JPH0830345A - Reference voltage circuit - Google Patents

Abstract

PURPOSE:To provide a reference voltage circuit to be used for application fields for which versatility is further required. CONSTITUTION:This circuit is composed of a 1st transistor 1, 2nd transistor 2, 3rd transistor 3, resistor 4, 1st power source 8, 1st output terminal of a reference voltage circuit 9 and 2nd output terminal of a reference voltage circuit 10. The 1st transistor 1 is an N channel depression type MOS transistor, its drain terminal is connected to the plus output of the 1st power source 8 and its source terminal and gate terminal are connected to the drain terminal of the 2nd transistor 2. The 2nd transistor 2 is an N channel enhancement type or depression type MOS transistor of which the absolute value of a threshold voltage is smaller than that of the 1st transistor 1, its source terminal is connected to the minus output of the 1st power source 8 and its gate terminal is connected to the output of a source follower circuit 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device having a built-in reference voltage circuit, for example, a reference voltage generating IC, a regulator IC, a DC-DC converter IC, an AC-
Voltage converter such as DC converter IC, voltage detection I
A reference voltage circuit for generating a constant current in a semiconductor integrated circuit device having a constant current circuit and a circuit for generating a reference voltage in a C, an AD converter, and other ICs, and in particular, a MOSFET (insulated gate type electric field) The present invention relates to a technique effectively used for a reference voltage circuit built in a semiconductor integrated circuit device composed of an effect transistor).

[0002]

2. Description of the Related Art As a conventional reference voltage circuit using a MOS transistor, there is often used a reference voltage circuit in which a depletion type MOS transistor and an enhancement type MOS transistor, which are disclosed in Japanese Patent Publication No. 4-65546, are connected in series. Was there. The conventional reference voltage circuit has an advantage that the power consumption is small and the temperature coefficient can be adjusted, but has a drawback that the output impedance becomes large when the power consumption is reduced.
In other words, when it is attempted to use a low current consumption characteristic of a CMOS IC or the like, a depletion type MOS transistor and an enhanced type MO transistor are required.
It is necessary to reduce the current flowing through the S transistor,
In that case, the output impedance becomes high.
More specifically, if the output terminal of the conventional reference voltage circuit is connected to, for example, the gate terminal of a MOS voltage comparator to form a comparison circuit with another input voltage, the other input voltage will be near the output voltage of the reference voltage circuit. When this happens, the output of the voltage comparator becomes a voltage detector that inverts. However, when the inversion occurs, the output voltage of the voltage detector changes due to the parasitic capacitance existing between the gate and drain terminals of the MOS transistor that constitutes the voltage detector. The variation of the output voltage is transmitted to the output of the reference voltage circuit, and the output voltage of the reference voltage circuit is temporarily deviated. Such a voltage detection circuit has been used for the purpose of detecting the battery voltage in the related art, and since it was rarely necessary to operate at high speed, it was not a big problem. However, in recent years, due to the downsizing and weight saving of portable devices, a lot of DC-DC converters with low power consumption have been demanded. A voltage detector for comparing the reference voltage with another input voltage is also required inside the DC-DC converter.
In the case of the DC converter, it is necessary to perform the comparison operation at high speed, which is difficult to realize with the conventional reference voltage circuit.

In a conventional reference voltage circuit in which a depletion type MOS transistor and an enhancement type MOS transistor disclosed in Japanese Patent Publication No. 4-65546 are connected in series, the output voltage value itself changes when the output current is taken out. , Had a fatal flaw. That is, the reference voltage circuit is formed in the semiconductor integrated circuit,
If the reference voltage circuit output is taken out of the semiconductor integrated circuit, the output voltage of the reference voltage circuit may change not only by attaching a resistive load, but also by the leak current. It was difficult to take it out directly. That is, many application circuits in which the reference voltage output is taken out of the semiconductor integrated circuit are used in voltage converters, etc. However, in order to enable these applications, an impedance conversion circuit such as a differential amplifier is added to perform impedance conversion. It was necessary to take the output of the circuit out of the semiconductor integrated circuit. However, the addition of the impedance conversion circuit causes an increase in chip area and power consumption, and at the same time, an error of the impedance conversion circuit causes a decrease in accuracy.

In the conventional reference voltage circuit in which the depletion type MOS transistor and the enhancement type MOS transistor disclosed in Japanese Patent Laid-Open No. 4-65546 are connected in series, the output voltage of the reference voltage circuit is the depletion type MOS transistor and the enhancement type MOS transistor. The output voltage of the reference voltage circuit cannot be adjusted because it is determined by the sum of the threshold voltages of the MOS transistors of the type. Therefore, if the conventional reference voltage circuit is applied to a voltage converter or a voltage detector, the output voltage of the voltage converter and the detection voltage of the voltage detector are the output voltage of the reference voltage circuit, the output voltage of the voltage converter, and the voltage detector. It could only be adjusted by adjusting the magnification with the detection voltage of. In other words, a voltage adjustment circuit must be provided separately from the reference voltage circuit,
It had the drawback of increasing the chip area and power consumption. Furthermore, in the example in which a plurality of voltage converters and a plurality of voltage detectors are built in the semiconductor integrated circuit, it becomes a larger drawback. That is, when the output voltage or the detection voltage of the plurality of voltage converters or the plurality of voltage detectors is adjusted by the conventional reference voltage circuit, the second reference voltage output in which the reference voltage is once adjusted is created and further There is a first method for adjusting the magnification for the voltage converters and the voltage detectors, and a second method for individually adjusting the magnifications for the respective voltage converters and voltage detectors. However, the first method has a disadvantage that the error due to the adjustment is duplicated and the accuracy is remarkably deteriorated by the two adjustments, and the second method has a large number of adjustment points, resulting in a larger chip area. It has the drawback of increasing the power consumption and power consumption.

In addition, the conventional patent publication No. Hei 4-6554
In the conventional reference voltage circuit of 6, when the output voltage of the voltage converter or the detection voltage of the voltage detector is high, the ratio between the reference voltage output and the output voltage of the voltage converter or the detection voltage of the voltage detector increases. . In other words, a high voltage is once converted to a low voltage, and a comparison operation or error amplification operation is performed at a low voltage, which causes a large error. Therefore, the accuracy is high when the output voltage of the voltage converter or the detection voltage of the voltage detector is high. Has the serious drawback of decreasing.

[0006] Also, the conventional patent publication No. Hei 4-6554.
In the reference voltage circuit in which the depletion type MOS transistor and the enhancement type MOS transistor are connected in series in 6, when the power supply voltage becomes high, most of the power supply voltage is accumulated between the source terminal and the drain terminal of the depletion type MOS transistor. Therefore, there is a drawback that the output voltage shifts as the power supply voltage increases. In order to overcome this drawback, a device structure of a MOS transistor is devised, that is, a more advanced process technology capable of forming a MOS transistor structure called LDD having a drain diffusion layer having a low impurity concentration is preferably used. Needed to build a production line that did. That is, a general N channel M
OS transistor, eg gate oxide film thickness 200-80
In a 0 angstrom MOS transistor, when a voltage of about 7 V or more is applied between the source terminal and the drain terminal, the saturation current is rapidly deteriorated due to the increase of the substrate current due to the generation of hot electrons. When the above voltage is applied, it is difficult to maintain good output characteristics. Therefore, there is a drawback that various devises are required even in an IC of about 9 V or higher.

[0007] Further, the conventional patent publication No. Hei 4-6554.
In the reference voltage circuit in which the depletion type MOS transistor and the enhancement type MOS transistor in 6 are connected in series, when the load circuit has a large load fluctuation, that is, when the load output repeatedly turns on and off at high speed, the reference voltage is changed as described above. It had a drawback that the voltage output fluctuated for a short period due to the influence. Therefore, if the output of the reference voltage is supplied to a plurality of circuits and it is inconvenient if the output voltage of the reference voltage circuit fluctuates even for a short period of time, it is necessary to prepare a reference voltage circuit for each supply circuit. there were. The conventional reference voltage circuit has a low current consumption, for example, 1 μA.
When a reference voltage is generated with the following consumption current, the channel length becomes 10 as a depletion type MOS transistor and an enhancement type MOS transistor.
A MOS transistor having a channel width of about 0 μm and a width of about 10 μm is required, and an area of about 3000 square micrometer is required for one circuit, so that a large number of areas on a semiconductor integrated circuit are required to form a plurality of circuits. Therefore, there is a drawback in that it is immediately costly to incorporate a plurality of conventional reference voltage circuits in a semiconductor integrated circuit and operate a circuit to which a plurality of reference voltage outputs are supplied in a complete manner. .

Further, the prior art patent publication No. 4-655
In the conventional reference voltage circuit of No. 46, it was easy to adjust the temperature coefficient of the output of the reference voltage circuit, but it was difficult to realize a constant current circuit whose temperature coefficient can be adjusted freely. In particular, it has been difficult to realize a constant current circuit with a small temperature coefficient. In other words, if the output of a reference voltage circuit with a small temperature coefficient is connected to the gate terminal of a MOS transistor to form a constant current circuit, the threshold voltage of the MOS transistor changes with temperature, so the current value of the constant current circuit changes with temperature. There is a problem that it will end up. Even in the conventional reference voltage circuit, the conductivity coefficient of the depletion type MOS transistor and the conductivity coefficient of the enhancement type MOS transistor are adjusted to attach a temperature coefficient to the output voltage of the reference voltage circuit and the output of the reference voltage circuit is connected to the gate terminal. By canceling the temperature change of the threshold voltage of the MOS transistor, a constant current circuit with a small temperature coefficient could be made, but it is theoretically impossible to realize a constant current circuit without a temperature coefficient. It was

[0009]

The first problem to be solved by the present invention is that the temperature coefficient of the output voltage of the reference voltage circuit can be adjusted, which is the low power consumption which was the advantage of the subordinate reference voltage circuit. In addition to the characteristics of the standard voltage circuit, the output impedance of the standard voltage circuit is small and the output of the reference voltage circuit can be taken out of the semiconductor integrated circuit. It can be used in voltage converters that are difficult to apply with the reference voltage circuit and other application fields that require a reference voltage circuit with a low output impedance. It can be used in voltage converters and other application fields where the ability to extract the output current from the output improves performance and ease of use. To provide a reference voltage circuit capable.

Further, the second problem to be solved by the present invention
The problems of the present invention are: adjustment of the output voltage of the reference voltage circuit, which is difficult with the conventional reference voltage circuit, stable operation at an input voltage higher than that of the conventional reference voltage circuit, a plurality of reference voltage output terminals without mutual interference. Is provided more easily than the conventional reference voltage circuit without increasing the current consumption and chip area.
Therefore, it is an object of the present invention to provide a reference voltage circuit that can be used in an application field in which more versatility is required.

Further, the third problem to be solved by the present invention
Is to realize a constant current circuit that can adjust the temperature coefficient and a constant current circuit that can adjust the output current, so that it is difficult to make from the output voltage of the conventional reference voltage circuit. By realizing a constant current circuit that can adjust the current, it is possible to configure a constant current circuit that can be used in application fields that require a voltage converter, other constant temperature coefficient constant current circuit, and a constant current circuit that can adjust the current. It is to provide a reference voltage circuit.

[0012]

A first transistor which is a depletion type MOS transistor, a second transistor which is a MOS transistor of the same conductivity type as the first transistor, and a source follower circuit,
A first voltage supply terminal, a second voltage supply terminal, a voltage supply terminal 1 to the source follower circuit, and a voltage supply terminal 2 to the source follower circuit are provided, and the drain terminal of the first transistor is the first terminal. Connect to the voltage supply terminal of
The gate terminal of the transistor and the source terminal of the first transistor are connected to the drain terminal of the second transistor, and the source terminal of the second MOS transistor is connected to the second voltage supply terminal. The gate terminal is connected to the output terminal of the source follower circuit or the terminal obtained by dividing the output voltage of the source follower circuit, and the input terminal of the source follower circuit is connected to the connection point of the first transistor and the second transistor, and the source follower is connected. A reference output voltage is taken out from the output terminal of the circuit, and the source follower circuit includes a third transistor, which is a MOS transistor of the same conductivity type as the first transistor, and a load of the source follower circuit.
The drain terminal of the transistor is connected to the voltage supply terminal 1 to the source follower circuit, the gate terminal of the third transistor is used as the input terminal of the source follower circuit, and the first terminal of the load of the source follower circuit is the third transistor. Connected to the source terminal of the source follower circuit, the second terminal of the load of the source follower circuit is connected between the voltage supply terminals 2 of the source follower circuit, and the connection point between the third transistor and the load of the source follower circuit is the source follower circuit. By using the output terminal of, the temperature coefficient of the output voltage can be adjusted with low power consumption, the output impedance is small, and the output of the output of the reference voltage circuit to the outside of the semiconductor integrated circuit can also be output from the output of the reference voltage circuit. It is possible to realize a reference voltage circuit which can be taken out. Further, it is possible to realize a reference voltage circuit capable of adjusting the output voltage of the reference voltage circuit, which is difficult with the conventional reference voltage circuit. Further, by applying the sixth transistor, which is on / off controlled from outside the reference voltage circuit, to the load of the source follower circuit, it is possible to realize a reference voltage circuit capable of switching the consumption current and the output impedance in the operating state and the standby state.

Further, a plurality of source follower circuits are additionally provided, and all the inputs of the added plurality of source follower circuits are connected to the connection point of the first transistor and the second transistor, and the plurality of added source follower circuits are added. By individually setting the output of each as the reference voltage output terminal,
A plurality of reference voltage output terminals without mutual interference can be provided more easily than the conventional reference voltage circuit without increasing the current consumption or the chip area.

Further, the source follower circuit is composed of a third transistor which is a MOS transistor of the same conductivity type as the first transistor, a source resistance and a load of the source follower circuit, and the drain terminal of the third transistor is the source. It is connected to the voltage supply terminal 1 to the follower circuit, the gate terminal of the third transistor is used as the input terminal of the source follower circuit, the first terminal of the source resistor is connected to the source terminal of the third transistor, and the first terminal of the source resistor is connected. Two
The terminal is connected to the first terminal of the load of the source follower circuit, the second terminal of the load of the source follower circuit is connected between the voltage supply terminal 2 to the source follower circuit, and the source resistance and the load of the source follower circuit are connected. By using the connection point of as the output terminal of the source follower circuit, it is possible to realize a reference voltage circuit capable of stable operation at a higher input voltage than the conventional reference voltage circuit.

Further, in the source follower circuit consisting of the third transistor, which is a MOS transistor of the same conductivity type as the first transistor, and the load of the source follower circuit, a seventh MOS transistor of a conductivity type different from that of the first transistor is provided. Or a seventh transistor and an eighth transistor which are MOS transistors of the same conductivity type as the first transistor, or a seventh transistor and an eighth transistor are added, and a source follower circuit is used when the seventh transistor is added. To the voltage supply terminal 1 to the source follower circuit, the drain terminal of the seventh transistor and the seventh transistor are disconnected. The gate terminal of and the drain end of the third transistor Connected to, disconnect the load voltage supply terminal 2 and the source follower circuit to the source follower circuit when adding the eighth transistor is none, 8
The source terminal of the transistor is connected to the voltage supply terminal 2 to the source follower circuit, the drain terminal of the eighth transistor and the gate terminal of the eighth transistor are connected to the second terminal of the load of the source follower circuit, The connection point between the drain terminal of the third transistor, the third transistor and the load of the source follower circuit is used as the output terminal of the source follower circuit, and the gate terminal of the seventh transistor is connected to the drain terminal of the seventh transistor, An output voltage to the constant current circuit can be taken out from a connection point between the third transistor and the seventh transistor and a connection point between the load of the source follower circuit and the eighth transistor,
By supplying the output voltage to the constant current circuit to the gate terminal of the MOS transistor that forms the constant current circuit, the temperature coefficient can be adjusted freely and at the same time the output current of the constant current circuit can be adjusted freely. Can be realized.

[0016]

Next, the method and operation of the present invention will be described with reference to examples.

Example 1 FIG. 1 is a circuit diagram of Example 1 of the present invention. 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 4 is a resistor, 8 is a first power supply, Reference numeral 9 is a first output terminal of the reference voltage circuit, and 10 is a second output terminal of the reference voltage circuit. The first transistor is an N-channel depletion type MOS transistor and the drain terminal is the first
The positive terminal of the power source of the
Connected to the drain terminal of the transistor. Second
Is a depletion type MOS transistor with an absolute value of the threshold voltage smaller than that of the N-channel enhanced type or the first transistor. The source terminal is the negative output of the first power supply and the gate terminal is the source follower circuit. Connected to the output.
The source follower circuit is composed of a third transistor and a resistor, the third transistor is an N-channel MOS transistor, the drain terminal is the positive output of the first power supply, the source terminal is the resistor, and the gate terminal is the first transistor. It is connected to the contact of the second transistor. The other terminal of the resistor, which is different from the terminal connected to the second transistor, is connected to the negative output of the first power supply. Assume that the first power supply voltage is higher than the sum of the absolute value of the threshold voltage of the first transistor, the threshold voltage of the second transistor and the threshold voltage of the third transistor by about 0.1 V or more. , The first transistor, the second transistor, and the third transistor respectively operate in the saturation region because the voltage between the drain terminal and the source terminal becomes higher than the value obtained by subtracting the threshold voltage from the voltage between the gate terminal and the source terminal. To do. In the circuit of FIG. 1, the current flowing between the drain terminal and the source terminal of the first transistor is IM1, the conductivity coefficient of the first transistor is KM1,
When the threshold voltage of the first transistor is VTM1, the equation 1 holds because the voltage between the gate terminal and the source terminal of the first transistor is 0 volt.

[0018]

[Equation 1]

In the circuit of FIG. 1, the current flowing between the drain terminal and the source terminal of the second transistor is IM2,
When the conductivity coefficient of the second transistor is KM2, the threshold voltage of the second transistor is VTM2, and the contact voltage between the third transistor and the resistor is VOUT1, the voltage between the gate terminal and the source terminal of the second transistor is VOU.
Since it is T1, Equation 2 holds.

[0020]

[Equation 2]

In the circuit of FIG. 1, the current flowing between the drain terminal and the source terminal of the third transistor is IM3,
When the conductivity coefficient of the third transistor is KM3, the threshold voltage of the third transistor is VTM3, and the contact voltage between the first transistor and the second transistor is VOUT2, the gate terminal and the source terminal of the third transistor are Since the voltage is the difference between VOUT1 and VOUT2, Formula 3 holds.

[0022]

(Equation 3)

In the circuit of FIG. 1, when the current flowing through the resistor is IR and the resistance value is R, the voltage across the resistor is VO.
Since it is UT1, Formula 4 is established.

[0024]

[Equation 4]

Currents IM1 and I flowing between the drain and source terminals of the first and second transistors, respectively.
Since M2 is the same, when VOUT1 is obtained from Equation 1 and Equation 2, Equation 5 is obtained.

[0026]

(Equation 5)

Next, the threshold voltage VTM10 at the temperature of the first transistor of 25 ° C. and the temperature change ΔV of the threshold voltage of the first transistor per 1 ° C.
TM1, the threshold voltage VTM20 of the second transistor at a temperature of 25 ° C., the temperature change amount ΔVTM2 of the threshold voltage of the second transistor per 1 ° C.,
Assuming that the threshold voltage VTM30 at the temperature of the third transistor 25 ° C. and the temperature change amount ΔVTM3 per 1 ° C. of the threshold voltage of the third transistor V
TM1, VTM2, and VTM3 are as shown in Formula 6, Formula 7, and Formula 8.

[0028]

(Equation 6)

(Equation 7)

(Equation 8)

Next, the conductivity coefficient KM10 of the first transistor at a temperature of 25 ° C., the temperature change rate ΔKM1 of the conductivity of the first transistor per 1 ° C., the conductivity coefficient KM20 of the second transistor at a temperature of 25 ° C., the second Change rate ΔKM2 per 1 ° C. of the conductivity of the above transistor, and the conductivity coefficient KM3 of the third transistor at a temperature of 25 ° C.
0, the temperature change rate ΔKM3 of the conductivity of the third transistor per 1 ° C., the resistance value RO of the resistor at a temperature of 25 ° C.,
If the rate of temperature change per degree Celsius of the resistance value of the resistor is ΔR, then K
M1, KM2, KM3, and R are as shown in Expression 9, Expression 10, Expression 11, and Expression 12.

[0030]

[Equation 9]

[Equation 10]

[Equation 11]

(Equation 12)

When the equations 6 to 12 are substituted into the equation 5 and the first transistor and the second transistor are formed on the same semiconductor substrate, the conductivity of the first transistor is 1
Since the temperature change rate ΔKM1 per degree Celsius and the temperature change rate ΔKM2 per degree Celsius of the conductivity of the second transistor are almost equal, if ΔKM1 = ΔKM2, then VO
UT1 is as shown in Equation 13.

[0032]

(Equation 13)

From the result of Expression 13, it is understood that the output voltage of the reference voltage circuit and its temperature change rate are determined only by the threshold voltage and the conductivity coefficient of the first transistor and the second transistor.

The temperature change amount of the threshold voltage of the MOS transistor per 1 ° C. is generally from -4 mV to -1.
When it is formed on the same semiconductor substrate with mV, the values are almost the same. Since the conductivity coefficient of the transistor can be freely set by selecting the channel width and the channel length of the transistor, the conductivity coefficient KM10 of the first transistor at a temperature of 25 ° C. and the conductivity coefficient KM20 of the second transistor at a temperature of 25 ° C. should be selected. Thus, the change amount of the output voltage VOUT1 of the reference voltage circuit per 1 ° C. can be adjusted.
Specifically, when the conductivity coefficient KM10 of the first transistor at a temperature of 25 ° C. and the conductivity coefficient KM20 of the second transistor at a temperature of 25 ° C. are made equal, the temperature change amount per 1 ° C. of the output voltage of the reference voltage circuit is calculated. It can be almost zero. Furthermore, the temperature of the first transistor is 25 ° C.
When the conductivity coefficient KM10 of the second transistor is larger than the conductivity coefficient KM20 of the second transistor at a temperature of 25 ° C., the amount of temperature change per 1 ° C. of the output voltage of the reference voltage circuit can be a positive value. Temperature of 25
When the conductivity coefficient KM10 at the temperature of 2 ° C. is made smaller than the conductivity coefficient KM20 at the temperature of the second transistor of 25 ° C., the temperature change amount per 1 ° C. of the output voltage of the reference voltage circuit can be a negative value. Furthermore, it can be seen from the result of Expression 13 that the conductivity coefficient and the resistance value of the third transistor do not affect the output voltage of the reference voltage circuit and the temperature change amount. Therefore, the conductivity coefficient and the resistance value of the third transistor can be freely selected regardless of the temperature characteristics of the reference voltage circuit.

When the output impedance of the source follower circuit composed of the third transistor and the resistance is ROUT, the resistance is set to a value larger than the on-resistance of the third transistor, and the current consumption of the entire reference voltage circuit is set to be low. , The output impedance R of the source follower circuit
OUT is as shown in Expression 14. If the transconductance of the third transistor is gm3, gm3>
> 1 / R,

[0036]

[Equation 14]

Since the current flowing between the source terminal and the drain terminal of the third transistor is equal to the current flowing through the resistor, the output impedance of the first output of the reference voltage circuit is the conductivity coefficient of the third transistor and the resistance value. Determined only by. Therefore, irrespective of the output voltage of the reference voltage circuit and the temperature change amount, even if the current flowing between the source terminal and the drain terminal of the third transistor is reduced by increasing the resistance value R, the third transistor Since the output impedance ROUT of the source follower circuit can be reduced by increasing the conductivity coefficient KM3, it is possible to set the output impedance of the first output of the reference voltage circuit to a sufficiently low value while realizing low current consumption, and to reduce load fluctuations. It is possible to realize a reference voltage circuit with extremely fast response.

Although not shown in the circuit of FIG. 1, the third
By connecting a capacitor between the gate terminal and the source terminal of the transistor, the output response characteristics to the power supply voltage fluctuation can be accelerated. In this example 1, the substrates of the first transistor and the third transistor are connected to the source terminals of the respective transistors.
It may be connected to the negative output of the power supply. In this example 1, the third transistor may be an N-channel enhancement type MOS transistor or a depletion type MOS transistor. However, when the third transistor is an N-channel depletion type MOS transistor, the second transistor is operated in the saturation region, so that the gate terminal of the third transistor,
It is desirable to set the resistance value R to be low so that the voltage between the source terminals becomes 0 V or more.

When the output impedance does not need to be low, the output voltage can be taken out from the second output terminal. For example, when the output voltage of the reference voltage circuit with a temperature change amount of 0 and the output voltage of the reference voltage circuit with a negative temperature change amount are required, the first output terminal of the reference voltage circuit is set to the reference of the temperature change amount of 0. If the conductivity coefficient KM10 of the first transistor at a temperature of 25 ° C. and the conduit coefficient KM20 of the second transistor at a temperature of 25 ° C. are adjusted so that the voltage circuit output is obtained, the amount of temperature change from the second output terminal of the reference voltage circuit is adjusted. The negative reference voltage circuit output can be taken.

Further, in this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are provided and supplied separately. You may do it. FIG. 12 is a circuit diagram of a modified example of Example 1, in which the positive output side and the negative output side of the power source of the first power source are separately supplied with voltage to the source follower circuit, but either the negative side or the positive side is supplied. It can be shared.

Example 2 FIG. 2 is a circuit diagram of Example 2 of the present invention, in which 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 5 is a fourth transistor, and 8 is a first transistor. Power source, 9 is a first output terminal of the reference voltage circuit, and 10 is a second output terminal of the reference voltage circuit. The first transistor is an N-channel depletion type MOS transistor, and the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type MOS or a depletion type MOS whose absolute value of threshold voltage is smaller than that of the first transistor.
In the transistor, the source terminal is connected to the negative output of the first power supply, and the gate terminal is connected to the output of the source follower circuit. The source follower circuit includes a third transistor and a fourth transistor, the third transistor is an N-channel MOS transistor, and the drain terminal of the third transistor is connected to the positive output of the first power supply and the third output.
The source terminal of the transistor is the drain terminal of the fourth transistor, and the gate terminal of the third transistor is the first terminal.
Connected to the contact between the transistor and the second transistor. The fourth transistor is an N-channel depletion type MOS transistor, and the source terminal and gate terminal of the fourth transistor are connected to the negative output of the first power supply.

In Example 2, as in Example 1, since Equation 1 and Equation 2 are established, Equation 5 is established, and Equation 6 and Equation 7 are established.
The numbers 9 and 10 are also the same as those in the example 1, and thus the number 13 is also in the example 1.
As in Example 1, the output voltage of the reference voltage circuit and the temperature change amount can be freely adjusted, and at the same time, the output impedance of the first output of the reference voltage circuit is set to a sufficiently low numerical value, as in Example 1. A reference voltage circuit that can be set and has an extremely fast response to a load change can be realized. In Example 2, the resistor of Example 1 is replaced with a fourth transistor which is a fourth transistor. In some cases, the depletion type transistor of Example 2 is more advantageous in area than the resistor of Example 1.

Furthermore, in Example 1, the power supply voltage is higher than the sum of the absolute value of the threshold voltage of the first transistor, the threshold voltage of the second transistor and the threshold voltage of the third transistor. , The first transistor, the second transistor, and the third transistor operate in the saturation region where the voltage between the drain terminal and the source terminal is higher than the value obtained by subtracting the threshold voltage from the voltage between the gate terminal and the source terminal, respectively. As a result, a constant reference voltage was obtained.

When an N-channel depletion type MOS transistor having the same conductivity coefficient is selected as the third transistor and the fourth transistor in the example 2, the first output voltage VOUT1 of the reference voltage circuit and the first output voltage VOUT1 of the reference voltage circuit are selected. 2 becomes equal to the output voltage VOUT2. In Example 1, the lower limit power supply voltage at which the output voltage of the reference voltage circuit becomes constant is the absolute value of the threshold voltage of the first transistor, the threshold voltage of the second transistor, and the threshold voltage of the third transistor. It was about 0.1 V or more from the sum of the depletion voltage, but in the case of Example 2, N-channel depletion type MOS transistors having the same conductivity coefficient were selected as the third transistor and the fourth transistor. The lower limit power supply voltage at which the output voltage of the voltage circuit becomes constant is about 0.1 V or more, which is lower than the sum of the absolute value of the threshold voltage of the first transistor and the threshold voltage of the second transistor. A reference voltage circuit suitable for operation can be realized.

Further, in this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are the same as in the modification of the first example. May be provided and supplied separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 3 FIG. 3 is a circuit diagram of Example 3 of the present invention. 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 4 is a resistor, 8 is a first power supply, 9 is the first output terminal of the reference voltage circuit, 10 is the second output terminal of the reference voltage circuit,
Reference numeral 11 is an output terminal to the constant current circuit, 12 is a seventh transistor, 13 is a ninth transistor, and 14 is a load of the constant current circuit. As in Example 1, the first transistor is an N-channel depletion type MOS transistor, the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or a depletion type M that has a smaller absolute value of the threshold voltage than the first transistor.
In the OS transistor, the source terminal is connected to the negative output of the first power supply, and the gate terminal is connected to the output of the source follower circuit. The source follower circuit is composed of a third transistor and a resistor, the third transistor is an N-channel MOS transistor, the source terminal is connected to the resistor, and the gate terminal is connected to the contact point between the first transistor and the second transistor. . The other terminal of the resistor, which is different from the terminal connected to the second transistor, is connected to the negative output of the first power supply.

Furthermore, in Example 3, a seventh transistor, which is a P-channel enhanced type MOS transistor, is provided, and the source terminal of the seventh transistor is the positive output of the first power supply and the gate terminal of the seventh transistor. And the drain terminal are connected to the drain terminal of the third transistor, and the connection point of the third transistor and the seventh transistor serves as an output terminal to the constant current circuit. The ninth transistor is a P-channel enhancement type constant current circuit transistor, the source terminal of which is connected to the positive output of the power source of the first power source, and the gate terminal of the ninth transistor is connected to the output terminal of the constant current circuit. ing. Further, the load of the constant current circuit is connected between the drain terminal of the ninth transistor and the negative output terminal of the first power source. In the case of the example 3, as in the case of the example 1, the expressions 1 to 13 stand. Number 1 to number 4
By substituting 2 and the equation 13 into the current IR flowing in the resistor, the equation 15 is obtained.

[0048]

(Equation 15)

The current IR flowing through the resistor matches the current flowing between the source terminal and drain terminal of the seventh transistor, and the current flowing between the source terminal and drain terminal of the seventh transistor and the source of the ninth transistor. When the seventh transistor and the ninth transistor are formed by MOS transistors having the same threshold voltage, the ratio of the current flowing between the terminal and the drain terminal becomes the ratio of the conductivity coefficients of the respective transistors, so the current flowing through the load. The value can be freely set by adjusting the ratio of the conductivity coefficients. That is, since the current flowing through the load of the constant current circuit, which is the output current of the constant current circuit, can be set to be a constant multiple of the current IR flowing through the resistor, regardless of the ambient temperature, the temperature characteristic of the current IR flowing through the resistor can be freely set. The output current of the constant current circuit can be freely controlled in the same manner if it can be controlled to.

FIG. 4 shows the calculation result of the equation 15, and the current IR flowing through the resistor is calculated using the three parameters shown in the table of FIG. 5. In the case 2, the temperature characteristic becomes almost zero. . The values of the parameters in the table of FIG. 5 are such that, in the case of a MOS transistor and a thin film resistor formed on a semiconductor substrate, the temperature change amount of the threshold voltage of the transistor per 1 ° C. is −1.0 mV to −4 mV. Temperature change rate of conductivity from 1% to 0.3% to 0.9
%, The rate of temperature change of the resistance value of the resistor per 1 ° C 0.01%
To 0.1%. The result of the experiment tends to cause a deviation in the direction lower than room temperature, but this is because the temperature change rate of the conductivity coefficient of the transistor tends to be slightly higher than the high temperature, but in practice, There is no problem at all.

In this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are the same as in the modification of the first example. May be provided and supplied separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 4 FIG. 6 is a circuit diagram of Example 4 of the present invention, in which 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 6 is a fifth transistor, and 8 is a fifth transistor. 1 is a power supply, 9 is a first output terminal of the reference voltage circuit, 10 is a second output terminal of the reference voltage circuit, 17 is a tenth transistor, and 18 is a voltage detection resistor 1. As in Example 1, the first transistor is an N-channel depletion type MOS transistor, and the drain terminal is the positive output of the first power supply.
The source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or depletion type MOS transistor having an absolute value of the threshold voltage smaller than that of the first transistor. The source terminal is a negative output of the first power supply and the gate terminal is a source follower circuit. Connected to the output of. The source follower circuit includes a third transistor and a fifth transistor,
Is a N-channel MOS transistor,
The drain terminal of the third transistor is the positive output of the first power supply, the source terminal of the third transistor is the drain terminal of the fifth transistor, and the gate terminal of the third transistor is the first transistor and the second transistor. It is connected to the contact of the transistor. The fifth transistor is an N-channel enhancement type MOS transistor, the drain terminal of the fifth transistor is the source terminal of the third transistor, the source terminal of the fifth transistor is the negative output of the first power supply, and the fifth The gate terminal of the transistor is a bias input terminal. The bias circuit includes a voltage detection resistor 1 and a tenth transistor. The tenth transistor is an N-channel enhancement type MOS transistor. The drain terminal of the tenth transistor is the voltage detection resistor 1 and the source terminal of the tenth transistor. Is the first
The gate terminal of the tenth transistor is connected to the drain terminal of the tenth transistor at the negative output of the power source. The voltage detection resistor 1 is connected between the positive output of the first power supply and the drain terminal of the tenth transistor.

Also in Example 4, as in Example 1, since Equation 1 and Equation 2 are established, Equation 5 is established, and Equation 6, Equation 7, and Equation 9,
Since the expression 10 is also the same as that of the example 1, and the expression 13 is also the same as that of the example 1, the output voltage of the reference voltage circuit and the temperature change amount can be freely adjusted in the example 4 as in the case of the example 1. The output impedance of the reference voltage circuit is as shown in Equation 14 as in Example 1, but in Example 4, the current IM3 flowing between the drain terminal and the source terminal of the third transistor increases the voltage of the power supply due to the action of the bias circuit. To increase.
That is, since the voltage applied to the voltage detection resistor 1 increases as the power supply voltage increases, the current flowing through the voltage detection resistor 1 increases. Therefore, the current flowing between the source terminal and the drain terminal of the tenth transistor is the voltage detection resistor 1 Since it is equal to the current that flows in, it increases as the voltage of the power supply increases. Since the fifth transistor and the tenth transistor are generally connected as a current mirror circuit,
For example, if the fifth transistor and the tenth transistor are formed in the semiconductor integrated circuit with the same structure and have the same size, the currents flowing between the source terminal and the drain terminal are also equal. Therefore, the output impedance of the source follower circuit is as shown in Equation 14 as in Example 1, but the current IM3 flowing through the third transistor increases as the power supply voltage increases, so that the output impedance of the source follower circuit increases. And further decrease. In general, the switching speed of a CMOS IC increases as the power supply voltage increases, the output of the reference voltage circuit is easily affected by the load circuit, and the reference voltage circuit is required to have a lower output impedance. The circuit of Example 4 can realize a circuit that meets such a demand. In this example, the current flowing through the fifth transistor increases as the power supply voltage increases, but of course the voltage supplied to the gate terminal of the fifth transistor is constant when it is desired to suppress the consumption current when the power supply voltage is high. May be

In this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are the same as in the modification of the first example. May be provided and supplied separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 5 FIG. 7 is a circuit diagram of Example 5 of the present invention. 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 6 is a fifth transistor, and 8 is a second transistor. 1 is a power supply, 9 is a first output terminal of the reference voltage circuit, 10 is a second output terminal of the reference voltage circuit, 17 is a tenth transistor, 18 is a voltage detection resistor 1, and 19 is a source resistor. As in Example 1, the first transistor is an N-channel depletion type MOS transistor, the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or depletion type MOS transistor in which the absolute value of the threshold voltage is smaller than that of the first transistor.
The source terminal is connected to the negative output of the first power supply, and the gate terminal is connected to the output of the source follower circuit. The source follower circuit includes a third transistor, a source resistor and a fifth transistor, and the third transistor is N
In the channel MOS transistor, the drain terminal of the third transistor is the positive output of the first power supply, the source terminal of the third transistor is the source resistance, and the gate terminal of the third transistor is the first transistor and the second transistor. Connected to the contact of the transistor. The source resistor is connected between the source terminal of the third transistor and the drain terminal of the fifth transistor. The fifth transistor is an N-channel enhancement type MOS transistor, the source terminal of the fifth transistor is the negative output of the first power supply, and the gate terminal of the fifth transistor is the bias input terminal. The bias circuit includes a voltage detection resistor 1 and a tenth transistor. The tenth transistor is an N-channel enhancement type MOS transistor. The drain terminal of the tenth transistor is the voltage detection resistor 1 and the source terminal of the tenth transistor. Is connected to the negative output of the first power supply, and the gate terminal of the tenth transistor is connected to the drain terminal of the tenth transistor. The voltage detection resistor 1 is connected to the positive output of the first power supply and the first output.
It is connected to the drain terminal of the 0 transistor.

Also in Example 5, as in Example 1, since Equation 1 and Equation 2 are established, Equation 5 is established, and Equation 6, Equation 7, and Equation 9,
Since the expression 10 is also the same as that of the example 1, and the expression 13 is also the same as that of the example 1, the output voltage of the reference voltage circuit and the temperature change amount can be freely adjusted in the example 5 as in the case of the example 1. The output impedance of the reference voltage circuit is a value larger than that of the example 1 because the source resistance is connected in series with respect to the value of the equation (14). However, in Example 5, as in Example 4, the current IM3 flowing between the drain terminal and the source terminal of the third transistor increases as the voltage of the power supply increases due to the action of the bias circuit, and further, the action of the source resistance causes the current IM3 to flow in each transistor. The voltage applied between the source terminal and the drain terminal is appropriately divided.

FIG. 8 shows the voltage applied between the source terminal and the drain terminal of each transistor of Example 5. Patent publication
Depletion type MO in 4-65546
In a conventional reference voltage circuit in which an S-transistor and an enhancement-type MOS transistor are connected in series, most of the power-supply voltage is applied between the source terminal and the drain terminal of the depletion-type MOS transistor when the power-supply voltage increases, and the power-supply voltage of 9V In the above cases, a stable reference voltage could not be obtained. On the other hand, the reference voltage circuit of Example 5 operates stably up to 14 V or higher because the voltage applied between the source terminal and the drain terminal of each transistor is appropriately divided. That is, when the transistors having the same structure are used as the first transistor, the second transistor, and the third transistor, stable operation can be maintained up to a power supply voltage higher than the conventional reference voltage circuit by about 5V or more.

In this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are the same as in the modification of the first example. May be provided and supplied separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 6 In Example 6, the resistance of the circuit of Example 1 is divided into two resistors, resistor 1 and resistor 2, as shown in FIG. 9, and the gate terminal of the second transistor is connected to the dividing point. The output of the reference voltage can be adjusted. 9 shows Example 6 of the present invention, 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 9 is a first output terminal of a reference voltage circuit, and 10 is a first voltage terminal of the reference voltage circuit. 2 is an output terminal, 20 is a resistor 1, and 21 is a resistor 2. The first transistor is an N-channel depletion type MOS transistor, and the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or a depletion type M that has a smaller absolute value of the threshold voltage than the first transistor.
In the OS transistor, the source terminal is connected to the negative output of the first power supply, and the gate terminal is connected to the output of the source follower circuit. The source follower circuit is composed of a third transistor and a resistor, the third transistor is an N-channel MOS transistor, the drain terminal is the positive output of the first power supply, the source terminal is the resistor 1, and the gate terminal is the first transistor. And the contact of the second transistor. The other terminal different from the terminal connected to the second transistor of the resistor 1 is the resistor 2 and the resistor 1 of the resistor 2
The other terminal different from the terminal connected to is connected to the negative output of the first power supply. Formula 1 is the same as Example 1, but Formula 2 is because the gate terminal of the second transistor is connected to the connection point of the resistors 1 and 2 obtained by dividing the resistor of Example 1 into two. Resistance value of R1, resistance 2
If the resistance value of R is R2, the resistance value of the resistance is expressed by Equation 16.

[0060]

[Equation 16]

The current IM2 flowing between the drain terminal and the source terminal of the second transistor is as shown in Equation 17.

[0062]

[Equation 17]

The difference between equation 17 and equation 2 is that VO in equation 17
Only the term obtained by dividing the resistance value of the resistor 2 by the sum of the resistance values of the resistors 1 and 2 is added to the UT 1. The ratio of the resistance values, that is, the value obtained by dividing the resistance value of the resistance 2 by the sum of the resistance values of the resistance 1 and the resistance 2, indicates that the resistance 1 and the resistance 2 are made of the same kind of element in the semiconductor integrated circuit. Since the rate of change is 0,
When the calculation is performed using the equation 17 instead of the equation 2, the first output voltage VOUT1 of the reference voltage circuit is as shown in the equation 18.

[0064]

(Equation 18)

That is, in Example 1, since the output voltage of the reference voltage circuit is determined only by the parameters of the first transistor and the second transistor, the output voltage cannot be freely adjusted, but in Example 6, It can be freely adjusted by appropriately selecting the ratio of the resistance values of the resistors 1 and 2.

A thin film resistor formed on a semiconductor substrate is used as the resistor, and an appropriate trimming means such as laser trimming and fuse trimming technique, a value stored in a non-volatile memory or a volatile memory, and a value parallel to the resistor based on this value. Alternatively, the output voltage of the reference voltage circuit can be adjusted to a desired value by adjusting the resistance value by applying a technique of turning on / off the switching elements supplied in series. Further, even if the resistors 1 and 2 are provided outside the semiconductor integrated circuit for adjustment, the reference voltage circuit of this example has a sufficiently low output impedance, so there is no problem unlike the conventional reference voltage circuit. In other words, also in this example, the output impedance of the reference voltage circuit is as in the case of Example 1, and can be set to a sufficiently low value while realizing low current consumption. Also the resistance 1,
The current flowing through the resistor 2 is represented by the equation 15 in Example 1, but is represented by the equation 19 in this example.

[0067]

[Formula 19]

That is, it is understood that the output current of the constant current circuit as well as the output voltage of the reference voltage circuit is affected only by the ratio of the resistance 1 and the resistance 2 as compared with Examples 1 and 3.
As described above, the temperature characteristic of the output current of the constant current circuit can be freely controlled. Moreover, by adding a seventh transistor and a ninth transistor to this example as in Example 3 to form a circuit of a modified example of Example 6 as shown in FIG. 13, the output current of the constant current circuit The temperature characteristic can be freely controlled, and at the same time, the output current of the constant current circuit can be freely adjusted by selecting the ratio of the resistor 1 and the resistor 2 as well as the output voltage of the reference voltage circuit.

In this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are the same as in the modification of the first example. May be provided so as to be commonly used separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 7 FIG. 10 shows Example 7 of the present invention, in which 1 is a first transistor,
2 is a second transistor, 3 is a third transistor, 4
Is a resistor, 7 is a sixth transistor, 8 is a first power supply, and 9
Is a first output terminal of the reference voltage circuit, 10 is a second output terminal of the reference voltage circuit, and 30 is an on / off control terminal. The first transistor is an N-channel depletion type MOS transistor, and the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or depletion type MOS transistor having an absolute value of the threshold voltage smaller than that of the first transistor. The source terminal is a negative output of the first power supply and the gate terminal is a source follower circuit. Connected to the output of. The source follower circuit is composed of a third transistor, a resistor and a sixth transistor, the third transistor is an N-channel MOS transistor, the drain terminal is the positive output of the first power supply, and the source terminal is the sixth transistor. The drain terminal and the gate terminal are connected to the contacts of the first transistor and the second transistor. The sixth transistor is an N-channel enhancement type MOS transistor, the source terminal is connected to the resistor, the gate terminal is an on / off control terminal, and the on / off control voltage is supplied from the outside of the reference voltage circuit. The resistor is connected to the source terminal of the sixth transistor and the negative output of the first power supply. When a voltage for turning on the sixth transistor with a sufficiently low resistance is applied to the on / off control terminal, the circuit operation and characteristics become exactly the same as in Example 1.

Next, when a voltage for turning off the sixth transistor is applied to the on / off control terminal, the gate terminal of the first transistor is connected to the source terminal by the resistor, and the voltage of the gate terminal and the source terminal becomes 0V. Is turned off and the sixth transistor is also turned off, so that almost no current flows into the reference voltage circuit except the leak current of the MOS transistor. That is, it can be generally called a standby mode, and when the output terminal of the reference voltage circuit is the connection point of the sixth transistor and the third transistor, the output voltage of the first power supply is in the standby state. It has the same voltage as the positive output. In the standby state, if the output voltage of the reference voltage circuit is set to the same voltage as the negative output of the first power supply, the output of the reference voltage circuit may be taken out from the connection point of the sixth transistor and the resistor.

In the reference voltage circuit having the standby mode, the current consumption in the operating state can generally be increased in many cases, that is, in the reference voltage circuit having no standby mode, the resistance value R of the resistor is between 100 KΩ and 50 MΩ. It is desirable to reduce the current consumption by setting the resistance value R to 100Ω when there is a standby mode.
There are often few problems even if the value is lowered to an appropriate value between 100 KΩ and 100 KΩ. In this case, the output impedance of the source follower circuit is as shown in Expression 20, and a reference voltage circuit having a lower output impedance can be realized.

[0073]

(Equation 20)

If the load of the source follower circuit shown in the previous example such as a resistor, a depletion MOS transistor, and an enhancement MOS transistor for the standby mode is connected in parallel with the resistor of this example and the sixth transistor, The normal reference voltage output can be taken out even in the standby mode.

Further, in this example, the power source of the source follower circuit is the first power source common to the first transistor and the second transistor, but the second power source and the third power source are similar to the modification of the first example. May be provided and supplied separately. As in Example 1, the positive output side, the negative output side, or both of the first power supply can be separately provided.

Example 8 FIG. 11 is a circuit diagram of Example 8 of the present invention. 1 is a first transistor, 2 is a second transistor, 3 is a third transistor, 4 is a resistor, 8 is a first power supply, 9 is a first output terminal of the reference voltage circuit, 10 is a second output terminal of the reference voltage circuit, 12 is a seventh transistor, 13 is a ninth transistor, 22 is an eighth transistor, and 23 is an eleventh transistor. Transistor, 24 is load 1 of constant current circuit, 25 is load 2 of constant current circuit, 26 is output terminal 1 to constant current circuit, 27 is output terminal 2 to constant current circuit, 28 is second power supply, 29 Is a third power supply. As in Example 1, the first transistor is an N-channel depletion type MOS transistor, the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or depletion type MOS transistor having an absolute value of the threshold voltage smaller than that of the first transistor. The source terminal is a negative output of the first power supply and the gate terminal is a source follower circuit. Connected to the output of. The source follower circuit includes a third transistor, a resistor, a seventh transistor, and an eighth transistor. The third transistor is an N-channel MOS transistor, the source terminal is the resistor, and the gate terminal is the first transistor and the first transistor. It is connected to the contact of the second transistor. The other terminal of the resistor, which is different from the terminal connected to the third transistor, is connected to the terminal to which the drain terminal and the gate terminal of the eighth transistor are connected. The seventh transistor is a P-channel enhanced type MOS transistor, the source terminal of the seventh transistor is the positive output of the second power supply, and the gate terminal and drain terminal of the seventh transistor are the drain of the third transistor. Connected to the terminal, the connection point of the third transistor and the seventh transistor is the output terminal 1 to the constant current circuit.
Becomes The eighth transistor is an N-channel enhanced type MOS transistor, the source terminal of the eighth transistor is the negative output of the third power source, and the gate terminal and drain terminal of the eighth transistor is the third resistor of the resistance.
Connected to a terminal different from the connection point with the transistor of
The connection point between the resistor and the eighth transistor serves as the output terminal 2 to the constant current circuit. The ninth transistor is a P-channel enhancement type constant current circuit transistor, the source terminal of which is connected to the positive output of the second power source, and the gate terminal of the ninth transistor is connected to the output terminal 1 of the constant current circuit. Has been done. Further, the load 1 of the constant current circuit is connected between the drain terminal of the ninth transistor and the negative output terminal of the second power source. The eleventh transistor is an N-channel enhancement type constant current circuit transistor, the source terminal of which is connected to the negative output of the power source of the third power source, and the gate terminal of the eleventh transistor is connected to the output terminal 2 of the constant current circuit. Has been done. Further, the load 2 of the constant current circuit is connected between the drain terminal of the eleventh transistor and the positive output terminal of the third power source.

In the case of Example 8 as well, as in Example 3, the current flowing through the resistor is as in equation 15, and the temperature characteristic of the output current of the constant current circuit can be freely set. Further, the current flowing in the load 1 of the constant current circuit can be freely adjusted by selecting MOS transistors of the same type for the seventh transistor and the ninth transistor and setting the conductivity coefficient to an appropriate ratio, as in Example 3. . Further, the current flowing through the load 2 of the constant current circuit can be freely set by adjusting the eighth transistor and the eleventh transistor. Further, in this example, the constant current circuit is different not only between the first power source but also the first power source,
It is shown that it is possible to configure between the second power supply and between the third power supply. That is, by using the reference voltage circuit of the present invention, it is possible to provide a constant current circuit in an application circuit including a plurality of power supplies, in which the temperature characteristics can be freely controlled between the plurality of power supplies and the output current can be freely controlled.

Example 9 FIG. 14 is a circuit diagram of Example 9 of the present invention, in which 1 is a first transistor, 2 is a second transistor, 8 is a first power supply, and 9 is a power supply.
Is a first output terminal of the reference voltage circuit, 10 is a second output terminal of the reference voltage circuit, 31 is a first source follower circuit, 32 is a plurality of source follower circuits, 33 is a power source 1, 34 of the source follower circuit. Is a power supply 2 for the source follower circuit. The first transistor is an N-channel depletion type MOS transistor, and the drain terminal is connected to the positive output of the first power supply, and the source terminal and the gate terminal are connected to the drain terminal of the second transistor. The second transistor is an N-channel enhancement type or depletion type MOS transistor having an absolute value of threshold voltage smaller than that of the first transistor. The source terminal is the negative output of the first power supply and the gate terminal is the first output. It is connected to the output of the source follower circuit. The output of the first source follower circuit is connected to the gate terminal of the second transistor, and all the inputs of the plurality of source follower circuits are connected to the connection point of the first transistor and the second transistor. The output of the reference voltage circuit is the second output terminal of the reference voltage circuit which is the connection point of the first transistor and the second transistor, and the first output of the reference voltage circuit which is the output terminal of the first source follower circuit. It can be taken out from the output terminal of the source follower circuit of Mitsutake.

The power source of the first source follower circuit and the plurality of source follower circuits may be supplied from the first power source or may be separately provided. Although the first source follower circuit and the plurality of source follower circuits may be any of those shown in Examples 1 to 8, if the same type of source follower circuit is selected for the first source follower circuit and the plurality of source follower circuits, , Easy to control temperature characteristics and output voltage characteristics. That is, when the current is not constantly taken out from the outputs of the first source follower circuit and the plurality of source follower circuits or the same current is taken out,
The output voltages of the source follower circuit and the plurality of source follower circuits are all the same.

The most advantageous point of the circuit of this example is that
This means that there is almost no mutual interference between multiple source follower circuits. That is, even if one of the outputs of the plurality of source follower circuits fluctuates due to the load fluctuation, it has almost no effect on the outputs of the other source follower circuits. In application fields such as voltage converters and composite power supplies, it is often composed of both analog and digital circuit sections, and the analog section is easily affected by the switching operation of the digital circuit section. It is a reference voltage circuit that can minimize the influence from the digital section to the analog section through the reference voltage circuit.

In the description of the circuit operation up to this point, the case where the reference voltage circuit is configured by N-channel MOS transistors has been described. However, the P-channel depletion type MOS transistor and the P-channel enhancement type MOS transistor are When they can be formed on the same substrate, it is clear that the same operation can be realized by reversing the polarities in the above description.

Further, it is possible to replace one FET or resistor of the circuit examples so far with a series or parallel combination of a plurality of FETs or resistors of the same kind, and even if they are replaced, operation is possible. It is clear that the principle does not change.

[0083]

As shown in Examples 1 to 9, the temperature characteristics of the output voltage of the reference voltage circuit can be freely adjusted by adjusting the conductivity of the first transistor and the second transistor. By adjusting the resistance value of the load which is the load of the third transistor and the source follower circuit and the transistor conductivity, the output impedance can be freely adjusted to a low value irrespective of the temperature characteristics. In the case of being provided in, the output can be taken out of the semiconductor integrated circuit, and at the same time, the reference voltage circuit in which the output voltage does not change even if the current is taken out from the output of the reference voltage circuit can be realized.

As shown in Example 3, the temperature characteristics of the output voltage of the reference voltage circuit are adjusted by adjusting the conductivity of the first transistor and the second transistor with respect to the temperature change rate of the resistance. It is possible to realize a reference voltage circuit in which the temperature coefficient of the constant voltage circuit can be adjusted freely.

As shown in Example 4, a CMOS IC in which a lower output impedance is required for the reference voltage circuit due to a change in factors outside the reference voltage circuit such as the power supply voltage
It is possible to realize a reference voltage circuit that can deal with the above.

As shown in Example 5, a MOS having the same performance as the temperature characteristic of the output voltage can be freely adjusted.
When the circuit is composed of transistors, it is possible to realize a reference voltage circuit that operates stably up to a voltage higher than that of the conventional reference voltage circuit, that is, has a lower operation lower limit voltage and a higher operation upper limit voltage than the conventional reference voltage circuit.

As shown in Example 6, the temperature characteristic of the output voltage can be freely adjusted by adjusting the ratio of the values of the resistance 1 and the resistance 2 of the load of the source follower circuit, and at the same time, the output voltage can be freely adjusted. It is possible to realize an adjustable reference voltage circuit. As shown in Example 6, the temperature characteristics of the output voltage of the reference voltage circuit are adjusted by adjusting the conductivity of the first transistor and the second transistor with respect to the temperature change rate of the resistance. By adjusting the ratio of the values of resistance 1 and resistance 2 of the load, it is possible to realize a reference voltage circuit in which the temperature coefficient of the constant current circuit and the output current of the constant current circuit can be adjusted freely.

As shown in Example 7, it is possible to switch between the standby state and the operating state, and it is possible to realize a reference voltage circuit having an output impedance lower than that in the standby state in the operating state.

In addition to the first power source as shown in Example 8,
The second power source and the third power source are provided, and the temperature coefficient of the constant current circuit and the output current of the constant current circuit as shown in Examples 3 and 6 are provided between the second power source and the third power source. It is possible to realize a reference voltage circuit that can be freely adjusted.

By preparing the reference voltage circuit of the present invention and a plurality of source follower circuits as shown in Example 9, a reference voltage circuit having a plurality of reference voltage outputs with almost no mutual interference between outputs can be constructed. You can

[Brief description of drawings]

FIG. 1 is a circuit diagram of Example 1 of the present invention.

FIG. 2 is a circuit diagram of Example 2 of the present invention.

FIG. 3 is a circuit diagram of Example 3 of the present invention.

FIG. 4 is a graph showing a temperature change of a current flowing through a resistor according to Example 3 of the present invention.

FIG. 5 is a parameter table of transistors and resistors according to Example 3 of the present invention.

FIG. 6 is a circuit diagram of Example 4 of the present invention.

FIG. 7 is a circuit diagram of Example 5 of the present invention.

FIG. 8 is a graph showing the voltage between the source terminal and the drain terminal of each transistor of Example 5 of the present invention.

FIG. 9 is a circuit diagram of Example 6 of the present invention.

FIG. 10 is a circuit diagram of Example 7 of the present invention.

FIG. 11 is a circuit diagram of Example 8 of the present invention.

FIG. 12 is a circuit diagram of a modified example of Example 1 of the present invention.

FIG. 13 is a circuit diagram of a modified example of Example 6 of the present invention.

FIG. 14 is a circuit diagram of Example 9 of the present invention.

[Explanation of symbols]

1 is the first transistor. 2 is the second transistor. Three
Is the third transistor. 4 is resistance. 5 is the fourth transistor. 6 is the fifth transistor. 7 is the sixth transistor. 8 is the first power supply. 9 is the first output terminal of the reference voltage circuit. 10 is the second output terminal of the reference voltage circuit. 11 is an output terminal to the constant current circuit. 12 is a 7th transistor. Thirteen
Is the ninth transistor. 14 is a constant current circuit load. 15
Is the source follower circuit part. 16 is a constant current circuit part.
17 is a tenth transistor. 18 is a voltage detection resistor. 1
9 is a source resistance. 20 is a resistor 1.21, 21 is a resistor 2.22 is an eighth transistor. 23 is the eleventh transistor. Two
4 is a constant current circuit load 1. 25 is a constant current circuit load 2.
26 is an output terminal 1 to the constant current circuit, 27 is an output terminal 2 to the constant current circuit, and 28 is a second power supply. 29 is the third power supply.
30 is an on / off control terminal. 31 is a first source follower circuit. 32 is a plurality of source follower circuits. 33 is a power supply 1 for the source follower circuit, and 34 is a power supply 2 for the source follower circuit.

Claims (7)

[Claims] 1. A first transistor which is a depletion type MOS transistor, a second transistor which is a MOS transistor of the same conductivity type as the first transistor, a source follower circuit, and a first voltage supply terminal. A second voltage supply terminal, a voltage supply terminal 1 to the source follower circuit, and a voltage supply terminal 2 to the source follower circuit are provided, and the drain terminal of the first transistor is connected to the first voltage supply terminal, The gate terminal of the first transistor and the source terminal of the first transistor are connected to the second terminal.
Connected to the drain terminal of the transistor, the source terminal of the second transistor to the second voltage supply terminal, and the gate terminal of the second transistor to the output terminal of the source follower circuit or the output voltage of the source follower circuit. The input terminal of the source follower circuit is connected to the connection point of the first transistor and the second transistor, and the connection point of the first transistor and the second transistor and the output terminal of the source follower circuit. A reference voltage circuit that can extract the reference output voltage from both or one side. 2. A source follower circuit comprises a third transistor, which is a MOS transistor of the same conductivity type as the first transistor, and a load of the source follower circuit,
The drain terminal of the third transistor is connected to the voltage supply terminal 1 for the source follower circuit, and the gate terminal of the third transistor is used as the input terminal of the source follower circuit.
The first terminal of the load of the source follower circuit is connected to the source terminal of the third transistor, and the second terminal of the load of the source follower circuit is connected between the voltage supply terminals 2 to the source follower circuit, The reference voltage circuit according to claim 1, wherein a connection point between the transistor and the load of the source follower circuit is an output terminal of the source follower circuit. 3. A source follower circuit comprises a third transistor which is a MOS transistor of the same conductivity type as the first transistor, a source resistor and a load of the source follower circuit, and the drain terminal of the third transistor is a source follower. It is connected to the voltage supply terminal 1 to the circuit, the gate terminal of the third transistor is used as the input terminal of the source follower circuit, the first terminal of the source resistance is connected to the source terminal of the third transistor, and the second terminal of the source resistance is connected. The terminal is connected to the first terminal of the load of the source follower circuit, the second terminal of the load of the source follower circuit is connected to the voltage supply terminal 2 to the source follower circuit, and the source resistance and the load of the source follower circuit are connected. The reference voltage circuit according to claim 1, wherein the connection point is an output terminal of the source follower circuit. 4. The load of the source follower circuit is a resistor, a fourth transistor which is a depletion type MOS transistor of the same conductivity type as the first transistor, or a MOS transistor of the same conductivity type as the first transistor. A fifth transistor or a sixth transistor which is a MOS transistor of the same conductivity type as that of the first transistor, wherein both ends of the resistor are respectively a first terminal and a second terminal, or a fourth transistor The drain terminal of the fifth transistor as the first terminal and the gate terminal of the fourth transistor and the source terminal of the fourth transistor as the second terminal, or the drain terminal of the fifth transistor as the first terminal. Terminal, the source terminal of the fifth transistor is the second terminal, and the gate terminal of the fifth transistor is the reference voltage circuit The bias voltage input terminal from the outside is used, or the drain terminal of the sixth transistor is the first terminal, the source terminal of the sixth transistor is the second terminal, and the gate terminal of the sixth transistor is the reference voltage circuit. 2. The reference voltage circuit according to claim 1, wherein the on / off control voltage input terminal is externally applied. 5. The load of the source follower circuit comprises:
5. A composite element in which an element selected from the resistor, the fourth transistor of claim 4, the fifth transistor of claim 4, and the sixth transistor of claim 4 are combined, and the first terminal of each element. And the second terminal are connected in series, or the first terminals of the respective elements are connected in parallel, and the second terminals of the respective elements are connected in parallel,
Alternatively, the reference voltage circuit according to claim 1, wherein the directly connected composite elements are further connected in parallel to be connected in series and parallel. 6. The source follower circuit according to claim 2, wherein the source follower circuit includes a third transistor, which is a MOS transistor of the same conductivity type as the first transistor, and a load of the source follower circuit. The seventh transistor, which is a conductive type MOS transistor, or the same conductive type MO as the first transistor.
The eighth transistor, which is an S transistor, or the seventh transistor
In the circuit in which both the transistor and the eighth transistor are added, when the seventh transistor is added, the voltage supply terminal 1 to the source follower circuit is disconnected from the third transistor, and the seventh transistor Is connected to the voltage supply element 1 for the source follower circuit, the drain terminal of the seventh transistor and the gate terminal of the seventh transistor are connected to the drain terminal of the third transistor, and the eighth transistor is connected. When adding, the voltage supply terminal 2 to the source follower circuit and the load of the source follower circuit are not disconnected, the source terminal of the eighth transistor is connected to the voltage supply terminal 2 to the source follower circuit, and the eighth transistor Drain terminal and 8th
The gate terminal of the transistor is connected to the second terminal of the load of the source follower circuit, and the connection point between the drain terminal of the third transistor and the load of the third transistor and the source follower circuit is output from the source follower circuit. The connection point between the third transistor and the seventh transistor, the load of the source follower circuit, and the terminal
The reference voltage circuit according to claim 1, wherein an output voltage to the constant current circuit can be taken out from a connection point with the transistor of. 7. A voltage supply terminal 1 for a source follower circuit.
The reference voltage circuit according to claim 1, wherein both or one of the first voltage supply terminal and the combination of the voltage supply terminal 2 for the source follower circuit and the second voltage supply terminal are common.