JP2012049925A - Voltage supply circuit for crystal oscillation circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage supply circuit for a crystal oscillation circuit which can maintain a constant power consumption of the crystal oscillation circuit.SOLUTION: There is provided a voltage supply circuit for a crystal oscillation circuit, in which the voltage supply circuit and the crystal oscillation circuit are formed by the same process. The voltage supply circuit includes a current supply, a first PMOS, a first NMOS, and a regulator unit. The current supply is connected between a voltage supply and an output terminal, and the output terminal outputs a reference voltage. A gate and a drain of the first PMOS are connected to a gate and a drain of the first NMOS respectively, and the first PMOS and the first NMOS are connected between the output terminal and the earth. The regulator unit generates an operating voltage to the crystal oscillation circuit as a voltage supply of the crystal oscillation circuit in accordance with the reference voltage.

Description

  The present invention relates generally to a voltage source circuit, and more particularly to a self-adjustment voltage source circuit for a crystal oscillation circuit.

  Oscillators are often used in semiconductor technology as timing modules, logic gates, oscillator chips, and the like. Conventional oscillators include a quartz crystal plate with a pair of capacitors having initial resistors. An RC circuit formed by capacitors and resistors can help adjust the timing of the oscillator. The oscillator buffer and the quartz crystal plate are connected in parallel. By generating an amplified and converted signal, a conventional oscillator buffer operates like an inverter. The crystal oscillator, RC circuit and oscillator buffer provide a predetermined waveform at a predetermined frequency.

  The power dissipation of the oscillator will be determined by the operating frequency of the oscillator buffer, the capacitor and the working voltage. Generally speaking, the power of the oscillator needs to be kept small. Since the preset operating frequency and the capacitance of the capacitor are fixed and reduce the power consumption accordingly, the operating voltage of the oscillator buffer will be taken into account. Due to the bandwidth of the oscillator buffer, the amplified gain will vary with operating voltage changes, processing parameters and capacitors. However, in many practical applications, this gain variation often results in a long oscillation trigger time or even the crystal oscillator circuit cannot oscillate. Thus, in order for the oscillator to operate normally, the working voltage of the oscillator buffer is set to a higher value to accommodate process variations, but such a setting can cause unnecessary power consumption in normal circumstances. It will cause.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a voltage source circuit for a crystal oscillation circuit that can maintain a constant power consumption of the crystal oscillation circuit.

  The present invention aims at a voltage source circuit suitable for providing a working voltage to a crystal oscillation circuit, and the voltage source circuit and the crystal oscillation circuit are formed by the same process. The voltage source circuit includes a current source, a first P-type transistor, a first N-type transistor, and a regulator unit. A current source is coupled between the voltage source and the output end. The first P-type transistor has a source connected to an output terminal and a gate and a drain connected to each other, and the output terminal outputs a reference voltage to the regulator unit. The first N-type transistor has a gate and a drain connected to the drain of the first P-type transistor and a source connected to ground. A regulator unit is connected between the output end and the crystal oscillation circuit, and the regulator unit is arranged to generate a working voltage to the crystal oscillation circuit as a voltage source according to the reference voltage.

  One aspect of the invention provides a voltage source circuit suitable for supplying a working voltage to a crystal oscillation circuit, in which the voltage source circuit and the crystal oscillation circuit are formed by the same process. The voltage source circuit includes a current source, a first voltage drop unit, a first P-type transistor, a first N-type transistor, a second voltage drop unit, and a regulator unit. A current source is coupled between the voltage source and the output end. The first voltage drop unit has one end connected to the output terminal, and the output terminal outputs a reference voltage. The first P-type transistor has a source connected to the other end of the first voltage drop unit, and a gate and a drain connected to each other. The first N-type transistor has a gate and a drain connected to the drain of the first P-type transistor. A second voltage drop unit is connected between the source of the first N-type transistor and ground. A regulator unit is connected between the output end and the crystal oscillation circuit, and the regulator unit is arranged to generate a working voltage to the crystal oscillation circuit as a voltage source according to the reference voltage.

  One aspect of the invention provides a voltage source circuit suitable for supplying a working voltage to a crystal oscillation circuit, in which the voltage source circuit and the crystal oscillation circuit are formed by the same process. The voltage source circuit includes a current source, a first P-type transistor, a first N-type transistor, and a regulator unit. A current source is coupled between the voltage source and the output end. The first N-type transistor has a drain connected to the output terminal and a gate connected to the drain, and the output terminal outputs a reference voltage. The first P-type transistor has a gate and a drain connected to each other, a source connected to the source of the first N-type transistor, and the drain is connected to ground. A regulator unit is connected between the output end and the crystal oscillation circuit, and the regulator unit is arranged to generate a working voltage to the crystal oscillation circuit as a voltage source according to the reference voltage.

  One aspect of the invention provides a voltage source circuit suitable for supplying a working voltage to a crystal oscillation circuit, in which the voltage source circuit and the crystal oscillation circuit are formed by the same process. The voltage source circuit includes a current source, a first voltage drop unit, a first P-type transistor, a first N-type transistor, a second voltage drop unit, and a regulator unit. A current source is coupled between the voltage source and the output end. The first voltage drop unit has one end connected to the output terminal, and the output terminal outputs a reference voltage. The first N-type transistor has a drain connected to the other end of the first voltage drop unit and a gate connected to the drain. The first P-type transistor has a gate and a drain connected to each other and a source connected to the source of the first N-type transistor. A second voltage drop unit is connected between the drain of the first P-type transistor and ground. A regulator unit is connected between the output end and the crystal oscillation circuit, and the regulator unit is arranged to generate a working voltage to the crystal oscillation circuit as a voltage source according to the reference voltage.

Action

  That is, since the embodiment of the present invention employs a transistor threshold value that varies according to changes in process conditions in order to control the working voltage of the P-type transistor and the N-type transistor, the power consumption of the crystal oscillation circuit is further reduced. It will not fluctuate.

  In view of the above, embodiments of the present invention employ transistor thresholds that vary with changes in process conditions to control the working voltage of P-type and N-type transistors, so that the transistor transconductance value and As the current value decreases, the power consumption of the crystal oscillation circuit is minimized. Also adopt a proportional to absolute temperature current source or a complementary to absolute temperature current source, and adjust a positive temperature coefficient resistor or negative temperature coefficient resistor Such a current source implements temperature compensation on the crystal oscillator circuit.

1 is a block diagram showing a voltage source circuit and a crystal oscillation circuit according to an embodiment of the present invention. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention. It is the schematic which shows the transistor electric current value in a different process condition. It is the schematic which shows the transistor transconductance value in a different process condition. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention. It is a circuit diagram which shows the voltage source circuit and crystal oscillation circuit concerning another embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a voltage source circuit and a crystal oscillation circuit according to an embodiment of the present invention. In FIG. 1, the voltage source circuit 100 and the crystal oscillation circuit 102 are formed by the same process. The voltage source circuit 100 includes a current source I 1, a P-type transistor Q 1, an N-type transistor M 1, a stabilization capacitor Cd, and a regulator (regulator) unit 104. The P-type transistor Q1 is, for example, a P-channel metal-oxide-semiconductor (PMOS) field effect transistor. The N-type transistor M1 is, for example, an N-channel metal-oxide-semiconductor (NMOS) field effect transistor. The current source I1 is an absolute temperature current source proportional current source or an absolute temperature complementary current source. The current source I1 is connected between the voltage source VDD and the output terminal OUT. The P-type transistor Q1 has a source connected to the output terminal OUT, and the gate of the P-type transistor Q1 is connected to its drain. N-type transistor M1 has a gate and a drain connected to the drain of P-type transistor Q1, and a source connected to ground GND. The stabilization capacitor Cd is connected between the output terminal OUT and the ground GND. The regulator unit 104 is connected between the output terminal OUT and the crystal oscillation circuit 102.

  The voltage dropped on the P-type transistor Q1 and the N-type transistor M1 generates a reference voltage at the output terminal OUT. Since the regulator unit 104 stabilizes the reference voltage and generates a working voltage to the crystal oscillation circuit 102, it is provided as a voltage source for the crystal oscillation circuit 102. The P-type transistor Q1 and the N-type transistor M1 in this embodiment are substantially equivalent to a diode device, and the connection positions of the P-type transistor Q1 and the N-type transistor M1 are interchanged. In other words, the terminal connected to the current source I1 is connected to the P-type transistor Q1 or the N-type transistor M1, and the N-type transistor M1 or the P-type transistor Q1 is connected to the ground GND correspondingly. According to different manufacturing conditions, the voltage source circuit 100 outputs a corresponding working voltage to the crystal oscillation circuit 102 to reduce power consumption of the crystal oscillation circuit 102. Furthermore, the type of current source employed (eg, absolute temperature proportional current source or absolute temperature complementary current source) performs temperature compensation on the crystal oscillation circuit 102, so that the crystal oscillation circuit 102 is utilized more efficiently. The

  FIG. 2 is a circuit diagram showing a voltage source circuit and a crystal oscillation circuit according to another embodiment of the present invention. In FIG. 2, the regulator unit 104 includes an operational amplifier A1, a P-type transistor Q2, a resistor R1, and a resistor R2. The P-type transistor Q2 has a gate connected to the output terminal of the operational amplifier A1, a source connected to the voltage source VDD, and a drain connected to the crystal oscillation circuit 102. Resistors R1 and R2 are connected in series between the drain of P-type transistor Q2 and ground GND. The common connection point of the resistors R1 and R2 is connected to the positive input terminal of the operational amplifier A1 and to the negative input terminal of the operational amplifier A1. It should be noted that the regulator unit 104 in this embodiment is for illustration purposes only and is not intended to be limiting. Any circuit capable of stabilizing the reference voltage can be provided as the regulator unit 104 in this embodiment.

  The crystal oscillation circuit 102 includes a P-type transistor Q3, an N-type transistor M2, a resistor R3, a crystal (crystal) XTAL, a capacitor C1, and a capacitor C2. The P-type transistor Q3 includes a source connected to the regulator unit 104 for receiving a working voltage provided by the regulator unit 104, a drain connected to the output terminal XTALout of the crystal oscillation circuit 102, and an N-type transistor M2. And a gate connected to the gate. N-type transistor M2 has a drain and a source connected to the drain of P-type transistor Q3 and to ground GND. Resistor R3 and crystal XTAL are connected in parallel to an inverter formed by P-type transistor Q3 and N-type transistor M2 (ie, resistor R3 and crystal XTAL are connected in parallel between the gate and drain of N-type transistor M2). Connected). Capacitors C1 and C2 are connected between two ends of crystal XTAL and ground GND, respectively. Capacitors C1 and C2 provide the crystal XTAL with the load necessary for parallel resonance.

As the circuit depicted in FIG. 2 shows, the power dissipated by transistors Q3 and M2 correlates with the current size drained through the transistors or by the size of the transconductance of transistors Q3 and M2. The currents of the transistors Q3 and M2 during the period in the saturation region are expressed by the following Equation 1.
[Equation 1]
I = k (Vgs−Vt) ²

Where I represents current, k represents a constant, Vgs represents the voltage difference between the gate and source, and Vt represents the transistor threshold voltage. In addition, the transconductance Gm of the transistors Q3 and M2 is derived as Equation 2 by differentiating Equation 1.

  As shown in Equation 1, when the threshold voltage of the transistor increases, the transconductance of the transistor and the current flowing through the transistor decrease. That is, the smaller the transconductance Gm of the transistor and the current flowing through the transistor, the smaller the power consumption of the transistor.

  Since different threshold voltage values are generated by original transistors with different process conditions, such as FF corner process conditions or SS corner process conditions, the threshold voltage values increase according to such changing manufacturing conditions. Or decrease. Assuming the same operating voltage value, when the threshold voltage value decreases (ie, FF corner process conditions), the transistor transconductance and the current flowing through the transistor increase, and the power consumption by the transistor increases. To do. Conversely, when the threshold voltage value increases (i.e., SS corner process conditions), the transistor transconductance and the current flowing through the transistor decrease and the power consumption by the transistor decreases.

  In this embodiment of the invention, the voltage sources of transistors Q3 and M2 are not only the working voltage stabilized and amplified by regulator unit 104, but also the sum of the voltage drop values of transistors Q1 and M1 (ie, on output OUT). Of reference voltage). Since transistors Q1 and M1 and transistors Q3 and M2 are formed by the same process, when process parameters change, transistors Q1 and M1 are affected and produce the same variation in threshold voltage values. Therefore, transistors Q1 and M1 indirectly affect the working voltage of crystal oscillator circuit 102 provided by regulator unit 104, thereby preventing unnecessary power consumption.

  For example, in the FF corner process condition, the threshold voltage of the transistors Q3 and M2 decreases, so the threshold value is narrowed and the transistors Q3 and M2 are turned on. Therefore, when operating under the same working voltage, the power consumption of transistors Q3 and M2 increases. In addition, since the transistors Q1 and M1 are also affected by the FF corner process conditions, the voltage dropped on the transistors Q1 and M1 is reduced. Conversely, the reference voltage on the output OUT (ie, the sum of the voltage drop values on transistors Q1 and M1) also decreases. At the same time, the regulator unit 104 reduces the stabilized and amplified operating voltage. As the threshold voltages of transistors Q3 and M2 are affected and reduced by the FF corner process conditions, the working voltage provided to transistors Q3 and M2 is also reduced as a result. Under such circumstances, although the working voltage provided by the regulator unit 104 is reduced, the reduced working voltage can still maintain the normal operation of the transistors Q3 and M2. Also, the reduced working voltage reduces the voltage difference between the gate and source and reduces transistor transconductance and current outflow through transistors Q3 and M2, thus reducing power consumption of transistors Q3 and M2.

  It should be noted that in another embodiment of the invention, the voltage source circuit 100 of FIGS. 1 and 2 further includes a regulating resistor. 3A to 3B are circuit diagrams showing a voltage source circuit and a crystal oscillation circuit according to another embodiment of the present invention. A stabilizing capacitor Cd is connected between the output terminal OUT and the ground GND. The adjusting resistor Ra is set to a connection path between the transistor Q1 and the transistor M1, or a connection path between the ground GND and the transistor Q1. Among them, the adjusting resistor Ra is a positive temperature coefficient resistor or a negative temperature coefficient resistor. Since the temperature compensation on the crystal oscillation circuit 102 is performed by selecting an appropriate type of resistor, the crystal oscillation circuit 102 can be used more efficiently.

  FIG. 4A is a schematic diagram showing transistor current values under different process conditions. FIG. 4B is a schematic diagram showing transistor transconductance values at different process conditions. In FIG. 4A and FIG. 4B, FIG. 4A shows transistor current sizes at different process conditions and temperatures, whereas FIG. 4B shows transistor transconductance sizes at different process conditions and temperatures. Is shown. As shown in FIGS. 4A and 4B, compared to a conventional crystal oscillator circuit, the voltage source circuit 100 utilizing this embodiment of the invention dramatically reduces the transconductance and current values at different process conditions and temperatures. Reduced to. In particular, under the process conditions of the FF corner and −45 ° C., the current value is reduced to half and the transconductance value is reduced to 0.3 times. Moreover, even when the transconductance value and the current value are minimum (that is, the SS corner process condition and −95 ° C.) under all the process conditions and temperatures, if the technique of this embodiment is adopted, The same transconductance value and current value of the crystal oscillation circuit are maintained. Thus, even when the transistor threshold voltages are at their maximum, the technique disclosed by this embodiment of the invention still successfully maintains the normal operation of the crystal oscillator circuit 102. Therefore, while maintaining the normal operation of the crystal oscillation circuit 102, the technique disclosed by this embodiment reduces the transconductance value and current value of the transistor and thereby protects the crystal oscillation circuit 102 from power consumption. .

  In another embodiment of the invention, the number of transistors depicted in FIG. 2 as being coupled to current source I1 is not limited to transistors Q1 and M1. FIG. 5 is a circuit diagram showing a voltage source circuit and a crystal oscillation circuit according to another embodiment of the present invention. In FIG. 5, the difference between the voltage source circuit 500 and the voltage source 100 of FIG. 2 is that the voltage source circuit 500 of this embodiment further includes a voltage drop unit 502 and a voltage drop unit 504. A voltage drop unit 502 is connected between the output terminal OUT and the source of the P-type transistor Q1, while a voltage drop unit 504 is connected between the source of the N-type transistor M1 and the ground GND. The voltage drop unit 502 includes at least one P-type transistor Q4 connected in series between the current source I1 and the P-type transistor Q1, and the P-type transistor Q4 has a gate and a source connected to each other. Similarly, the voltage drop unit 504 includes at least an N-type transistor M3 connected in series between the source of the N-type transistor M1 and the ground GND, and the N-type transistor M3 has a gate and a drain connected to each other.

  By adjusting the number of transistors in voltage drop units 502 and 504 according to practical circumstances, the user can vary the magnitude of the working voltage provided by voltage source circuit 500 under different process conditions. Since it can be determined, power consumption of the crystal oscillation circuit 102 is minimized. The working principles of the voltage source circuit 500 and the crystal oscillation circuit 102 in this embodiment are similar to those of the voltage source circuit 100 and the crystal oscillation circuit 102 depicted in FIG. 2, and thus have ordinary knowledge in the art. A person skilled in the art can extract the operation of the apparatus in this embodiment by using the embodiment shown in FIG. 2, and further description thereof will be omitted.

  In another embodiment of the invention, the P-type transistor Q1 and voltage drop unit 502 depicted in FIG. 5 can be replaced with an N-type transistor M1 and voltage drop unit 504, respectively. FIG. 6 is a circuit diagram showing a voltage source circuit and a crystal oscillation circuit according to another embodiment of the present invention. In FIG. 6, the voltage drop unit 504 in the voltage source circuit 600 is connected between the output terminal OUT and the drain of the N-type transistor M1. The source of the N-type transistor M1 is connected to the source of the P-type transistor Q1, the drain of the P-type transistor Q1 is connected to the voltage drop unit 502, and the other end of the voltage drop unit 502 is connected to the ground GND. . The operating principles of the voltage source circuit 600 and the crystal oscillation circuit 102 in this embodiment are similar to those of the voltage source circuit 100 and the crystal oscillation circuit 102 depicted in FIG. 2, and thus further description thereof is omitted. The circuit structure comprising the voltage drop unit 502, the voltage drop unit 504, the transistor Q1, and the transistor M1 in FIGS. 5 and 6 is the circuit comprising the adjustment resistor Ra, the transistor Q1, and the transistor M1 in FIGS. 3A to 3C. Since the structure can be replaced and temperature compensation is performed on the crystal oscillation circuit 102, the crystal oscillation circuit 102 is used more efficiently.

  As described above, the present invention has been disclosed by the embodiments. However, the present invention is not intended to limit the present invention, and within the scope of the technical idea of the present invention, as can be easily understood by those skilled in the art, Appropriate changes and modifications can be made, so that the scope of protection of the patent right must be determined on the basis of the scope of claims and the equivalent area.

100 (500, 600) voltage source circuit 102 crystal oscillation circuit 104 regulator unit 502, 504 voltage drop unit
Q1 First P-type transistor Q2 Second P-type transistor Q3 Third P-type transistor Q4 Fourth P-type transistor M1 First N-type transistor M2 Second N-type transistor M3 Third N-type transistor VDD Voltage source I1 Current source GND Ground OUT Output terminal XTALout Crystal oscillation circuit Output terminal A1 operational amplifier R1, R2, R3 resistor C1, C2 capacitor Cd stabilization capacitor XTAL crystal

Claims (28)

A voltage source circuit adapted to provide a working voltage to a crystal oscillation circuit, wherein the voltage source circuit and the crystal oscillation circuit are formed in the same process, and the voltage source circuit includes:
A current source coupled between the voltage source and the output;
A first P-type transistor having a source connected to the output terminal and a gate and a drain connected to each other, wherein the output terminal outputs a reference voltage;
A first N-type transistor having a gate and drain coupled to the drain of the first P-type transistor and a source coupled to ground;
A regulator unit connected between the output terminal and the crystal oscillation circuit and arranged to generate the working voltage to the crystal oscillation circuit as a voltage source of the crystal oscillation circuit according to the reference voltage. Source circuit.   The voltage source circuit according to claim 1, wherein the voltage source is an absolute temperature proportional current source or an absolute temperature complementary current source.   The adjusting resistor is disposed in a connection path between the source and the output terminal of the first P-type transistor, and the adjusting resistor is a positive temperature coefficient resistor or a negative temperature coefficient. The voltage source circuit according to claim 1, wherein the voltage source circuit is a resistor.   Furthermore, an adjustment resistor is included, and the adjustment resistor is disposed in a connection path between the drain of the first P-type transistor and the drain of the first N-type transistor, and the adjustment resistor is a positive temperature coefficient resistor. The voltage source circuit according to claim 1, wherein the voltage source circuit is a negative temperature coefficient resistor.   Furthermore, an adjustment resistor is included, and the adjustment resistor is installed in a connection path between the source of the first N-type transistor and the ground, and the adjustment resistor is a positive temperature coefficient resistor or a negative temperature coefficient resistor. The voltage source circuit according to claim 1, wherein the voltage source circuit is a voltage generator. The regulator unit is:
An operational amplifier having a negative input connected to the output;
A second P-type transistor having a gate connected to an output terminal of the operational amplifier, a source connected to the voltage source, and a drain connected to the crystal oscillation circuit;
A first resistor connected to the drain of the second P-type transistor and a positive input terminal of the operational amplifier;
The voltage source circuit according to claim 1, further comprising: a second resistor connected between the positive input terminal of the operational amplifier and the ground. The crystal oscillation circuit is:
A third P-type transistor having a source coupled to the regulator unit;
A second N-type transistor having a gate connected to the gate of the third P-type transistor, a drain connected to the drain of the third P-type transistor, and a source connected to the ground;
A third resistor connected in parallel with a crystal between the gate and drain of the second N-type transistor;
A first capacitor coupled between the first end of the crystal and the ground;
The voltage source circuit according to claim 6, further comprising: a second capacitor connected between the second end of the crystal and the ground.   The first to third P-type transistors are P-channel metal-oxide-semiconductor (PMOS) field effect transistors, and the first to second N-type transistors are N-channel metal oxides. 8. The voltage source circuit according to claim 7, wherein the voltage source circuit is a semiconductor (N-channel metal-oxide-semiconductor = NMOS) field effect transistor. A voltage source circuit adapted to provide a working voltage to a crystal oscillation circuit, wherein the voltage source circuit and the crystal oscillation circuit are formed in the same process, and the voltage source circuit includes:
A current source coupled between the voltage source and the output;
A first voltage drop unit having a first end connected to the output end, wherein the output end outputs a reference voltage;
A first P-type transistor having a source coupled to the other end of the first voltage drop unit and a gate and a drain coupled to each other;
A first N-type transistor having a gate and a drain coupled to the drain of the first P-type transistor;
A second voltage drop unit coupled to the source and ground of the first N-type transistor;
A regulator unit connected between the output terminal and the crystal oscillation circuit and arranged to generate the working voltage to the crystal oscillation circuit as a voltage source of the crystal oscillation circuit according to the reference voltage. Source circuit.   The first voltage drop unit has at least one second P-type transistor connected in series between the current source and the first P-type transistor, and has a gate and a drain connected to each other. Item 10. The voltage source circuit according to Item 9.   The second voltage drop unit has at least one second N-type transistor connected in series between the first N-type transistor and the ground, and the second N-type transistor has a gate and a drain connected to each other. The voltage source circuit according to 10.   The voltage source circuit according to claim 9, wherein the voltage source is an absolute temperature proportional current source.   The voltage source circuit according to claim 9, wherein the voltage source is an absolute temperature complementary current source. The regulator unit is:
An operational amplifier having a negative input connected to the output;
A third P-type transistor having a gate connected to the output terminal of the operational amplifier, a source connected to the voltage source, and a drain connected to the crystal oscillation circuit;
A first resistor connected between the drain of the third P-type transistor and a positive input terminal of the operational amplifier;
The voltage source circuit according to claim 11, further comprising: a second resistor connected between the positive input terminal of the operational amplifier and the ground. The crystal oscillation circuit is:
A fourth P-type transistor having a source coupled to the regulator unit;
A third N-type transistor having a gate connected to the gate of the fourth P-type transistor, a drain connected to the drain of the fourth P-type transistor, and a source connected to the ground;
A third resistor connected in parallel with the crystal between the gate and drain of the third N-type transistor;
A first capacitor coupled between the first end of the crystal and the ground;
The voltage source circuit according to claim 14, further comprising: a second capacitor coupled between the second end of the crystal and the ground.   16. The voltage source circuit according to claim 15, wherein the first to fourth P-type transistors are PMOS transistors, and the first to third N-type transistors are NMOS transistors. A voltage source circuit adapted to provide a working voltage to a crystal oscillation circuit, wherein the voltage source circuit and the crystal oscillation circuit are formed in the same process, and the voltage source circuit includes:
A current source coupled between the voltage source and the output;
A first N-type transistor having a drain connected to the output terminal and a gate connected to the drain, the output terminal outputting a reference voltage;
A first P-type transistor having a gate and a drain coupled to each other, and a source coupled to a source of the first N-type transistor, the drain of which is coupled to ground;
A regulator unit connected between the output terminal and the crystal oscillation circuit and arranged to generate the working voltage to the crystal oscillation circuit as a voltage source of the crystal oscillation circuit according to the reference voltage. Source circuit.   The voltage source circuit according to claim 17, wherein the voltage source is an absolute temperature proportional current source or an absolute temperature complementary current source. The regulator unit is:
An operational amplifier having a negative input connected to the output;
A second P-type transistor having a gate connected to an output terminal of the operational amplifier, a source connected to the voltage source, and a drain connected to the crystal oscillation circuit;
A first resistor connected to the drain of the second P-type transistor and a positive input terminal of the operational amplifier;
The voltage source circuit according to claim 17, comprising: a second resistor connected between the positive input terminal of the operational amplifier and the ground. The crystal oscillation circuit is:
A third P-type transistor having a source coupled to the regulator unit;
A second N-type transistor having a gate connected to the gate of the third P-type transistor, a drain connected to the drain of the third P-type transistor, and a source connected to the ground;
A third resistor connected in parallel with a crystal between the gate and drain of the second N-type transistor;
A first capacitor coupled between the first end of the crystal and the ground;
The voltage source circuit according to claim 19, further comprising: a second capacitor connected between the second end of the crystal and the ground.   21. The voltage source circuit according to claim 20, wherein the first to third P-type transistors are PMOS transistors, and the first to second N-type transistors are NMOS transistors. A voltage source circuit adapted to provide a working voltage to a crystal oscillation circuit, wherein the voltage source circuit and the crystal oscillation circuit are formed in the same process, and the voltage source circuit includes:
A current source coupled between the voltage source and the output;
A first voltage drop unit having a first end connected to the output end, wherein the output end outputs a reference voltage;
A first N-type transistor having a drain connected to the other end of the first voltage drop unit and a gate connected to the drain;
A first P-type transistor having a gate and a drain coupled to each other and a source coupled to a source of the first N-type transistor;
A second voltage drop unit connected between the drain of the first P-type transistor and ground;
A regulator unit connected between the output terminal and the crystal oscillation circuit and arranged to generate the working voltage to the crystal oscillation circuit as a voltage source of the crystal oscillation circuit according to the reference voltage. Source circuit.   The first voltage drop unit has at least one second N-type transistor connected in series between the current source and the first N-type transistor, and has a gate and a drain connected to each other. Item 23. The voltage source circuit according to Item 22.   The second voltage drop unit has at least one second P-type transistor connected in series between the first P-type transistor and the ground, and the second P-type transistor has a gate and a drain connected to each other. Item 24. The voltage source circuit according to Item 23.   The voltage source circuit according to any one of claims 22 to 24, wherein the voltage source is an absolute temperature proportional current source or an absolute temperature complementary current source. The regulator unit is:
An operational amplifier having a negative input connected to the output;
A third P-type transistor having a gate connected to the output terminal of the operational amplifier, a source connected to the voltage source, and a drain connected to the crystal oscillation circuit;
A first resistor connected between the drain of the third P-type transistor and a positive input terminal of the operational amplifier;
The voltage source circuit according to claim 24, further comprising: a second resistor between the positive input terminal of the operational amplifier and the ground. The crystal oscillation circuit is:
A fourth P-type transistor having a source coupled to the regulator unit;
A third N-type transistor having a gate connected to the gate of the fourth P-type transistor, a drain connected to the drain of the fourth P-type transistor, and a source connected to the ground;
A third resistor connected in parallel with the crystal between the gate and drain of the third N-type transistor;
A first capacitor coupled between the first end of the crystal and the ground;
The voltage source circuit according to claim 26, further comprising: a second capacitor connected between the second end of the crystal and the ground.   28. The voltage source circuit according to claim 27, wherein the first to fourth P-type transistors are PMOS transistors, and the first to third N-type transistors are NMOS transistors.

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