CN108365825A - Digital tunable capacitor circuit - Google Patents
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- CN108365825A CN108365825A CN201810465951.4A CN201810465951A CN108365825A CN 108365825 A CN108365825 A CN 108365825A CN 201810465951 A CN201810465951 A CN 201810465951A CN 108365825 A CN108365825 A CN 108365825A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/38—Positive-feedback circuit arrangements without negative feedback
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Abstract
本发明涉及一种数字可调电容电路，包括第一运算放大器、第一电容和增益模块；所述的第一运算放大器的反向输入端连接第一电阻和第二电阻；所述的第一电阻和第二电阻与第一运算放大器组成反向放大电路；所述的第一电容的一端连接第一运算放大器的反向输入端；所述的增益模块连接于第一运算放大器的输出端与第一电容的另一端之间。本发明可以通过数字模拟转换器DAC对电容在电路上的实际等效电容进行数字调节，可以对绝大部分有源滤波器进行频响调节，而不像传统电路那样需要不同的开关和电容进行转并联那样调节；不仅可以简化电路，并且调节范围和分辨率更高，对于绝大部分的有源滤波电路都是适用的。
The present invention relates to a digital adjustable capacitance circuit, comprising a first operational amplifier, a first capacitor and a gain module; the inverting input terminal of the first operational amplifier is connected to the first resistor and the second resistor; the first The resistor and the second resistor form an inverse amplifying circuit with the first operational amplifier; one end of the first capacitor is connected to the reverse input terminal of the first operational amplifier; the gain module is connected to the output terminal of the first operational amplifier and between the other ends of the first capacitor. The invention can digitally adjust the actual equivalent capacitance of the capacitor on the circuit through the digital-to-analog converter DAC, and can adjust the frequency response of most active filters, unlike traditional circuits that require different switches and capacitors. It can not only simplify the circuit, but also have a higher adjustment range and resolution, which is applicable to most active filter circuits.
Description
技术领域technical field
本发明涉及电子测量技术领域，尤其是一种数字可调电容电路。The invention relates to the technical field of electronic measurement, in particular to a digital adjustable capacitance circuit.
背景技术Background technique
很多电路对不同频响需要不同的电容进行调节，多数的情况下是通过模拟开关连接多个电容，通过对模拟开关的控制，实现电容之间的串并联，从而得到需要的电容。这样的电路一般只能调节有限的电容值，并且调节的电容值多数都是确定在一定的范围内的。Many circuits require different capacitors to adjust different frequency responses. In most cases, multiple capacitors are connected through an analog switch. Through the control of the analog switch, the capacitors are connected in series and parallel to obtain the required capacitor. Such a circuit generally can only adjust a limited capacitance value, and most of the adjusted capacitance values are determined within a certain range.
发明内容Contents of the invention
本发明要解决的技术问题是：提供一种数字可调电容电路，可以解决对多种频率信号的滤波处理，减少开关和电容数量。The technical problem to be solved by the present invention is to provide a digital adjustable capacitor circuit, which can solve the filtering process of signals of various frequencies and reduce the number of switches and capacitors.
本发明解决其技术问题所采用的技术方案是：一种数字可调电容电路，包括第一运算放大器、第一电容和增益模块；所述的第一运算放大器的反向输入端连接第一电阻和第二电阻；所述的第一电阻和第二电阻与第一运算放大器组成反向放大电路；所述的第一电容的一端连接第一运算放大器的反向输入端；所述的增益模块连接于第一运算放大器的输出端与第一电容的另一端之间。The technical solution adopted by the present invention to solve the technical problems is: a digital adjustable capacitor circuit, including a first operational amplifier, a first capacitor and a gain module; the inverting input terminal of the first operational amplifier is connected to the first resistor and the second resistor; the first resistor and the second resistor and the first operational amplifier form an inverting amplifier circuit; one end of the first capacitor is connected to the inverting input of the first operational amplifier; the gain module Connected between the output end of the first operational amplifier and the other end of the first capacitor.
进一步的说，本发明所述的增益模块包括第二运算放大器和数字模拟转换器；所述的第二运算放大器的同向输入端连接数字模拟转换器的参考电压输入端；第二运算放大器的反向输入端连接第五电阻和第六电阻；所述的第二运算放大器的输出端连接第一电容；所述的数字模拟器的输出端连接第三电阻和第四电阻；所述的第三电阻与第一运算放大器的输出端相连接；所述的第四电阻接地。Further, the gain module of the present invention includes a second operational amplifier and a digital-to-analog converter; the same input terminal of the second operational amplifier is connected to the reference voltage input terminal of the digital-to-analog converter; the second operational amplifier The reverse input terminal is connected to the fifth resistor and the sixth resistor; the output terminal of the second operational amplifier is connected to the first capacitor; the output terminal of the digital simulator is connected to the third resistor and the fourth resistor; The three resistors are connected with the output terminal of the first operational amplifier; the fourth resistor is grounded.
再进一步的说，本发明所述的数字模拟转换器的电源端输入电压为+3.3V，接地端输入电压为-1.4V。Furthermore, the input voltage of the power terminal of the digital-to-analog converter of the present invention is +3.3V, and the input voltage of the ground terminal is -1.4V.
再进一步的说，本发明所述的第五电阻、第六电阻以及第二运算放大器对第三电阻和第四电阻的衰减进行等比例放大。Furthermore, the fifth resistor, the sixth resistor and the second operational amplifier in the present invention amplify the attenuation of the third resistor and the fourth resistor in equal proportion.
本发明的有益效果是，解决了背景技术中存在的缺陷，可以通过数字模拟转换器DAC对电容在电路上的实际等效电容进行数字调节，可以对绝大部分有源滤波器进行频响调节，而不像传统电路那样需要不同的开关和电容进行转并联那样调节；不仅可以简化电路，并且调节范围和分辨率更高，对于绝大部分的有源滤波电路都是适用的。The beneficial effect of the present invention is that it solves the defects in the background technology, can digitally adjust the actual equivalent capacitance of the capacitor on the circuit through the digital-to-analog converter DAC, and can adjust the frequency response of most active filters , unlike traditional circuits that require different switches and capacitors to be adjusted in parallel; not only can the circuit be simplified, but also the adjustment range and resolution are higher, which is applicable to most active filter circuits.
附图说明Description of drawings
下面结合附图和实施例对本发明进一步说明。The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
图1是基本电路一的电路原理图；Fig. 1 is the circuit schematic diagram of basic circuit one;
图2是基本电路二的电路原理图；Fig. 2 is the circuit schematic diagram of basic circuit two;
图3是本发明的电路原理图。Fig. 3 is a schematic circuit diagram of the present invention.
具体实施方式Detailed ways
现在结合附图和优选实施例对本发明作进一步详细的说明。这些附图均为简化的示意图，仅以示意方式说明本发明的基本结构，因此其仅显示与本发明有关的构成。The present invention will now be described in further detail in conjunction with the accompanying drawings and preferred embodiments. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the configurations related to the present invention.
如图1所示的基本电路一，可以推导出来公式1：The basic circuit 1 shown in Figure 1 can be derived from Formula 1:
如图2所示的基本电路二推导：The second derivation of the basic circuit shown in Figure 2:
V2＝GAIN×VO V 2 =GAIN×V O
所以：so:
所以可以得到公式2So we can get formula 2
通过公式1和公式2对比，可以发现：公式1的等效电容C＝C1，公式2的等效电容C＝C1·GAIN。By comparing formula 1 and formula 2, it can be found that: the equivalent capacitance C=C1 in formula 1, and the equivalent capacitance C=C 1 ·GAIN in formula 2.
因为在C1和运放输出端增加了一个增益模块，所以等效电容就改变了，可以认为增益模块对电容C1进行了调节。Because a gain block is added between C1 and the output of the op amp, the equivalent capacitance changes, and it can be considered that the gain block adjusts the capacitor C1.
如果增益GAIN>1，则是对电容进行放大调节，如果GAIN<1，这电容进行衰减调节。If the gain GAIN>1, the capacitor is adjusted for amplification, and if GAIN<1, the capacitor is adjusted for attenuation.
如果 if
可以看出来电容调节是等段的。因为底数是2N是不变的，而D是可以等段增加的。It can be seen that the capacitance adjustment is equal. Because the base is 2, N is unchanged, and D can be increased in stages.
如果 if
可以发现分母是改变的，分子是不变的，这样的调节就不是线性的了。所以本发明主要是用于的状态下的调节。It can be found that the denominator is changed and the numerator is unchanged, so the adjustment is not linear. So the present invention is mainly used for adjustment in the state.
具体电路如图3所示，R1、R2、R3、R4、R5、R6是电阻；C1是电容；U1，U3是运放；U2是DAC；R1、R2和U1组成基本的反向放大电路；U2是对C1的调节DAC，主要通过调节流过C1的电容来调节实际的等效电容；U3是为了对前级衰减进行等比例放大；The specific circuit is shown in Figure 3. R1, R2, R3, R4, R5, and R6 are resistors; C1 is a capacitor; U1, U3 are operational amplifiers; U2 is a DAC; R1, R2, and U1 form a basic reverse amplifier circuit; U2 is the adjustment DAC for C1, which mainly adjusts the actual equivalent capacitance by adjusting the capacitance flowing through C1; U3 is for proportionally amplifying the attenuation of the previous stage;
运放U1和U3上的供电电压为VCC和VEE，一般VCC给+15V，VEE给-15V；The power supply voltage on the operational amplifier U1 and U3 is VCC and VEE, generally VCC is +15V, and VEE is -15V;
U2上的电压给-1.4V和+3.3V，因为输入信号时交流信号，相对地是有正负的，如果低端电压不小于0，则负端信号就不能调节了，所以供电的低端需要一个负电压，只要保证电压差在DAC的供电范围内就可以了。The voltage on U2 is -1.4V and +3.3V, because the input signal is an AC signal, which is relatively positive and negative. If the low-end voltage is not less than 0, the negative-end signal cannot be adjusted, so the low-end of the power supply A negative voltage is required, as long as the voltage difference is within the power supply range of the DAC.
R3和R4是为了把输出信号衰减到DAC可以处理的范围内再输入到DAC之中，这样才能正常处理信号。R3 and R4 are to attenuate the output signal to the range that the DAC can handle before inputting it into the DAC, so that the signal can be processed normally.
R5和R6和U3是对R3和R4的衰减进行等比例放大。R5 and R6 and U3 are to amplify the attenuation of R3 and R4 in equal proportion.
输入信号Vi，输出信号为Vo，根据原理图推导：The input signal Vi, the output signal is Vo, deduced according to the schematic diagram:
D是输入到DAC的数据，数据范围为0～2N-1；N是DAC的位数D is the data input to the DAC, the data range is 0~2 N -1; N is the number of bits of the DAC
所以so
使：Make:
R4＝R5，R3＝R6 R 4 =R 5 , R 3 =R 6
所以so
因为：because:
所以：so:
所以：so:
这可以看出来，实际的电容经过了的衰减。所以该电路对电容的调节是0到 It can be seen that the actual capacitor after attenuation. So the circuit adjusts the capacitance from 0 to
整个电路的框架为输入信号、输出信号、供电电源、调节电容和调节所用的DAC。通过调节DAC来调节流过电容的电流的大小，从而调节输出端和电容于运放的连接端的等效电容大小，从而调节整个电路的频响。The frame of the whole circuit is input signal, output signal, power supply, adjusting capacitor and DAC used for adjustment. By adjusting the DAC to adjust the size of the current flowing through the capacitor, thereby adjusting the equivalent capacitance of the output terminal and the connection terminal of the capacitor to the operational amplifier, thereby adjusting the frequency response of the entire circuit.
本发明可以使用在有源模拟滤波电路上，在如今工业领域内对信号的滤波电路随处可见。很多电子测量设备当中都需要对信号进行滤波处理。所以该电路可以使用在大部分的工业设备之中。尤其是频率范围比较广的调节电路之中。还有一些体积限制但是需要很大的电容滤波电路中也可以使用该原理的对电容进行比例放大。The present invention can be used on an active analog filter circuit, and filter circuits for signals can be seen everywhere in the industrial field today. Signal filtering is required in many electronic measurement devices. So this circuit can be used in most industrial equipment. Especially in the regulation circuit with a wide frequency range. There are still some volume limitations but require a large capacitor filter circuit, which can also use this principle to scale up the capacitor.
以上说明书中描述的只是本发明的具体实施方式，各种举例说明不对本发明的实质内容构成限制，所属技术领域的普通技术人员在阅读了说明书后可以对以前所述的具体实施方式做修改或变形，而不背离发明的实质和范围。What is described in the above description is only the specific implementation of the present invention, and various illustrations do not limit the essence of the present invention. Those of ordinary skill in the art can modify or modify the previous specific implementation after reading the description. variations without departing from the spirit and scope of the invention.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU944076A1 (en) * | 1980-02-22 | 1982-07-15 | Ленинградский Ордена Ленина Политехнический Институт Им.М.И.Калинина | Bandpass active rc-filter |
| JPS59167109A (en) * | 1983-03-11 | 1984-09-20 | Nippon Telegr & Teleph Corp <Ntt> | Two-terminal impedance circuit |
| CN1362653A (en) * | 2000-12-30 | 2002-08-07 | 中国科学院大连化学物理研究所 | Computer-controlled fast linear conducting sample temperature raising unit |
| JP2002290208A (en) * | 2001-03-23 | 2002-10-04 | Tsuru Gakuen | Ultra-low frequency signal processing circuit |
| CN103138696A (en) * | 2011-11-29 | 2013-06-05 | 成都凯天电子股份有限公司 | Electric charge integrating amplifier |
| US20150123828A1 (en) * | 2013-11-06 | 2015-05-07 | Analog Devices Technology | Integrator output swing reduction |
| US20150229292A1 (en) * | 2014-02-12 | 2015-08-13 | Electronics And Telecommunications Research Institute | Second order loop filter and multi-order delta sigma modulator including the same |
| CN104954022A (en) * | 2015-07-17 | 2015-09-30 | 深圳市芯联电子科技有限公司 | Digital converter of rotary transformer and integrating circuit of digital converter |
| CN204836096U (en) * | 2015-07-08 | 2015-12-02 | 上海大学 | Piezoelectric acceleration sensor's charge amplifier |
| JP6215398B1 (en) * | 2016-06-22 | 2017-10-18 | 力晶科技股▲ふん▼有限公司 | Switched capacitor circuit and AD converter |
| CN208174644U (en) * | 2018-05-16 | 2018-11-30 | 常州同惠电子股份有限公司 | A kind of number tunable capacitor circuit |
| CN209375592U (en) * | 2019-01-24 | 2019-09-10 | 江门市川琪科技有限公司 | A kind of power amplifier circuit |
-
2018
- 2018-05-16 CN CN201810465951.4A patent/CN108365825A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU944076A1 (en) * | 1980-02-22 | 1982-07-15 | Ленинградский Ордена Ленина Политехнический Институт Им.М.И.Калинина | Bandpass active rc-filter |
| JPS59167109A (en) * | 1983-03-11 | 1984-09-20 | Nippon Telegr & Teleph Corp <Ntt> | Two-terminal impedance circuit |
| CN1362653A (en) * | 2000-12-30 | 2002-08-07 | 中国科学院大连化学物理研究所 | Computer-controlled fast linear conducting sample temperature raising unit |
| JP2002290208A (en) * | 2001-03-23 | 2002-10-04 | Tsuru Gakuen | Ultra-low frequency signal processing circuit |
| CN103138696A (en) * | 2011-11-29 | 2013-06-05 | 成都凯天电子股份有限公司 | Electric charge integrating amplifier |
| US20150123828A1 (en) * | 2013-11-06 | 2015-05-07 | Analog Devices Technology | Integrator output swing reduction |
| US20150229292A1 (en) * | 2014-02-12 | 2015-08-13 | Electronics And Telecommunications Research Institute | Second order loop filter and multi-order delta sigma modulator including the same |
| CN204836096U (en) * | 2015-07-08 | 2015-12-02 | 上海大学 | Piezoelectric acceleration sensor's charge amplifier |
| CN104954022A (en) * | 2015-07-17 | 2015-09-30 | 深圳市芯联电子科技有限公司 | Digital converter of rotary transformer and integrating circuit of digital converter |
| JP6215398B1 (en) * | 2016-06-22 | 2017-10-18 | 力晶科技股▲ふん▼有限公司 | Switched capacitor circuit and AD converter |
| CN208174644U (en) * | 2018-05-16 | 2018-11-30 | 常州同惠电子股份有限公司 | A kind of number tunable capacitor circuit |
| CN209375592U (en) * | 2019-01-24 | 2019-09-10 | 江门市川琪科技有限公司 | A kind of power amplifier circuit |
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