ic through the current compensation unit 3 and transmits it to the capacitor 44 to compensate the output voltage Vo by the first resistor 42 and the capacitor 44. The problem of delaying the rise to a stable voltage value due to the influence of a time constant τ enables the output voltage Vo to reach the stable voltage value sooner, thereby achieving the purpose of enhancing the output voltage Vo response of the operational amplifier device.

Referring to FIG. 5, for example, the gain resistor 25 is removed (ie, the first and second resistors 23 and 24 are open), and a capacitance value of the capacitor 44 is set to 0.01 uFarad. The first and second resistors 42, 43, the first to fourth resistors 311 to 314, the third to sixth resistors 26 to 29, and the first and third resistors 321, 323 When a resistance value of each is set to 10k ohms, and a resistance value of each of the first and second resistors 23, 24 and the second and fourth resistors 322, 324 is set to 5k ohms for example, the In the embodiment, the input voltage Vi and the output voltage Vo each change with time.

It can be seen from FIG. 5 that when the input voltage Vi rises from 0V to 5V, the output voltage Vo only rises by about 100us, that is, rises from 0V to 5V, which is increased from 0V compared to an input voltage vi in FIG. 2. When it reaches 5V, the corresponding output voltage vo will delay about 500us before it rises to 5V. The operational amplifier of this embodiment can really shorten a delay when the output voltage Vo reaches the stable voltage value (ie, 5V) Time (from the conventional reduction of about 500us to about 100us), and then to achieve the effect of improving the output voltage Vo response.

Referring to FIG. 6, a second embodiment of the operational amplifier device of the present invention is a modification of the first embodiment. The difference between the two is as follows: 1. The current compensation unit 3 further includes a non-inverting amplifier circuit 33. The non-inverting amplifier circuit 33 is used to receive the input voltage Vi and amplify the input voltage Vi to generate an adjustment voltage Vad. The non-inverting amplifier circuit 33 includes an operational amplifier 331, and first and second variable resistors 332 and 333. The operational amplifier 331 has a non-inverting input terminal for receiving the input voltage Vi, an inverting input terminal, and an output terminal for outputting the adjustment voltage Vad. The first variable resistor 332 is electrically connected between the inverting input terminal of the operational amplifier 331 and ground. The second variable resistor 333 is electrically connected between the inverting input terminal and the output terminal of the operational amplifier 331. 2. The first terminal of the first resistor 311 of the operational amplifier circuit 31 is electrically connected to the output terminal of the operational amplifier 331 of the non-inverting amplifier circuit 33 to receive the adjusted voltage Vad, so that the operational amplifier circuit 31 The error voltage Ve is generated by subtracting the adjusted voltage Vad from the amplified voltage Va, instead of generating the error voltage Ve by subtracting the input voltage Vi from the amplified voltage Va.

In this way, since the gain resistor 25 and the first and second variable resistors 332 and 333 are all variable resistors, by adjusting the gain resistor 25 and the first and second variable resistors A resistance value of each of the variable resistors 332 and 333 can change a gain of the corresponding amplification unit 2 and the non-inverting amplification circuit 33, so that the compensation current Ic follows the amplification unit 2 and the non-inverting amplification circuit 33. Each of these gains changes. For example, when the gain of each of the amplifying unit 2 and the non-inverting amplifying circuit 33 becomes K times larger (K≧2), the voltage value of the error voltage Ve generated by the operational amplifying circuit 31 increases, and further The current value of the compensation current Ic generated by the voltage-current conversion circuit 32 according to the error voltage Ve also increases accordingly, so that the delay time required when the output voltage Vo reaches the stable voltage value can be shortened more quickly. In short, the speed at which the output voltage Vo rises is related to the current value of the compensation current Ic.

In summary, by generating the compensation current Ic and transmitting it to the capacitor 44 by the current compensation unit 3, the delay time required when the output voltage Vo reaches the stable voltage value can be shortened. Embodiment The purpose of the output voltage Vo response of the operational amplifier device.

However, the above are only examples of the present invention, and the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still classified as Within the scope of the invention patent.

2‧‧‧Amplification unit 20‧‧‧ First operational amplifier 21‧‧‧ Second operational amplifier 22‧‧‧ Third operational amplifier 23‧‧‧ First resistor 24‧‧‧ Second resistor 25‧‧‧ Gain resistors 26~29 ‧‧‧ third to sixth resistors 201 ‧‧‧ non-inverting input terminal 202 ‧ ‧‧ inverting input terminal 3 ‧ ‧ ‧ current compensation unit 31 ‧ ‧ ‧ operational amplifier circuit 311 ~ 314 ‧‧‧ First to fourth resistor 315‧‧‧Operation amplifier 32‧‧‧Voltage current conversion circuit 321~324‧‧‧ First to fourth resistor 325‧‧‧Operation amplifier 33‧‧‧Non-inverted Amplifier circuit 331‧‧‧Operation amplifier 332‧‧‧First variable resistor 333‧‧‧Second variable resistor 4‧‧‧Operation amplifier unit 41‧‧‧Operation amplifier 42, 43‧‧‧ The second resistor 44‧‧‧ capacitor Ic‧‧‧ compensation current N1‧‧‧ common contact Va‧‧‧ amplified voltage Vad‧‧‧ adjusted voltage Ve‧‧‧ error voltage Vi‧‧‧ input voltage Vo‧‧‧‧ The output voltage

Other features and functions of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is a circuit diagram illustrating a conventional operation amplification device; FIG. 2 is a simulation diagram illustrating the conventional operation amplification The changes of an input voltage and an output voltage of the device with respect to time respectively; FIG. 3 is a circuit diagram illustrating a first embodiment of the operational amplification device of the present invention; FIG. 4 is a circuit diagram illustrating the operational amplification of the first embodiment An amplification unit of the device; FIG. 5 is a simulation diagram illustrating the change of an input voltage and an output voltage of the embodiment with respect to time; and FIG. 6 is a circuit block diagram illustrating a second of the operational amplification device of the present invention. Examples.

2‧‧‧Amplification unit

20‧‧‧The first operational amplifier

21‧‧‧ Second operational amplifier

22‧‧‧The third operational amplifier

23‧‧‧ First resistor

24‧‧‧Second resistor

25‧‧‧Gain resistor

26~29‧‧‧ Third to sixth resistors

201‧‧‧Non-inverting input

202‧‧‧Inverting input

3‧‧‧Current compensation unit

31‧‧‧Operation amplifier circuit

311~314‧‧‧ First to fourth resistors

315‧‧‧Operational amplifier

32‧‧‧Voltage current conversion circuit

321~324‧‧‧ First to fourth resistors

325‧‧‧Operational amplifier

4‧‧‧Amplification unit

41‧‧‧Operational amplifier

42, 43‧‧‧ First and second resistors

44‧‧‧Capacitor

Ic‧‧‧Compensation current

N1‧‧‧ common contact

Va‧‧‧amplified voltage

Ve‧‧‧Error voltage

Vi‧‧‧Input voltage

Vo‧‧‧ output voltage

Claims (10)

An operational amplification device with improved output voltage response includes: an amplification unit that receives an output voltage and amplifies the output voltage to generate an amplified voltage; and a current compensation unit that receives an input voltage and is electrically connected to the The amplifying unit receives the amplified voltage, and adjusts and generates a compensation current according to the amplified voltage and the input voltage; and an operational amplifier unit for receiving the input voltage and electrically connecting the amplifier unit and the current compensation unit to receive The compensation current from the current compensation unit adjusts and generates the output voltage according to the input voltage and the compensation current, and outputs the output voltage to the amplifying unit, the speed at which the output voltage rises is related to one of the compensation current Current value. The operational amplifier device according to claim 1, wherein the current compensation unit includes an operational amplifier circuit for receiving the input voltage, and is electrically connected to the amplification unit to receive the amplified voltage and reduce the amplified voltage by the input The voltage generates an error voltage, and a voltage-current conversion circuit is electrically connected to the operational amplifier circuit to receive the error voltage and generate the compensation current according to the error voltage. The operational amplifier device according to claim 2, wherein the operational amplifier circuit includes a first resistor having a first terminal for receiving the input voltage, and a second terminal, a second resistor having A first end electrically connected to the amplifying unit to receive the amplified voltage, and a second end, a third resistor electrically connected between the second end of the second resistor and ground, an operational amplifier having An inverting input terminal electrically connected to the second terminal of the first resistor, a non-inverting input terminal electrically connected to the second terminal of the second resistor, and an output terminal outputting the error voltage, and a first Four resistors are electrically connected between the inverting input terminal and the output terminal of the operational amplifier. The operational amplifier device according to claim 1, wherein the current compensation unit includes a non-inverting amplifier circuit for receiving the input voltage and amplifying the input voltage to generate an adjustment voltage. An operational amplifier circuit The non-inverting amplifier circuit and the amplifier unit are connected to receive the adjusted voltage and the amplified voltage, respectively, and subtract the adjusted voltage to generate an error voltage, and a voltage-current conversion circuit is electrically connected to the operational amplifier circuit to Receive the error voltage, and generate the compensation current according to the error voltage. The operational amplifier device according to claim 4, wherein the non-inverting amplifier circuit includes an operational amplifier having a non-inverting input terminal for receiving the input voltage, an inverting input terminal, and an output of the adjusted voltage The output terminal of a first variable resistor is electrically connected between the inverting input terminal of the operational amplifier and ground, and a second variable resistor is electrically connected between the inverting input terminal of the operational amplifier and Between the output terminals. The operational amplifier device according to claim 4, wherein the operational amplifier circuit includes a first resistor having a first terminal electrically connected to the non-inverting amplifier circuit to receive the adjusted voltage, and a second terminal, a The second resistor has a first end electrically connected to the amplifying unit to receive the amplified voltage, and a second end, a third resistor electrically connected between the second end of the second resistor and ground , An operational amplifier having an inverting input terminal electrically connected to the second terminal of the first resistor, a non-inverting input terminal electrically connected to the second terminal of the second resistor, and an output of the error voltage The output terminal and a fourth resistor are electrically connected between the inverting input terminal and the output terminal of the operational amplifier. The operational amplifier device according to claim 2 or 4, wherein the voltage-current conversion circuit includes a first resistor having a first terminal connected to ground, and a second terminal, a second resistor having a power A first terminal connected to the operational amplifier circuit to receive the error voltage, and a second terminal, an operational amplifier having an inverting input terminal electrically connected to the second terminal of the first resistor, and an electrically connected to the second terminal The non-inverting input end of the second end of the resistor, and an output end, a third resistor, are electrically connected between the inverting input end and the output end of the operational amplifier, and a fourth resistor, electrically A common contact between the fourth resistor, the non-inverting input terminal of the operational amplifier and the second terminal of the second resistor is provided between the non-inverting input terminal and the output terminal of the operational amplifier The compensation current. The operational amplifying device according to claim 1, wherein the amplifying unit has a non-inverting input terminal and an inverting input terminal which are electrically connected to the operational amplifying unit and cooperate with each other to receive the output voltage. The amplifying unit includes a The first operational amplifier has a first non-inverting input terminal electrically connected to the non-inverting input terminal of the amplifying unit, a first inverting input terminal, and a first output terminal, a first resistor electrically connected at Between the first inverting input terminal and the first output terminal of the first operational amplifier, a second operational amplifier has a second non-inverting input terminal and a first terminal electrically connected to the inverting input terminal of the amplifying unit Two inverting input terminals, and a second output terminal, a second resistor, electrically connected between the second inverting input terminal and the second output terminal of the second operational amplifier, a gain resistor, electrically connected Between the first inverting input of the first operational amplifier and the second inverting input of the second operational amplifier, a third resistor has a first output electrically connected to the first operational amplifier The first end of the terminal, and a second end, a fourth resistor, are electrically connected between the second end of the third resistor and ground, and a fifth resistor has a circuit electrically connected to the second operational amplifier The first terminal of the second output terminal, and a second terminal, a third operational amplifier, have a third non-inverting input terminal electrically connected to the second terminal of the third resistor, and an electric connection to the fifth resistor A third inverting input terminal of the second end of the amplifier, and a third output terminal outputting the amplified voltage, and a sixth resistor, electrically connected between the third inverting input terminal of the third operational amplifier and the Between the third output. The operational amplifier device according to claim 8, wherein the gain resistor is a variable resistor. The operational amplifier device according to claim 1, wherein the amplifying unit has a non-inverting input terminal and an inverting input terminal which are electrically connected to the operational amplifying unit and cooperate with each other to receive the output voltage. The operational amplifying unit includes An operational amplifier has a non-inverting input terminal for receiving the input voltage, an inverting input terminal, and an output terminal, a first resistor electrically connected to the inverting input terminal of the operational amplifier and the Between the output terminals, a second resistor is electrically connected between the inverting input terminal of the operational amplifier and ground, and a capacitor having a non-inverting input electrically connecting the output terminal of the operational amplifier and the amplification unit The first end of the terminal, and a second end, the second end of the capacitor is electrically connected to the current compensation unit to receive the compensation current, and is electrically connected to the inverting input terminals of the operational amplifier and the amplification unit, the capacitor The voltage across is used as the output voltage.

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