CN208190606U - Operational amplification circuit - Google Patents
Operational amplification circuit Download PDFInfo
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- CN208190606U CN208190606U CN201820840915.7U CN201820840915U CN208190606U CN 208190606 U CN208190606 U CN 208190606U CN 201820840915 U CN201820840915 U CN 201820840915U CN 208190606 U CN208190606 U CN 208190606U
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Abstract
The utility model embodiment discloses a kind of operational amplification circuit.Operational amplification circuit includes: control unit, generates output control signal according to input signal and output signal；Output unit, for generating output electric current under the action of output controls signal, output unit includes output capacitance, and output capacitance is by the charge or discharge of output electric current to generate output signal；Over-current protecting unit; temperature control current is obtained according to the operating temperature of operational amplification circuit; when operating temperature is more than or equal to set temperature, temperature control current and operating temperature are positively correlated, and over-current protecting unit adjusts output control signal according to temperature control current to limit output electric current.The utility model obtains temperature control current by detection to operating temperature, to guarantee delivery efficiency, response speed and the driving capability of operational amplification circuit when operating temperature be in zone of reasonableness, according to temperature control current limitation export electric current when operating temperature is excessively high to reduce circuit power consumption and operating temperature.
Description
Technical field
The utility model relates to electronic circuit technology fields, and in particular, to a kind of operational amplification circuit.
Background technique
In many applications, operational amplifier (Operation Amplifier, OPA) needs to drive biggish load electricity
Hold, the capacitance of load capacitance is generally several microfarads and is pulled to more than ten microfarads.
Fig. 1 shows a kind of operational amplification circuit 100 in the prior art, and wherein operational amplifier U0 is according to input signal
The Vin0 and output signal Vout0 fed back generates output control signal, output control signal control transistor P0 or crystal
Pipe N0, so that output capacitance Cout0 is constantly pulled up the output electric current Iout0 charge and discharge that transistor or pull-down transistor provide
Electricity, and then pole plate provides output voltage Vout0 on it.
In general, input signal Vin0 is usually low and high level signal, high power supply voltage VDD mono- in operational amplification circuit
As larger (more than ten volts to 20 volts).If operational amplification circuit does not have overcurrent protection mechanism, when the frequency of input signal is higher
When, the power consumption of operational amplification circuit can be very high, causes the operating temperature of operational amplification circuit excessively high, or even will appear operation amplifier
The phenomenon that chip where circuit is burned.
For this phenomenon, a variety of design methods are proposed in the industry at present to avoid the operating temperature mistake of operational amplification circuit
It is high.
The first prior art controls operating temperature by detecting the gate source voltage of transistor P0 and N0.Specifically, when
When the absolute value of the gate source voltage of transistor P0 or the gate source voltage of transistor N0 rise to certain numerical value, by transistor P0 and N0
Gate source voltage be limited in setting numerical value so that transistor P0 and N0 generate conducting electric current limited.The shortcomings that this method
It is, regardless of high power supply voltage VDD is set as much, when the gate source voltage of transistor P0 and N0 reach certain numerical value, crystal
The conducting degree of pipe P0 and N0 can all be limited.However in the lesser situation of high power supply voltage VDD, even if operating temperature and electricity
Road power consumption is not high, and the conducting electric current of transistor P0 and N0 can also be limited when gate source voltage reaches certain numerical value, so that operation
Delivery efficiency, response speed and the driving capability of amplifying circuit reduce.
Second of prior art is on the basis of the first above-mentioned prior art further according to high power supply voltage VDD
Numerical Control exports electric current, it may be assumed that when high power supply voltage VDD is lower, the not gate source voltage of limit transistor P0 and N0；When high electricity
When the voltage VDD higher of source, the gate source voltage of limit transistor P0 and N0 are to achieve the purpose that limitation output electric current, so that operation is put
The operating temperature of big circuit no longer rises.However, the shortcomings that this prior art is cannot to be controlled according to the frequency of input signal
The size for exporting electric current, when the frequency of input signal is lower, even if the grid of high power supply voltage VDD higher, transistor P0 and N0
Source voltage is also higher, and the power consumption and operating temperature of operational amplification circuit will not be excessively high, therefore at this moment limit transistor P0 and N0
Gate source voltage be not necessarily to；Meanwhile if the frequency of input signal is higher, even when limiting transistor P0 and N0
Gate source voltage, the power consumption and operating temperature of operational amplification circuit can also increase.
It therefore, is the operating temperature for solving the problems, such as operational amplification circuit, the prior art has some limitations.
Utility model content
In order to solve the above-mentioned problems of the prior art, the utility model passes through the operating temperature to operational amplification circuit
Detection obtain temperature control current, thus when operating temperature be in zone of reasonableness guarantee operational amplification circuit delivery efficiency,
Response speed and driving capability, when operating temperature is excessively high according to temperature control current limit output electric current to reduce circuit power consumption and work
Make temperature.
The utility model provides a kind of operational amplification circuit characterized by comprising control unit is believed according to input
Number and output signal generate output control signal；Output unit is connected to receive the output control with described control unit
Signal, the output unit are used to generate output electric current under the action of the output controls signal, and the output unit includes
Output capacitance, the output capacitance is by the output electric current charge or discharge to generate the output signal；Over-current protecting unit,
It is connected with the output unit and described control unit, the over-current protecting unit is according to the work of the operational amplification circuit
Temperature obtains temperature control current, when the operating temperature is more than or equal to set temperature, the temperature control current and the operating temperature
It is positively correlated, the over-current protecting unit adjusts the output control signal according to the temperature control current to limit the output electricity
Stream.
Preferably, described control unit includes operational amplifier, the first input end of the operational amplifier and second defeated
Enter end and receive the input signal and the output signal respectively, the output end of the operational amplifier provides the output control
Signal.
Preferably, when the operating temperature is less than or equal to the set temperature, the temperature control current is similar to 0, works as institute
When stating operating temperature more than or equal to the set temperature, the temperature control current and the operating temperature are in a linear relationship.
Preferably, the output control signal includes first control signal and second control signal, and the output unit is also
Including the first transistor being sequentially connected in series between high power supply voltage and low supply voltage with P-channel and with N-channel
Two-transistor, the first transistor and the second transistor are controlled by the first control signal and second control
Signal processed, the first transistor or second transistor conducting are to generate the output electric current.
Preferably, the over-current protecting unit includes: third transistor, and first end receives the high power supply voltage, and second
End is connected with the control terminal of the first transistor, and control terminal receives the first sampled voltage；4th transistor, first end receive institute
Low supply voltage is stated, second end is connected with the control terminal of the second transistor, and control terminal receives the second sampled voltage；And electricity
Generation module is pressed, first sampled voltage and second sampled voltage are generated according to the temperature control current, when the temperature control
When electric current is more than or equal to given threshold and effective first control signal, the third crystal is connected in first sampled voltage
Pipe, when the temperature control current is more than or equal to the given threshold and effective second control signal, the second sampling electricity
The 4th transistor is connected in pressure.
Preferably, the temperature control current includes the first temperature control current and the second temperature control current, the voltage generating module packet
Include: the first current source provides first temperature control current according to the operating temperature, and passes through current-mirror structure for the first benchmark
Spill current between electric current and first temperature control current is converted into the first sample rate current；Second current source, according to the work
Temperature provides second temperature control current, and will be between the second reference current and second temperature control current by current-mirror structure
Spill current be converted into the second sample rate current；First resistor, according to first sample rate current the third transistor control
End processed provides first sampled voltage；And second resistance, according to second sample rate current in the 4th transistor
Control terminal provides second sampled voltage.
Preferably, the third transistor includes N-channel field-effect tube, and the first end of the first resistor receives the height
Supply voltage, the second end of the first resistor are connected with the control terminal of the third transistor, first sample rate current by
The first end of the first resistor flows to second end；4th transistor includes P-channel field-effect transistor (PEFT) pipe, the second resistance
First end receives low supply voltage, and the second end of the second resistance is connected with the control terminal of the 4th transistor, and described the
Two sample rate currents flow to first end by the second end of the second resistance.
Preferably, first temperature control current is equal to second temperature control current, and first reference current is equal to described
Second reference current, the current-mirror structure in first current source have phase with the current-mirror structure in second current source
Deng proportionality coefficient.
Preferably, the high power supply voltage is less than or equal to first temperature control current, the proportionality coefficient and described first
The product of the resistance value of resistance.
Operational amplification circuit provided by the utility model directly obtains temperature control electricity according to the operating temperature of operational amplification circuit
Stream, when operating temperature is more than certain threshold value, the over-current protecting unit in operational amplification circuit can utilize temperature control current
Limitation output electric current, so as to reducing the power consumption of operational amplifier, preventing operating temperature excessively high and influencing operational amplifier
It works normally, avoid operating temperature is excessively high operational amplifier is caused to damage.Meanwhile when operating temperature is in zone of reasonableness,
Over-current protecting unit in operational amplification circuit will not limit output electric current, thus in the normal situation of operating temperature
It ensure that the delivery efficiency, response speed and driving capability of operational amplification circuit.
Detailed description of the invention
By referring to the drawings to the description of the utility model embodiment, above-mentioned and other mesh of the utility model
, feature and advantage will be apparent from.
Fig. 1 shows a kind of operational amplification circuit in the prior art.
Fig. 2 shows the circuit diagrams of the operational amplification circuit of the utility model embodiment.
Fig. 3 shows the relation schematic diagram in the utility model embodiment between operating temperature and temperature control current.
Fig. 4 a and Fig. 4 b show the circuit diagram of over-current protecting unit in Fig. 2.
Fig. 5 shows the flow diagram of the over-current protection method of the operational amplification circuit of the utility model embodiment.
Specific embodiment
Hereinafter reference will be made to the drawings is more fully described the utility model.In various figures, identical element is using similar
Appended drawing reference indicate.For the sake of clarity, the various pieces in attached drawing are not necessarily to scale.In addition, not having in figure
The lead-out wire other than corresponding driving electrodes and sensing electrode is drawn, and certain well known parts may be not shown.
Many specific details of the utility model, such as the structure of device, material, size, place are described hereinafter
Science and engineering skill and technology, to be more clearly understood that the utility model.But just as the skilled person will understand,
The utility model can not be realized according to these specific details.
Fig. 2 shows the circuit diagrams of the operational amplification circuit of the utility model embodiment.
As shown in Fig. 2, the operational amplification circuit 1000 of the utility model embodiment includes control unit, output unit 1100
And over-current protecting unit 1200.In the present embodiment, control unit is realized by operational amplifier U1, however the utility model
Embodiment is without being limited thereto, and those skilled in the art can realize control unit with other circuits as the case may be to generate output
Control signal.
Operational amplifier U1 has first input end, the second input terminal, the first output end and second output terminal, in which: the
One input terminal receives input signal Vin；Second input terminal receives the output signal Vout fed back by output unit 1100；The
One output end provides first control signal gop；Second output terminal provides second control signal gon.Specifically, operational amplifier U1
For generating output control signal according to input signal Vin and output signal Vout, input signal Vin is usually low and high level letter
Number, output control signal generally includes first control signal gop and second control signal gon.When input signal Vin is high level
When signal, first control signal gop carries out pulling drive to output unit 1100；When input signal Vin is low level signal,
Second control signal gon carries out drop-down driving to output unit 1100.
Output unit 1100 is used to generate output electric current Iout under the action of output controls signal, and according to output electric current
Iout generates output signal Vout.Specifically, as shown in Fig. 2, output unit 1100 includes output capacitance Cout, the first transistor
P1 and second transistor N1.The first transistor P1 and second transistor N1 are sequentially connected in series in high power supply voltage VDD and low power supply
Between voltage VSS, the common node of the first transistor P1 and second transistor N1 provide defeated to the first end of output capacitance Cout
Electric current Iout out, so that output capacitance Cout is constantly charged by output electric current Iout, discharges and generates output in its first end
Voltage Vout.The second end of output capacitance Cout receives low supply voltage VSS, and low supply voltage VSS is, for example, to refer to ground voltage.
Below mainly by taking the first transistor P1 is P-channel field-effect transistor (PEFT) pipe, second transistor N1 is N-channel field-effect tube as an example to this implementation
Example is specifically described, however the embodiments of the present invention are without being limited thereto, and those skilled in the art can be according to actual needs
Other kinds of transistor is set by the first transistor P1 and second transistor N1, and according to same circuit theory to operation
Other parts in amplifying circuit make corresponding variation.
In specific work process, the first transistor P1 and second transistor N1 are controlled by first control signal gop
With second control signal gon, when first control signal gop by the first transistor P1 be connected when (in the present embodiment: first crystal
The gate source voltage Vgs1 of pipe P1 is less than 0 and the absolute value of the gate source voltage Vgs1 of the first transistor P1 is greater than the first transistor P1's
When the absolute value of threshold voltage, the first transistor P1 conducting, the gate source voltage Vgs1 of the first transistor P1 is equal to the first control letter
The difference of number gop and high power supply voltage VDD), the conducting electric current of the first transistor P1 is as output electric current Iout to output capacitance
The first end of Cout charges；(in the present embodiment: second when second transistor N1 is connected second control signal gon
When the gate source voltage Vgs2 of transistor N1 is greater than the threshold voltage of second transistor N1, second transistor N1 conducting, the second crystal
The gate source voltage Vgs2 of pipe N1 is equal to the difference of second control signal gon and low supply voltage VSS), the conducting of second transistor N1
Electric current discharges to the first end of output capacitance Cout as output electric current Iout, so as to adjust output voltage Vout.
In the practical work process of operational amplification circuit, since the output capacitance Cout as load is usually larger, high
The voltage value of supply voltage VDD is also higher (for example, more than ten volts to 20 volts), will when the frequency of input signal Vin is higher
Cause the power consumption of operational amplification circuit higher, so that work temperature is very high, when work temperature is more than certain value, operation amplifier
The normal work of circuit will be affected, and operational amplifier is possibly even damaged.Therefore, the utility model embodiment provides
Operational amplification circuit 1000 further include over-current protecting unit 1200.
As shown in Fig. 2, over-current protecting unit 1200 is used for work temperature (for example, operation according to operational amplification circuit
The temperature of chip where amplifying circuit) temperature control current I_temp is obtained, and output control letter is adjusted according to temperature control current I_temp
Number with limit under certain condition output electric current Iout, to avoid work temperature excessively high and influence operational amplification circuit 1000
Normal work, and operational amplification circuit 1000 is prevented to be damaged under higher work temperature.
Fig. 3 shows the relation schematic diagram in the utility model embodiment between operating temperature and temperature control current.Wherein, horizontal axis
Work temperature is characterized, the longitudinal axis characterizes temperature control current I_temp.
As shown in figure 3, illustrating the operating temperature of operational amplification circuit when work temperature is less than or equal to set temperature T0
In the reasonable scope, the temperature control current I_temp that over-current protecting unit 1200 provides at this time is similar to 0, and output unit 1100 provides
Output electric current Iout will not be influenced substantially by over-current protecting unit 1200；When work temperature is more than or equal to set temperature
When T0, illustrate that the operating temperature of operational amplification circuit 1000 is excessively high, over-current protecting unit 1200 provides and work temperature line at this time
Property relevant temperature control current I_temp, relationship slope is k (as shown in figure 3, k is greater than 0), thus output unit 1100 provide it is defeated
Electric current Iout will be restricted out, so that work temperature reduces.
Preferably, set temperature T0 is not higher than 85 DEG C.
It should be noted that relationship slope k should not be too large, it is excessively quick to operating temperature otherwise to will lead to operational amplification circuit
Sense, so as to cause output electric current with operating temperature oscillation, the output bad phenomenons such as electric current is unstable.Those skilled in the art can be with
Relationship slope k is configured according to concrete conditions such as chip package, dissipating-heat environments.
Fig. 4 a and Fig. 4 b show the circuit diagram of over-current protecting unit in Fig. 2.
As shown in Figs. 4a and 4b, the over-current protecting unit in the utility model embodiment includes third transistor N2, the 4th
Transistor P2 and voltage generating module (including first voltage generation module 1210 and second voltage generation module 1220).Below
It is specifically described so that third transistor N2 is N-channel field-effect tube, the 4th transistor P2 is P-channel field-effect transistor (PEFT) pipe as an example.
As shown in fig. 4 a, third transistor N2 and first voltage generation module 1210 pass through control first control signal gop
The gate source voltage Vgs1 for adjusting the first transistor P1, to limit the conducting electric current of the first transistor P1.Specifically, third crystal
The first end (drain electrode) of pipe N2 receives high power supply voltage VDD, and second end (source electrode) is connected with the control terminal of the first transistor P1, controls
End (grid) processed receives the first sampled voltage Vs1；First voltage generation module 1210 is used to generate the first temperature according to work temperature
Electric current I_temp1 is controlled, and the first sampled voltage Vs1 is generated according to the first temperature control current I_temp1.As the first temperature control current I_
When temp1 is more than or equal to given threshold I0 and first control signal gop effective, third transistor is connected in the first sampled voltage Vs1
N2 is to draw high first control signal gop, to raise the gate source voltage Vgs1 of the first transistor P1.When the first transistor P1 is by
When one control signal gop conducting, since the gate source voltage Vgs1 of the first transistor P1 is elevated, the first transistor P1's is led
Logical degree decline, the output electric current Iout provided by the first transistor P1 are limited；And when the first transistor P1 is not by the first control
When signal gop processed is connected, the first transistor P1 is able to maintain off state.
Specifically, as shown in fig. 4 a, first voltage generation module 1210 includes first resistor Ru and the first current source.First
The first end of resistance Ru receives high power supply voltage VDD, and second end is connected to provide first and adopt with the control terminal of third transistor N2
Sample voltage Vs1.First current source include the first reference current source A11, the first temperature control current source A12 and by transistor N11 and
The first current-mirror structure that N12 is formed.Wherein, the first reference current source A11 provides the first reference current I_ref1, the first temperature control
Current source A12 provides the first temperature control current I_temp1 according to work temperature；In the first current-mirror structure, transistor N11 with
The size ratio of transistor N12 is that (i.e. the proportionality coefficient of the first current-mirror structure is W1 to 1:W1, and 0) W1 is greater than, transistor N11 is received
Spill current between first reference current I_ref1 and the first temperature control current I_temp1, so that transistor N12 be made to be capable of providing stream
The first sample rate current Is1, the first sample rate current Is1 through first resistor Ru flows to second end by the first end of first resistor Ru,
Voltage drop Vru=(I_ref1-I_temp1) W1Ru at the both ends first resistor Ru, the gate source voltage of the first transistor P1
Vgs1=Vru+VgsN2, wherein VgsN2 is the gate source voltage of third transistor N2.
After work temperature is more than set temperature T0, with the raising of work temperature, the first temperature control current I_temp1 increases
Greatly, the first sampled voltage Vs1 increases, thus in the effective situation of first control signal gop, the pull-up energy of third transistor N2
The conducting degree of power enhancing, the first transistor P1 reduces, and is reduced by the output electric current Iout that the first transistor P1 is provided.
Similarly, as shown in Figure 4 b, the 4th transistor P2 and second voltage generation module 1220 pass through the second control of control
Signal gon adjusts the gate source voltage Vgs2 of second transistor N1, to limit the conducting electric current of second transistor N1.Specifically,
The first end (source electrode) of 4th transistor P2 receives low supply voltage VSS, the control of second end (drain electrode) and second transistor N1
End is connected, and the control terminal (grid) of the 4th transistor P2 receives the second sampled voltage Vs2；Second voltage generation module 1220 is used for
The second temperature control current I_temp2 is generated according to work temperature, and the second sampling electricity is generated according to the second temperature control current I_temp2
Press Vs2.When the second temperature control current I_temp2 is more than or equal to given threshold I0 and second control signal gon effective, the second sampling
The 4th transistor P2 is connected to drag down second control signal gon, to drag down the gate source voltage of second transistor N1 in voltage Vs2
Vgs2.When second transistor N1 is connected by second control signal gon, since the gate source voltage Vgs2 of second transistor N1 is drawn
It is low, therefore the conducting degree decline of second transistor N1, the output electric current Iout that is provided by second transistor N1 are limited；And work as
When second transistor N1 is not connected by second control signal gon, second transistor N1 is able to maintain off state.
Specifically, as shown in Figure 4 b, second voltage generation module 1220 includes second resistance Rd and the second current source.Second
The first end of resistance Rd receives low supply voltage VSS, and second end is connected to provide second and adopt with the control terminal of the 4th transistor P2
Sample voltage Vs2.Second current source include the second reference current source A21, the second temperature control current source A22 and by transistor P21 and
The second current-mirror structure that P22 is formed.Wherein, the second reference current source A21 provides the second reference current I_ref2, the second temperature control
Current source A22 provides the second temperature control current I_temp2 according to work temperature；In the second current-mirror structure, transistor P21 with
The size ratio of transistor P22 is that (i.e. the proportionality coefficient of the second current-mirror structure is W2 to 1:W2, and 0) W2 is greater than, transistor P21 is received
Spill current between second reference current I_ref2 and the second temperature control current I_temp2, so that transistor P22 be made to be capable of providing stream
The second sample rate current Is2, the second sample rate current Is2 through second resistance Rd flows to first end by the second end of second resistance Rd,
Voltage drop Vrd=(I_ref2-I_temp2) W2Rd at the both ends second resistance Rd, the gate source voltage of second transistor N1
Vgs2=Vrd+VsgP2, wherein VsgP2 refers to the source gate voltage of the 4th transistor P2.
After work temperature is more than set temperature T0, with the raising of work temperature, the second temperature control current I_temp2 increases
Greatly, the second sampled voltage Vs2 reduces, thus in the effective situation of second control signal gon, the drop-down energy of the 4th transistor P2
The conducting degree of power enhancing, second transistor N1 reduces, and is reduced by the output electric current Iout that second transistor N1 is provided.
It should be noted that temperature control current I_temp includes the first temperature control current I_temp1 and the second temperature control current I_
Temp2, i.e. the first temperature control current I_temp1 and the second temperature control current I_temp2 meet relation schematic diagram shown in Fig. 3.
Preferably, the first temperature control current I_temp1 is equal to the second temperature control current I_temp2, the first reference current I_ref1
Equal to the second reference current I_ref2, the proportionality coefficient W1 of the first current-mirror structure and the proportionality coefficient W2 of the second current-mirror structure
It is equal.
Preferably, transistor N11, N12 in the first current-mirror structure are N-channel field-effect tube, the second current-mirror structure
In transistor P21, P22 be P-channel field-effect transistor (PEFT) pipe, however the utility model embodiment is without being limited thereto.
Further, when the first temperature control current I_temp1 rises to the first reference current I_ref1, the second temperature control current I_
When temp2 rises to the second reference current I_ref2, work temperature is no more than 160 DEG C.When the first temperature control current I_temp1 (or
Second temperature control current I_temp2) when reaching given threshold I0, work temperature is about 150 DEG C.
Over-current protecting unit 1200 still limits output electric current Iout when work temperature is not high in order to prevent, excellent
High power supply voltage VDD can be set smaller than equal to the first reference current I_ref1, proportionality coefficient W1 and the first electricity by selection of land
Hinder the product of the resistance value of Ru.To which when work temperature is not high, the first transistor P1 being capable of fully on, output electric current Iout
It will not be limited.
Operational amplification circuit provided by the embodiment of the utility model is directly obtained according to the operating temperature of operational amplification circuit
Temperature control current, when operating temperature is more than certain threshold value, the over-current protecting unit in operational amplification circuit can utilize temperature
It controls current limit and exports electric current, so as to reduce the power consumption of operational amplifier, prevent operating temperature excessively high and influence operation and put
The normal work of big device avoids operating temperature is excessively high operational amplifier is caused to damage.Meanwhile when operating temperature is in zone of reasonableness
When interior, the over-current protecting unit in operational amplification circuit will not limit output electric current, thus normal in operating temperature
In the case of ensure that the delivery efficiency and driving capability of operational amplification circuit.
Fig. 5 shows the flow diagram of the over-current protection method of the operational amplification circuit of the utility model embodiment, including
Step S210 to S230.
Operational amplification circuit includes control unit and output unit.Control unit is for example realized by operational amplifier, wherein
Operational amplifier generates output control signal according to input signal and output signal, and output unit controls signal according to the output
It generates output electric current and accumulates or discharge charge under the action of exporting electric current Iout to generate output signal.
Specifically, output control signal generally includes first control signal gop and second control signal gon, output unit
Including the first transistor being sequentially connected in series between high power supply voltage and low supply voltage with P-channel and with N-channel
Two-transistor.The first transistor and second transistor are controlled by first control signal and second control signal, first crystal
Pipe or second transistor conducting are to generate output electric current Iout.
In step S210, the work temperature of detection calculations amplifying circuit.
In step S220, temperature control current I_temp is obtained according to work temperature, when work temperature is more than or equal to setting
When temperature T0, temperature control current I_temp and work temperature are positively correlated.Preferably, when work temperature is less than or equal to set temperature T0
When, setting temperature control current I_temp is similar to 0；When work temperature is more than or equal to set temperature T0, temperature control current I_ is set
Temp is in a linear relationship with work temperature.
In step S230, output control signal is adjusted to limit output electric current Iout according to temperature control current I_temp.Tool
Body step are as follows: the first sampled voltage and the second sampled voltage are generated according to temperature control current I_temp；In the control of the first transistor
End offer pull-up path (such as the third transistor by being connected between high power supply voltage and the control terminal of the first transistor is real
It is existing), when temperature control current I_temp is more than or equal to given threshold I0 and effective first control signal, in the conducting of the first sampled voltage
Draw path；And pull-down path is provided (such as by being connected to low supply voltage and the second crystal in the control terminal of second transistor
The 4th transistor between the control terminal of pipe is realized), when temperature control current I_temp is more than or equal to given threshold I0 and the second control
When signal is effective, the second sampled voltage turns on pull-down path.
As a kind of specific embodiment, temperature control current I_temp includes the first temperature control current I_temp1 and the second temperature control
Electric current I_temp2 includes: to provide the first benchmark according to the step of temperature control current the first sampled voltage of generation and the second sampled voltage
Electric current I_ref1 and the second reference current I_ref2；It will according to the first proportionality coefficient W1 (such as being realized by the first current-mirror structure)
Spill current between first reference current I_ref1 and the first temperature control current I_temp1 is converted into the first sample rate current, according to
Two proportionality coefficient W2 (such as by the second current-mirror structure realize) are by the second reference current I_ref2 and the second temperature control current I_
Spill current between temp2 is converted into the second sample rate current；It is provided respectively according to the first sample rate current and the second sample rate current again
First sampled voltage and the second sampled voltage.Preferably, the first temperature control current I_temp1 is equal to the second temperature control current I_temp2,
First reference current I_ref1 is equal to the second reference current I_ref2, the first proportionality coefficient W1 and is equal to the second proportionality coefficient W2.
In a preferred embodiment, set temperature T0 is not higher than 85 DEG C, when the first temperature control current I_temp1 is equal to the first base
When quasi- electric current I_ref1, the second temperature control current I_temp2 are equal to the second reference current I_ref2, work temperature is no more than 160
℃。
In conclusion the operational amplification circuit that various embodiments of the utility model provides is directly according to the work of operational amplification circuit
Make temperature and obtains temperature control current, overcurrent protection list when operating temperature is more than certain threshold value, in operational amplification circuit
Member can using temperature control current limitation output electric current, so as to reduce the power consumption of operational amplifier, prevent operating temperature excessively high and
It influences the normal work of operational amplifier, avoid operating temperature is excessively high operational amplifier is caused to damage.Meanwhile at operating temperature
When in zone of reasonableness, the over-current protecting unit in operational amplification circuit will not limit output electric current, thus working
It ensure that the delivery efficiency and driving capability of operational amplification circuit in normothermic situation.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in process, method, article or equipment including the element.
It is as described above according to the embodiments of the present invention, these embodiments details all there is no detailed descriptionthe,
Also not limiting the utility model is only the specific embodiment.Obviously, as described above, many modification and change can be made
Change.These embodiments are chosen and specifically described to this specification, is in order to preferably explain the principles of the present invention and actually to answer
With so that skilled artisan be enable to utilize the utility model and repairing on the basis of the utility model well
Change use.The utility model is limited only by the claims and their full scope and equivalents.
Claims (9)
1. a kind of operational amplification circuit characterized by comprising
Control unit generates output control signal according to input signal and output signal；
Output unit is connected to receive the output control signal with described control unit, and the output unit is used in institute
Generation exports electric current under the action of stating output control signal, and the output unit includes output capacitance, and the output capacitance is by institute
Output electric current charge or discharge are stated to generate the output signal；
Over-current protecting unit is connected with described control unit and the output unit, and the over-current protecting unit is according to the fortune
The operating temperature for calculating amplifying circuit obtains temperature control current, when the operating temperature is more than or equal to set temperature, the temperature control electricity
Stream is positively correlated with the operating temperature, the over-current protecting unit according to the temperature control current adjust the output control signal with
Limit the output electric current.
2. operational amplification circuit according to claim 1, which is characterized in that described control unit includes operational amplifier,
The first input end of the operational amplifier and the second input terminal receive the input signal and the output signal respectively, described
The output end of operational amplifier provides the output and controls signal.
3. operational amplification circuit according to claim 1, which is characterized in that
When the operating temperature is less than or equal to the set temperature, the temperature control current is similar to 0,
When the operating temperature is more than or equal to the set temperature, the temperature control current is linearly closed with the operating temperature
System.
4. operational amplification circuit according to claim 3, which is characterized in that the output control signal includes the first control
Signal and second control signal,
The output unit further includes the first crystal being sequentially connected in series between high power supply voltage and low supply voltage with P-channel
Pipe and the second transistor with N-channel, the first transistor and the second transistor are controlled by first control
Signal processed and the second control signal, the first transistor or second transistor conducting are to generate the output electricity
Stream.
5. operational amplification circuit according to claim 4, which is characterized in that the over-current protecting unit includes:
Third transistor, first end receive the high power supply voltage, and second end is connected with the control terminal of the first transistor, control
End processed receives the first sampled voltage；
4th transistor, first end receive the low supply voltage, and second end is connected with the control terminal of the second transistor, control
End processed receives the second sampled voltage；And
Voltage generating module generates first sampled voltage and second sampled voltage according to the temperature control current,
When the temperature control current is more than or equal to given threshold and effective first control signal, first sampled voltage is led
Lead to the third transistor, when the temperature control current is more than or equal to the given threshold and effective second control signal,
The 4th transistor is connected in second sampled voltage.
6. operational amplification circuit according to claim 5, which is characterized in that the temperature control current includes the first temperature control current
With the second temperature control current, the voltage generating module includes:
First current source provides first temperature control current according to the operating temperature, and passes through current-mirror structure for the first base
Spill current between quasi- electric current and first temperature control current is converted into the first sample rate current；
Second current source provides second temperature control current according to the operating temperature, and passes through current-mirror structure for the second base
Spill current between quasi- electric current and second temperature control current is converted into the second sample rate current；
First resistor provides the first sampling electricity in the control terminal of the third transistor according to first sample rate current
Pressure；And
Second resistance provides the second sampling electricity in the control terminal of the 4th transistor according to second sample rate current
Pressure.
7. operational amplification circuit according to claim 6, which is characterized in that
The third transistor includes N-channel field-effect tube, and the first end of the first resistor receives the high power supply voltage, institute
The second end for stating first resistor is connected with the control terminal of the third transistor, and first sample rate current is by the first resistor
First end flow to second end；
4th transistor includes P-channel field-effect transistor (PEFT) pipe, and the first end of the second resistance receives low supply voltage, and described the
The second end of two resistance is connected with the control terminal of the 4th transistor, and second sample rate current is by the of the second resistance
Two ends flow to first end.
8. operational amplification circuit according to claim 7, which is characterized in that
First temperature control current is equal to second temperature control current, and first reference current is equal to the second benchmark electricity
Stream,
The current-mirror structure in current-mirror structure and second current source in first current source has equal ratio
Coefficient.
9. operational amplification circuit according to claim 8, which is characterized in that
The high power supply voltage is less than or equal to the resistance value of first temperature control current, the proportionality coefficient and the first resistor
Product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820840915.7U CN208190606U (en) | 2018-05-31 | 2018-05-31 | Operational amplification circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820840915.7U CN208190606U (en) | 2018-05-31 | 2018-05-31 | Operational amplification circuit |
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| CN208190606U true CN208190606U (en) | 2018-12-04 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019227822A1 (en) * | 2018-05-31 | 2019-12-05 | 北京集创北方科技股份有限公司 | Operational amplification circuit and method for overcurrent protection thereof |
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2018
- 2018-05-31 CN CN201820840915.7U patent/CN208190606U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019227822A1 (en) * | 2018-05-31 | 2019-12-05 | 北京集创北方科技股份有限公司 | Operational amplification circuit and method for overcurrent protection thereof |
| US11196386B2 (en) | 2018-05-31 | 2021-12-07 | Chipone Technology (Beijing) Co., Ltd | Operation amplification circuit and over-current protection method therefor |
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