阅读说明：本技术 一种单电源供电数字自动增益控制放大电路及其控制方法 (A kind of single supply power supply digital resources obtainment amplifying circuit and its control method ) 是由 王士兴 曹文文 田冬 于 2019-07-26 设计创作，主要内容包括：本发明属于电子电路技术领域,涉及一种单电源供电数字自动增益控制放大电路及其控制方法。所述电路包括自动增益控制电路,与自动增益控制电路连接的程控增益放大电路、DAC放大电路,程控增益放大电路的同向输入端与直流偏置电路连接,程控增益放大电路的反向输入端通过电容接地；程控增益放大电路的输出端连接至DAC放大电路的输入端,DAC放大电路的输出端连接至自动增益控制电路的ADC采样电路的输入端,ADC采样电路集成于MCU的内部。通过采用单电源供电及直流偏置电路的设计,直流偏置电路通过对交流信号的直流成分隔离,为后级电路提供合适的直流偏置,保证程控增益放大电路及DAC放大电路只对输入的交流信号进行放大。(The invention belongs to electronic circuit technology field, it is related to a kind of single supply power supply digital resources obtainment amplifying circuit and its control method.The circuit includes automatic gain control circuit, programme-controlled gain amplifying circuit, the DAC amplifying circuit being connect with automatic gain control circuit, the noninverting input of programme-controlled gain amplifying circuit is connect with DC bias circuit, and the reverse input end of programme-controlled gain amplifying circuit passes through capacity earth；The output end of programme-controlled gain amplifying circuit is connected to the input terminal of DAC amplifying circuit, and the output end of DAC amplifying circuit is connected to the input terminal of the ADC sample circuit of automatic gain control circuit, and ADC sample circuit is integrated in the inside of MCU.By using single supply power supply and the design of DC bias circuit, DC bias circuit is isolated by the flip-flop to AC signal, suitable direct current biasing is provided for late-class circuit, guarantees that programme-controlled gain amplifying circuit and DAC amplifying circuit only amplify the AC signal of input.)

The digital resources obtainment amplifying circuit 1. a kind of single supply is powered, which is characterized in that including automatic gain control circuit (1), programme-controlled gain amplifying circuit (2), the DAC amplifying circuit (3) being connect with the automatic gain control circuit (1), the journey The noninverting input of control gain amplifying circuit (2) is connect with DC bias circuit (4), the programme-controlled gain amplifying circuit (2) Reverse input end passes through capacity earth；The output end of the programme-controlled gain amplifying circuit (2) is connected to DAC amplifying circuit (3) Input terminal, the output end of the DAC amplifying circuit (3) are connected to the ADC sample circuit (5) of automatic gain control circuit (1) Input terminal, the ADC sample circuit (5) are integrated in the inside of MCU.

The digital resources obtainment amplifying circuit 2. single supply according to claim 1 is powered, which is characterized in that described The SPI interface of MCU is connected with the SPI interface of programme-controlled gain amplifying circuit (2), and the MCU passes through GPIO and DAC amplifying circuit (3) Read-write Catrol port is connected with data port.

The digital resources obtainment amplifying circuit 3. single supply according to claim 1 is powered, which is characterized in that it is described from Dynamic gain control circuit (1) includes MCU circuit, power circuit and the clock circuit of integrated ADC function.

The digital resources obtainment amplifying circuit 4. single supply according to claim 3 is powered, which is characterized in that the electricity Source circuit respectively with DC bias circuit (4), programme-controlled gain amplifying circuit (2), DAC amplifying circuit (3) and automatic growth control The positive supply of circuit (1) is connected, the DC bias circuit (4), programme-controlled gain amplifying circuit (2), DAC amplifying circuit (3) and The negative supply of automatic gain control circuit (1) is grounded.

The digital resources obtainment amplifying circuit 5. single supply according to claim 1 is powered, which is characterized in that described straight Stream biasing circuit (4) is made of resistance, capacitor and parallel connection type voltage reference, and measured signal is inputted by capacitor one end, another in capacitor One end is connected to parallel connection type voltage reference by resistance, is output to programme-controlled gain amplification electricity after carrying out direct current biasing to measured signal Road.

The digital resources obtainment amplifying circuit 6. single supply according to claim 1 is powered, which is characterized in that the journey Control gain amplifying circuit (2) include eight stage gains, respectively 1,2,5,10,20,50,100 and 200 times.

The digital resources obtainment amplifying circuit 7. single supply according to claim 1 is powered, which is characterized in that described The quantity of DAC amplifying circuit (3) is multiple.

The digital resources obtainment amplifying circuit 8. single supply according to claim 1 is powered, which is characterized in that described DAC amplifying circuit (3) constitutes amplifying circuit in the same direction by current-output type DAC and operational amplifier；Wherein,

The output signal of the programme-controlled gain amplifying circuit (2) inputs DAC amplifying circuit (3) by the end in the same direction of operational amplifier, The reverse input end of the operational amplifier is connected to the current output terminal Iout1 of current-output type DAC；

The reference input V of the output end connection current-output type DAC of the operational amplifier_refAs DAC amplifying circuit (3) Output, be connected to the input terminal of ADC sample circuit (5)；

The feedback resistance Rfb pin of the current-output type DAC is by capacity earth, and the current-output type be DAC's and line number Word port is connected to the GPIO of MCU.

The digital resources obtainment amplifying circuit 9. single supply according to claim 8 is powered, which is characterized in that the electricity Stream output D/A C is made of inverted T shaped R-2R resistor network.

10. a kind of control based on the described in any item single supply power supply digital resources obtainment amplifying circuits of claim 1-9 Method processed, which is characterized in that specifically comprise the following steps:

Step 1, ADC sample circuit (5) acquire and quantify in real time the output signal of DAC amplifying circuit (3), and MCU passes through internal APB Bus access ADC sample circuit (5) obtains the quantized value of ADC sample circuit (5)；

The data that step 2, the MCU acquire ADC sample circuit (5) are analyzed, and are obtained by peak detection algorithm current The peak value of DAC amplifying circuit (3) output signal；

Step 3, by the peak value compared with the expectation peak value of setting, and calculate the proportionate relationship of present peak value Yu desired peak value, It obtains each amplifying circuit under current gain state and needs the gain factor adjusted；

Step 4, the MCU preferentially adjust the gain of programme-controlled gain amplifying circuit (2) by SPI interface, when programme-controlled gain amplifies When the gain of circuit (2) is unable to satisfy the setting value currently needed, then by GPIO adjustment DAC amplifying circuit (3) output valve, Complete the adjustment to circuit gain.

Technical field

The invention belongs to electronic circuit technology fields, are related to digital Auto Gain circuit, and in particular to a kind of single supply confession Electric digital resources obtainment amplifying circuit and its control method.

Background technique

In the electronic circuit of instrumentation devices, in particular for usually all setting in the circuit of collecting sensor signal It is equipped with and is powered using positive-negative power, for adjusting automatic growth control (the Automatic Gain of input signal gain Control, hereinafter referred to as " AGC ") amplifying circuit.

Currently, since the output of most sensors is bipolarity AC analogue signal, and amplitude output signal is small, dynamic Range is wide.The amplifying electric circuit with auto-gain-controlling function for only using dual power supply, can just provide for Back end data acquisition module Meet its input range requirement and complete sensor signal, the digitized processing to analog physical amount just may be implemented.

The above-mentioned amplifying electric circuit with auto-gain-controlling function using dual power supply, in system other circuits without negative supply demand When, it to be also individually for the circuit configuration negative electricity source circuit, causes the power circuit complexity of system, hardware cost to increase, reliability It reduces.Simultaneously as the efficiency of negative supply translation circuit is generally lower than positive supply translation circuit, therefore increased negative supply electricity Road also results in circuit power consumption increase, and power consumption embodies particularly evident in battery powered equipment.

Summary of the invention

It is an object of the invention to overcome the above-mentioned prior art, a kind of single supply power supply digital Auto Gain is provided Amplifying circuit and its control method are controlled, solves dual power supply automatic gain amplifying circuit bring system complex, power consumption increases Greatly, the disadvantages of hardware cost increases, system reliability reduces.

To achieve the above object, the present invention provides the following technical scheme that

On the one hand, the present invention provides a kind of single supply power supply digital resources obtainment amplifying circuits, including increase automatically Beneficial control circuit, the programme-controlled gain amplifying circuit connecting with the automatic gain control circuit, DAC amplifying circuit are described program-controlled The noninverting input of gain amplifying circuit is connect with DC bias circuit, and the reverse input end of the programme-controlled gain amplifying circuit is logical Cross capacity earth；The output end of the programme-controlled gain amplifying circuit is connected to the input terminal of DAC amplifying circuit, the DAC amplification The output end of circuit is connected to the input terminal of the ADC sample circuit of automatic gain control circuit, and the ADC sample circuit is integrated in The inside of MCU.

Further, the SPI interface of the MCU is connected with the SPI interface of programme-controlled gain amplifying circuit, for controlling program-controlled increasing The gain of beneficial amplifying circuit；The MCU is connected by GPIO with the Read-write Catrol port of DAC amplifying circuit and data port, is used In the gain of control DAC amplifying circuit, to realize closed-loop control.

Further, the automatic gain control circuit includes the MCU circuit, power circuit and clock electricity of integrated ADC function Road, wherein power circuit is powered using single supply, and input signal is necessary for AC signal, and the gain of two-stage amplifying circuit is only to input AC signal is effective, to DC bias circuit provide bias voltage without gain effect.

Further, the power circuit respectively with DC bias circuit, programme-controlled gain amplifying circuit, DAC amplifying circuit and The positive supply of automatic gain control circuit is connected, the DC bias circuit, programme-controlled gain amplifying circuit, DAC amplifying circuit and The negative supply of automatic gain control circuit is grounded.

Further, the DC bias circuit is made of resistance, capacitor and parallel connection type voltage reference, and measured signal is by capacitor One end input, is connected to parallel connection type voltage reference by resistance in the capacitor other end, to defeated after measured signal progress direct current biasing Programme-controlled gain amplifying circuit is arrived out.

Further, the programme-controlled gain amplifying circuit includes eight stage gains, respectively 1,2,5,10,20,50,100 and 200 Times.

Further, the quantity of the DAC amplifying circuit is multiple.

Further, the DAC amplifying circuit constitutes amplifying circuit in the same direction by current-output type DAC and operational amplifier；Its In,

The output signal of the programme-controlled gain amplifying circuit inputs DAC amplifying circuit, institute by the end in the same direction of operational amplifier The reverse input end for stating operational amplifier is connected to the current output terminal Iout1 of current-output type DAC；

The reference input V of the output end connection current-output type DAC of the operational amplifier_refAs DAC amplifying circuit Output, be connected to the input terminal of ADC sample circuit；

The feedback resistance Rfb pin of the current-output type DAC by capacity earth, the current-output type DAC's and Row digital port is connected to the GPIO of MCU.

Further, the current-output type DAC is made of inverted T shaped R-2R resistor network.

On the other hand, the present invention also provides a kind of controlling parties of single supply power supply digital resources obtainment amplifying circuit Method specifically comprises the following steps:

Step 1, ADC sample circuit acquire in real time, quantify the output signal of DAC amplifying circuit, and MCU is total by internal APB Line accesses ADC sample circuit, obtains the quantized value of ADC sample circuit；

The data that step 2, the MCU acquire ADC sample circuit are analyzed, and are obtained by peak detection algorithm current The peak value of DAC amplifying circuit output signal；

Step 3, by the peak value compared with the expectation peak value of setting, and calculate the ratio pass of present peak value and it is expected peak value System obtains each amplifying circuit under current gain state and needs the gain factor adjusted；

Step 4, the MCU preferentially adjust the gain of programme-controlled gain amplifying circuit by SPI interface, when programme-controlled gain amplifies When the gain of circuit is unable to satisfy the setting value currently needed, then pass through the output valve of GPIO adjustment DAC amplifying circuit, completion pair The adjustment of circuit gain.

Compared with prior art, technical solution provided by the invention includes following the utility model has the advantages that supplying by using single supply The design of electricity and DC bias circuit, DC bias circuit are isolated by the flip-flop to prime AC signal, are rear class electricity Road provides suitable direct current biasing, and programme-controlled gain amplifying circuit and DAC amplifying circuit this two-stage amplifying circuit are only to input AC signal amplifies, and there is no gain effects for the bias voltage provided biasing circuit；Meanwhile by ADC sample circuit collection At in the inside of MCU, guarantee respectively it is normally functioning simultaneously, realize the simplification of circuit structure；The automatic growth control is put Big circuit has the advantages that structure is simple, low in energy consumption, at low cost, solves dual power supply automatic gain amplifying circuit and brings System complex, power consumption increase, hardware cost increase, system reliability reduce the disadvantages of.

In addition, the SPI interface of MCU is connected with the SPI interface of programme-controlled gain amplifying circuit, for controlling programme-controlled gain amplification Circuit gain；MCU is connected by GPIO with the Read-write Catrol port of DAC amplifying circuit and data port, for controlling DAC amplification Circuit gain, to realize closed-loop control.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of single supply provided by the invention power supply digital resources obtainment amplifying circuit；

Fig. 2 is the structural schematic diagram of DC bias circuit provided by the invention；

Fig. 3 is the structural schematic diagram of programme-controlled gain amplifying circuit provided by the invention；

Fig. 4 is the structural schematic diagram of DAC amplifying circuit provided by the invention；

Fig. 5 is the internal structure chart of DAC amplifying circuit provided by the invention；

Fig. 6 is the digital quantity and amplification factor graph of relation of DAC amplifying circuit provided by the invention.

Wherein: 1 is automatic gain control circuit；2 be programme-controlled gain amplifying circuit；3 be DAC amplifying circuit；4 is inclined for direct current Circuits；5 be ADC sample circuit.

Specific embodiment

The invention will be described in further detail with reference to the accompanying drawings and embodiments, and described specific embodiment is only to this Invention explains, and is not intended to limit the invention.