JP4501555B2 - Current detection circuit - Google Patents

Description

  The present invention relates to a current detection circuit that detects a current flowing through an electric element from a voltage between terminals of the electric element.

When detecting the current flowing through the circuit, the current value of the current flowing through the element is detected based on the voltage generated at both ends of the resistance element and the semiconductor element. For example, in Patent Document 1, a current value of a current flowing through a power MOS transistor is detected based on a voltage between the drain and source of the power MOS transistor.
Japanese Patent Laid-Open No. 11-252909

  A voltage generated at both ends of an electric element such as a resistance element or a semiconductor element changes not only due to a change in current flowing through the electric element but also due to a temperature change. Therefore, the current flowing through the electric element cannot be accurately detected unless the change in the voltage between the terminals of the electric element caused by the temperature change is compensated.

  An object of this invention is to provide the current detection circuit which can detect correctly the electric current which flows through an electric element.

In order to achieve the above object, a current detection circuit according to an aspect of the present invention is a current detection circuit that detects a detection target current flowing in a two-terminal circuit from a voltage between terminals at both ends of the current detection target two-terminal circuit. A pair of input stages for inputting a voltage between terminals at both ends of the two-terminal circuit, and a voltage between the terminals input from the input stage is amplified with an amplification factor based on a control signal, corresponding to the detection target current An amplification circuit that generates a detection signal to be generated, and an amplification factor setting unit that generates the control signal whose temperature dependency characteristic is adjustable and reflects the temperature dependency characteristic of the control signal in the temperature dependency characteristic of the detection signal. the amplification factor setting unit includes means for applying a voltage corresponding to a common potential different pair of elements having temperature coefficient, the current flowing in each of said pair of elements in accordance with the voltage corresponding to the potential of the common Depends on temperature difference Generating a differential current having a characteristic, and generating the control signal that receives the differential current and that corresponds to the differential current and reflects a temperature-dependent characteristic of the differential current. Means for providing to an input stage, and the amplification factor setting unit is configured to provide a differential current that depends on a difference between currents flowing through the pair of elements by a voltage corresponding to the common potential applied to the pair of elements. And the temperature dependence characteristic in the detection signal is adjusted .
The temperature dependent characteristic of the differential current may be adjusted so as to cancel the temperature dependent characteristic in the detection signal by a voltage corresponding to a common potential applied to the pair of elements.

  By adopting such a configuration, a detection signal corresponding to the current flowing in the current detection target two-terminal circuit is output from the amplifier circuit, but the temperature-dependent characteristics in the detection signal can be adjusted. Thus, for example, by adjusting the detection signal so that there is no temperature-dependent characteristic, a signal corresponding to the current flowing through the two-terminal circuit is obtained by making a constant detection signal even if the temperature of the two-terminal circuit subject to current detection changes Can be output as

The amplification factor setting unit includes the pair of elements having different temperature coefficients, a variable power source that generates the common potential, and a common potential applied to the pair of elements from the common potential generated by the variable power source. and applying means for applying to said pair of elements to generate a voltage corresponding to, by a voltage corresponding to the common potential is applied to the pair of elements, a current corresponding to the current flowing through the pair of elements corresponding to said difference current and first and second current source supplying respectively, and generates the differential current corresponding to the difference between the first current source of flowing current and the second current fed by the current source Yes a difference current generation circuit for outputting a signal, said difference current generation circuit 3 to flow current respectively corresponding to the differential current based on the output signal of the fourth, and the fifth and sixth current source for and the third current source and the fifth Current source, a first fixed potential and is connected in series between the lower second fixed potential the fixed potential of the first, conductive of the third current source and the fifth current sources is connected to the first resistor between the one end of the resistor of the first is connected to one of said pair of input stage, said fourth current source and the sixth current source, the is connected in series between a first fixed potential and said second fixed potential, a second resistor connected between the current source of the current source and the sixth said 4 one end of the resistor of the second is connected to the other of said pair of input stage, the difference of the current flowing depending on a common potential generating the variable power supply to said first and said second current source by adjusting the difference current corresponding to, it may adjust the temperature dependent characteristic of the detection signal.
In this case, by adjusting the differential current corresponding to the difference between the currents flowing through the first and second current sources depending on the common potential generated by the variable power supply, the temperature-dependent characteristic in the detection signal is adjusted. You may adjust so as to cancel.
Further, the first fixed potential may be a power supply potential, and the second fixed potential may be a ground potential.
The pair of elements may be resistance elements, and the resistance values may be the same at a certain temperature.
Further, the first and the second resistor may have the same resistance value.
Further, the third and the fourth current source has the same current flows, said fifth and said sixth current source may be the same current flows.
Further, the third, the fourth, the fifth and the sixth current source may be the same current flows.

  Further, the two-terminal circuit for the current detection target may be one electric element.

  In this case, the electric element may be a resistor.

  The electrical element may be a semiconductor element.

  The electrical element may be a resistance element formed on a semiconductor substrate.

  The electric element may be a MOS transistor, and the input stage may receive a voltage between terminals between the drain and the source of the MOS transistor.

  The electrical element may be a diode, and the input stage may input a voltage between terminals between an anode and a cathode of the diode.

  The electric element may be a bipolar transistor, and the input stage may input a voltage between terminals between a collector and an emitter of the bipolar transistor.

  The current detection target two-terminal circuit may be formed of a plurality of electric elements.

  ADVANTAGE OF THE INVENTION According to this invention, even if there exists a temperature change, the electric current detection circuit which can detect correctly the electric current which flows through an electrical element is realizable.

FIG. 1 is a configuration diagram showing a current detection circuit according to an embodiment of the present invention.
The current detection circuit includes a pair of input terminals Vin1 and Vin2, a constant current source CS11 and a constant current source CS12 connected to the power supply voltage VCC, a P-channel MOS transistor M11 and a P-channel MOS transistor M12, and an amplifier. The circuit 20 is provided.

  The input terminals Vin1 and Vin2 are terminals connected to both ends of the current detection target electric element, and the gate of the transistor M12 is connected to the input terminal Vin1. The gate of the transistor M11 is connected to the input terminal Vin2.

  The source of the transistor M11 is connected to the output terminal of the constant current source CS11 and one differential input terminal (−) of the differential amplifier circuit 20. The source of the transistor M12 is connected to the output terminal of the constant current source CS12 and the other differential input terminal (+) of the differential amplifier circuit 20. The drain of the transistor 11 and the drain of the transistor 12 are connected to the ground GND. The constant current source CS11 and the constant current source CS12 are set to output currents having the same current value.

  The amplification circuit 20 is a circuit that has a variable temperature dependence characteristic of the amplification factor, cancels the temperature dependence characteristic of the current detection target electric element, and generates an output current corresponding to the current flowing through the electric element.

2 is a circuit diagram showing a configuration example of the amplifier circuit 20 in FIG. 1. Elements common to those in FIG. 1 are denoted by the same reference numerals as in FIG.
The amplifier circuit 20 includes a differential amplifier 20a, the differential amplifier 20a, and amplification factor setting units 20b and 20c.

  The differential amplifier 20a includes four N-channel MOS transistors M21, M22, M23, and M24, two P-channel MOS transistors M25 and M26, and a constant current source CS25.

  The amplification factor setting unit 20b includes a constant current source CS21, a resistor R21, and a constant current source CS22 connected in series between the power supply voltage VCC and the ground GND. The amplification factor setting unit 20c includes a constant current source CS23, a resistor R22, and a constant current source CS24 connected in series between the power supply voltage VCC and the ground GND.

  The connection point between the constant current source CS21 and the resistor R21 constitutes one input terminal (−) of the amplifier circuit 20, is connected to the source of the transistor M11, and is connected to the gate of the transistor M21 of the differential amplifier 20a. Has been. The connection point between the constant current source CS22 and the resistor 21 is connected to the gate of the transistor M22 of the differential amplifier 20a.

  The connection point between the constant current source CS23 and the resistor R22 constitutes the other input terminal (+) of the amplifier circuit 20, is connected to the source of the transistor M12, and is connected to the gate of the transistor M23 of the differential amplifier 20a. Has been. The connection point between the resistor 22 and the constant current source CS24 is connected to the gate of the transistor M24 of the differential amplifier 20a.

  The source of the transistor M25 of the differential amplifier 20a is connected to the power supply voltage VCC, and the drain of the transistor M25 is connected to the drain of the transistor M21 and the drain of the transistor M24. The source of the transistor M21 and the source of the transistor M24 are connected to the ground GND via the constant current source CS25.

The source of the transistor M26 is connected to the power supply voltage VCC, and the drain of the transistor M26 is connected to the drain of the transistor M23 and the drain of the transistor M22. The source of the transistor M23 and the source of the transistor M22 are connected to the ground GND via the constant current source CS25.
The gate of the transistor M25 and the gate of the transistor M26 are connected to the drain of the transistor M21. The drain of the transistor M26 is connected to the output terminal Io. The output terminal Io is a terminal that outputs a detection signal Sout corresponding to a current flowing through an electric element that is a current detection target.
The amplification factor setting unit 20b and the amplification factor setting unit 20c are circuits for setting the amplification factor of the differential amplification unit 20a, and the output currents of the constant current source circuits CS21 to CS24 become control currents for setting the amplification factor. .
FIG. 3 is a diagram illustrating circuit examples of the amplification factor setting unit 20b and the amplification factor setting unit 20c.

The circuit of FIG. 3 includes a reference current generation circuit 30, and the reference current generation circuit 30 includes a variable voltage source V31.
The variable voltage source V31 is a voltage source that can arbitrarily adjust the output voltage. The output voltage output from the anode of the variable voltage source V31 is a negative input terminal (−) of an operational amplifier (hereinafter referred to as an operational amplifier) OP31 and an operational amplifier OP32. Negative input terminal (−). The cathode of the variable voltage source V31 is connected to the ground GND.

  The positive input terminal (+) of the operational amplifier OP31 is connected to the drain of the P-channel MOS transistor M31 and one end of the resistor R31. The other end of the resistor R31 is connected to the ground GND. The output terminal of the operational amplifier OP31 is commonly connected to the gates of the transistor M31 and the P-channel MOS transistor M32.

  The source of the transistor M31 and the source of the transistor M32 are commonly connected to the power supply voltage VCC, and the transistor M31 and the transistor M32 constitute a mirror circuit.

The positive input terminal (+) of the operational amplifier OP32 is connected to the drain of the P-channel MOS transistor M33 and one end of the resistor R32, and the other end of the resistor R32 is connected to the ground GND. The output terminal of the operational amplifier OP32 is commonly connected to the gates of the transistor M33 and the P-channel MOS transistor M34.
The resistor R31 and the resistor R32 have the same resistance value when the element temperature is T0, and their temperature-dependent characteristics are different from each other.

  The source of the transistor M33 and the source of the transistor M34 are connected to the power supply voltage VCC, and the transistor M33 and the transistor M34 constitute a mirror circuit. The drain of the transistor M34 is connected to the drain of the N-channel MOS transistor M35.

  The drain and gate of the transistor M35 and the gate of the N-channel MOS transistor M36 are connected, and the transistor M35 and the transistor M36 constitute a mirror circuit. The source of the transistor M35 and the source of the transistor M36 are connected to the ground GND.

The drain of the transistor M32 and the drain of the transistor M36 of the reference current generating circuit 30 are connected to the drain and gate of the N-channel MOS transistor M41 and the gates of the N-channel MOS transistors M42, M43, and M44.
The sources of the transistors M41 to M44 are commonly connected to the ground GND, and these transistors M41 to M44 form a mirror circuit.

  The drain of the transistor M42 is connected to the drain and gate of the P-channel MOS transistor M45 and the gates of the P-channel MOS transistors M46 and M47. The sources of the transistors M45 to M47 are connected to the power supply voltage VCC, and the transistors M45 to M47 form a mirror circuit.

  A resistor R21 is connected between the drain of the transistor M43 and the drain of the transistor M46, and a resistor R22 is connected between the drain of the transistor M44 and the drain of the transistor M47. That is, the reference current generating circuit 30 and the transistors M41 to M47 constitute constant current source circuits CS21 to CS24.

  The output currents of the constant current source CS21, constant current source CS22, constant current source CS23, and constant current source CS24 are set to the same current value, and the resistors R21 and R22 are set to the same resistance value.

Next, the operation of the current detection circuit shown in FIGS. 1 to 3 will be described.
The input terminals Vin1 and Vin2 are connected to a terminal of an electric element that is a current detection target.

  Here, the output current of the constant current source CS11 and the output current of the constant current source CS12 are set to the same current value, and the differential input terminal of the amplifier circuit 20 has a high impedance. As a result, the current flowing through the transistor M11 and the current flowing through the transistor M12 become equal, so the gate-source voltage of the transistor M11 and the gate-source voltage of the transistor M12 are equal.

  Therefore, the potential difference between the source of the transistor M11 and the source of the transistor M12 is equal to the potential difference between the gate of the transistor M11 and the gate of the transistor M12, and the offset voltage applied by the transistor M11 and the transistor M12 is constant current sources CS11, It is determined by the output current of CS12. That is, the differential input terminals (+) and (−) of the amplifier circuit 20 are input with the voltage between both terminals to be detected, and the voltage between the gate and source of the transistors M11 and M12 is a constant current source. It is determined by the output current of CS11 and CS12.

  The differential amplifier 20a in the amplifier circuit 20 performs differential amplification of the voltage across the current detection target. The amplification factor of the amplifier circuit 20 is adjusted based on a control current having temperature dependent characteristics. The temperature dependence characteristic of the control current having the temperature dependence is set so as to cancel the temperature dependence of the electric element that is the target of current detection and the temperature dependence of the amplifier circuit 20.

  For example, the detection signal Sout output from the output terminal Io when the voltage v1 is input to the gate of the transistor M21 and the voltage v2 is input to the gate of the transistor M23 will be described.

If the current values of the output currents of the constant current source CS21, constant current source CS22, constant current source CS23 and constant current source CS24 are Ik, and the resistance values of the resistors R21 and R22 are Rk, the voltage drop in the resistors R21 and R22 Vk is given by the following equation.
Vk = IkRk (1)

If the source potentials of the transistors M21, M22, M23, and M24 are Vs, the drain current I21 of the transistor M21, the current value of the drain current of the transistor M22 are I22, the drain current I23 of the transistor M23, and the N-channel MOS transistor M24. The drain current I24 is given by the following equation.
I21 = K (v1-Vs-Vt) ² (2)
I22 = K (v1-Vk-Vs-Vt) ² (3)
I23 = K (v2-Vs-Vt) ² (4)
I24 = K (v2-Vk-Vs-Vt) ² (5)

In Expressions (2) to (4), Vt is a threshold voltage of each of the transistors M21 to M24, and K is given by the following expression.
K = (μCox / 2) (W / L) (6)
In Expression (6), μ is the mobility of the transistors M21 to M24, Cox is the gate capacitance per unit area of the transistors M21 to M24, W is the gate width, and L is the gate length.

The transistors M25 and M26 form a mirror circuit. The drain of the transistor M25 is connected to the drains of the transistors M21 and M24, and the drain of the transistor M26 is connected to the drains of the transistors M22 and M23. Has been. Therefore, the detection signal Sout output from the output terminal Io is given by the following equation.
Sout = (I21 + I24) − (I22 + I23) (7)
Substituting the equations (2) to (5) into the equation (7), the following equation is obtained.
Sout = 2KVk (v1-v2) (8)

Here, when Expression (1) and Expression (6) are substituted into Expression (8) and the voltage drop at the electric element to which Vin1 and Vin2 are connected is ΔV, the following expression is obtained.
Sout = 2 (μCox / 2) (W / L) IkRkΔV (9)
As can be seen from the equation (9), the amplification factor of the current detection circuit can be appropriately set by the current value Ik. That is, the output currents of the constant current source CS21, constant current source CS22, constant current source CS23, and constant current source CS24 are control currents that set the amplification factor of the current detection circuit.

  Furthermore, in the current detection circuit according to the present invention, the temperature dependence characteristic of the control current (temperature dependence characteristic of the current value Ik) is adjusted, whereby the temperature dependence of the voltage drop ΔV in the electric element and the temperature of the amplifier circuit 20 are adjusted. The dependency is eliminated. That is, the temperature dependence characteristics of Ik are adjusted so as to cancel out the voltage drop ΔV, the mobility μ of the MOS transistor, and the resistance value Rk. Therefore, it is possible to obtain the detection signal Sout having almost temperature dependency.

Here, the operation of the amplification factor setting units 20b and 20c involved in the amplification circuit 20 in setting the amplification factor and eliminating temperature dependence will be described.
Since the output voltage of the variable voltage source V31 in the reference current generating circuit 30 is supplied to the negative input terminal (−) of each operational amplifier OP31 and operational amplifier OP32, it is connected to the positive input terminal (+) of the operational amplifier OP31. A voltage equal to the output voltage of the variable voltage source V31 is applied to the resistor R31 and the resistor R32 connected to the positive input terminal (+) of the operational amplifier OP32. If the output voltage of the variable voltage source V31 is Vx, the resistance value of the resistor R31 is Ra, and the resistance value of the resistor R32 is Rb, the current I31 flowing through the resistor R31 and the current I32 flowing through the resistor R32 are expressed by the following equations (10), ( 11).
I31 = Vx / Ra (10)
I32 = Vx / Rb (11)

  The reference current generating circuit 30 uses a resistor R31 and a resistor R32 that have the same resistance value when the element temperature is T0 and have different temperature-dependent characteristics. Here, if the temperature coefficient of the resistor R31 is Ka, the temperature coefficient of the resistor R32 is Kb, the element temperature of each resistor is T, and the resistance value when the resistance values of the resistors R31 and R32 are equal is R0, the equation ( The current I31 of 10) and the current I32 of formula (11) are given by the following formulas (12) and (13).

I31 = Vx / R0 {1 + Ka (T−T0)} (12)
I32 = Vx / R0 {1 + Kb (T−T0)} (13)
Since the transistor M31 and the transistor M32 form a mirror circuit, the drain current I33 of the transistor M32 is equal to the current I31 flowing through the resistor R31. Since the transistor M33 and the transistor M34 constitute a mirror circuit, the drain current I34 of the transistor M34 is equal to the current I32 flowing through the resistor R32. Since the drain of the transistor M34 is connected to the drain of the transistor M35, the drain current I34 of the transistor M34 becomes the drain current of the transistor M35.

Since the transistor M35 and the transistor M36 constitute a mirror circuit, the drain current I35 of the transistor M36 is equal to the drain current I34 of the N-channel MOS transistor M35. The reference current generating circuit 30 outputs a differential current I30 between the drain current I33 of the transistor M32 and the drain current I35 of the transistor M36. The differential current I30 is given by the following equation (14).
I30 = I33-I35 = I31-I32 (14)

Substituting Equation (12) and Equation (13) into Equation (14) yields the following Equation (15).
I30 = Vx (Kb−Ka) (T−T0) / [R0 {1+ (Kb + Ka) (T−T0) + KbKa (T−T0) ² }] (15)
Here, it is preferable to set the temperature coefficient Ka of the resistor R31 and the temperature coefficient Kb of the resistor R32 so as to satisfy the following expression (16) in the temperature range during use.

1 >> (Kb + Ka) (T−T0) + KbKa (T−T0) ² (16)
As long as the expression (16) is substantially satisfied, the expression (15) can be approximated as the following expression (17).
I30 = Vx (Kb−Ka) (T−T0) / R0 (17)
As can be seen from the equation (17), the output current I30 becomes 0 (zero) when T = T0, and the temperature change rate (dI30 / dT) of the differential current I30 is given by the following equation (18). .
dI30 / dT = Vx (Kb−Ka) / R0 (18)

  As can be seen from the equation (18), the temperature change rate (dIout / dT) of the differential current I30, that is, the temperature dependence characteristic, can be arbitrarily adjusted by changing the output voltage Vx of the variable voltage source V31.

  Therefore, in this embodiment, the output voltage Vx of the variable voltage source V31 is adjusted, and the temperature-dependent characteristic of the differential current l30 is set to a characteristic that cancels the temperature-dependent characteristic of the electric element to be detected and the amplifier circuit 20. .

  The differential current I30 is input to the drain of the transistor M41. The drain currents of the transistors M42, M43, and M44 are equal to the differential current I30. On the other hand, since the drain of the transistor M42 is connected to the drain of the transistor M45, the drain currents of the transistors M45 to M47 are also equal to the differential current I30.

  The drain currents of the transistors M43, M44, M46, and M47 are output currents of the constant current sources CS21 to CS24, and become control currents that set the amplification factor in the differential amplifier 20a by flowing through the resistor R21 or R22. These control currents have a temperature-dependent characteristic of the differential current I30, and cancel the temperature-dependent characteristic of the electric element to be detected and the temperature-dependent characteristic in the amplifier circuit 20. Therefore, the detection signal Sout output from the amplifier circuit 20 does not change depending on the temperature. In other words, the detection signal Sout is a signal corresponding to the current flowing through the electric element and is a highly accurate signal that does not change due to a temperature change.

  The current detection circuit of the present invention is not limited to the above embodiment, and various modifications can be made. The modification and various uses of the current detection circuit of the present invention will be described.

(1) The electric element that is a current detection target may be an electric element whose voltage drop changes in accordance with a change in current, and may be a general electric element, a resistor as a semiconductor element, a transistor, a diode, or the like.
FIG. 4 is a circuit diagram showing an output stage of the power supply device.
As shown in FIG. 4, in the case of detecting the current flowing through the transistor M52 at the output stage of the power supply device including the N-channel MOS transistors M51 and M52, the inductor L51, the capacitor C51, and the diode D51, the transistor M52 Are connected to the input terminals Vin1 and Vin2 of the current detection circuit shown in FIGS.

  Note that the transistor M51 and the transistor M52 are independently turned on and off, and when both are turned off, a current is passed through the inductor L51 and the capacitor C52 via the diode D51. Therefore, when detecting the current flowing through the transistor M52, the current value is obtained by sampling the voltage between the drain and the source while the transistor M52 is on.

  When the electric element to be detected is a resistor, input terminals Vin1 and Vin2 are connected to both ends thereof. When the electric element to be detected is a diode, input terminals Vin1 and Vin2 are connected to the anode and the cathode. When the electric element to be detected is a bipolar transistor, input terminals Vin1 and Vin2 are connected to the collector and emitter thereof.

  (2) Instead of an electric element that is a current detection target, a current flowing through an electric circuit including a plurality of elements may be detected.

  (3) In the above embodiment, the temperature dependence characteristic in the detection signal Sout is eliminated, but it is also possible to have a predetermined temperature dependence characteristic.

  (4) The resistors R31 and R32 in the reference current detection circuit 30 can be changed to the same type of element as the electric element to be detected. In this way, it becomes easy to cancel the temperature dependence characteristics in the detection signal Sout over a wide range.

It is a block diagram which shows the current detection circuit which concerns on embodiment of this invention. FIG. 2 is a circuit diagram illustrating a configuration example of an amplifier circuit in FIG. 1. It is a figure which shows the circuit example of an amplification factor setting part. It is the circuit diagram which showed the output stage of the power supply device.

Explanation of symbols

20 amplifying circuit 20a differential amplifying unit 20b gain setting unit 20c gain setting unit 30 reference current generating circuit Vin1, Vin2 input terminal Sout detection signal

Claims (17)

A current detection circuit for detecting a detection target current flowing in the two-terminal circuit from a voltage between terminals of the two-terminal circuit of the current detection target;
A pair of input stages for inputting a voltage between terminals at both ends of the two-terminal circuit;
An amplifying circuit for amplifying the inter-terminal voltage input from the input stage with an amplification factor based on a control signal, and generating a detection signal corresponding to the detection target current;
An amplification factor setting unit that generates the control signal having an adjustable temperature-dependent characteristic and reflects the temperature-dependent characteristic of the control signal in the temperature-dependent characteristic of the detection signal;
The amplification factor setting unit
It means for applying a voltage corresponding to a common potential different pair of elements having temperature coefficients,
Means for generating a differential current having a temperature-dependent characteristic that depends on a difference between currents flowing in each of the pair of elements according to a voltage according to the common potential;
Means for receiving the differential current and generating the control signal corresponding to the differential current and reflecting the temperature-dependent characteristic of the differential current and supplying the control signal to the pair of input stages of the amplifier circuit;
The amplification factor setting unit adjusts a temperature characteristic of a differential current depending on a difference between currents flowing in each of the pair of elements by a voltage according to the common potential applied to the pair of elements, and the detection A current detection circuit characterized by adjusting a temperature dependence characteristic in a signal. The temperature-dependent characteristic of the differential current is adjusted so as to cancel out the temperature-dependent characteristic in the detection signal by a voltage corresponding to a common potential applied to the pair of elements. Current detection circuit. The amplification factor setting unit
The pair of elements having different temperature coefficients;
A variable power supply for generating the common potential ;
Applying means for generating a voltage corresponding to a common potential applied to the pair of elements from a common potential generated by the variable power source and applying the voltage to the pair of elements;
By voltage corresponding to the common potential is applied to the pair of elements, and the first and second current sources supplying a current corresponding to the current flowing through the pair of elements respectively,
A differential current generating circuit that generates the differential current corresponding to the difference between the current flowing through the first current source and the current flowing through the second current source and outputs a signal corresponding to the differential current;
And a third, fourth, electrodeposition of the fifth and sixth current sources supplying a current corresponding to the differential current based on the signal output of the differential current generating circuit, respectively,
Said third current source and the fifth current source is connected in series between the lower than the first fixed potential the fixed potential and the first second fixed potential, said third between the current source and said fifth current source being connected to the first resistor, one end of the resistor of the first is connected to one of said pair of input stage,
Said fourth current source and the sixth current source, the first is connected in series between a fixed potential and said second fixed potential, said fourth current source and said between the sixth current source being connected to the second resistor, one end of the resistor of the second is connected to the other of said pair of input stage,
By adjusting the difference current corresponding to the difference of the current flowing depending on a common potential generating the variable power supply to said first and said second current source, adjusting the temperature dependence of the detection signal current detecting circuit according to claim 1, characterized in that. By adjusting the differential current corresponding to the difference between the currents flowing through the first and second current sources depending on a common potential generated by the variable power supply, the temperature dependent characteristic in the detection signal is canceled out. The current detection circuit according to claim 3, wherein the current detection circuit is adjusted. The current detection circuit according to claim 3 or 4, wherein the first fixed potential is a power supply potential, and the second fixed potential is a ground potential. The current detection circuit according to claim 3, wherein the pair of elements are resistance elements, and the resistance values are the same at a certain temperature. The current detection circuit according to any one of claims 3 to 6 first and the second resistor are characterized by having the same resistance value. The third and the fourth current source has the same current flows, any one of claims 3 to 7 wherein the fifth and the sixth current source is characterized by passing the same current The current detection circuit described in 1. The third, the fourth, the fifth and the sixth current source are current detection circuit according to claim 8, characterized in that flow the same current. The current two-terminal circuit to be detected, the current detection circuit according to any one of claims 1 to 9, characterized in that the first electrical element. The current detection circuit according to claim 10 , wherein the electric element is a resistor. The current detection circuit according to claim 10 , wherein the electrical element is a semiconductor element. The current detection circuit according to claim 10 , wherein the electrical element is a resistance element formed on a semiconductor substrate. The electrical element is a MOS transistor,
The current detection circuit according to claim 10 , wherein the input stage inputs a terminal voltage between a drain and a source of the MOS transistor. The electrical element is a diode;
The current detection circuit according to claim 10 , wherein the input stage inputs a voltage between terminals between an anode and a cathode of the diode. The electrical element is a bipolar transistor;
The current detection circuit according to claim 10 , wherein the input stage inputs a terminal voltage between a collector and an emitter of the bipolar transistor. The current two-terminal circuit to be detected, the current detection circuit according to any one of claims 1 to 9, characterized in that it is formed by a plurality of electrical elements.

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