JP5925362B1 - Temperature compensation circuit - Google Patents

Abstract

A highly accurate current source and voltage source are made possible with a simple circuit configuration. A first transistor pair circuit; and a second transistor pair circuit connected to a subsequent stage of the first transistor pair circuit and operating to generate a constant current. A base is connected to a collector of one transistor of one transistor pair circuit, a collector is connected to a base of the first transistor pair circuit, and an emitter is connected to one emitter of the second transistor pair circuit. A transistor that includes a transistor that controls gain, and of the transistor pair of the second transistor pair circuit, to which the emitter of the transistor that controls gain is connected is diode-connected, and the second transistor Between the collector and emitter of the transistor in the pair circuit, and the emitter and output terminal A temperature compensating circuit resistance element is connected between the. [Selection] Figure 13

Description

  The present invention relates to a temperature compensation circuit.

  There is a great demand for a current source that can output a constant current even when the temperature changes. When the output of such a current source is connected to a resistor that can be regarded as having a temperature coefficient of zero, it can be used as a voltage source that can obtain a constant voltage even when the temperature changes. These current sources and voltage sources are often used as reference sources for analog-to-digital (AD) converters and digital-to-analog (DA) converters. When high precision AD conversion processing and DA conversion processing are to be performed, if the output of the reference source fluctuates with respect to temperature changes, the desired accuracy cannot be obtained. Therefore, regarding such a current source (or a voltage source using the current source), the stability (output accuracy) is important.

Patent Document 1 relates to a stabilized current source circuit. For example, referring to FIG. 2, since the collector-emitter current of the transistor Q3 decreases as the temperature rises, the circuit has a negative temperature coefficient. As the value increases, the output current decreases. Patent Document 2 discloses a constant current source circuit with two-terminal temperature compensation, for example referring to the FIG. 3, the circuit of the current I _P with a circuit and a positive temperature coefficient of the current I _N having a negative temperature coefficient Are combined to cancel out the large negative and positive temperature coefficients and achieve a low temperature coefficient. In the circuit of FIG. 3, the output current changes greatly depending on the power supply voltage. Patent Document 3 relates to a constant current generation circuit. The circuit shown has a positive temperature characteristic, and the output current increases as the temperature increases.

U.S. Pat. No. 4,260,945 US Pat. No. 4,792,748 U.S. Pat. No. 4,563,632

  In order to confirm the fluctuation of the output current, a test circuit (FIG. 11) similar to the circuit illustrated in the drawing of Patent Document 3 was assumed. The test circuit of FIG. 11 is a 100 μA current source that operates the potential V_R (band gap voltage: BGV) across the resistor RPTC connected to the emitter of Q4 at about 10% of the base-emitter voltage (VBE) of Q3. This is a design example.

  In the circuit of FIG. 11, VBE of Q3 = VBE + V_R of Q4. The emitter current of Q3 and the emitter current of Q4 are almost evenly distributed by the pair of PNP bipolar transistors of Q1 and Q2, and each becomes about 50 μA. In this case, the base-emitter potential (Q3_VBE) of Q3 when the emitter current of Q3 was 50 μA was around 0.6V.

  If 10% of 0.6V is BGV, which is the voltage between terminals of RPTC, the value is 0.06V (60 mV), and as a result, the base-emitter potential (Q4_VBE) of Q4 is calculated as 0.54V. . From this, the emitter current when the base-emitter potential (Q4_VBE) of the transistor Q4 is 0.54V is obtained.

  From two types of experiments on the circuit of FIG. 11 using a circuit simulator and an actually manufactured circuit, the emitter current was about 8 μA when Q4_VBE was 0.54V. As a result, in order to flow an emitter current of 50 μA through Q4, the emitter area of Q4 is six times the emitter area of Q3 (or an element having the same characteristics as Q3 is used by connecting six elements in parallel as Q4). It is.

  From this experiment, the temperature coefficient of the circuit of FIG. 11 was positive, and the value was determined to be approximately 3000 ppm / degree. This means that the output current varies by 0.3% per one degree of temperature change. That is, at the temperature that is the operation range of the circuit, the current of the current source fluctuates by about 30% with respect to a change of 100 degrees. The fluctuation of the output current at this level has a problem that it cannot be used as a constant current source requiring high accuracy as described above.

  An object of the present invention is to provide a temperature compensation circuit capable of providing a highly accurate current source and voltage source with a simple circuit configuration.

In order to achieve the above object and the like, a temperature compensation circuit according to one embodiment of the present invention includes first to sixth transistors, first and second resistance elements, and includes first to third transistors. The bases are connected to the transistors, the bases of the fourth and fifth transistors are connected, the collector of the first transistor and the collector of the fourth transistor are connected, and the second transistor The collector of the transistor and the collector of the fifth transistor are connected, the base and collector of the second transistor are connected, and the collector of the sixth transistor is the base of the first to third transistors. The base of the sixth transistor is connected to the collector of the first transistor and the collector of the fourth transistor, and the sixth transistor The emitter of the transistor is connected to the emitter of the fifth transistor, the emitters of the first to third transistors are connected to the input terminal, and the emitters of the fourth and fifth transistors are connected to the output terminal. The base and collector of the fifth transistor are connected, the first resistance element is connected between the collector and emitter of the fifth transistor, and the emitter and output terminal of the fifth transistor The 2nd resistance element is connected between these.
A temperature compensation circuit according to another aspect of the present invention includes first to ninth transistors, first and second resistance elements, and bases are connected from the first transistor to the third transistor. The bases of the fourth transistor to the sixth transistor are connected to each other, the bases of the seventh and eighth transistors are connected to each other, and the collectors of the first to third transistors are connected to the fourth transistor. To the emitters of the sixth transistor, the bases and collectors of the second and fifth transistors, respectively, and the collectors of the first transistor and the fourth transistor, respectively. The collector of the sixth transistor is connected to the collector of the eighth transistor, and the collector of the ninth transistor is connected to the fourth to sixth transistors. The base of the ninth transistor is connected to the collector of the fifth transistor, the base of the ninth transistor is connected to the collector of the fourth transistor and the collector of the seventh transistor, and the emitter of the ninth transistor Is connected to the emitter of the eighth transistor, the emitters of the first to third transistors are connected to the input terminal, the emitters of the seventh and eighth transistors are connected to the output terminal, The base and collector of the eighth transistor are connected, the first resistance element is connected between the collector and emitter of the eighth transistor, and between the emitter and output terminal of the eighth transistor. A second resistance element is connected.

  According to one embodiment of the present invention, a temperature compensation circuit capable of obtaining a highly accurate output current with a simple circuit configuration is provided.

It is a figure which shows the structural example of the temperature compensation circuit which concerns on one Embodiment of this invention. It is a figure which shows the structural example which provided the starting circuit in the circuit of FIG. It is a figure which shows the structural example which provided the phase compensation circuit in the circuit of FIG. FIG. 2 is a diagram illustrating temperature output current characteristics of the temperature compensation circuit of FIG. 1. FIG. 2 is a diagram illustrating temperature output current characteristics of the temperature compensation circuit of FIG. 1. 6 is a diagram illustrating a temperature output current characteristic of the circuit of Comparative Example 1 with respect to temperature. FIG. FIG. 6 is a diagram illustrating a temperature output current characteristic of the circuit of Comparative Example 2 with respect to temperature. 10 is a diagram illustrating a temperature output current characteristic of a circuit of Comparative Example 3 with respect to temperature. FIG. It is a figure which contrasts and shows the temperature output current characteristic with respect to the circuit of this embodiment, and the circuit of Comparative Examples 1-3. FIG. 2 is a diagram exemplifying a power supply voltage / current characteristic of the temperature compensation circuit of FIG. 1. FIG. 3 is a diagram illustrating the output frequency resistance characteristics versus frequency of the temperature compensation circuit of FIG. 1. It is a figure which shows the test circuit by the structural example of the constant current circuit by a prior art example. It is a figure which shows the structural example of the temperature compensation circuit by 2nd Embodiment of this invention. It is a figure which illustrates the temperature output current characteristic with respect to the temperature compensation circuit of 2nd Embodiment. It is a figure which illustrates the temperature output current characteristic with respect to the temperature compensation circuit of 2nd Embodiment. It is a figure which illustrates the versus frequency output resistance characteristic of the temperature compensation circuit of 2nd Embodiment. It is a figure which illustrates the time change of the output current characteristic at the time of starting of the temperature compensation circuit of 2nd Embodiment. It is a figure which shows the structural example of the temperature compensation circuit by 3rd Embodiment of this invention. It is a figure which illustrates the temperature output current characteristic with respect to the temperature compensation circuit of 3rd Embodiment. It is a figure which illustrates the versus frequency output resistance characteristic of the temperature compensation circuit of 3rd Embodiment. It is a figure which illustrates the saturation current characteristic with respect to the input voltage of the temperature compensation circuit of 3rd Embodiment. It is a figure which illustrates the time change of the output current characteristic at the time of starting of the temperature compensation circuit of 3rd Embodiment.

A temperature compensation circuit having a temperature compensation function according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a configuration example of the temperature compensation circuit 1 of the present embodiment. Temperature compensating circuit 1 is a two-terminal circuit, having a simple structure comprising bipolar transistors Q1 to Q5, resistors _R N, the _{R P.}

Q1 and Q2 are PNP pair transistors that share their respective bases. The P1 and Q2 PNP pair circuits operate in the same manner as the current mirror circuit if the base-emitter voltages are equal.
Q3 and Q4 are NPN-type pair transistors that share their respective bases.
Each emitter of Q1 and Q2 is connected to a positive voltage side terminal (V _H ). The collectors of Q1 and Q3 are connected. The respective collectors of Q2 and Q4 are also connected. Q4 is a transistor having a diode-like connection in which the base and the collector are connected.
The emitter of Q3 is connected to the negative voltage side terminal (V _L ). The emitter of Q4 is connected to a _{V L} through a resistor _{R P.}
A resistor _RN is connected between the base and emitter of Q4 (that is, between the collector and emitter).
The base of Q5 is connected to the respective collectors of Q1 and Q3. The collector of Q5 is connected to the respective bases of Q1 and Q2. The emitter of Q5 is connected to the emitter of Q4. Transistors Q1 to Q5 are all in a grounded emitter operation.
The collector of Q5 is connected to the base of Q1, and the collector of Q1 is connected to the base of Q5, thereby forming a positive feedback path. The collector of Q5 is connected to the base of Q2, the collector of Q2 is connected to the base of Q3, and the collector of Q3 is connected to the base of Q5, thereby forming a negative feedback path.
The pair of Q3 and Q4 has a circuit configuration (inverse wideler current source circuit) obtained by inverting a circuit known as a wideler current source circuit. A wideler current source circuit is described, for example, in US Pat. No. 3,320,439.

In the constant current circuit 1, the operational relationship between Q3 and Q4 corresponding to the wideler current source circuit is switched by inverting and amplifying the output of Q3 by Q5. Q5 constitutes a multiple feedback circuit that simultaneously performs positive feedback and negative feedback, and has the effect of greatly increasing the control gain of the entire circuit.
The R _P resistor for determining a positive temperature versus current, is R _N is a resistor for determining the negative temperature versus current. By precisely adjusting the resistance value of R _P and R _N, it is possible to obtain a good versus temperature current characteristic (temperature coefficient TC approximately 0). In this case, when the emitter area ratio between Q3 and Q4 is set to about 1: 2 to 3, particularly good circuit characteristics can be obtained, but this configuration is not essential to the present invention.

The constant current circuit 1 of FIG. 1, a known positive temperature linear characteristic: the (PTAT Proportional-To-Absolute- Temperature) circuit showing a (for example, see U.S. Patent 4,563,632 Pat), adding a resistor R _N Can be realized. The operation when the constant current circuit 1 is designed as a current source with an output current of 100 μA will be described below. The current from _VH is almost evenly distributed by the P1 and Q2 PNP transistor pairs, each of which is approximately 50 μA. Since the emitter current of Q1 is 50 μA, the emitter current of Q3 is also 50 μA (the left side of the circuit). Since the emitter current of Q2 is 50 .mu.A, the collector current of Q2 is also approximately 50 .mu.A next, when the current plus the base current of Q1 and Q2 is small, is distributed as a current to the collector current and the resistor R _N of Q4. Emitter current of subsequent Q4, current and emitter current is summed synthesized resistor slight and current distributed to the R _N Q5 at approximately 50 .mu.A, all flows into the resistor R _P (circuit right). Assuming here the bandgap voltage (BGV = _R terminal voltage of _P) and 60 mV, as described with respect to the conventional example of FIG. 11, Q3 based - the emitter potential (Q3_VBE) and 0.6V, Q4 The base-emitter potential (Q4_VBE) is determined to be 0.54V.

The collector current of Q2 is 50 .mu.A, to be distributed as a current to the collector current and the resistor _{R N} of Q4, the collector current of Q4 is naturally smaller than 50 .mu.A. Assuming that the collector current of Q4 is ½ of 25 μA, the emitter (saturation) current when the base-emitter potential (Q4_VBE) of Q4 is 0.54 V is about 8 μA. From this result, it can be seen that the condition for satisfying 25 μA as the emitter (saturation) current in Q4 is that the emitter area of Q4 is about three times that of Q3. Note that an element having the same characteristics as Q3 may be connected in parallel as three elements as Q4.

As the transistors Q1 to Q5, suitable transistors having characteristics corresponding to a required output current can be selected. Also, the constant of the resistor _R P, _{R N} is required output current characteristics can be determined based on the characteristics of the transistor Q1 to Q5. Furthermore, the transistors Q1 and Q2 and the transistors Q3 and Q4 can obtain the best temperature-to-current characteristics when thermally coupled closely.
As described above, the circuit configuration of the temperature compensation circuit 1 according to the embodiment of the present invention is very simple, and is a constant current circuit that operates in a current mode based on the band gap potential theory. In the temperature compensation circuit of this embodiment, a temperature-compensated constant current characteristic can be obtained.
Further, according to this circuit, a large output impedance can be obtained, the current change is very small with respect to the change of the operating voltage, and the constant current accuracy can be greatly improved. This is realized by a circuit configuration in which a large amount of positive feedback and moderate negative feedback are compatible.
Further, in the present invention, a two-terminal operation is possible, and an arrangement design can be freely made at an arbitrary position in an electronic circuit, and the application range is wide.
Further, this circuit can operate with a low potential difference, and when a silicon bipolar transistor is used, a saturation operation can be started from a low voltage of about 0.6 to 0.7 V (an example at 100 μA / 300 K). . Therefore, power loss can be reduced and efficiency is improved.

In this embodiment, a PNP type element is used on the positive electrode side (upper part of the circuit diagram) and an NPN type element is used on the negative or ground electrode side, but the + side PNP circuit operation and the − side NPN circuit operation are symmetrical. It is possible to operate even with a circuit configuration replaced with.
Further, since the current noise is small and the 1 / f corner frequency is low, it can be used as a low voltage, low noise current source.

Examples Next, examples relating to the temperature compensation circuit 1 of the above-described embodiment will be described. First, the structure provided with the starting circuit for starting the temperature compensation circuit 1 is demonstrated. FIG. 2 shows a configuration example of the temperature compensation circuit 1 including the starting circuit 10. The temperature compensation circuit 1 of FIG. 2 has a configuration in which a starter circuit 10 having a current source I1 is connected between the emitter and collector of Q1 in the configuration example of FIG.

The base current of the circuit using the PNP transistor (Q1 and Q2 in FIGS. 1 and 2) in which the emitter is connected to the positive voltage side terminal (V _H ) is not limited to the temperature compensation circuit 1 of the present embodiment. It is. Therefore, even if a potential (V _H −V _L ) is applied after power-on, the base currents of Q1 and Q2 cannot flow out because Q5 is cut off. In order to solve this, Q5 is started immediately upon power-on. Q5 is an NPN transistor, and its base current is an inflow direction current. In the circuit illustrated in FIG. 2, the circuit 1 is started up (started up) by adding a current source I1 as the starting circuit 10 and supplying a base current to Q5. As the current source I1, a current source having a small current of about 1/1000 of the circuit current (output current I _OUT ) is sufficient. For example, a junction FET (JFET) having a small saturation current (IDSS) can be used. The current source I1 is not a component of the present invention.

  Next, a configuration example in which a phase compensation circuit is provided in order to improve the characteristics of the temperature compensation circuit 1 will be described. In the temperature compensation circuit 1 illustrated in FIG. 1, a phase compensation circuit may be required in actual operation. This is the case where the phase transition becomes large in the AC band due to the large control gain of the entire circuit due to the multiple feedback circuit that simultaneously performs positive feedback and negative feedback, resulting in an oscillation condition. In the temperature compensation circuit 1 illustrated in FIG. 3, a phase compensation circuit 20 including a capacitive element C1 and a resistor R1 is connected between the collector and emitter of Q3 with respect to the circuit of FIG. With this phase compensation circuit 20, the AC gain of the temperature compensation circuit 1 can be adjusted to ensure the necessary phase margin. The capacitive element C1 and the resistor R1 are not essential elements in the present invention.

Next, output current characteristics obtained by the temperature compensation circuit 1 (FIG. 1) of the present embodiment will be described. The operation characteristics of this circuit were verified by a circuit simulator. Temperature compensation by this circuit is quadratic function compensation, and after the compensation, the locus draws a cubic function curve. 4A and 4B show changes in the output current when the circuit ambient temperature is changed in the range of −55 to 125 ° C. in the temperature compensation circuit 1. In both graphs, the range of the output current value when the power supply voltage (V _H −V _L ) is changed from 1 V to 10 V is indicated by light ink. As shown in FIG. 4A, the output current value was in the range of approximately 99.88 to 100.15 μA, the output current fluctuation range was approximately 0.3%, and the temperature coefficient ΔTC was 20 ppm / degree. In FIG. 4B, the output current value (vertical axis of the graph) is shown in units of 10 μA, but it can be seen that the change in the output current value is negligible over the entire temperature range.

  Next, the circuit illustrated in FIG. 1 of Patent Document 1 described above, the circuit illustrated in FIG. 3 of Patent Document 2, and a constant current circuit having a configuration similar to that illustrated in Patent Document 3 ( The result of performing the operation simulation under the same conditions for FIG. 11) of the present application will be described. 5 to 7 show graphs of the temperature output current characteristics with respect to the simulation results of the circuits (Comparative Examples 1 to 3) of Patent Documents 1 to 3. FIG. In these graphs, the unit of the vertical axis indicating the output current value is the same as in FIG. 4B. First, in the case of Comparative Example 1, as shown in FIG. 5, the circuit showed a negative temperature coefficient, and an output current change of about 130 to 63 μA was observed in the temperature range of −55 to 125 ° C. In the case of Comparative Example 2, the output current value is higher than that in the case of Comparative Example 1 by providing resistors R1 and R2 (see FIG. 3 of Patent Document 2) related to (determining) positive and negative temperature coefficients. 6 is suppressed, it can be seen from FIG. 6 that when the power supply voltage is changed between 1 and 10 V, the output current value fluctuates in the range of about 5 to 8 μA. In the case of Comparative Example 3, as shown in FIG. 7, the circuit showed a positive temperature coefficient, and an output current change of about 72 to 132 μA was observed in the temperature range of −55 to 125 ° C. FIG. 8 is a graph in which the graphs of FIGS. 4B to 7 are overlapped, and according to the temperature compensation circuit 1 of the present embodiment, a dramatic improvement in output current accuracy with respect to the comparative example is apparent.

  Next, other operating characteristics of the temperature compensation circuit 1 of the present embodiment will be described. FIG. 9 shows a power supply voltage output current characteristic of the temperature compensation circuit 1. As shown in FIG. 9, in the temperature compensation circuit 1 of the present embodiment, the output current rises steeply when the power supply voltage approaches 0.5V, and reaches approximately the rated output current value (100 μA) at about 0.7V. I understand that. FIG. 10 shows an example of the frequency output resistance value characteristic of the temperature compensation circuit 1. As shown in FIG. 10, the temperature compensation circuit 1 of the present embodiment can obtain an extremely high numerical value of about 1 GΩ (−180 dB) as an output resistance value (dynamic impedance) in a range of direct current (DC) to 1 Hz.

  According to the temperature compensation circuit 1 of the present embodiment having the above-described configuration, the current linearity with respect to the temperature can be improved, and the change in the output current due to the temperature change can be reduced. Also, the output impedance with respect to the signal frequency can be increased. Further, the output current accuracy with respect to changes in the power supply voltage (operating voltage) can be greatly improved. Further, the operation start voltage (VK: V_Knee) can be reduced, and the shoulder characteristics can be improved. For example, this circuit can be operated from a low voltage of about 0.6 to 0.7 V in the case of a silicon bipolar transistor under the conditions of an output current Io = 100 μA and a temperature of 300K.

Second Embodiment Next, a second embodiment that is an application example of the temperature compensation circuit 1 of the above-described embodiment will be described. FIG. 12 shows an example of a temperature compensation circuit 30 configured by applying the temperature compensation circuit 1 of the first embodiment. In the temperature compensation circuit 30 illustrated in FIG. 12, a transistor Q6 is added to the temperature compensation circuit 1 in FIG. The base of Q6 is connected to the bases of Q1 and Q2 and its own collector, and is further connected to the collector of Q5. The emitter of Q6 is connected to the input terminal _{V H} with the emitter of Q1, Q2. The temperature compensation circuit 30 of the present embodiment is provided with a current source I1 corresponding to the start-up circuit 10 of the first embodiment, a capacitive element C1 corresponding to the phase compensation circuit 20, and a resistance element R1.

In the configuration of FIG. 12, the current from VH is divided into three equal parts as collector currents of Q1, Q2, and Q6 by a current mirror circuit formed of PNP-type bipolar transistors. The emitter current of Q3 corresponds to the collector current of Q1, while the current of Rp corresponds to the sum of the collector currents of Q2 and Q6. Therefore, the collector current of Q3 and the current ratio of Rp are approximately 1: 2. In the circuit configuration illustrated in FIG. 12, the collector load resistance value of Q5 is reduced by adding Q6, which is diode-connected, in the case of FIG. As a result, the control gain as the circuit is also reduced, the circuit operation is stabilized, and the capacity of the phase correcting capacitive element C1 can be reduced, or the capacitive element can be omitted. The temperature compensation circuit 30 shown in FIG. 12 is particularly suitable for realization as a moric IC. The transistors Q1, Q3, and Q6 may be replaced with MOS-FETs. In this case, the base, emitter and collector of the bipolar transistor may be connected in correspondence with the gate, source and drain of the MOS-FET.

Next, the result of verifying the operating characteristics of the temperature compensation circuit 30 according to the second embodiment of FIG. 12 using a circuit simulator will be described. FIG. 13 shows an example of output current characteristics obtained by the temperature compensation circuit 30 of the present embodiment. Temperature compensation by this circuit is quadratic function compensation, and after the compensation, the locus draws a cubic function curve. FIG. 13 shows a change in output current when the circuit ambient temperature is changed in the range of −55 to 125 ° C. in the temperature compensation circuit 30. The power supply voltage (V _H −V _L ) was 1V. In this case, the output current value range was approximately 99.86 to 100.18 μA, the output current fluctuation range was approximately 0.3%, and the temperature coefficient ΔTC was 20 ppm / degree. Next, FIG. 14 shows an output current characteristic with respect to temperature when the power supply voltage is changed in the range of 1 to 10 V in the temperature compensation circuit 30. When the power supply voltage is set to 10 V, the output current fluctuation range becomes the largest, but it is still 99.3 to 100.6 μA, which is only 1.3%.

  FIG. 15 shows an example of the frequency output resistance characteristic of the temperature compensation circuit 30. As shown in FIG. 15, the temperature compensation circuit 30 of the present embodiment has an output resistance value (dynamic impedance) of −167 to −− in the range of direct current (DC) to 1 Hz when the power supply voltage is changed from 1 to 10 V. An extremely high value of 155 dB is obtained.

  FIG. 16 shows an example of the frequency output current characteristic when the temperature compensation circuit 30 is started. As shown in FIG. 16, in the temperature compensation circuit 30 of this embodiment, when the power supply voltage is 1V, it takes about 150 μs for the output current to reach a steady state, but the power supply voltage is 2 to 10V. In general, it is suppressed to about 20 μs. Thus, it can be seen that the temperature compensation circuit 30 of this embodiment is excellent in the rise of the output current at the time of startup.

Next, another example in which the temperature compensation circuit 1 (FIG. 1) of the first embodiment is applied will be described as a third embodiment. FIG. 17 shows a temperature compensation circuit 30A according to another application example. The temperature compensation circuit 30A according to the third embodiment is based on the temperature compensation circuit 30 in FIG. 12, and the current mirror having the same configuration is arranged in front of the current mirror circuit (input terminal _VH side) by Q1, Q2, and Q6 in FIG. The circuit (transistors Q7 to Q9) is connected in cascade. With the configuration of FIG. 17, in addition to the reduction of the control gain and the capacitance of the phase correction capacitance element C1 in the temperature compensation circuit 30 of FIG. 12, the output resistance value is about 10 times that in the case of the first embodiment of FIG. Can be increased. However, since the operating voltage of the circuit increases by the base-emitter voltage (VBE (about 0.6 V)) of the added current mirror circuit, it is necessary to pay attention to the specifications of the application circuit. Also in the temperature compensation circuit 30A of FIG. 17, MOS-FETs can be used instead of the bipolar transistors Q1, Q2, and Q6 to Q9, as in the case of FIG.

Next, the results of verifying the operating characteristics of the temperature compensation circuit 30 according to the third embodiment of FIG. 17 using a circuit simulator will be described. FIG. 18 shows an example of output current characteristics obtained by the temperature compensation circuit 30A of the present embodiment. FIG. 18 shows a change in output current when the circuit ambient temperature is changed in the range of −55 to 125 ° C. in the temperature compensation circuit 30A. The power supply voltage (V _H −V _L ) was changed in the range of 2 to 10V. In this case, the range of the output current value is approximately 99.86 to 100.15 μA, and as in the second embodiment, the range of the output current fluctuation is approximately 0.3%, and the temperature coefficient ΔTC is 20 ppm / degree. .

  FIG. 19 shows an example of the resistance characteristic against frequency output of the temperature compensation circuit 30A. As shown in FIG. 19, the temperature compensation circuit 30A of the present embodiment has an output resistance value (dynamic impedance) of −230 to −230 in the range of direct current (DC) to 1 Hz when the power supply voltage is changed from 1 to 10V. An extremely high value of 190 dB can be obtained.

  FIG. 20 shows an example of the saturation characteristic of the output current with respect to the input voltage of the temperature compensation circuit 30A. The example of the output current characteristic with respect to frequency at the time of starting is shown. As shown in FIG. 20, in the temperature compensation circuit 30A of the present embodiment, it is understood that a saturation output current of 100 μA can be obtained in a region where the power supply voltage is about 1.3 V or more.

FIG. 21 shows an example of the time change characteristic of the output current when the temperature compensation circuit 30A is activated. As shown in FIG. 21, in the temperature compensation circuit 30A of this embodiment, when the power supply voltage is 1V, it takes about 930 μs for the output current to reach a steady state, but the power supply voltage is 2 to 10V. In general, it is suppressed to about 20 μs. Thus, it can be seen that the temperature compensation circuit 30A of the present embodiment is excellent in the rise of the output current at the time of startup.
As described above, according to the second and third embodiments which are the application examples described above, a temperature compensation circuit with higher performance can be provided on the basis of the temperature compensation circuit 1.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. In addition, a part of the configuration of the embodiment can be replaced with another configuration, and another configuration can be added to the configuration of a certain embodiment.

Q1 to Q9 Transistor C1 Capacitance elements R _P , R _N , R 1, R _L , R _{REF1 to} R _REF7 Resistance elements

Claims (4)

Comprising first to sixth transistors, and first and second resistance elements;
The bases are connected from the first transistor to the third transistor,
The bases of the fourth and fifth transistors are connected to each other,
The collector of the first transistor and the collector of the fourth transistor are connected;
The collector of the second transistor and the collector of the fifth transistor are connected;
The base and collector of the second transistor are connected,
The collector of the sixth transistor is connected to the bases of the first to third transistors;
The base of the sixth transistor is connected to the collector of the first transistor and the collector of the fourth transistor;
The emitter of the sixth transistor is connected to the emitter of the fifth transistor;
The emitters of the first to third transistors are connected to the input terminal,
The emitters of the fourth and fifth transistors are connected to the output terminal,
The base and collector of the fifth transistor are connected,
A first resistance element is connected between the collector and emitter of the fifth transistor;
A second resistance element is connected between the emitter of the fifth transistor and the output terminal;
Temperature compensation circuit. The temperature compensation circuit according to claim 1,
A MOS-FET is applied as the first to third transistors, and the base, emitter, and collector of each transistor are connected to correspond to the gate, source, and drain of each MOS-FET.
Temperature compensation circuit. Comprising first to ninth transistors, and first and second resistance elements;
The bases are connected from the first transistor to the third transistor,
The bases are connected from the fourth transistor to the sixth transistor,
The bases of the seventh and eighth transistors are connected to each other,
The collectors of the first to third transistors are connected to the emitters of the fourth to sixth transistors, respectively.
The bases and collectors of the second and fifth transistors are respectively connected;
The collector of the first transistor and the collector of the fourth transistor are connected;
The collector of the sixth transistor and the collector of the eighth transistor are connected,
The collector of the ninth transistor is connected to the bases of the fourth to sixth transistors and the collector of the fifth transistor;
The base of the ninth transistor is connected to the collector of the fourth transistor and the collector of the seventh transistor;
The emitter of the ninth transistor is connected to the emitter of the eighth transistor;
The emitters of the first to third transistors are connected to the input terminal,
The emitters of the seventh and eighth transistors are connected to the output terminal,
The base and collector of the eighth transistor are connected,
A first resistance element is connected between the collector and emitter of the eighth transistor;
A second resistance element is connected between the emitter and output terminal of the eighth transistor;
Temperature compensation circuit. The temperature compensation circuit according to claim 3,
MOS-FET is applied as the first to sixth transistors, and the base, emitter, and collector of each transistor are connected to correspond to the gate, source, and drain of each MOS-FET.
Temperature compensation circuit.

Images