JP5925357B1 - Temperature compensation circuit - Google Patents

Abstract

A highly accurate voltage source is obtained with a simple circuit configuration. A first transistor pair circuit that bisects a current, and a second transistor pair circuit that is connected to a subsequent stage of the first transistor pair circuit and that operates to generate a constant current. And a transistor for controlling the gain through the base current of the first transistor pair circuit. A resistance element for extracting a reference voltage is connected between one emitter of the transistor pair of the second transistor pair circuit and the negative power supply line. [Selection] Figure 1

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. Such output voltage fluctuations also pose a problem in obtaining a highly accurate reference voltage.

  An object of the present invention is to provide a temperature compensation circuit capable of obtaining a highly accurate reference voltage 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 fifth transistors, first and second resistance elements, and the first and second transistors are The bases are connected, the bases of the third and fourth transistors are connected, the collector of the first transistor and the collector of the third transistor are connected, and the collector of the second transistor And the collector of the fourth transistor are connected, the collector of the fifth transistor is connected to the bases of the first and second transistors, and the base of the fifth transistor is connected to the collector of the first transistor. The third transistor is connected to the collector of the third transistor, and the emitter of the fifth transistor is connected to the emitter of the fourth transistor. The emitters of the transistors are connected to the positive power supply line, the emitters of the third and fourth transistors are connected to the negative power supply line, the base and collector of the fourth transistor are connected, The first resistance element is connected between the collector and the emitter of the first transistor, and the second resistance element is connected between the emitter and the negative power supply line of the fourth transistor. A third resistance element is connected between the second resistance element and the negative power supply line; a voltage between the terminals of the second resistance element; a voltage between the terminals of the third resistance element; The voltage across the series circuit of the second resistance element and the third resistance element is taken out as a reference voltage.
A temperature compensation circuit according to another aspect of the present invention is a sixth transistor having the basic configuration and operating in synchronization with the first transistor, the emitter of which is connected to a positive power supply line, and the collector thereof Includes a transistor connected to a negative power supply line via a fourth resistance element, and is configured to take out a voltage between terminals of the fourth resistance element as a reference voltage.
Furthermore, a temperature compensation circuit according to another aspect of the present invention is a seventh transistor having the basic configuration and operating in synchronization with the first transistor, the emitter of which is connected to a negative power supply line, The collector includes a transistor connected to a positive power supply line via a fifth resistance element, and is configured to take out the voltage between the terminals of the fifth resistance element as a reference voltage.

  According to one embodiment of the present invention, a temperature compensation circuit that can obtain a highly accurate reference voltage 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 one Embodiment of this invention. It is a figure which shows the structural example of the temperature compensation circuit by other embodiment of this invention. It is a figure which illustrates the temperature output current characteristic of the temperature compensation circuit of FIG. It is a figure which illustrates the temperature output voltage characteristic with respect to the temperature compensation circuit of FIG. It is a figure which illustrates the temperature output voltage characteristic with respect to the temperature compensation circuit of FIG. It is a figure which illustrates the temperature output voltage characteristic with respect to the temperature compensation circuit of FIG. It is a figure which illustrates the temperature output voltage characteristic with respect to the temperature compensation circuit of FIG. It is a figure which illustrates the frequency compensation voltage fluctuation removal ratio characteristic with respect to the temperature compensation circuit of FIG. It is a figure which illustrates the frequency compensation voltage fluctuation removal ratio characteristic with respect to the temperature compensation circuit of FIG.

First Embodiment A temperature compensation circuit of the present invention will be described according to an embodiment thereof 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 temperature compensation 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.

Temperature compensating circuit 1 in 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 temperature compensation 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 25 μA, which is 1/2 of the collector current of Q4, 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 a constant current circuit that operates in a current mode is provided 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, an application example of the embodiment of the present invention will be described as a second embodiment. FIG. 12 shows an example of a temperature compensation circuit 30 configured by applying the temperature compensation circuit 1 of the present embodiment. In the following description, the input terminal V _H of the temperature compensation circuit 30 to the positive supply line and the output terminal V _L is assumed to be connected to the negative supply line.

  As shown in FIG. 12, a series circuit of a capacitive element C1 and a resistor R1 is connected between the collector and emitter of Q3. This series circuit has a configuration corresponding to the phase compensation circuit 20 described with reference to FIG. Further, a current source corresponding to the activation circuit 10 described with reference to FIG. 2 is provided between the emitter and collector of Q1.

In the temperature compensation circuit 30 illustrated in FIG. 12, first, a load resistor _RL is connected between the resistor _RP and the output terminal V _L of the temperature compensation circuit 1 in FIG. In this configuration, since the inter-terminal voltage of the connected resistor R _L to the output terminal V _L is constant with high accuracy regardless of the temperature variation, it is possible to obtain the reference voltage V _REF1 that is temperature compensated. Further, as the inter-terminal voltage of the resistor R _P, which is connected to the emitter of the transistors Q4, as in the case of R _L, it is possible to obtain the reference voltage V _REF2 precision. Further, the between the Q4 emitter terminal and _{V L} of _{R P can} also be obtained a reference voltage having a value of _{V REF1 + V REF2 = V REF3} . Reference voltage _V REF1 _{~V REF3 can} be adjusted by changing the resistance value of R L, _{R P.} The reference voltages V _{REF1 to} V _REF3 can be used as independent voltage sources. Thus, a plurality of high-precision reference voltage sources can be easily obtained by applying the temperature compensation circuit 1 of FIG.

  Next, another configuration example of the temperature compensation circuit 30 that can be used as a reference voltage source will be described. FIG. 13 shows an example of the temperature compensation circuit 30 according to another configuration. Referring to FIG. 13, the temperature compensation circuit 30 includes a transistor Q6 that operates in synchronization with the transistor Q1, and a transistor Q7 that operates in synchronization with the transistor Q3. In the temperature compensation circuit 30 of FIG. 13, the same temperature compensated current as Q1 and Q3 can be obtained by the added Q6 and Q7. That is, if Q1 and Q2 have the same characteristics, the VBEs of Q1 and Q2 sharing the base are equal, and the emitter currents of Q1 and Q2 are also equal. In the original current mirror circuit, it is known that the collector current of the other BJT follows the same current as the collector current of the diode-connected bipolar transistor (BJT). On the other hand, BJT exhibits a positive temperature proportionality characteristic represented by KT / q (K: Boltzmann constant, T: temperature (K), q: quantity of electricity (Coulomb)) with respect to VBE. Compensation circuit 30 provides a temperature compensated VBE that decreases with increasing temperature with respect to the collector current. Therefore, if Q1, Q3 and Q6 and Q7 in FIGS. 12 and 13 are BJTs having the same characteristics, Q1 and Q6 and Q3 and Q7 are subjected to the same temperature compensation from the same temperature compensated VBE. Collector current can be obtained.

Referring now to FIG. 13, the emitter of Q6 is connected to V _H , the collector is connected to V _L via resistor R _REF4 , the emitter of Q7 is connected to V _L , and the collector is connected to V _L via resistor R _REF5. Connected to _H. R _REF4, if the voltage across the terminals of _{R REF5} and _{V REF4, V REF5, V REF4} , as _{V REF5,} the collector of the power supply voltage _(V H -V _L) and the transistors Q6, Q7 - emitter saturation voltage _{V sat} As the difference, it is possible to independently obtain voltages close to positive and negative power supply voltages. The value of V _sat is about 50 mV when the collector-emitter current of each transistor is 50 μA.

Next, the result of verifying the operation characteristics of the temperature compensation circuit 30 of FIG. 13 using a circuit simulator will be described. Similar to the basic configuration of FIG. 1, the temperature compensation by the circuit 30 is quadratic function compensation, and after the compensation, the locus draws a cubic function curve. First, FIG. 14 shows a change in the output current when the temperature around the circuit in the temperature compensation circuit 30 is changed in the range of −55 to 125 ° C. The graph of FIG. 14 shows the range of the output current value obtained when the power supply voltage (V _H −V _L ) is changed from 1 V to 10 V in light black. As shown in FIG. 14, the output current value is in the range of approximately 99.87 to 10.14 μA, the output current fluctuation range is approximately 0.3%, and the temperature coefficient ΔTC is approximately 20 ppm / degree. .

Next, FIGS. 15 to 18 show changes in the output voltages V _{REF1 to} V _REF4 when the circuit ambient temperature is changed in the range of −55 to 125 ° C. in the temperature compensation circuit 30. FIG. The load resistances R _{REF1 to} R _REF4 are 1 kΩ, 5 kΩ, 466.7 Ω, 10.066 kΩ, respectively, and the range of output voltage values obtained when the power supply voltage (V _H −V _L ) is changed from 1 V to 10 V is set. Shown in light ink. As shown in FIGS. 15 to 18, the output voltage values are generally V _REF1 = 99.87 to 10.14 mV, V _REF2 = 53.23 to 53.48 mV, and V _REF3 = 99.85 to _100.2 mV. , V _REF4 = 498.7 to _501.2 mV, it was confirmed that a highly accurate value was obtained. For V _REF5, it is considered that a value substantially equivalent to V _REF4 can be obtained on condition that the characteristic of Q7 is comparable to that of Q6.

Next, FIGS. 19 and 20 _{show the} frequency and power supply voltage fluctuation rejection ratio (PSRR ₎ relating to the output voltages V _REF1 and V _REF4 when the circuit ambient temperature is changed in the range of −55 to 125 ° C. in the temperature compensation circuit 30. ). FIG. 19 shows the case where the output voltage V _REF1 = 100 mV (R _REF1 = 1 kΩ), and FIG. 20 shows the case where the output voltage V _REF4 = 500 mV (R _REF4 = 10.066 kΩ). 19 and 20 show a comparison of the effect of adding a capacitance element CL (1 nF and 100 nF) in parallel with the load resistance RL for compensating for the decrease in PSRR in the frequency region of 10 Hz or higher. Yes.
As is well known, PSRR represents the ability to remove voltage fluctuations in a device when there is a fluctuation in the input supply voltage for that device,
PSRR (dB) = 20 log (ΔVsupply / ΔVout)
Can be expressed as ΔVsupply is a fluctuation of the power supply voltage, and ΔVout is a fluctuation of the output voltage of the target device.
Referring to FIG. 19, in the region where the input frequency is DC to 1 Hz, the temperature compensation circuit 30 of FIG. 13 shows a value of about −120 dB with respect to V _REF1 . This figure shows that it is possible to suppress variation in power supply voltage to approximately 1/10 ^6. Referring to FIG. 20, in the region where the input frequency is DC to 10 Hz or less, the temperature compensation circuit 30 of FIG. 13 shows a value of about −90 _{dB with} respect to V _REF4 . This indicates that the fluctuation of the power supply voltage can be suppressed to approximately 1/10 ⁵ to 1/10 ⁴ .

  As described above, according to the temperature compensation circuit 30 of the present embodiment, it is possible to obtain a highly accurate current source and voltage source that are not easily affected by temperature changes.

In the examples of FIGS. 12 and 13, the PNP transistor is arranged on the V _H side and the NPN transistor is arranged on the V _L side, but may be reversed in accordance with the corresponding arrangement of Q1 to Q4. In FIG. 13, the circuits of the reference voltages V _{REF1 to} V _{REF3 and} the circuits of V _REF4 and V _REF5 can be provided independently, and either of them may be provided alone.

  The present invention is not limited to the embodiments described above, and includes various modifications. 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 Q7 Transistor C1 Capacitance elements R _P , R _N , R 1, R _L , R _{REF1 to} R _REF5 Resistance elements

Claims (3)

Comprising first to fifth transistors, and first and second resistance elements;
The bases of the first and second transistors are connected to each other,
The bases of the third and fourth transistors are connected to each other,
The collector of the first transistor and the collector of the third transistor are connected;
The collector of the second transistor and the collector of the fourth transistor are connected;
The collector of the fifth transistor is connected to the bases of the first and second transistors;
The base of the fifth transistor is connected to the collector of the first transistor and the collector of the third transistor;
The emitter of the fifth transistor is connected to the emitter of the fourth transistor;
The emitters of the first and second transistors are connected to the positive power supply line,
The emitters of the third and fourth transistors are connected to the negative power supply line,
The base and collector of the fourth transistor are connected,
A first resistance element is connected between the collector and emitter of the fourth transistor;
A second resistance element is connected between the emitter of the fourth transistor and the negative power supply line;
A third resistance element is connected between the second resistance element and the negative power supply line, and the voltage between the terminals of the second resistance element, the voltage between the terminals of the third resistance element, and the first The voltage across the series circuit of the second resistance element and the third resistance element is configured to be taken out as a reference voltage ,
The first resistive element is a resistor that determines negative temperature versus current;
The second resistive element is a resistor that determines positive temperature versus current;
Temperature compensation circuit. Comprising first to fifth transistors, and first and second resistance elements;
The bases of the first and second transistors are connected to each other,
The bases of the third and fourth transistors are connected to each other,
The collector of the first transistor and the collector of the third transistor are connected;
The collector of the second transistor and the collector of the fourth transistor are connected;
The collector of the fifth transistor is connected to the bases of the first and second transistors;
The base of the fifth transistor is connected to the collector of the first transistor and the collector of the third transistor;
The emitter of the fifth transistor is connected to the emitter of the fourth transistor;
The emitters of the first and second transistors are connected to the positive power supply line,
The emitters of the third and fourth transistors are connected to the negative power supply line,
The base and collector of the fourth transistor are connected,
A first resistance element is connected between the collector and emitter of the fourth transistor;
A second resistance element is connected between the emitter of the fourth transistor and the negative power supply line;
A sixth transistor operating in synchronization with the first transistor, the transistor having an emitter connected to the positive power supply line and a collector connected to the negative power supply line via a fourth resistance element; The terminal voltage of the fourth resistance element is taken out as a reference voltage ,
The first resistive element is a resistor that determines negative temperature versus current;
The second resistive element is a resistor that determines positive temperature versus current;
Temperature compensation circuit. Comprising first to fifth transistors, and first and second resistance elements;
The bases of the first and second transistors are connected to each other,
The bases of the third and fourth transistors are connected to each other,
The collector of the first transistor and the collector of the third transistor are connected, the collector of the second transistor and the collector of the fourth transistor are connected,
The collector of the fifth transistor is connected to the bases of the first and second transistors;
The base of the fifth transistor is connected to the collector of the first transistor and the collector of the third transistor;
The emitter of the fifth transistor is connected to the emitter of the fourth transistor;
The emitters of the first and second transistors are connected to the positive power supply line,
The emitters of the third and fourth transistors are connected to the negative power supply line,
The base and collector of the fourth transistor are connected,
A first resistance element is connected between the collector and emitter of the fourth transistor;
A second resistance element is connected between the emitter of the fourth transistor and the negative power supply line;
A seventh transistor operating in synchronization with the third transistor, the emitter of which is connected to the negative power supply line and the collector of which is connected to the positive power supply line via a fifth resistor element; The terminal voltage of the fifth resistance element is taken out as a reference voltage ,
The first resistive element is a resistor that determines negative temperature versus current;
The second resistive element is a resistor that determines positive temperature versus current;
Temperature compensation circuit.

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