CN115373460A - Voltage reference source and integrated circuit - Google Patents
Voltage reference source and integrated circuit Download PDFInfo
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- CN115373460A CN115373460A CN202211128436.XA CN202211128436A CN115373460A CN 115373460 A CN115373460 A CN 115373460A CN 202211128436 A CN202211128436 A CN 202211128436A CN 115373460 A CN115373460 A CN 115373460A
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- G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
- G05F1/56—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
- G05F1/565—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor
- G05F1/567—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor for temperature compensation
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Abstract
The invention discloses a voltage reference source and an integrated circuit, and relates to the technical field of integrated circuits, wherein a first output end of an adjustable current generation module is connected with a delta VGS generation module, and a second output end of the adjustable current generation module is connected with an output module; the delta VGS generation module is connected with the first transistor, and the output end of the delta VGS generation module is connected with the output module; the transistor and the first transistor in the delta VGS generation module work in a sub-threshold region, the delta VGS generation module is used for outputting delta VGS voltage, and the adjustable current generation module is used for adjusting the delta VGS voltage to be a value of the threshold voltage of the first transistor extending to absolute zero degree so as to output reference voltage. When the value of the Δ VGS voltage is equal to the value of the threshold voltage of the first transistor extending to absolute zero degrees, the output reference voltage is made constant independent of temperature under given process conditions and device dimensions, and the current flowing to the output module is made to have uT 2 A characteristic reference current.
Description
Technical Field
The present invention relates to the field of integrated circuit technologies, and in particular, to a voltage reference source and an integrated circuit.
Background
The conventional bandgap voltage reference source can provide a reference voltage with an extremely low temperature coefficient, so that the bandgap voltage reference source is widely applied to various integrated circuit products, but due to the structural characteristics of the bandgap voltage reference source, the bandgap voltage reference source generally has the disadvantages of high power consumption and large area. Under the application occasions that a battery-free power supply system based on energy collection or battery power supply needs to meet the requirement of ultra-long standby time, a reference source needs to have the performance of nano-watt or even pico-watt power consumption, and the products are sensitive to the cost of chip area due to the characteristic of large-scale deployment, while a band-gap reference source is usually in the micro-watt level and has large area, so that the band-gap reference source is not suitable for the applications.
The nano watt power consumption voltage reference source is usually realized based on the threshold voltage of the MOS transistor extending to the absolute zero value VTH0, most MOS transistors in the circuit work under the sub-threshold condition so as to achieve the purpose of extremely low power consumption, and the circuit is realized without a passive resistor so as to achieve the purposes of reducing the area of a chip and reducing the cost. Common realization modes of the circuit comprise a double-tube structure, a three-tube structure, a circuit structure based on the zero-temperature-drift operating point characteristic of an MOS (metal oxide semiconductor) transistor and a circuit structure based on uT (ultra-thin transistor) 2 Reference to the voltage source configuration of the current, etc. The double-tube structure and the triple-tube structure have high sensitivity to the process and are difficult to control in temperature coefficient although the power consumption is extremely low and the structures are simple. The current research on the circuit structure based on the zero temperature drift operating point characteristic of the MOS transistor is not sufficient.
The most fully studied reference source of nanowatt power consumption based on the threshold voltage of MOS transistors, which is currently composed of two parts, the first one, which generates a reference voltage with uT 2 The second portion generates a low temperature coefficient voltage reference based on the threshold voltage in a combination of VGS and Δ VGS. In a typical CMOS nano watt power consumption voltage reference source structure based on threshold voltage, uT is provided 2 The characteristic reference current generation circuit of (1) is generally composed of four core transistors and a current mirror, and the low temperature coefficient voltage reference generated by combining VGS and delta VGS based on threshold voltage is composed of at least three transistors. Therefore, without the need of auxiliary circuits such as current mirrors, a typical structure of a nanowatt power consumption reference source based on the threshold voltage of MOS transistors is composed of at least seven transistors, and the voltage reference thus generated usually does not have the capability of driving a resistive load, and a driving buffer circuit needs to be additionally added.
Therefore, how to reduce the number of transistors in the voltage reference source and provide a reference source with a simple structure is a problem that needs to be solved by those skilled in the art.
Disclosure of Invention
The invention aims to provide a voltage reference source, which can generate a low-temperature coefficient reference voltage by only arranging a small number of transistors and has uT 2 A characteristic reference current; another object of the present invention is to provide an integrated circuit that requires only a small number of transistors to generate a low temperature coefficient reference voltage and has a uT 2 A characteristic reference current.
In order to solve the above technical problem, the present invention provides a voltage reference source, which includes a first transistor, a Δ VGS generation module, an adjustable current generation module, and an output module;
the adjustable current generation module comprises at least a first output end and a second output end, the first output end is connected with the delta VGS generation module, and the second output end is connected with the output module; the delta VGS generation module is connected with the first transistor, and the output end of the delta VGS generation module is connected with the output module;
the delta VGS generation module is used for outputting delta VGS voltage, and the adjustable current generation module is used for adjusting the delta VGS voltage to be a value of the threshold voltage of the first transistor extending to absolute zero degree so as to output reference voltage.
Optionally, the output module includes an output transistor, a gate of the output transistor is connected to the output end of the Δ VGS generation module, a drain of the output transistor is connected to the second output end, and the output transistor operates in a saturation region.
Optionally, the threshold voltage of the first transistor is equal to the threshold voltage of the output transistor, and the output end of the Δ VGS generation module is directly connected to the gate of the output transistor.
Optionally, the output end of the Δ VGS generation module is connected to the buffer, the buffer is connected to the gate of the output transistor, and the buffer is used to compensate for an error caused by a difference between the threshold voltage of the first transistor and the threshold voltage of the output transistor.
Optionally, the buffer is a linear buffer.
Optionally, the linear buffer includes an operational amplifier, and a feedback network connected to the operational amplifier, and the output terminal of the Δ VGS generation module is connected to the operational amplifier.
Optionally, the adjustable current generating module includes a current mirror, and the current mirror includes a first output end transistor connected to the first output end, and a second output end transistor connected to the second output end.
Optionally, the Δ VGS generation module includes a Δ VGS generation unit, the Δ VGS generation unit includes a second transistor and a third transistor, a drain of the second transistor is connected to a source of the third transistor, a drain of the third transistor is connected to the first output terminal, and a gate of the second transistor and a gate of the third transistor are both connected to the first output terminal.
Optionally, the Δ VGS generation module includes a plurality of Δ VGS generation units, and the Δ VGS generation units are connected in series; the current mirror comprises first output end transistors in one-to-one correspondence with the delta VGS generation units, and the first output end transistors are connected with the corresponding delta VGS generation units.
The invention also provides an integrated circuit comprising a voltage reference source as claimed in any one of the preceding claims.
The invention provides a voltage reference source, which comprises a first transistor, a delta VGS generation module, an adjustable current generation module and an output module; the adjustable current generation module comprises at least a first output end and a second output end, the first output end is connected with the delta VGS generation module, and the second output end is connected with the output module; the delta VGS generation module is connected with the first transistor, and the output end of the delta VGS generation module is connected with the output module; the delta VGS generation module is used for adjusting the delta VGS voltage to be a value of the threshold voltage of the first transistor extending to absolute zero degree, so as to output a reference voltage.
The specific value of the delta VGS voltage can be adjusted through the adjustable current generation module, when the value of the delta VGS voltage is equal to the value of the threshold voltage of the first transistor extending to absolute zero degree, the output reference voltage is constant which is not changed along with temperature under the given process condition and the device size, and the current flowing to the output module is enabled to have uT 2 A characteristic reference current. By embedding a circuit structure combining VGS and delta VGS with uT 2 In the characteristic reference current circuit structure of (3), a reference voltage having a low temperature coefficient is obtained by adjusting a ratio coefficient of a current. Except for the auxiliary circuit, the whole functions of the two can be realized by only needing four transistors at least, and the using number of the transistors is greatly reduced.
The invention also provides an integrated circuit which also has the beneficial effects, and the description is omitted.
Drawings
In order to more clearly illustrate the embodiments or technical solutions of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a voltage reference source according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a specific voltage reference source according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another exemplary voltage reference source according to an embodiment of the present invention;
FIG. 4 shows the output voltage V of the voltage reference source REF Curve as a function of temperature.
In the figure: the amplifier comprises a delta VGS generation module 1, a delta VGS generation unit 11, an adjustable current generation module 2, an output module 3, a buffer 4, a first transistor M1, a second transistor M2/M21/M22 … M2N, a third transistor M3/M31/M32 … M3N, an output transistor M4, a first output end transistor M5/M51/M52 … M5N, a second output end transistor M6, an operational amplifier A1 and a feedback network beta 1.
Detailed Description
The core of the invention is to provide a voltage reference source. In the prior art, with uT 2 The characteristic reference current generation circuit of (1) is generally composed of four core transistors and a current mirror, and the low temperature coefficient voltage reference generated by combining VGS and delta VGS based on threshold voltage is composed of at least three transistors. Therefore, without considering auxiliary circuits such as a current mirror, a typical structure of a nanowatt power consumption reference source based on the threshold voltage of a MOS transistor is composed of at least seven transistors.
The voltage reference source provided by the invention comprises a first transistor, a delta VGS generation module, an adjustable current generation module and an output module; the adjustable current generation module comprises at least a first output end and a second output end, the first output end is connected with the delta VGS generation module, and the second output end is connected with the output module; the delta VGS generation module is connected with the first transistor, and the output end of the delta VGS generation module is connected with the output module; the delta VGS generation module is used for adjusting the delta VGS voltage to be a value of the threshold voltage of the first transistor extending to absolute zero degree, so as to output a reference voltage.
The specific value of the delta VGS voltage can be adjusted through the adjustable current generation module, when the value of the delta VGS voltage is equal to the value of the threshold voltage of the first transistor extending to absolute zero degree, the output reference voltage is constant which is not changed along with temperature under the given process condition and device size, and the current flowing to the output module is enabled to have uT 2 A characteristic reference current. Embedding a circuit structure with a combination of VGS and Δ VGS 2 In the characteristic reference current circuit structure of (3), a reference voltage having a low temperature coefficient is obtained by adjusting a ratio coefficient of a current. Except for the auxiliary circuit, the whole functions of the two can be realized by only needing four transistors at least, and the using number of the transistors is greatly reduced.
In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a voltage reference source according to an embodiment of the present invention.
Referring to fig. 1, in the embodiment of the present invention, the voltage reference source includes a first transistor M1, a Δ VGS generation module 1, an adjustable current generation module 2, and an output module 3; the adjustable current generation module 2 comprises at least a first output end and a second output end, the first output end is connected with the delta VGS generation module 1, and the second output end is connected with the output module 3; the delta VGS generation module 1 is connected with the first transistor M1, and the output end of the delta VGS generation module 1 is connected with the output module 3; the transistor in the Δ VGS generation module 1 and the first transistor M1 both operate in a sub-threshold region, the Δ VGS generation module 1 is configured to output a Δ VGS voltage, and the adjustable current generation module 2 is configured to adjust the Δ VGS voltage to a value where the threshold voltage of the first transistor M1 extends to absolute zero, so as to output a reference voltage.
The first transistor M1 is used for generating a gate-source voltage VGS, one end of the first transistor M1 is usually connected to ground, the other end of the first transistor M1 needs to be connected to the Δ VGS generating module 1, and the Δ VGS generating module 1 is used for generating a Δ VGS voltage. The delta VGS voltage is a voltage obtained by a difference between the gate-source voltages VGS corresponding to the two transistors, i.e., the delta VGS voltage. Therefore, the Δ VGS generation module 1 at least includes two transistors to generate two gate-source voltages VGS and perform a difference to obtain the Δ VGS voltage. The first transistor M1 is used for generating an output Δ VGS voltage in combination with the Δ VGS generation module 1, and then the Δ VGS voltage is adjusted by the adjustable current generation module 2, so as to obtain a reference voltage with a low temperature coefficient.
The adjustable current generating module 2 comprises at least a first output terminal and a second output terminal, wherein the first output terminal is connected to the Δ VGS generating module 1, the second output terminal is connected to the output module 3, and the output terminal of the Δ VGS generating module 1 is also connected to the output module 3. The adjustable current generation module 2 may be a current mirror or any other structure, and the adjustable current generation module 2 is configured to generate a current with an adjustable proportion, and may specifically adjust a proportion of a current flowing between the first output terminal and the second output terminal, so as to adjust the output voltage of the Δ VGS generation module 1.
The output module 3 generally has three terminals, one terminal is connected to the second output terminal of the adjustable current generating module 2, one terminal is connected to the output terminal of the Δ VGS generating module 1, and the last terminal is grounded.
In actual operation, the first transistor M1 and the transistors in the Δ VGS generation module 1 operate in a sub-threshold region, and the transistors are in a sub-threshold state. For details of the sub-threshold region, reference may be made to the prior art, and further description is omitted here.
Specifically, in the embodiment of the present invention, the output module 3 includes an output transistor M4, a gate of the output transistor M4 is connected to the output end of the Δ VGS generation module 1, a drain of the output transistor M4 is connected to the second output end, and the output transistor M4 operates in a saturation region.
The output module 3 may be specifically a transistor, that is, the output transistor M4, a gate of the output transistor M4 needs to be connected to the output terminal of the Δ VGS generating module 1, a drain of the output transistor M4 needs to be connected to the second output terminal of the adjustable current generating module 2, and a source of the output transistor M4 generally needs to be grounded. When the output transistor M4 works in a saturation region, the emitting junction and the collecting junction of the output transistor M4 are positively biased, and the collecting current is not controlled by the base current. When the Δ VGS voltage is equal to the threshold voltage of the first transistor M1 extending to the absolute zero, the reference voltage outputted by the voltage reference source provided by the embodiment of the present invention is equal to the threshold voltage of the output transistor M4 extending to the absolute zero, and the reference voltage has an extremely low temperature coefficient.
Specifically, the adjustable current generating module 2 includes a current mirror, and the current mirror includes a first output end transistor M5 connected to the first output end, and a second output end transistor M6 connected to the second output end.
Specifically, in the embodiment of the present invention, a current mirror is used as the adjustable current generating module 2, and the current mirror is used to control the output current ratio between the first output terminal and the second output terminal, so as to control the magnitude of the Δ VGS voltage output by the Δ VGS generating module 1. The current mirror comprises a first output end transistor M5 and a second output end transistor M6, wherein the first output end transistor M5 is connected with a first output end and is connected with the delta VGS generation module 1; the second output terminal transistor M6 is connected to the second output terminal and connected to the output module 3. Specifically, the gate of the first output end transistor M5 is connected to the gate of the second output end transistor M6, the drain of the first output end transistor M5 needs to be connected to the Δ VGS generation module 1, and the drain of the second output end transistor M6 needs to be connected to the output module 3.
Specifically, the Δ VGS generation module 1 includes a Δ VGS generation unit 11, where the Δ VGS generation unit 11 includes a second transistor M2 and a third transistor M3, a drain of the second transistor M2 is connected to a source of the third transistor M3, a drain of the third transistor M3 is connected to the first output terminal, and a gate of the second transistor M2 and a gate of the third transistor M3 are both connected to the first output terminal.
The drain of the second transistor M2 needs to be connected to the source of the third transistor M3, and the gate of the second transistor M2, the gate of the third transistor M3 and the drain of the third transistor M3 need to be connected to the first output terminal of the adjustable current generating module 2. The first transistor M1 is diode-connected to the second transistor M2, i.e., the drain and gate of the first transistor M1 are connected to the source of the second transistor M2. At this time, the connection between the drain of the second transistor M2 and the source of the third transistor M3 may output the Δ VGS voltage.
It should be noted that, because the circuit structure of the voltage reference source has a degenerate operating point, in a specific implementation, a start circuit needs to be added to the circuit provided in the embodiment of the present invention, and specific contents of the start circuit may refer to the prior art, which is not described herein again.
In the embodiment of the present invention, the Δ VGS voltage output by the Δ VGS generation module 1 needs to be adjusted by the adjustable current generation module 2 to be equal to the value of the threshold voltage of the first transistor M1 extending to absolute zero, and the finally output reference voltage is equal to the value of the threshold voltage of the output transistor M4 extending to absolute zero. Therefore, in the embodiment of the present invention, a buffer structure may be additionally disposed between the output end of the Δ VGS generation module 1 and the output module 3, and the detailed content thereof will be described in detail in the following embodiments of the present invention. In the embodiment of the present invention, the threshold voltage of the first transistor M1 may be set to be equal to the threshold voltage of the output transistor M4, and at this time, the buffering structure may be omitted, so that the output terminal of the Δ VGS generation module 1 is directly connected to the gate of the output transistor M4.
In the embodiment of the present invention, the output reference voltage is applied to the output transistor M4 to generate a pull-down current. The pull-down current can be mirrored to the first output terminal transistor M5 through the second output terminal transistor M6 to supply power, so that the dependence of the adjustable current generation module 2 on an external power supply is reduced, and the interference of the external current on the voltage reference source provided by the embodiment of the invention is reduced.
According to the voltage reference source provided by the embodiment of the invention, the specific value of the Δ VGS voltage can be adjusted through the adjustable current generation module 2, when the value of the Δ VGS voltage is equal to the value of the threshold voltage of the first transistor M1 extending to absolute zero, the output reference voltage is a constant which does not change with temperature under given process conditions and device sizes, and the current flowing to the output module 3 is made to have uT 2 A characteristic reference current. By embedding a circuit structure combining VGS and delta VGS with uT 2 In the characteristic reference current circuit structure of (3), a reference voltage having a low temperature coefficient is obtained by adjusting a ratio coefficient of a current. With the exception of auxiliary circuitry, a minimum of four transistors is required to achieve all of the work of bothThe number of transistors used can be greatly reduced.
The detailed structure of a voltage reference source provided by the present invention will be described in detail in the following embodiments of the present invention.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a specific voltage reference source according to an embodiment of the present invention.
Different from the above embodiment of the invention, the embodiment of the invention further defines the structure of the voltage reference source on the basis of the above embodiment of the invention, and the rest of the contents are described in detail in the above embodiment of the invention and are not described again here.
Referring to fig. 2, in the embodiment of the present invention, the Δ VGS generation module 1 includes a plurality of Δ VGS generation units 11, and the Δ VGS generation units 11 are connected in series; the current mirror includes first output end transistors M5 corresponding to the Δ VGS generation units 11, and the first output end transistors M5 are connected to the corresponding Δ VGS generation units 11.
That is, in the embodiment of the present invention, a plurality of Δ VGS generation units 11 may be provided in total, and the plurality of Δ VGS generation units 11 need to be connected in series with each other. In this case, the Δ VGS generation units 11 are connected in series, which means that the output end of the previous Δ VGS generation unit 11 in the current direction is connected to the end of the next Δ VGS generation unit 11 that originally needs to be connected to the first transistor M1, that is, the output end of the previous Δ VGS generation unit 11 in the current direction needs to be connected to the source of the second transistor M2 in the next Δ VGS generation unit 11, so as to form a series structure. In this case, in the series configuration, the Δ VGS generation unit 11 located at the head needs to be connected to the first transistor M1, and the Δ VGS generation unit 11 located at the tail needs to be connected to the output module 3.
Accordingly, a plurality of first output transistors M5 are disposed in the current mirror to form a plurality of first output terminals, and the first output transistors M5 and the Δ VGS generating units 11 need to be in one-to-one correspondence. The first output end transistor M5 needs to be connected to the corresponding Δ VGS generating unit 11, specifically, the drain of the first output end transistor M5 needs to be connected to the drain of the third transistor M3 in the corresponding Δ VGS generating unit 11 in the current mirror provided with a plurality of first output end transistors M5, and the gate of each first output end transistor M5 needs to be connected to the second output end transistor M6, so as to form N current proportion parameters from K1 to KN.
In the embodiment of the present invention, the plurality of Δ VGS generation units 11 are arranged to conveniently adjust the temperature coefficient, and adjust different current magnitudes according to actual needs, so that the voltage reference source is adapted to various temperature coefficients, and can work under various working conditions.
The detailed structure of a voltage reference source provided by the present invention will be described in detail in the following embodiments of the present invention.
Referring to fig. 3 and 4, fig. 3 is a schematic structural diagram of another specific voltage reference source according to an embodiment of the invention; FIG. 4 shows the output voltage V of the voltage reference source REF Curve as a function of temperature.
Different from the above embodiment of the invention, the embodiment of the invention further defines the structure of the voltage reference source on the basis of the above embodiment of the invention, and the rest of the contents are described in detail in the above embodiment of the invention and are not described again here.
Referring to fig. 3, in the embodiment of the present invention, the voltage reference source further includes a buffer 4, the output terminal of the Δ VGS generation module 1 is connected to the buffer 4, the buffer 4 is connected to the gate of the output transistor M4, and the buffer 4 is used for compensating an error caused by a difference between the threshold voltage of the first transistor M1 and the threshold voltage of the output transistor M4.
When the threshold voltage of the first transistor M1 is different from the threshold voltage of the output transistor M4, a buffer 4 needs to be disposed between the Δ VGS generation module 1 and the output module 3, that is, the output terminal of the Δ VGS generation module 1 is connected to the buffer 4, and the buffer 4 is connected to the gate of the output transistor M4. The buffer 4 can compensate for errors caused by different threshold voltages between the first transistor M1 and the output transistor M4, and can provide a reference voltage V as the output buffer 4 REF The ability to drive a resistive load.
Specifically, in the embodiment of the present invention, the buffer 4 is specifically a linear buffer 4, the linear buffer 4 may specifically include an operational amplifier A1, and a feedback network β 1 connected to the operational amplifier A1, an output end of the Δ VGS generation module 1 is connected to the operational amplifier A1, and an output end of the operational amplifier A1 is used for connecting to the output module 3.
The implementation principle of the voltage reference source will be described below by taking fig. 3 as an example.
The first transistor M1 is a diode-connected MOS transistor, the gate-source voltage of which is VGS1, the drain of the first transistor M1 is connected to the source of the second transistor M21, the Δ VGS circuit structure formed by the second transistor M21 and the third transistor M31 is such that the drain-source voltage of the second transistor M21 is the difference between the gate-source voltages VGS of the two transistors of the second transistor M21 and the third transistor M31, and the difference is Δ VGS1, the N Δ VGS circuit structures are connected in series as shown in fig. 3, the voltage obtained at the output end of the series of N Δ VGS circuits is V0, the operational amplifier A1 and the feedback network β 1 form a linear buffer 4 with a feedback coefficient β 1, which serves to compensate for errors caused by the difference between the threshold voltages of the first transistor M1 and the output transistor M4 on the one hand, and to provide a reference voltage V as the output buffer 4 on the other hand REF The ability to drive a resistive load. V0 obtains a reference voltage V through a linear buffer A1/beta 1 REF ：
V 0 ＝V GS1 +AV GS1 +ΔV GS2 +…+ΔV GSN
V REF V 0 /β 1
At this time, the reference voltage V REF The gate applied to the output transistor M4 generates a current Id4, and the output transistor M4 is designed to operate in the saturation region in the embodiment of the present invention, the expression of the current is approximated as:
the second output terminal transistor M6, the first output terminal transistors M51, M52 to M5N constitute a current mirror, and ratios between the width-to-length ratios of the first output terminal transistors M51, M52 to M5N and the width-to-length ratio of the second output terminal transistor M6 are K1, K2 to KN, respectively. The first transistor M1, the second transistors M21 to M2N, and the third transistors M31 to M3N are proposed to operate in the sub-threshold region, and the drain current-voltage relationship of the first transistor M1 is:
I d1 ＝I d4 (K1+K2+…+KN)
in the above formula
T is absolute temperature, k is Boltzmann constant, q is electron electric quantity, μ n Is the electron mobility, C ox Is the gate oxide unit area capacitance and n is the sub-threshold gradient factor. If V REF Is a temperature independent reference voltage and has a value exactly equal to the threshold voltage VTH4 of the output transistor M4 extended to a value VTH4 — 0 of absolute zero degrees, I can be known from the above formula d4 ＝Kμ n T 2 Where K is a constant coefficient independent of temperature, and the currents of other branches are all equal to I d4 In proportion. So that the circuit can generate the signal with uT 2 And outputting the characteristic current. Is to be full of V REF Is a temperature-independent reference voltage and has a value exactly equal to the value VTH40 of the threshold voltage VTH4 of the output transistor M4, which extends to absolute zero, according to the above formula, and I d4 ＝Kμ n T 2 The following can be obtained:
V 0 ＝V TH1 +αV T
where VTH1 has a negative temperature coefficient and α is a positive temperature coefficient whose value is mainly determined by the current mirror scaling factor and the transistor size scaling, V0 can be made equal to VTH1 — 0 by adjusting these parameters, i.e. the threshold voltage of the first transistor M1 is extended to a value of absolute zero. As long as the feedback coefficient β 1 of the linear buffer 4 is adjusted such that:
V TH4_0 ＝V TH1_0 /β 1
when the above conditions are satisfied, I can be obtained d4 ＝Kμ n T 2 And when V0 is equal to VTH1_0,V REF Equal to VTH4_0, where VTH1_0 and VTH4_0 are values when the threshold voltages of the first transistor M1 and the output transistor M4, respectively, are extended to absolute zero, both constants that do not change with temperature given the process conditions and device dimensions. Therefore, the circuit realized by the invention can generate uT at the same time 2 The characteristic current and the reference voltage of low temperature coefficient, because the circuit only uses the transistor, and the transistor mainly works in the subthreshold region, the circuit has the advantages of extremely low power consumption and small area, and the circuit simultaneously provides the linear buffer driving function of the embedded reference voltage. The linear voltage buffer 4 can also be omitted if the threshold voltages of the first transistor M1 and the output transistor M4 are equal and the reference voltage does not require additional driving capability, as shown in fig. 2. Because the circuit has a degenerate operating point, in the specific implementation, a starting circuit is required to be added to the circuit provided by the invention, and the structure of the starting circuit is determined according to the specific situation.
Compared with fig. 3, in fig. 1 of the present application, specifically, in fig. 3, the first transistor M1 and the output transistor M4 are designed as transistors with equal threshold voltages, the linear buffer 4 formed by the operational amplifier A1 and the feedback network β 1 in fig. 3 is removed, and in the N Δ VGS circuit structures connected in series in fig. 3, N takes a value of 1, that is, only one Δ VGS circuit structure is used. The output voltage is modified by adjusting the ratio K between the first output terminal transistor M5 and the second output terminal transistor M6. Since the circuit has degeneracy points, the actual circuit needs to be started up to work, the content of which is determined by the specific situation, and is therefore only shown in schematic block form in fig. 1. Output reference voltage V REF The theoretical value of (1) is a value when the threshold voltage of the output transistor M4 extends to absolute zero, in this embodiment, a typical 65nm CMOS process is adopted, and a curve of the reference voltage changing with temperature is obtained through simulation, as shown in fig. 4, the reference voltage value is 596mV, the voltage temperature coefficient between forty degrees centigrade and one hundred twenty five degrees centigrade is 13ppm, and the total current is about 200nA. The core structure of the circuit comprises only the first transistor M1. The second transistor M2, the third transistor M3 and the output transistor M4 are four transistors in total, and uT is realized 2 The current source and the low temperature drift voltage source have two functions. The current source structure provided by the application can be realized by using not only an NMOS but also a PMOS, and only the NMOS transistor and the PMOS transistor in the figure need to be interchanged and inverted.
The invention also provides an integrated circuit comprising the voltage reference source provided by any one of the embodiments of the invention. For the rest of the structure of the integrated circuit, reference may be made to the prior art, and further description is omitted here.
The voltage reference source provided by the embodiment of the invention can generate the reference voltage with low temperature coefficient by only a small number of transistors and has uT 2 The characteristic reference current can correspondingly achieve smaller area of the integrated circuit, and is beneficial to miniaturization of the integrated circuit.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
The voltage reference source and the integrated circuit provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, it is possible to make various improvements and modifications to the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
Claims (10)
1. A voltage reference source is characterized by comprising a first transistor, a delta VGS generation module, an adjustable current generation module and an output module;
the adjustable current generation module comprises at least a first output end and a second output end, the first output end is connected with the delta VGS generation module, and the second output end is connected with the output module; the delta VGS generation module is connected with the first transistor, and the output end of the delta VGS generation module is connected with the output module;
the transistor in the delta VGS generation module and the first transistor work in a sub-threshold region, the delta VGS generation module is used for outputting a delta VGS voltage, and the adjustable current generation module is used for adjusting the delta VGS voltage to be a value of extending the threshold voltage of the first transistor to absolute zero degree so as to output a reference voltage.
2. The voltage reference source according to claim 1, wherein the output module comprises an output transistor, a gate of the output transistor is connected to the output terminal of the Δ VGS generation module, a drain of the output transistor is connected to the second output terminal, and the output transistor operates in a saturation region.
3. The voltage reference source of claim 2, wherein the threshold voltage of the first transistor is equal to the threshold voltage of the output transistor, and the output of the Δ VGS generation module is directly connected to the gate of the output transistor.
4. The voltage reference source according to claim 2, further comprising a buffer, wherein the output terminal of the Δ VGS generation module is connected to the buffer, the buffer is connected to the gate of the output transistor, and the buffer is configured to compensate for an error caused by a difference between the threshold voltage of the first transistor and the threshold voltage of the output transistor.
5. The voltage reference source of claim 4, wherein the buffer is a linear buffer.
6. The voltage reference source of claim 5, wherein the linear buffer comprises an operational amplifier and a feedback network coupled to the operational amplifier, wherein the output of the Δ VGS generation module is coupled to the operational amplifier.
7. The voltage reference source of claim 1, wherein the adjustable current generation module comprises a current mirror including a first output transistor connected to the first output terminal and a second output transistor connected to the second output terminal.
8. The voltage reference source according to claim 7, wherein the Δ VGS generation module comprises a Δ VGS generation unit, the Δ VGS generation unit comprises a second transistor and a third transistor, a drain of the second transistor is connected to a source of the third transistor, a drain of the third transistor is connected to the first output terminal, and a gate of the second transistor and a gate of the third transistor are both connected to the first output terminal.
9. The voltage reference source of claim 8, wherein the Δ VGS generation module comprises a plurality of Δ VGS generation units, the Δ VGS generation units being connected in series with each other; the current mirror comprises first output end transistors in one-to-one correspondence with the delta VGS generation units, and the first output end transistors are connected with the corresponding delta VGS generation units.
10. An integrated circuit comprising a voltage reference source according to any of claims 1 to 9.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007066046A (en) * | 2005-08-31 | 2007-03-15 | Ricoh Co Ltd | Reference voltage generating circuit and constant voltage circuit using the reference voltage generating circuit |
| CN102279610A (en) * | 2011-04-13 | 2011-12-14 | 清华大学 | Sub-threshold reference voltage source with extremely low power consumption and wide temperature range |
| CN104035471A (en) * | 2014-06-27 | 2014-09-10 | 东南大学 | Current mode bandgap reference voltage source with subthreshold current compensation function |
| US20160266598A1 (en) * | 2015-03-10 | 2016-09-15 | Qualcomm Incorporated | Precision bandgap reference |
| DE102015122521A1 (en) * | 2015-12-22 | 2017-06-22 | Infineon Technologies Ag | Voltage reference circuit |
| JP2017126280A (en) * | 2016-01-15 | 2017-07-20 | ローム株式会社 | Reference voltage source and semiconductor device |
| CN112327990A (en) * | 2020-11-06 | 2021-02-05 | 电子科技大学 | Output voltage adjustable low-power consumption sub-threshold reference voltage generating circuit |
| CN112438018A (en) * | 2018-06-29 | 2021-03-02 | 华为技术有限公司 | Operational amplifier, radio frequency circuit and electronic equipment |
| CN114690831A (en) * | 2022-03-21 | 2022-07-01 | 电子科技大学 | Current self-biased series CMOS band-gap reference source |
-
2022
- 2022-09-16 CN CN202211128436.XA patent/CN115373460B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007066046A (en) * | 2005-08-31 | 2007-03-15 | Ricoh Co Ltd | Reference voltage generating circuit and constant voltage circuit using the reference voltage generating circuit |
| CN102279610A (en) * | 2011-04-13 | 2011-12-14 | 清华大学 | Sub-threshold reference voltage source with extremely low power consumption and wide temperature range |
| CN104035471A (en) * | 2014-06-27 | 2014-09-10 | 东南大学 | Current mode bandgap reference voltage source with subthreshold current compensation function |
| US20160266598A1 (en) * | 2015-03-10 | 2016-09-15 | Qualcomm Incorporated | Precision bandgap reference |
| DE102015122521A1 (en) * | 2015-12-22 | 2017-06-22 | Infineon Technologies Ag | Voltage reference circuit |
| JP2017126280A (en) * | 2016-01-15 | 2017-07-20 | ローム株式会社 | Reference voltage source and semiconductor device |
| CN112438018A (en) * | 2018-06-29 | 2021-03-02 | 华为技术有限公司 | Operational amplifier, radio frequency circuit and electronic equipment |
| CN112327990A (en) * | 2020-11-06 | 2021-02-05 | 电子科技大学 | Output voltage adjustable low-power consumption sub-threshold reference voltage generating circuit |
| CN114690831A (en) * | 2022-03-21 | 2022-07-01 | 电子科技大学 | Current self-biased series CMOS band-gap reference source |
Non-Patent Citations (2)
| Title |
|---|
| 仲召扬;李严;: "低功耗高性能的全MOS电压基准源设计", 微处理机, no. 03, 21 May 2020 (2020-05-21) * |
| 闫涛涛 等: "1.6GHz 高线性度低功耗CMOS 驱动放大器", 信息技术, no. 9, 30 September 2008 (2008-09-30) * |
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