Constant voltage source circuit

Abstract

This constant voltage source circuit is provided with a resistor (R1) with one end connected to a power supply voltage (VCC), an element (Zp) with one end connected to the other end of the resistor (R1), an element (Zn) with one end connected to the other end of the element (Zp) and the other end connected to the ground, and a differential amplifier (A1) with a non-inverting input terminal connected to a connection point between the resistor (R1) and the element (Zp), and an inverting input terminal connected to the other end of the element (Zn). One of the element (Zp) and the element (Zn) causes a voltage drop having a positive temperature coefficient, and the other one of the element (Zp) and the element (Zn) causes a voltage drop having a negative temperature coefficient.

Description

Constant voltage source circuit

[0001] The present invention relates to a constant voltage source circuit that outputs a reference voltage.

[0002] A reference voltage is required for circuit operation. A constant voltage source circuit that outputs a reference voltage must be stable against changes in both power supply voltage and temperature. A BGR (Bandgap Reference) circuit is one circuit that achieves this performance. A BGR circuit combines a voltage with a negative temperature coefficient and a voltage with a positive temperature coefficient to compensate for temperature characteristics and generate a reference voltage that is independent of temperature.

[0003] The configuration of a conventional BGR circuit disclosed in Non-Patent Document 1 is shown in FIG. １００ , Q １０１ and operational amplifier OP １００ and resistance R １００ ~R １０２ In this circuit, a voltage with a negative temperature coefficient is generated by the transistor Q １００ Base-emitter voltage V ＢＥ is used.

[0004] Two transistors Q １００ , Q １０１ When these transistors Q operate at different current densities, １００ , Q １０１ The difference in base-emitter voltage ΔV ＢＥ is proportional to the absolute temperature. ＢＥ is used as a voltage with a positive temperature coefficient. １００ , Q １０１ In order to operate the transistor Q at different current densities, １００ The emitter area of ​​the transistor Q １０１ The emitter area is larger than that of the operational amplifier OP １００ Output voltage V ＲＥＦ is expressed as equation (1). ＲＥＦ =V ＢＥ + (1 + R １０１ / R １００ ) ΔV ＢＥ ...(1)

[0005] The conventional BGR circuit uses two transistors Q with different current densities. １００ , Q １０１ In the example of Figure 12, the current I １ The path through which the current I flows ２ Therefore, it was difficult to reduce the power consumption of the circuit.

[0006] In the example of FIG. 12, the transistor Q １００ The emitter area of ​​transistor Q １０１ However, to accurately adjust the temperature coefficient, it is necessary to adjust the total emitter area by changing the number of parallel transistors with the same emitter length, rather than by changing the emitter length of a single transistor. This makes it difficult to reduce the circuit area.

[0007] Bang-Sup Song, et al., “A Precision Curvature-CompensatedCMOS Bandgap Reference”, IEEE JOURNAL OF SOLID-STATECIRCUITS, vol.18, no.6, DECEMBER 1983

[0008] The present invention has been made to solve the above-mentioned problems, and has an object to provide a constant voltage source circuit that is small in area and low in power consumption and that is capable of compensating for temperature characteristics with a single current path.

[0009] The constant voltage source circuit of the present invention comprises a first resistor having one end connected to a first power supply voltage, a first element having one end connected to the other end of the first resistor, a second element having one end connected to the other end of the first element and the other end connected to a second power supply voltage, and a differential amplifier having a positive phase input terminal connected to the connection point between the first resistor and the first element and a negative phase input terminal connected to the other end of the second element, wherein one of the first element and the second element generates a voltage drop having a positive temperature coefficient, and the other of the first element and the second element generates a voltage drop having a negative temperature coefficient.

[0010] According to the present invention, first and second elements are connected in series between a first power supply voltage and a second power supply voltage, one of which generates a voltage drop with a positive temperature coefficient and the other of which generates a voltage drop with a negative temperature coefficient, and the voltages across the first and second elements are input to a differential amplifier, thereby unifying the current path in the core portion of the circuit.As a result, the present invention can realize a constant voltage supply circuit that is small in area and low in power consumption.The use of the constant voltage supply circuit of the present invention can improve the performance of comparators, current mirrors, etc.

[0011] FIG. 1 is a circuit diagram showing the configuration of a constant voltage source circuit according to a first embodiment of the present invention. FIG. 2 is a circuit diagram showing another configuration of the constant voltage source circuit according to the first embodiment of the present invention. FIG. 3 is a circuit diagram showing another configuration of the constant voltage source circuit according to the first embodiment of the present invention. FIG. 4 is a circuit diagram showing the configuration of a constant voltage source circuit according to a second embodiment of the present invention. FIG. 5 is a circuit diagram showing the configuration of a current source according to the second embodiment of the present invention. FIG. 6 is a circuit diagram showing the configuration of a constant voltage source circuit according to a third embodiment of the present invention. FIG. 7 is a circuit diagram showing a configuration in which the input offset voltage of an operational amplifier is taken into consideration in a conventional BGR circuit. FIG. 8 is a circuit diagram showing a configuration in which the input offset voltage of an operational amplifier is taken into consideration in a constant voltage source circuit according to a third embodiment of the present invention. FIG. 9 is a circuit diagram showing the configuration of an operational amplifier according to a third embodiment of the present invention. FIG. 10 is a circuit diagram showing the configuration of a constant voltage source circuit according to a fourth embodiment of the present invention. FIG. 11 is a circuit diagram showing the output voltage V of the constant voltage source circuit according to the fourth embodiment of the present invention.ＲＥＦ 12 is a circuit diagram showing the configuration of a conventional BGR circuit.

[0012] [First embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a circuit diagram showing the configuration of a constant voltage source circuit according to a first embodiment of the present invention. The constant voltage source circuit of this embodiment has one end connected to a power supply voltage V ＣＣ Resistor R connected to (first power supply voltage) １ and one end is resistor R １ and a voltage drop V having a positive temperature coefficient is connected to the other end of Ｚｐ Element Z where ｐ And one end is element Z ｐ and the other end is connected to ground (second power supply voltage), and a voltage drop V Ｚｎ Element Z where ｎ The positive input terminal is connected to the resistor R １ and Element Z ｐ and a differential amplifier A whose inverting input terminal is connected to the ground. １ It consists of:

[0013] Voltage drop V Ｚｐ The temperature characteristic of can be expressed as equation (2), and the voltage drop V Ｚｎ The temperature characteristic of can be expressed as in equation (3), where T is the temperature. ∂V Ｚｐ / ∂T>0 ... (2) ∂V Ｚｎ / ∂T<0 ... (3)

[0014] Therefore, the voltage drop V Ｚｐ , V Ｚｎ If the temperature coefficient of satisfies equation (4), then the voltage V Ｚｐ +V Ｚｎ is independent of temperature. Ｚｐ / ∂T|=|∂V Ｚｎ / ∂T | ... (4)

[0015] Voltage drop V Ｚｐ , V Ｚｎ is element Z ｐ , Z ｎ If the current I throughＺｐ +V Ｚｎ is the power supply voltage V ＣＣ It is also independent of the resistance R １ and Element Z ｐ Voltage V at the connection point １ =V ｃｃ -R １ I=V Ｚｐ +V Ｚｎ , the power supply voltage V ＣＣ and temperature independent differential amplifier A １ and the ground potential V ２ =0 to the differential amplifier A １ The input is input to the inverted input terminal of the differential amplifier A. １ If the amplification factor of the differential amplifier is A, １ The reference voltage V ＲＥＦ is expressed as in equation (5). ＲＥＦ = A (V Ｚｐ +V Ｚｎ ) ... (5)

[0016] Thus, in this embodiment, the power supply voltage V ＣＣ and an arbitrary reference voltage V ＲＥＦ It is possible to obtain the voltage drop V Ｚｐ , V Ｚｎ is element Z ｐ , Z ｎ If the current I through the element Z is dependent on the ｎ and ground, a temperature independent current source IS １ By inserting element Z ｐ , Z ｎ The current I passing through the Ｚｐ +V Ｚｎ is the power supply voltage V ＣＣ It is independent of element Z. ｎ and current source IS １ Voltage V at the connection point ２ V ＣＳ Then, the resistance R １ and Element Z ｐ Voltage V at the connection point １ is V ｃｃ -R １ I=V ＣＳ +V Ｚｐ +V ＺｎThis becomes:

[0017] Alternatively, as shown in FIG. １ is given by the temperature independent current source IS ２ By replacing it with ｐ , Z ｎ The current I passing through the reference voltage V may be constant. ＲＥＦ is expressed as equation (5).

[0018] In the above explanation, the conditions for temperature independence were derived. However, in the design of BGRs, in addition to designs that eliminate temperature dependence, designs are also made to accommodate requirements for changes in control voltage that depend on temperature T. Specifically, because the operation of a transistor connected downstream of a constant voltage source circuit changes with temperature, there are applications in which the constant voltage source circuit is provided with a function to compensate for the temperature characteristics of the downstream transistor. In such applications, the temperature coefficient is not designed to be zero, but is intentionally left as it is, thereby optimizing the operation of the entire circuit.

[0019] In the present invention, a BGR circuit with an adjusted temperature coefficient to compensate for the temperature characteristics of the subsequent circuit is called a BGR circuit with a temperature control function. Ｚｐ / ∂T|≠|∂V Ｚｎ / ∂T|, it can be operated as a BGR circuit with a temperature control function. １ The reference voltage V ＲＥＦ is A (V Ｚｐ +V Ｚｎ ), so the voltage drop V Ｚｐ , V Ｚｎ If the temperature coefficient of the differential amplifier A is known, １ Based on the amplification factor A, the reference voltage V ＲＥＦ Therefore, the temperature coefficient of the reference voltage V ＲＥＦ It is possible to achieve a desired temperature coefficient of .

[0020] [Second Example] Next, the element Z of the first example ｐ , Z ｎ 4 is a circuit diagram showing the configuration of a constant voltage source circuit according to a second embodiment of the present invention. The constant voltage source circuit of this embodiment has a resistor R１ and one end is resistor R １ Resistor R connected to the other end ２ and the base and collector are resistors R ２ An NPN bipolar transistor Q connected to the other end of １ and one end of the transistor Q １ The other end is connected to the emitter of the resistor R １ , R ２ and transistor Q １ A current source IS that flows a constant current I １ The positive input terminal is connected to the resistor R １ and R ２ and the inverting input terminal is connected to the connection point of the transistor Q １ The emitter and current source IS １ A differential amplifier A connected to the connection point １ It consists of:

[0021] In this embodiment, the positive temperature coefficient (α[ / K], R=R ＠Ｔ＝０ Resistor R having a resistance of (1 + αT) ２ Element Z ｐ Resistance R ２ Specific examples that can realize this include resistors using metal materials such as gold and tungsten, and non-silicide N in Si-CMOS processes. ＋ Diffusion layer (Non-Silicide N ＋ Diffused) resistor, non-silicide P ＋ Diffusion layer (Non-Silicide P ＋ Examples of such resistors include a resistor using a N-type diffused metal (N-type), a resistor using an N-type well (N-type well), and the like.

[0022] Resistance R ２ When a temperature-independent current I flows through the Ｚｐ is R ２＠Ｔ＝０ I. Voltage drop V Ｚｐ Temperature coefficient of ∂V Ｚｐ / ∂T is expressed as in equation (6), and takes a positive value if α>0. Ｚｐ / ∂T = ∂(R ２ I) / ∂T = αR ２＠Ｔ＝０ I... (6)

[0023] Also, the resistance R ２ When a temperature-dependent current I flows through the Ｚｐ Temperature coefficient of ∂V Ｚｐ / ∂T is expressed as in equation (7). Ｚｐ / ∂T = ∂(R ２ I) / ∂T = (∂R ２ / ∂T)・I+R ２ · (∂I / ∂T) ... (7)

[0024] Resistance R ２ By selecting the temperature coefficient of and the temperature coefficient of the current I, the voltage drop V shown in equation (7) can be calculated. Ｚｐ The temperature coefficient of is positive. To cancel the negative temperature coefficient, ２ It is desirable that both the temperature coefficient of and the temperature coefficient of the current I are positive.

[0025] In this embodiment, a diode-connected bipolar transistor Q １ Element Z ｎ In a CMOS process, a parasitic bipolar transistor Q １ The voltage drop V Ｚｎ is the transistor Q １ Base-emitter voltage V ＢＥ（Ｑ１） The voltage drop V Ｚｎ Temperature coefficient of ∂V Ｚｎ / ∂T is expressed as in equation (8) and takes a negative value. Ｚｎ / ∂T = ∂V ＢＥ（Ｑ１） / ∂T = {V ＢＥ（Ｑ１） -(4+m)V Ｔ -E ｇ / q} / T...(8)

[0026] m is the power exponent of the temperature characteristic of minority carrier mobility, V Ｔ is the thermal voltage, E ｇ is the band gap energy of the semiconductor used, and q is the electron charge. Ｚｐ , V Ｚｎ If the temperature coefficient of satisfies equation (4), then the voltage V Ｚｐ +V Ｚｎ =R ２ I+V ＢＥ（Ｑ１）is independent of temperature. ２ and transistor Q １ The current I passing through the current source IS １ Since the voltage V Ｚｐ +V Ｚｎ =R ２ I+V ＢＥ（Ｑ１） is the power supply voltage V ＣＣ It is also independent of

[0027] Transistor Q １ The emitter and current source IS １ Voltage V at the connection point ２ V ＣＳ Then, the resistance R １ and R ２ Voltage V at the connection point １ is V ｃｃ -R １ I=V ＣＳ +V ＢＥ（Ｑ１） +R ２ I. Voltage V １ , the power supply voltage V ＣＣ and temperature independent differential amplifier A １ The voltage V ２ differential amplifier A １ The input is input to the inverted input terminal of the differential amplifier A. １ If the amplification factor of the differential amplifier is A, １ The reference voltage V ＲＥＦ is expressed as in equation (9). ＲＥＦ = A (R ２ I+V ＢＥ（Ｑ１） ) ... (9)

[0028] Thus, in this embodiment, the power supply voltage V ＣＣ and an arbitrary reference voltage V ＲＥＦ can be obtained.

[0029] Next, a method for setting the temperature coefficient in this embodiment will be described. In the case of a design that eliminates temperature dependency within a desired temperature T range, the transistor Q is set to satisfy the formula (10) at the temperature T. １ Base-emitter voltage V ＢＥ（Ｑ１） and resistance R ２ and current I are determined.ＢＥ（Ｑ１） / ∂T|=|∂(R ２ I) / ∂T|...(10)

[0030] Base-emitter voltage V ＢＥ（Ｑ１） is the transistor Q １ Furthermore, the desired reference voltage V ＲＥＦ and the base-emitter voltage V ＢＥ（Ｑ１） and resistance R ２ and the current I, the differential amplifier A is calculated by equation (11). １ Determine the amplification factor A of A = V ＲＥＦ / (V ＢＥ（Ｑ１） +R ２ I) ...(11)

[0031] On the other hand, in the case of a design that compensates for the temperature characteristics of the subsequent circuit, the reference voltage V ＲＥＦ Then, the transistor Q is set so that the temperature characteristic of the circuit of this embodiment is closest to the inverse characteristic of the temperature characteristic of the subsequent circuit in the temperature range to be used. １ Base-emitter voltage V ＢＥ（Ｑ１） and resistance R ２ and current I and differential amplifier A １ In the case of a design that compensates for the temperature characteristics of the subsequent circuit, the base-emitter voltage V ＢＥ（Ｑ１） and resistance R ２ It should be noted that the optimum values ​​of the current I and the amplification factor A differ not only for each manufacturing process but also for each application.

[0032] Next, the current source IS １ The realization method of the current source IS １ 1 is a circuit diagram showing the configuration of a current source IS １ One end is connected to the power supply voltage V ＣＣ Resistor R connected to １０ and the base and collector are resistors R １０ An NPN bipolar transistor Q connected to the other end of １０ and the base and collector of transistor Q １０ and an NPN bipolar transistor Q whose emitter is connected to ground.１１ and the base is resistor R １０ The collector is connected to the other end of the transistor Q １ The emitter (voltage V ２ ) connected to an NPN bipolar transistor Q １２ and one end of the transistor Q １２ The other end of the resistor R is connected to the emitter of ＥＥ It consists of:

[0033] Transistor Q １０ , Q １１ The sum of the base-emitter voltages is 2V ＢＥ（ＱＩ） , transistor Q １２ The base-emitter voltage is V ＢＥ（ＱＣＳ） Then, the current source IS １ The amount of current I drawn by the ＢＥ（ＱＩ） -V ＢＥ（ＱＣＳ） ) / R ＥＥ ...(12)

[0034] This current I flows through the resistance R ２ The voltage drop caused by passing through ２ I. Voltage drop R ２ Temperature coefficient of I ∂ (R ２ I) / ∂T is expressed as in equation (13).

[0035]

[0036] Resistance R ２ Temperature coefficient α and resistance R ＥＥ The temperature coefficient β of R is set to α>0, β<0. ＥＥ , R2, 2V ＢＥ（ＱＩ） , V ＢＥ（ＱＣＳ） By appropriately selecting each parameter, the voltage drop R ２ Temperature coefficient of I ∂ (R ２ I) / ∂T takes a positive value. Resistor R with a negative temperature coefficient β ＥＥ Specific examples that can realize this include undoped semiconductor resistors and non-silicide N in Si-CMOS processes. ＋ Polycrystalline layer (Non-Silicide N ＋Examples of such resistors include resistors using a high resistance polycrystalline layer (High Resistance Poly) and resistors using a high resistance polycrystalline layer (High Resistance Poly).

[0037] In this embodiment, the transistor Q １ A current source IS is connected between the emitter of １ is inserted, but the current source IS １ and transistor Q １ The emitter of the differential amplifier A １ and the inverting input terminal of the resistor R １ , the current source IS ２ It may be replaced with:

[0038] [Third embodiment] Next, the differential amplifier A of the first and second embodiments １ 6 is a circuit diagram showing the configuration of a constant voltage source circuit according to a third embodiment of the present invention. In this embodiment, a current source IS １ The configuration shown in FIG. 5 is used as the above.

[0039] Differential amplifier A １ is an operational amplifier (OP) １ and one end is resistor R １ and R ２ The other end is connected to the operational amplifier OP １ Resistor R connected to the positive input terminal of ３ and one end of the transistor Q １ The emitter and current source IS １ (Transistor Q １２ The other end is connected to the junction point of the operational amplifier OP １ Resistor R connected to the negative input terminal of ４ And one end is an operational amplifier OP １ The other end of the resistor R is connected to the positive input terminal of ５ And one end is an operational amplifier OP １ The other end is connected to the inverting input terminal of the operational amplifier OP １ Resistor R connected to the output terminal ６ It consists of:

[0040] The resistance values ​​of resistors R3 and R4 are R ０and the values ​​of resistors R5 and R6 are AR ０ (A is the differential amplifier A １ Amplification factor). Resistance R １ and R ２ Voltage V at the connection point １ Resistance R ３ and R ５ Voltage is divided by the operational amplifier OP １ The voltage V ＲＥＦ -V ２ Resistance R ６ and R ４ Voltage is divided by the operational amplifier OP １ Input to the inverted input terminal of the operational amplifier OP １ When the amplification factor of the differential amplifier A is sufficiently large, １ The amplification factor of the resistance ratio AR ０ / R ０ = A. Differential amplifier A １ The gain A of the operational amplifier OP does not depend on the temperature. １ The power supply voltage V can be considered to have a sufficiently large amplification factor. ＣＣ In the range of １ The amplification factor A is the power supply voltage V ＣＣ It does not depend on either.

[0041] In the circuit of this embodiment, the operational amplifier OP １ Consider the influence of the input offset of the operational amplifier OP １００ The configuration taking into consideration the input offset voltage of the operational amplifier OP １００ The input offset voltage of V ＯＳ The operational amplifier OP １００ If the gain of the operational amplifier OP １００ Output voltage V ＲＥＦ is expressed by equation (14). ＲＥＦ =V ＢＥ + {(1+(R １０１ / R １００ )(ΔV ＢＥ -V ＯＳ ) ... (14)

[0042] From equation (14), the operational amplifier OP １００ Input offset voltage VＯＳ is {(1+(R １０１ / R １００ )) is multiplied by the operational amplifier OP １００ appears in the output of

[0043] In the constant voltage source circuit of this embodiment, the operational amplifier OP １ The configuration taking into consideration the input offset voltage of the operational amplifier OP １ If the gain of the operational amplifier OP １ The reference voltage V ＲＥＦ is expressed by equation (15).

[0044]

[0045] From equation (15), the reference voltage V ＲＥＦ The change in the operational amplifier OP １ Input offset voltage V ＯＳ Therefore, according to this embodiment, the reference voltage V ＲＥＦ It can be seen that the variation in

[0046] FIG. 9 shows the operational amplifier OP １ The example in FIG. 9 shows a specific circuit that realizes the above. １３ , Q １４ and resistance R １１ , R １２ and the tail current source I ＴＡＩＬ The figure shows an example of a differential operational amplifier using a grounded emitter amplifier circuit consisting of transistor Q. １３ The base is an operational amplifier (OP) １ The positive input terminal (in+) of the transistor Q １４ The base is an operational amplifier (OP) １ Inverting input terminal (in-), transistor Q １４ The collector of the operational amplifier OP １ This is the output terminal (out+).

[0047] In this embodiment, the transistor Q １ A current source IS is connected between the emitter of １ is inserted, but the current source IS１ and transistor Q １ The emitter and resistor R ４ and may be connected to the ground. １ Instead of providing a resistor R １ , the current source IS ２ It may be replaced with:

[0048] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described. Fig. 10 is a circuit diagram showing the configuration of a constant voltage source circuit according to the fourth embodiment of the present invention. The constant voltage source circuit of this embodiment is the same as the differential amplifier A of the third embodiment. １ An emitter follower circuit is added as an output buffer at the rear of the １ An NPN bipolar transistor Q connected to the output terminal of ２ One end is the power supply voltage V ＣＣ and the other end is connected to transistor Q ２ Resistor R connected to the collector of ７ and one end of the transistor Q ２ The other end of the resistor R is connected to the emitter of ８ It consists of:

[0049] Transistor Q ２ The base-emitter voltage is V ＢＥ（Ｑ２） Then, the output voltage of the emitter follower circuit is V ＲＥＦ is expressed by equation (16). ＲＥＦ = A (V ＢＥ（Ｑ１） +R ２ I)-V ＢＥ（Ｑ２） ...(16)

[0050] In addition, the output voltage V ＲＥＦ Temperature coefficient of ∂V ＲＥＦ / ∂T is expressed by equation (17).

[0051] ...(17)

[0052] Therefore, the differential amplifier A １If the amplification factor A is 1 or more, and the following equation (18) is satisfied, the output voltage V ＲＥＦ is independent of temperature.

[0053] ...(18)

[0054] In this embodiment, by adding an emitter follower circuit as an output buffer in the final stage, a high current supply capacity can be obtained, improving compatibility with the circuit connected in the subsequent stage. １ Amplification factor A and transistor Q １ , Q ２ Collector current and transistor Q １ , Q ２ By setting the emitter area and the output voltage V ＲＥＦ Temperature coefficient of ∂V ＲＥＦ The first term of / ∂T (AV ＢＥ（Ｑ１） -V ＢＥ（Ｑ２） ) / T can be adjusted. That is, with respect to the change in temperature T, ＢＥ（Ｑ１） -V ＢＥ（Ｑ２） ) / T, the temperature dependency of the constant voltage source circuit can be eliminated. Also, as in the second embodiment, by setting parameters to compensate for the temperature characteristics of the circuit connected in the subsequent stage, a BGR circuit with a temperature control function can be realized.

[0055] FIG. 11 shows the output voltage V ＲＥＦ The simulation results are shown below. When the temperature coefficient is set to 0 at temperature T = 312K, the power supply voltage V ＣＣ In the range of 3.2V to 5.5V, the output voltage V ＲＥＦ The minimum value of the power supply voltage V was 1.13695 V and the maximum value was 1.14099 V. ＣＣ Output voltage V ＲＥＦ The fluctuation of (V ＲＥＦｍａｘ -V ＲＥＦｍｉｎ ) / (V ＣＣｍａｘ -V ＣＣｍｉｎ ) × 100 ≒ 0.176%. ＲＥＦ The error rate of the temperature T and the power supply voltage V is 1 / 500, which is a sufficiently low value.ＣＣ It was confirmed that the goal of being independent of the

[0056] In this embodiment, the transistor Q １ A current source IS is connected between the emitter of １ is inserted, but the current source IS １ and transistor Q １ The emitter and resistor R ４ and may be connected to the ground. １ Instead of providing a resistor R １ , the current source IS ２ It may be replaced with:

[0057] In the first to fourth embodiments, the elements Z ｐ (Resistance R ２ ) and element Z ｎ (Transistor Q １ In this case, the element Z ｎ One end of the resistor R １ and element Z ｐ (Resistance R ２ ) to element Z ｎ and connected to the other end of element Z ｐ Connect the other end to ground or current source IS １ Element Z ｎ as the transistor Q １ When using a resistor R １ and the emitter is connected to element Z ｐ (Resistance R ２ ) can be connected to one end of the

[0058] In the first to fourth embodiments, the transistor Q １ Other than Q ２ , Q １０ ~Q １４For the transistor Q, a bipolar transistor or a MOS transistor with an unknown temperature coefficient may be used. When a MOS transistor is used, the base may be replaced with a gate, the collector with a drain, and the emitter with a source in the explanations of the first to fourth embodiments. When a CMOS process is used to manufacture the circuit, the transistor Q １ A parasitic bipolar may be used for

[0059] Furthermore, the power supply in the first to fourth embodiments may be a negative power supply instead of a positive power supply. In this case, in the explanation of the first to fourth embodiments, V ＣＣ is replaced with ground (first power supply voltage), and ground is replaced with -V ＣＣ (second power supply voltage).

[0060] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes.

[0061] (Note 1) The constant voltage source circuit of this embodiment comprises a first resistor having one end connected to a first power supply voltage, a first element having one end connected to the other end of the first resistor, a second element having one end connected to the other end of the first element and the other end connected to a second power supply voltage, and a differential amplifier having a positive phase input terminal connected to the junction point between the first resistor and the first element and a negative phase input terminal connected to the other end of the second element, wherein one of the first element and the second element generates a voltage drop having a positive temperature coefficient, and the other of the first element and the second element generates a voltage drop having a negative temperature coefficient.

[0062] (Supplementary Note 2) The constant voltage source circuit according to Supplementary Note 1 further includes a current source connected between the other end of the second element and the second power supply voltage, and configured to cause a constant current to flow through the first resistor and the first and second elements.

[0063] (Supplementary Note 3) In the constant voltage source circuit described in Supplementary Note 2, the current source comprises: a second resistor having one end connected to the first power supply voltage; a first transistor having a base or gate and a collector or drain connected to the other end of the second resistor; a second transistor having a base or gate and a collector or drain connected to the emitter or source of the first transistor and having the emitter or source connected to the second power supply voltage; a third transistor having a base or gate connected to the other end of the second resistor and a collector or drain connected to the other end of the second element; and a third resistor having one end connected to the emitter or source of the third transistor and the other end connected to the second power supply voltage.

[0064] (Supplementary Note 4) In the constant voltage source circuit according to Supplementary Note 1, the differential amplifier comprises an operational amplifier, a fourth resistor having one end connected to a connection point between the first resistor and the first element and the other end connected to a positive-phase input terminal of the operational amplifier, a fifth resistor having one end connected to the other end of the second element and the other end connected to a negative-phase input terminal of the operational amplifier, a sixth resistor having one end connected to the positive-phase input terminal of the operational amplifier and the other end connected to the second power supply voltage, and a seventh resistor having one end connected to the negative-phase input terminal of the operational amplifier and the other end connected to an output terminal of the operational amplifier, wherein when an amplification factor of the differential amplifier is A, values ​​R of the fourth and fifth resistors are ０ , the values ​​of the sixth and seventh resistors are AR ０ It is characterized in that:

[0065] (Appendix 5) A constant voltage source circuit of the present invention comprises a current source having one end connected to a first power supply voltage, a first element having one end connected to the other end of the current source, a second element having one end connected to the other end of the first element and the other end connected to a second power supply voltage, and a differential amplifier having a positive phase input terminal connected to a connection point between the current source and the first element and a negative phase input terminal connected to the other end of the second element, wherein one of the first element and the second element generates a voltage drop having a positive temperature coefficient, and the other of the first element and the second element generates a voltage drop having a negative temperature coefficient.

[0066] (Supplementary Note 6) In the constant voltage supply circuit described in any one of Supplementary Notes 1 to 5, one of the first element and the second element is a resistor, and the other of the first element and the second element is a diode-connected bipolar transistor.

[0067] (Supplementary Note 7) The constant voltage source circuit according to any one of Supplementary Notes 1 to 6 further includes an emitter follower circuit connected to the output terminal of the differential amplifier.

[0068] The present invention can be applied to a circuit that outputs a reference voltage.

[0069] A １ ...differential amplifier, OP １ ...op amp, Q １ , Q ２ , Q １０ ~Q １４ ...Bipolar transistor, IS １ , IS ２ , I ＴＡＩＬ ...Current source, R １ ~R ８ , R １０ ~R １２ , R ＥＥ …Resistance, Z ｐ , Z ｎ …element.

Claims

1. A constant voltage supply circuit comprising: a first resistor having one end connected to a first power supply voltage; a first element having one end connected to the other end of the first resistor; a second element having one end connected to the other end of the first element and the other end connected to a second power supply voltage; and a differential amplifier having a positive phase input terminal connected to the connection point between the first resistor and the first element and a negative phase input terminal connected to the other end of the second element, wherein one of the first element and the second element generates a voltage drop having a positive temperature coefficient, and the other of the first element and the second element generates a voltage drop having a negative temperature coefficient.

2. A constant voltage supply circuit as claimed in claim 1, further comprising a current source connected between the other end of said second element and said second power supply voltage, and configured to pass a constant current through said first resistor and said first and second elements.

3. A constant voltage supply circuit as claimed in claim 2, wherein said current source comprises: a second resistor having one end connected to said first power supply voltage; a first transistor having a base or gate and a collector or drain connected to the other end of said second resistor; a second transistor having a base or gate and a collector or drain connected to the emitter or source of said first transistor and an emitter or source connected to said second power supply voltage; a third transistor having a base or gate connected to the other end of said second resistor and a collector or drain connected to the other end of said second element; and a third resistor having one end connected to the emitter or source of said third transistor and the other end connected to said second power supply voltage.

4. In the constant voltage source circuit of claim 1, the differential amplifier comprises an operational amplifier, a fourth resistor having one end connected to the connection point between the first resistor and the first element and the other end connected to the positive-phase input terminal of the operational amplifier, a fifth resistor having one end connected to the other end of the second element and the other end connected to the negative-phase input terminal of the operational amplifier, a sixth resistor having one end connected to the positive-phase input terminal of the operational amplifier and the other end connected to the second power supply voltage, and a seventh resistor having one end connected to the negative-phase input terminal of the operational amplifier and the other end connected to the output terminal of the operational amplifier, wherein when the amplification factor of the differential amplifier is A, values ​​R of the fourth and fifth resistors are ０ Whereas, the values ​​of the sixth and seventh resistors are AR ０ 1. A constant voltage source circuit comprising:

Images