Constant current circuit

Abstract

To provide a constant current circuit capable of outputting a current in which an influence of a current amplification factor of a transistor is reduced.SOLUTION: A base current duplication circuit 3C duplicates a base current IBR of a transistor Tr2. A transistor MP4 duplicates a collector current IC of the transistor Tr2. The base current IBR duplicated by the base current duplication circuit 3C and the collector current IC duplicated by the transistor MP4 are added so as to be output as a PTAT current Iptat having a positive temperature characteristic. The base current duplication circuit 3C duplicates a sum (=2×IBR) of the base currents IBR of the transistors Tr1 and Tr2 and supplies the sum to bases of the transistors Tr1 and Tr2. A transistor MP8 duplicates a drain current of a transistor MP1 and outputs it as a CTAT current Ictat having a negative temperature characteristic. The PTAT current Iptat and the CTAT current Ictat are added to output a constant output current Iout with respect to a temperature.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a constant current circuit. [Background technology]

[0002] A known conventional constant current circuit is one that outputs a current having a positive temperature characteristic as shown in Fig. 4. This constant current circuit 100 is composed of a so-called BGR (Band Gap Reference) circuit, and the area ratio of two transistors Tr1 and Tr2 is set to 1:N. Furthermore, a current mirror circuit 21 supplies equal collector currents IC to the two transistors Tr1 and Tr2. The emitter currents IE of the above-mentioned transistors Tr1 and Tr2 are independent of the power supply VDD and have a positive temperature characteristic.

[0003] The conventional constant current circuit 100 shown in FIG. 4 replicates the collector current IC flowing through the transistors Tr1 and Tr2, and outputs it as a current having a positive temperature characteristic.

[0004] The emitter current IE can be expressed by the following equation (1) or (2).

[0005]

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[0006] Vbe1: base-emitter voltage of transistor Tr1, Vbe2: base-emitter voltage of transistor Tr2, R2: resistance value of resistor R2

[0007]

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[0008] IC: collector current of transistor Tr2, IBR: base current of transistor Tr2, βf: current amplification factor of transistor Tr2

[0009] By transforming equations (1) and (2), we obtain the following equation (3).

[0010]

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[0011] The current gain βf has temperature characteristics. Therefore, there is a problem that the collector current IC does not accurately have a positive temperature characteristic due to the influence of the temperature characteristics of the current gain βf.

[0012] Patent Document 1 proposes a circuit for canceling the influence of the current amplification factor βf in a constant voltage circuit that outputs a positive temperature characteristic, but this cannot be applied to a constant current source circuit.

[0013] As another conventional constant current circuit, a constant current circuit that outputs a current having a negative temperature characteristic as shown in Fig. 5 is known (Patent Document 2). This constant current circuit 101 is composed of a BGR circuit, as in Fig. 4, and is provided so that the area ratio of two transistors Tr1 and Tr2 is 1:N. A current mirror circuit 21 supplies equal collector currents IC to the two transistors Tr1 and Tr2.

[0014] The bases of transistors Tr1 and Tr2 are connected together, and a bandgap voltage VREF is supplied by dividing the power supply VDD using transistor MP1 and resistor R3. This bandgap voltage VREF is a constant voltage that is independent of temperature. Also, since resistor R3 has a positive temperature coefficient, the current IREF that flows through resistor R3 is independent of the power supply VDD and has a negative temperature characteristic.

[0015] In the conventional constant current circuit 101 shown in FIG. 5, the drain current ID of the transistor MP1 is replicated and output as a current having a negative temperature characteristic.

[0016] The drain current ID can be expressed by the following equation (4).

[0017]

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[0018] The base current IBR of each of the transistors Tr1 and Tr2 can be expressed by the following equation (5).

[0019]

number

[0020] Therefore, the drain current ID is expressed by the following equation (6).

[0021]

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[0022] The current gain βf has temperature characteristics. Therefore, there is a problem that the drain current ID does not accurately have a negative temperature characteristic due to the influence of the current gain βf. [Prior art documents] [Patent documents]

[0023] [Patent Document 1] European Patent No. 1792245 [Patent Document 2] US Patent Application Publication No. 2015 / 0227156 Summary of the Invention [Problem to be solved by the invention]

[0024] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a constant current circuit that can output a current with reduced influence of the current amplification factor of a transistor. [Means for solving the problem]

[0025] In order to achieve the above object, the constant current circuit according to the present invention comprises the following features [1] to [ 5 ] is one of its features. [1] a bandgap reference circuit including a first transistor and a second transistor whose bases are connected to each other, in which a PTAT current having a positive temperature characteristic flows through an emitter of the second transistor; a first current replicating circuit for replicating the base current of the second transistor; a second current replica circuit that replicates the collector current of the second transistor; A current obtained by adding the base current replicated by the first current replica circuit and the collector current replicated by the second current replica circuit is output as the PTAT current. death, the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the first current duplicating circuit includes a fourth transistor connected to the first current mirror circuit in a current mirror manner and duplicating the collector current, a fifth transistor having an area equal to that of the second transistor and having a collector to which the collector current duplicated by the fourth transistor is supplied, a base current compensation transistor forming a negative feedback circuit together with the fifth transistor and supplying a base current of the fifth transistor, and a second current mirror circuit duplicating the base current of the fifth transistor; the second current mirror circuit includes a sixth transistor that is current mirror connected to the first current mirror circuit and replicates the collector current; It is a constant current circuit. [ 2 ] a bandgap reference circuit including a first transistor and a second transistor whose bases are connected to each other, a first resistor to which a bandgap voltage generated at the bases of the first transistor and the second transistor is applied, and a third transistor connected in series to a high potential side of the first resistor, wherein a CTAT current having a negative temperature characteristic flows through the first resistor; a third current duplicating circuit that duplicates the sum of the base currents of the first transistor and the second transistor and supplies the duplicated sum to the bases of the first transistor and the second transistor; a fourth current replica circuit that replicates the current flowing through the third transistor as the CTAT current and outputs the replicated current. picture, the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the third current mirror circuit includes a fourth transistor connected to the first current mirror circuit in a current mirror manner and duplicating the collector current, a fifth transistor having an area equal to that of the second transistor and having a collector to which the collector current duplicated by the fourth transistor is supplied, a base current compensation transistor forming a negative feedback circuit together with the fifth transistor and supplying a base current of the fifth transistor, and a third current mirror circuit duplicating a current twice the base current of the fifth transistor; the fourth current replica circuit includes a seventh transistor replicating a current flowing through the third transistor; It is a constant current circuit. [ 3 ] a bandgap reference circuit including a first transistor and a second transistor whose bases are connected to each other, a first resistor to which a bandgap voltage generated at the bases of the first transistor and the second transistor is applied, and a third transistor connected in series to a high potential side of the first resistor, in which a PTAT current having a positive temperature characteristic flows in the emitter of the second transistor and a CTAT current having a negative temperature characteristic flows in the first resistor; a first current replicating circuit for replicating the base current of the second transistor; a second current replicating circuit for replicating the collector current of the second transistor; a third current duplicating circuit that duplicates the sum of the base currents of the first transistor and the second transistor and supplies the duplicated sum to the bases of the first transistor and the second transistor; a fourth current duplicating circuit that duplicates the current flowing through the third transistor as the CTAT current and outputs the duplicated current; a current obtained by adding the base current replicated by the first current replica circuit and the collector current replicated by the second current replica circuit is replicated as the PTAT current, and a sum of the replicated PTAT current and the CTAT current replicated by the fourth current replica circuit is output as an output current. It is a constant current circuit. [ 4 ] [ 3 In the constant current circuit according to the present invention, the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the first current duplicating circuit includes a fourth transistor that is current mirror connected to the first current mirror circuit and that duplicates the collector current, a fifth transistor that has an area equal to that of the second transistor and whose collector is supplied with the collector current duplicated by the fourth transistor, an eighth transistor through which a base current of the fifth transistor flows, and a ninth transistor that is current mirror connected to the eighth transistor and that duplicates the base current, the second current mirror circuit includes a sixth transistor that is current mirror connected to the first current mirror circuit and that replicates the collector current; the third current replicating circuit includes a tenth transistor connected to the eighth transistor in a current mirror configuration and replicating a current twice the base current; the fourth current replica circuit includes a seventh transistor replicating a current flowing through the third transistor; It is a constant current circuit. [ 5 ] [1]~[ 4] 13. The constant current circuit according to claim 12, the first transistor and the second transistor are bipolar transistors with an area ratio of 1:N, and a collector and an emitter are connected between a high potential power supply and a low potential power supply; the bandgap reference circuit includes a second resistor connected between the emitter of the second transistor and the low potential power supply, the second resistor having one end on the low potential power supply side connected to the emitter of the first transistor; It is a constant current circuit. Effect of the Invention

[0026] According to the present invention, it is possible to provide a constant current circuit capable of outputting a current with reduced influence of the current amplification factor of a transistor.

[0027] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a circuit diagram showing a constant current circuit according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a circuit diagram showing a constant current circuit according to a second embodiment of the present invention. [Diagram 3] FIG. 3 is a circuit diagram showing a constant current circuit according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a circuit diagram showing an example of a conventional constant current circuit. [Diagram 5] FIG. 5 is a circuit diagram showing an example of a conventional constant current circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] (First embodiment) A first specific embodiment of the present invention will be described below with reference to the drawings.

[0030] Fig. 1 is a circuit diagram showing a constant current circuit in the first embodiment. The constant current circuit 1 shown in Fig. 1 outputs a PTAT (Proportional To Absolute Temperature) current Iptat having a positive temperature characteristic with respect to temperature from an output terminal Tout, without depending on fluctuations in a power supply VDD. The constant current circuit 1 includes a band gap reference circuit (hereinafter abbreviated as "BGR circuit") 2, a transistor MP4 as a second current replica circuit, and a base current replica circuit 3 as a first current replica circuit.

[0031] The BGR circuit 2 includes transistors Tr1 and Tr2 as the first and second transistors, resistors R1 and R2, a transistor MP1 functioning as a third transistor, a resistor R3 functioning as a first resistor, and a current mirror circuit 21 functioning as a first current mirror circuit. The transistors Tr1 and Tr2 are composed of NPN-type bipolar transistors. The area ratio of the transistors Tr1 and Tr2 is set to 1:N. The resistors R1 and R2 have a positive temperature coefficient. The resistors R1 and R2 are connected in series between the emitter of the transistor Tr2 and the ground as a low-potential power supply. The connection point of the resistors R1 and R2 is connected to the emitter of the transistor Tr1. The resistor R2 functions as a second resistor. The bases of the transistors Tr1 and Tr2 are connected to each other. This makes it possible to obtain Vbe1=Vbe2+R2×IE. Vbe1 is the emitter-base voltage of the transistor Tr1, and Vbe2 is the emitter-base voltage of the transistor Tr2.

[0032] The PMOS transistor MP1 has a gate connected to the collector of the transistor Tr2, a source connected to a power supply VDD as a high potential power supply, and a drain connected to one end of the resistor R3 and the bases of both the transistors Tr1 and Tr2. The voltage obtained by dividing the power supply VDD by the transistor MP1 and the resistor R3 is supplied to the bases of the transistors Tr1 and Tr2.

[0033] The current mirror circuit 21 has PMOS transistors MP2 and MP3. The source of the transistor MP2 is connected to the power supply VDD, and the gate and drain are connected to the collector of the transistor Tr1. The gate of the transistor MP3 is connected to the gate and drain of the transistor MP2, the source is connected to the power supply VDD, and the drain is connected to the collector of the transistor Tr2. These transistors MP2 and MP3 supply the same collector current IC to the transistors Tr1 and Tr2, making the emitter currents IE equal.

[0034] According to the above-described BGR circuit 2, when the emitter currents IE of the transistors Tr1 and Tr2 are made equal to each other and Vbe1=Vbe2+R2×IE, the emitter current IE becomes a current that has a positive temperature characteristic and is not dependent on fluctuations in the power supply VDD.

[0035] The transistor MP4 functions as a sixth transistor and is connected in a current mirror circuit 21. To explain in detail, the transistor MP4 has a gate connected to the gate of the transistor MP2, a source connected to the power supply VDD, and a drain connected to the output terminal Tout. The transistor MP4 replicates the collector current IC of the transistors Tr1 and Tr2 and supplies it to the output terminal Tout.

[0036] The base current duplication circuit 3 is a circuit that duplicates the base current IBR of the transistors Tr1 and Tr2 and supplies it to the output terminal Tout. The base current duplication circuit 3 includes a PMOS transistor MP5, a transistor Tr3, an NMOS transistor MN1, and PMOS transistors MP6 and MP7. The transistor MP5 functions as a fourth transistor and is current-mirror-connected to the current mirror circuit 21. More specifically, the gate of the transistor MP5 is connected to the gate of the transistor MP2, and the source is connected to the power supply VDD. The collector current IC flowing through the transistor MP2 is copied to the transistor MP5.

[0037] The collector of transistor Tr3 is connected to the drain of transistor MP5, and the emitter is connected to ground. This causes transistor Tr3 to function as a fifth transistor, and a collector current IC is supplied from transistor MP5. Transistor Tr3 is also an NPN transistor like transistor Tr2, and is configured to have the same area as transistor Tr2. This causes the base current IBR of transistor Tr3 to be equal to the base current IBR of transistor Tr2.

[0038] The base of transistor MN1 is connected to the collector of transistor Tr3, and the source is connected to the base of transistor Tr3. Transistor MN1 functions as a base current compensation transistor, and a negative feedback circuit is formed by transistors Tr3 and MN1. This negative feedback circuit supplies the base current of transistor Tr3 from transistor MN1, a collector current IC from transistor MP5 flows to transistor Tr3, and a current equal to the base current IBR of transistors Tr2 and Tr3 flows in transistor MN1. Note that the base current compensation transistor can also be configured with an NPN-type bipolar transistor, but an NMOS-type transistor MN1 as in this embodiment has no base current error and can accurately replicate the base current IBR.

[0039] The transistors MP6 and MP7 are connected as a current mirror to form a second current mirror circuit. The transistor MP6 functions as an eighth transistor, with its drain and gate connected to the drain of the transistor MN1 and its source connected to the power supply VDD. The gate of the transistor MP7 functions as a ninth transistor, with its gate connected to the gate and drain of the transistor MP6, its source connected to the power supply VDD, and its drain connected to the output terminal Tout.

[0040] As a result, the base current IBR flowing through transistor MN1 is copied to transistor MP7 and supplied to the output terminal Tout. The current obtained by adding together the collector current IC of transistors Tr1 and Tr2 and the base current IBR of transistors Tr1 and Tr2, i.e., the emitter current IE of transistors Tr1 and Tr2, is output from the output terminal Tout as the PTAT current Iptat.

[0041] The above-mentioned collector current IC is expressed by the following equation (7) from equation (3) explained in the background art above, and an error occurs due to the current amplification factor βf of transistor Tr2.

[0042]

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[0043] The base current IBR of the transistor Tr2 replicated by the base current replica circuit 3 can be expressed by the following equation (8).

[0044]

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[0045] Therefore, the PTAT current Iptat, which is the sum of the collector current IC and the base current IBR, can be expressed by the following equation (9).

[0046]

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[0047] As is clear from equation (9), the PTAT current Iptat has accurate positive temperature characteristics that are not affected by βf.

[0048] Second embodiment Next, a constant current circuit of the present invention in a second embodiment will be described with reference to FIG. 2. The constant current circuit shown in FIG. 2 outputs a CTAT (Complementary to Absolute Temperature) current Ictat having a negative temperature characteristic with respect to temperature from an output terminal Tout, independent of fluctuations in the power supply VDD. The constant current circuit 1B includes a BGR circuit 2, a transistor MP8 as a fourth current duplication circuit, and a base current duplication circuit 3B as a third current duplication circuit. In FIG. 2, parts equivalent to those in the constant current circuit shown in FIG. 1 already described in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0049] The BGR circuit 2 is equivalent to that of the first embodiment described above, and therefore a detailed description thereof will be omitted. According to the BGR circuit 2 described above, when the emitter currents IE of the transistors Tr1 and Tr2 are made equal to each other and Vbe1=Vbe2+R2×IE is set, the base voltages of the transistors Tr1 and Tr2 become a bandgap voltage VREF that is constant with respect to temperature. The bandgap voltage VREF does not depend on the fluctuation of the power supply VDD. The resistor R3 has a resistance value with a positive temperature coefficient with respect to temperature. Therefore, the current IREF flowing through the resistor R3 has a negative temperature characteristic.

[0050] The PMOS transistor MP8 functions as a seventh transistor, with its gate connected to the gate of the transistor MP1, its source connected to the source of the transistor MP1, and its drain connected to the output terminal Tout. The drain current ID of the transistor MP1 is replicated by the transistor MP8 and output from the output terminal Tout as the CTAT current Ictat.

[0051] The base current duplication circuit 3B is a circuit that duplicates the sum (=2×IBR) of the base currents IBR of the transistors Tr1 and Tr2 and supplies the duplicated current to the bases of the transistors Tr1 and Tr2. The base current duplication circuit 3B includes a PMOS transistor MP5, a transistor Tr3, an NMOS transistor MN1, and PMOS transistors MP6 and MP9. The connections of the transistor MP5, the transistor Tr3, and the transistors MN1 and MP6 are the same as those of the constant current circuit 1 of FIG. 1 already described in the first embodiment, and therefore will not be described in detail here.

[0052] The transistors MP6 and MP9 are connected as a current mirror to form a third current mirror circuit. The drain and gate of the transistor MP6 are connected to the drain of the transistor MN1, and the source is connected to the power supply VDD. The gate of the transistor MP9 functioning as the tenth transistor is connected to the gate and drain of the transistor MP6, its source is connected to the power supply VDD, and its drain is connected to the bases of the transistors Tr1 and Tr2. The area ratio of the transistors MP6 and MP9 is set to 1:2.

[0053] As a result, a current 2×IBR, which is twice the base current IBR flowing through transistor MN1, is copied to transistor MP9 and supplied to the bases of transistors Tr1 and Tr2. This makes it possible to make the drain current ID of transistor MP1 equal to the current IREF flowing through resistor R3, and the current IREF is output as the CTAT current Ictat.

[0054] The base current IBR of the above-mentioned transistor Tr2 is expressed by equation (10), as described in the background art above.

[0055]

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[0056] Further, the drain current ID of the transistor MP1, the base current IBR of the transistors Tr1 and Tr2, and the current IREF flowing through the resistor R3 are expressed by the following equation (11). ID+2×IBR=IREF+2×IBR …(11) Therefore, the CTAT current Ictat can be expressed by the following equation (12).

[0057]

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[0058] As is clear from equation (12), the CTAT current Ictat has a highly accurate negative temperature characteristic that is not affected by βf.

[0059] Third embodiment Next, a constant current circuit of the present invention in a third embodiment will be described with reference to FIG. 3. The constant current circuit 1C shown in FIG. 3 outputs an output current Iout from an output terminal Tout that is independent of fluctuations in the power supply VDD and temperature. The constant current circuit 1C includes a BGR circuit 2, transistors MP4 and MP8, and a base current duplication circuit 3C as a first current duplication circuit and a third current duplication circuit. In FIG. 2, parts equivalent to the constant current circuits 1 and 1B shown in FIG. 1 and FIG. 2 already described in the first and second embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0060] The BGR circuit 2 is the same as the first and second embodiments described above, and therefore a detailed description thereof will be omitted. According to the above-described BGR circuit 2, the emitter current IE of the transistors Tr1 and Tr2 has a positive temperature characteristic, and the current IREF flowing through the resistor R3 has a negative temperature characteristic.

[0061] The base current duplication circuit 3C duplicates the base current IBR of the transistors Tr1 and Tr2 and supplies it to the output terminal Tout, and duplicates the base current 2×IBR, which is twice the current, and supplies it to the bases of the transistors Tr1 and Tr2. The base current duplication circuit 3C includes a PMOS transistor MP5, a transistor Tr3, an NMOS transistor MN1, and PMOS transistors MP6, MP7, and MP9.

[0062] The transistors MP5, Tr3, MP6, and MP7 are connected in the same manner as in the first embodiment shown in Fig. 1, and therefore detailed description thereof will be omitted here. The base current IBR of the transistors Tr1 and Tr2 is duplicated in the transistor MP7 and supplied to the output terminal Tout.

[0063] The transistor MP9 is connected in the same manner as in the second embodiment shown in Fig. 2, and therefore a detailed description thereof will be omitted here. A current 2 × IBR, which is twice the base current IBR of the transistors Tr1 and Tr2, is duplicated in the transistor MP9 and supplied to the bases of the transistors Tr1 and Tr2.

[0064] According to the above configuration, the sum of the PTAT current Ipata, which has a positive temperature characteristic and is not affected by βf, and the CTAT current Ictat, which has a negative temperature characteristic, is output as the output current Iout to the output terminal Vout, as shown in the following equation (13). The output current Iout is not affected by βf or the power supply VDD, and is a constant current regardless of temperature.

[0065]

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[0066] In addition, according to the above-described configuration, the first current duplication circuit that duplicates the base current IBR of transistor Tr2 and the third current duplication circuit that duplicates the sum of the base currents (=2×IBR) flowing through transistors Tr1 and Tr2, respectively, can share transistors MP5, Tr3, MN1, and MP6, thereby simplifying the configuration. [Explanation of symbols]

[0067] 1, 1B, 1C constant current circuit 2 BGR (Bandgap Reference) Circuit 3 Base current duplication circuit (first current duplication circuit) 3B Base current replica circuit (3rd current replica circuit) 3C Base current duplication circuit (first current duplication circuit, third current duplication circuit) 21 Current mirror circuit (first current mirror circuit) IBR Base Current IC Collector current Ictat CTAT current Iout Output current Iptat PTAT current MN1 transistor (base current compensation transistor) MP1 transistor (third transistor) MP4 transistor (second current replica circuit, sixth transistor) MP5 Transistor (4th Transistor) MP6 transistor (second current mirror circuit, third current mirror circuit, eighth transistor) MP7 transistor (second current mirror circuit, ninth transistor) MP8 transistor (4th current replica circuit, 7th transistor) MP9 transistor (third current mirror circuit, tenth transistor) R1 Resistor R2 resistance (second resistance) R3 resistance (1st resistance) Tr1 Transistor (first transistor) Tr2 Transistor (Second Transistor) Tr3 transistor (5th transistor) VDD power supply (high potential power supply) VREF bandgap voltage

Claims

1. a bandgap reference circuit including a first transistor and a second transistor whose bases are connected to each other, in which a PTAT current having a positive temperature characteristic flows through the emitter of the second transistor; a first current replicating circuit for replicating the base current of the second transistor; a second current duplicating circuit for duplicating the collector current of the second transistor; a current obtained by adding the base current replicated by the first current replica circuit and the collector current replicated by the second current replica circuit is output as the PTAT current; the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the first current duplicating circuit includes a fourth transistor connected to the first current mirror circuit in a current mirror manner and duplicating the collector current; a fifth transistor having an area equal to that of the second transistor and having a collector to which the collector current duplicated by the fourth transistor is supplied; a base current compensation transistor forming a negative feedback circuit together with the fifth transistor and supplying a base current of the fifth transistor; and a second current mirror circuit duplicating the base current of the fifth transistor; the second current mirror circuit includes a sixth transistor that is current mirror connected to the first current mirror circuit and replicates the collector current; Constant current circuit.

2. a bandgap reference circuit including a first transistor and a second transistor whose bases are connected to each other, a first resistor to which a bandgap voltage generated at the bases of the first transistor and the second transistor is applied, and a third transistor connected in series to a high potential side of the first resistor, wherein a CTAT current having a negative temperature characteristic flows through the first resistor; a third current duplicating circuit that duplicates the sum of the base currents of the first transistor and the second transistor and supplies the duplicated sum to the bases of the first transistor and the second transistor; a fourth current duplicating circuit that duplicates the current flowing through the third transistor as the CTAT current and outputs the duplicated current; the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the third current mirror circuit includes a fourth transistor connected to the first current mirror circuit in a current mirror manner and duplicating the collector current; a fifth transistor having an area equal to that of the second transistor and having a collector to which the collector current duplicated by the fourth transistor is supplied; a base current compensation transistor forming a negative feedback circuit together with the fifth transistor and supplying a base current of the fifth transistor; and a third current mirror circuit duplicating a current twice as large as the base current of the fifth transistor; the fourth current replica circuit includes a seventh transistor replicating a current flowing through the third transistor; Constant current circuit.

3. a bandgap reference circuit including a first transistor and a second transistor having bases connected to each other, a first resistor to which a bandgap voltage generated at the bases of the first transistor and the second transistor is applied, and a third transistor connected in series to a high potential side of the first resistor, in which a PTAT current having a positive temperature characteristic flows through the emitter of the second transistor and a CTAT current having a negative temperature characteristic flows through the first resistor; a first current replicating circuit for replicating the base current of the second transistor; a second current replicating circuit for replicating the collector current of the second transistor; a third current duplicating circuit that duplicates the sum of the base currents of the first transistor and the second transistor and supplies the duplicated sum to the bases of the first transistor and the second transistor; a fourth current duplicating circuit that duplicates the current flowing through the third transistor as the CTAT current and outputs the duplicated current; a current obtained by adding the base current replicated by the first current replica circuit and the collector current replicated by the second current replica circuit is replicated as the PTAT current, and a sum of the replicated PTAT current and the CTAT current replicated by the fourth current replica circuit is output as an output current. Constant current circuit.

4. 4. The constant current circuit according to claim 3, the bandgap reference circuit includes a first current mirror circuit that supplies equal collector currents to the collectors of the first transistor and the second transistor; the first current duplication circuit includes a fourth transistor that is current mirror connected to the first current mirror circuit and duplicates the collector current, a fifth transistor that has an area equal to that of the second transistor and whose collector is supplied with the collector current duplicated by the fourth transistor, an eighth transistor through which a base current of the fifth transistor flows, and a ninth transistor that is current mirror connected to the eighth transistor and duplicates the base current, the second current mirror circuit includes a sixth transistor that is current mirror connected to the first current mirror circuit and that replicates the collector current; the third current replicating circuit includes a tenth transistor connected to the eighth transistor in a current mirror configuration and replicating a current twice the base current; the fourth current replica circuit includes a seventh transistor replicating a current flowing through the third transistor; Constant current circuit.

5. The constant current circuit according to any one of claims 1 to 4, the first transistor and the second transistor are bipolar transistors with an area ratio of 1:N, and a collector and an emitter are connected between a high potential power supply and a low potential power supply; the bandgap reference circuit includes a second resistor connected between the emitter of the second transistor and the low potential power supply, the second resistor having one end on the low potential power supply side connected to the emitter of the first transistor; Constant current circuit.

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