Voltage generation circuit, oscillator circuit, and integrated circuit

Abstract

The present invention relates to a voltage generation circuit, an oscillator, and an integrated circuit, the oscillator having: a first circuit for outputting a reference voltage; a second circuit connected to the first circuit and including a resistor whose resistance value varies in response to a change in temperature; and a third circuit for generating a signal at a frequency corresponding to the reference voltage output from the first circuit, in which a value of the reference voltage output from the first circuit is adjusted by the second circuit in response to a change in temperature. According to an embodiment, an oscillator may provide a stable oscillation frequency by reverse-compensating a reference signal input to a core oscillation circuit for a temperature change.

Description

Technical Field

[0001] Embodiments relate to a voltage generation circuit, an oscillator device, and an integrated circuit. Background Art

[0002] An electronic device may have an oscillator that generates a signal having a set frequency. For example, the oscillator may generate a clock signal corresponding to the set frequency, and the electronic device may operate based on the clock signal of the oscillator. The oscillator must generate an accurate and stable clock signal to ensure the reliability of the electronic device.

[0003] An oscillator device includes a reference voltage generation circuit that generates a reference voltage (or drive voltage) and a core oscillation circuit that generates a signal having a frequency corresponding to the reference voltage. The frequency of the signal generated in the core oscillation circuit (i.e., the oscillation frequency) may be controlled according to the reference voltage and may be changed by various other factors. The various factors include, for example, temperature, the threshold voltage of a transistor, and mobility. For example, as the temperature increases, the mobility decreases, whereby the frequency decreases, and the threshold voltage decreases, whereby the frequency increases.

[0004] Thus, since the oscillation frequency of the signal output from the core oscillation circuit changes due to various factors such as temperature changes, it may not be possible to stably provide the set frequency. Therefore, it is necessary to develop a technique that can provide a stable frequency even when the temperature changes in the oscillator device. Summary of the Invention

[0005] Technical Problem

[0006] An object of an embodiment is to provide a voltage generation circuit, an oscillator device, and an integrated circuit that can provide a stable oscillation frequency by reversely compensating a reference signal input to an oscillator according to a temperature change.

[0007] Another object of an embodiment is to provide an oscillator device, a voltage generation circuit, and an integrated circuit that can provide a stable oscillation frequency even when the temperature changes by connecting a resistor whose resistance value changes according to temperature to a reference signal generation circuit that generates a reference signal to be input to an oscillator.

[0008] Technical Solution

[0009] According to an embodiment, an oscillator device includes: a first circuit configured to output a reference voltage; a second circuit connected to the first circuit and including a resistor whose resistance value changes according to a temperature change; and a third circuit configured to generate a signal having a frequency corresponding to the reference voltage output from the first circuit, wherein the second circuit adjusts a voltage value of the reference voltage output from the first circuit according to the temperature change.

[0010] The reference voltage can decrease as the temperature increases.

[0011] The second circuit can include: a first resistor having a first temperature coefficient; and a second resistor connected in series with the first resistor and having a second temperature coefficient different from the first temperature coefficient.

[0012] The rate of change of the reference voltage output by the first circuit according to temperature can be set based on the combined ratio between the resistance value of the first resistor and the resistance value of the second resistor.

[0013] The second circuit can include: a fourth circuit configured such that the resistance value of the first resistor and the resistance value of the second resistor have a first combined ratio; and a fifth circuit configured such that the resistance value of the first resistor and the resistance value of the second resistor have a second combined ratio.

[0014] The third circuit can have a loop structure in which a plurality of inverters connected in series are included and the output of the last inverter is input to the first inverter.

[0015] According to one embodiment, a voltage generation circuit includes: an amplifier configured to receive a first reference voltage and output a second reference voltage; a transistor controlled by the second reference voltage output by the amplifier; and a first circuit including a first resistor connected in series with the transistor and having a first temperature coefficient and a second resistor connected in series with the first resistor and having a second temperature coefficient different from the first temperature coefficient.

[0016] The voltage value of the second reference voltage output by the amplifier can be adjusted by the first resistor and the second resistor according to temperature changes.

[0017] The second reference voltage can decrease as the temperature increases.

[0018] The rate of change of the second reference voltage output by the amplifier according to temperature can be set based on the combined ratio between the resistance value of the first resistor and the resistance value of the second resistor.

[0019] The first circuit can include: a second circuit connected to the transistor and configured such that the resistance value of the first resistor and the resistance value of the second resistor have a first combined ratio; and a third circuit connected to the transistor and configured such that the resistance value of the first resistor and the resistance value of the second resistor have a second combined ratio.

[0020] According to an embodiment, an integrated circuit includes: a first circuit configured to output a reference voltage; and

[0021] A second circuit, connected to the first circuit and including a resistor, the resistance value of the resistor changing according to temperature, wherein the voltage value of the reference voltage output by the first circuit is adjusted by the second circuit according to the temperature change.

[0022] The reference voltage may decrease as the temperature increases.

[0023] The second circuit may include: a first resistor having a first temperature coefficient; and a second resistor connected in series with the first resistor and having a second temperature coefficient different from the first temperature coefficient.

[0024] Technical effects

[0025] According to an embodiment, a stable oscillation frequency can be provided by performing reverse compensation on a reference signal input from an oscillator device to a core oscillation circuit according to a temperature change.

[0026] According to an embodiment, by connecting a resistor whose resistance value changes according to temperature to a reference signal generation circuit, a stable oscillation frequency can be provided even when the temperature changes, wherein the reference signal generation circuit generates a reference signal to be input to a core oscillation circuit in an oscillator device. Description of the drawings

[0027] Figure 1 is a block diagram showing the configuration of an oscillator device according to an embodiment.

[0028] Figure 2 is a graph showing the relationship between a reference signal, temperature, and frequency according to an embodiment.

[0029] Figure 3 is a graph showing the relationship between a reference signal, temperature, and frequency according to an embodiment.

[0030] Figure 4 is a block diagram showing the circuit constituting an oscillator device according to an embodiment.

[0031] Figure 5 is a graph showing the relationship between temperature and frequency for each voltage according to an embodiment.

[0032] Figure 6 is a block diagram showing a voltage generation circuit of an oscillator device according to an embodiment.

[0033] Figure 7 is a block diagram showing a core oscillation circuit of an oscillator device according to an embodiment.

[0034] Figure 8is a graph showing the relationship between temperature and reference voltage according to an embodiment.

[0035] Figure 9 is a graph showing the test results of the relationship between temperature and error rate according to an embodiment.

[0036] Figure 10 is a graph showing the test results of the relationship between frequency and error rate according to an embodiment. Detailed Embodiments

[0037] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. When assigning reference numerals to components in the respective drawings, it should be noted that, even when the same components are shown in different drawings, the same reference numerals are assigned to the same components as much as possible. In addition, when describing the present disclosure, if a detailed description of a related known configuration or function is determined to obscure the gist of the present disclosure, its detailed description may be omitted.

[0038] In addition, when describing components of the present disclosure, terms such as first, second, A, B, (a), (B), etc. may be used. These terms are only intended to distinguish one component from another and are not intended to limit the nature, order, or sequence of the components. When a component is described as "connected" or "coupled" to another component, it should be understood that the component can be directly connected or coupled to the other component, but other components can also be "connected", "coupled", or "linked" between the respective components.

[0039] Hereinafter, the reference signal and the reference voltage may be used interchangeably.

[0040] Figure 1 is a block diagram showing the configuration of an oscillator device according to an embodiment.

[0041] Referring to Figure 1 , the oscillator device may include a reference voltage generation circuit 110, a linear regulator 120, a ring oscillator 130, etc. The reference voltage generation circuit 110 may generate a reference voltage based on externally applied power. The linear regulator 120 may regulate the reference voltage to a constant voltage and output the constant voltage. The ring oscillator 130 may perform oscillation through the regulated reference voltage to generate a pulse sequence.

[0042] The reference voltage generation circuit 110 may include an amplifier that receives and amplifies an external power supply voltage. The reference voltage may be generated from the output value of the amplifier.

[0043] The linear regulator 120 may receive the reference voltage generated by the reference voltage generation circuit 110 and output the reference voltage as a constant voltage at a specific ratio.

[0044] The ring oscillator 130 may include a plurality (e.g., an odd number) of inverters connected to each other in a loop shape. The ring oscillator 130 may be driven by a constant voltage VDDOSC sent from the linear regulator 120 and may output a pulse sequence having a constant frequency.

[0045] Figure 2 is a graph showing the relationship between a reference signal, temperature, and frequency according to an embodiment.

[0046] Referring Figure 2 , a constant voltage (e.g., a drive voltage or a power supply voltage VDDOSC) generated based on a reference signal may be provided to an oscillator (e.g., a ring oscillator or a core oscillation circuit). The oscillator may generate a signal having a frequency (e.g., an oscillation frequency) corresponding to the constant voltage. For example, the frequency of the signal generated by the core oscillation circuit may linearly vary in proportion to the amplitude of the power supply voltage VDDOSC.

[0047] According to one embodiment, even when the temperature changes, a power supply voltage VDDOSC having a constant voltage may be generated as a voltage having a constant amplitude. As described above, as the power supply voltage VDDOSC increases, the frequency of the signal generated by the oscillator may increase proportionally. For example, the frequency of the signal generated by an oscillator (e.g., a ring oscillator) may be determined by the following <Equation 1>.

[0048] [Equation 1]

[0049]

[0050] Referring to <Equation 1>, the frequency of the signal generated by the oscillator may be determined by the power supply voltage VDDOSC, the mobility μ of the transistor, and the threshold voltage V TH . The mobility μ and the threshold voltage V TH may increase or decrease respectively according to changes in temperature, as shown in <Equation 2> and <Equation 3>.

[0051] [Equation 2]

[0052] μ ∝ T -2.2

[0053] [Equation 3]

[0054] V TH (T) = V T0 -K(T - T0)

[0055] Referring to <Equation 2>, as the temperature increases, the mobility μ may decrease, and when the mobility μ decreases, the frequency may decrease according to <Equation 1>. Referring to <Equation 3>, as the temperature increases, the threshold voltage V THcan be reduced, and when the threshold voltage V TH is reduced, the frequency can increase according to <Equation 1>.

[0056] Referring to <Equation 1>, when the voltage level of the power supply voltage VDDOSC increases, the frequency can increase. The voltage level of the power supply voltage VDDOSC can be set low for low-power circuit design. Thus, for low-power circuit design, the voltage level of the power supply voltage VDDOSC is continuously reduced, and therefore, when the temperature rises, the threshold voltage V TH 's influence is becoming an important factor in frequency fluctuation.

[0057] Referring again to Figure 2 , even when a constant power supply voltage VDDOSC is supplied to the oscillator according to temperature, since the mobility μ of the transistor and the threshold voltage V TH vary according to temperature, the frequency of the signal output by the oscillator may also fluctuate. For example, as described above, as the voltage level of the power supply voltage VDDOSC is set lower, the influence of the threshold voltage V TH is relatively higher. Therefore, as the temperature increases, the frequency can increase as Figure 2 shown.

[0058] As described above, even when the voltage level of the power supply voltage VDDOSC remains constant, the frequency may fluctuate according to temperature changes. To solve this problem, according to one embodiment, the voltage level of the power supply voltage VDDOSC can be adjusted so that a signal of a constant frequency is output even when the temperature changes. For example, in various embodiments described below, instead of supplying the power supply voltage VDDOSC constantly, the power supply voltage VDDOSC can be set to be inversely proportional to the temperature in order to cancel out the frequency change caused by temperature changes.

[0059] Figure 3 is a graph showing the relationship between the reference signal, temperature, and frequency according to an embodiment.

[0060] Referring to Figure 3 , as described above, even when the voltage level of the power supply voltage VDDOSC is constantly supplied while the temperature rises, the frequency may increase due to other factors (e.g., the threshold voltage V TH ). Therefore, the power supply voltage VDDOSC can be reduced as the temperature rises. When the voltage level of the power supply voltage VDDOSC is reduced as the temperature rises, the increase in frequency caused by other factors (e.g., the threshold voltage V TH ) can be canceled out. In this way, even when the temperature in the oscillator rises as Figure 3 shown, the frequency of the signal output by the oscillator (e.g., the oscillation frequency) can be kept constant.

[0061] Figure 4 It is a block diagram showing a circuit constituting an oscillator device according to an embodiment.

[0062] Referring to Figure 4 , the oscillator device may include a voltage rectifier circuit 410 and a core oscillation circuit 420. The voltage rectifier circuit 410 generates a constant voltage from an externally applied power supply voltage.

[0063] The voltage rectifier circuit 410 may include a reference voltage generation circuit 411, a linear regulator 413, a temperature compensation circuit 412, etc. The reference voltage generation circuit 411 can generate a reference voltage based on the externally applied power. The linear regulator 413 can regulate the reference voltage to a constant voltage and output the regulated reference voltage. The temperature compensation circuit 412 can adjust the reference voltage according to temperature. The core oscillation circuit 420 may include a ring oscillator 421, and the ring oscillator 421 performs oscillation through the regulated reference voltage to generate a pulse sequence.

[0064] The reference voltage generation circuit 411 may include an amplifier that receives and amplifies the external power supply voltage. The reference voltage can be generated from the output value of the amplifier.

[0065] The linear regulator 413 can receive the reference voltage generated by the reference voltage generation circuit 411 and output the reference voltage as a constant voltage at a specific ratio. Since the constant voltage can be used as the power supply voltage of the ring oscillator 421, the constant voltage is called the power supply voltage.

[0066] The temperature compensation circuit 412 can be connected to the reference voltage generation circuit 411 and can control the reference voltage output by the reference voltage generation circuit 411 to be adjusted according to temperature changes. For example, the temperature compensation circuit 412 may include at least one resistor whose resistance value changes according to temperature. Since the resistance value of the resistor included in the temperature compensation circuit 412 changes according to temperature, the reference voltage output by the reference voltage generation circuit 411 can be adjusted according to temperature, and the adjusted reference voltage can be output. For example, the reference voltage output by the reference voltage generation circuit 411 may decrease as the temperature rises.

[0067] The ring oscillator 421 may include a plurality of (e.g., an odd number of) inverters connected to each other in a loop shape. The ring oscillator 421 may be driven by a constant voltage sent from the linear regulator 413 and may output a pulse sequence having a constant frequency. Since the constant voltage input to the ring oscillator 421 is generated corresponding to the reference voltage, the constant voltage may increase or decrease as the reference voltage increases or decreases. Since the reference voltage can be adjusted according to temperature changes as described above, the constant voltage can be adjusted according to temperature changes. The ring oscillator 421 of the core oscillation circuit 420 may receive the constant voltage adjusted according to temperature changes and generate a signal having a constant frequency regardless of temperature changes.

[0068] Figure 5 is a graph showing the relationship between temperature and frequency for each voltage according to an embodiment.

[0069] Referring to Figure 5 , as the supply voltage VDDOSC (e.g., constant voltage) increases, the frequency of the signal output by the oscillator may increase, as described above in <Equation 1>.

[0070] On the other hand, as described above with reference to Figure 2 , even when a constant supply voltage VDDOSC is supplied, the frequency of the signal output by the oscillator may increase as the temperature rises.

[0071] For example, when the supply voltage VDDOSC is 0.9V (501), 1.0V (502), and 1.1V (503), it can be confirmed that the frequency increases proportionally as the temperature increases from -50°C to 150°C. When the supply voltage VDDOSC is 0.9V (501), the frequency increase rate according to temperature rise can be 0.263 MHz / °C, and when the supply voltage VDDOSC is 1.0V (502), the frequency increase rate according to temperature rise can be 0.248 MHz / °C. When the supply voltage VDDOSC is 1.1V (503), the frequency increase rate according to temperature can be 0.184 MHz / °C. In addition, the frequency increase rate with respect to the supply voltage VDDOSC at -50°C can be 282.35 MHz / V, and the frequency increase rate with respect to the supply voltage VDDOSC at 0°C can be 292.88 MHz / V. The frequency increase rate with respect to the supply voltage VDDOSC at 25°C can be 279.15 MHz / V, the frequency increase rate with respect to the supply voltage VDDOSC at 100°C can be 246.35 MHz / V, and the frequency increase rate with respect to the supply voltage VDDOSC at 150°C can be 220.62 MHz / V.

[0072] Figure 5The shown curve graph can be represented by the following <Equation 4> and <Equation 5>.

[0073] [Equation 4]

[0074] freq = freq0 + α(temp - 25°) + β(VDDOSC - 1V)

[0075] [Equation 5]

[0076] VDDOSC - VDD0 + γ(temp - 25°)

[0077] In <Equation 4>, freq0 can represent the frequency of the signal output by the oscillator when the temperature is 25°C and the power supply voltage VDDOSC is 1V. α can represent the slope of the frequency that increases as the temperature rises, with the unit of Hz / °C. β can represent the slope of the frequency that increases as the power supply voltage VDDOSC increases, with the unit of Hz / V. In <Equation 5>, VDD0 can represent the power supply voltage VDDOSC at a temperature of 25°C. γ can represent the slope of the power supply voltage VDDOSC that increases as the temperature rises, with the unit of V / °C. Substituting <Equation 5> into the power supply voltage VDDOSC in <Equation 4>, it can be summarized as the following <Equation 6>.

[0078] [Equation 6]

[0079] freq = freq0 + α(temp - 25°) + β(VDD0 + γ(temp - 25°) - 1V)

[0080] = freq0 + (α + βγ)(temp - 25°) + β(VDD0 - 1)

[0081] According to the embodiment, referring to <Equation 6>, in order to constantly output the frequency freq0 at 25°C (e.g., room temperature) even when the temperature changes, α + βγ must be 0 and VDD0 must be 1V. Therefore, the slope γ of the power supply voltage VDDOSC according to the temperature change can be determined as in the following <Equation 7>.

[0082] [Equation 7]

[0083]

[0084] According to the embodiment, referring to <Equation 7>, by setting the power supply voltage VDDOSC to decrease by γ as the temperature rises as in <Equation 7>, the frequency of the signal output by the oscillator can be maintained constant regardless of the temperature. γ can be set by α and β as in <Equation 7>. According to the embodiment, α and β can be based on as Figure 5Determined by the simulation results shown. The simulation can set the optimal slope by measuring the frequencies at two points at any temperature.

[0085] Figure 6 is a block diagram showing a voltage generation circuit of an oscillator device according to an embodiment.

[0086] Referring to Figure 6 , a voltage rectifier circuit 600 (e.g., Figure 4 the voltage rectifier circuit 410) (or voltage generation circuit) that generates a constant voltage (e.g., power supply voltage VDDOSC) supplied to an oscillator (e.g., a core oscillation circuit) may include a reference voltage generation circuit 610, a temperature compensation circuit 620, a linear regulator 630, a first controller 640, etc.

[0087] According to an embodiment, the reference voltage generation circuit 610 may include a first amplifier 611, a first transistor M1, a second transistor M2, a third resistor R3, etc. The first amplifier 611 may receive a first reference voltage REF_OSC as a reference voltage through an inverting input terminal (-).

[0088] The output of the first amplifier 611 may be input to the gate terminals of the first transistor M1 and the second transistor M2. One terminal (e.g., a source terminal) of the first transistor M1 may be connected to the VDDI line, and the other terminal (e.g., a drain terminal) of the first transistor M1 may be connected to the temperature compensation circuit 620. The said other terminal of the first transistor M1 may be feedback-connected to the non-inverting input terminal (+) of the first amplifier 611. One terminal (e.g., a source terminal) of the second transistor M2 may be connected to the VDDI line, and the other terminal (e.g., a drain terminal) of the second transistor M2 may be connected to the third resistor R3.

[0089] Current may flow through the first transistor M1 and the second transistor M2 by the output signal of the first amplifier 611. The magnitude of the current flowing through the first transistor M1 (e.g., the current flowing from the source terminal to the drain terminal) may be controlled by the resistance value set in the temperature compensation circuit 620.

[0090] The temperature compensation circuit 620 may include a plurality of temperature compensation circuits connected in parallel with each other. For example, a first temperature compensation circuit, a second temperature compensation circuit,..., an Nth temperature compensation circuit may be connected in parallel. The first controller 640 may control a switching circuit (e.g., a transistor) included in each temperature compensation circuit, so as to allow at least one temperature compensation circuit among the plurality of temperature compensation circuits to be connected to the first transistor M1 of the reference voltage generation circuit 610.

[0091] Each temperature compensation circuit may include a switching circuit and resistors (e.g., a first resistor and a second resistor). For example, the first temperature compensation circuit may include a first switching circuit 621-A, a first -1 resistor 622-A, and a second -1 resistor 623A. The second temperature compensation circuit may include a second switching circuit 621-B, a first -2 resistor 622-B, and a second -2 resistor 623B. The Nth temperature compensation circuit may include an Nth switching circuit 621-N, a first -N resistor 622-N, and a second -N resistor 623N.

[0092] Each of the temperature compensation circuits may differently set the change in the resistance value according to temperature by combining two resistors. Each of the switching circuits 621-A, 621-B, …, 621-N may be turned on / off by a control signal from the first controller 640. Each of the switching circuits 621-A, 621-B, …, 621-N may be configured with a transistor (e.g., a MOSFET), but the present disclosure is not limited thereto.

[0093] The first resistors 622-A, 622-B, ……, 622-N and the second resistors 623-A, 623-B, ……, 623-N that constitute the respective temperature compensation circuits may have different temperature coefficients. For example, each resistor may have the characteristics shown in Table 1 below.

[0094] [Table 1]

[0095] Type Rsh TC1 Self-aligned silicide P+ diffusion 20.834 1.4835m Self-aligned silicide N+ diffusion 22.490 1.4690m Non-self-aligned silicide N+ diffusion 147.510 1.2919m Non-self-aligned silicide P+ diffusion 300.000 1.4330m HiR resistor 600 0.21175m MV self-aligned silicide N+ diffusion 22.500 1.3m MV self-aligned silicide P+ diffusion 24.600 1.43m MV non-self-aligned silicide N+ diffusion 112.000 1.24m MV non-self-aligned silicide P+ diffusion 293.000 1.28m

[0096] shows the sheet resistance of each resistor type. TC1 represents the temperature coefficient of each resistor type. For example, each resistor may have a different resistance based on temperature according to the value of TC1, and the unit of TC1 may be 1 / °C. Considering the sheet resistance and the temperature coefficient, the first resistors 622-A, 622-B, …, 622-N and the second resistors 623-A, 623-B, …, 623-N that constitute the respective temperature compensation circuits may be configured. For example, by adjusting the combination ratio of the two types of resistors, the temperature dependence characteristic slope of the voltage VREFA (hereinafter referred to as the second reference voltage) output by the reference voltage generation circuit 610 or the constant voltage (or the power supply voltage VDDOSC) output by the voltage generation circuit 600 may be adjusted. According to various embodiments, the first resistors 622-A, 622-B, …, 622-N may be configured as diffused resistors, and the second resistors 623-A, 623-B, …, 623-N may be configured as polysilicon resistors, but the embodiments described below are not limited thereto.

[0097] For example, the first switching circuit 621-A included in the first temperature compensation circuit can be controlled to the on state according to the control signal of the first controller 640, and the switching circuits 621-B to 621-N included in the remaining temperature compensation circuits can be controlled to the off state according to the control signal of the first controller 640. In this case, the first temperature compensation circuit can be connected to the first transistor M1 of the reference voltage generation circuit 610. Thus, when the first temperature compensation circuit is connected to the first transistor M1 of the reference voltage generation circuit 610, the rate of change (or slope) of the second reference voltage VREFA output by the reference voltage generation circuit 610 according to the temperature change can be determined as a first value according to the sheet resistance and the temperature coefficient TC1 of the first - 1 resistor 622-A and the second - 1 resistor 623-A.

[0098] The second switching circuit 621-B included in the second temperature compensation circuit can be controlled to the on state according to the control signal of the first controller 640, and the switching circuits included in the remaining temperature compensation circuits 621-A and 621-C to 621-N can be controlled to the off state according to the control signal of the first controller 640. In this case, the second temperature compensation circuit can be connected to the first transistor M1 of the reference voltage generation circuit 610. Thus, when the second temperature compensation circuit is connected to the first transistor M1 of the reference voltage generation circuit 610, the rate of change (or slope) of the second reference voltage VREFA output by the reference voltage generation circuit 610 according to the temperature change can be determined as a second value according to the sheet resistance and the temperature coefficient TC1 of the first - 2 resistor 622-B and the second - 2 resistor 623-B.

[0099] The Nth switching circuit 621-N included in the Nth temperature compensation circuit can be controlled to the on state according to the control signal of the first controller 640, and the switching circuits 621-A to 621-(N - 1) included in the remaining temperature compensation circuits can be controlled to the off state according to the control signal of the first controller 640. In this case, the Nth temperature compensation circuit can be connected to the first transistor M1 of the reference voltage generation circuit 610. Thus, when the Nth temperature compensation circuit is connected to the first transistor M1 of the reference voltage generation circuit 610, the rate of change (or slope) of the second reference voltage VREFA output by the reference voltage generation circuit 610 according to the temperature change can be determined as the Nth value according to the sheet resistance and the temperature coefficient TC1 of the first - N resistor 622-N and the second - N resistor 623-N.

[0100] The first controller 640 may select one temperature compensation circuit among a plurality of temperature compensation circuits based on the output frequency of the integrated circuit that provides the oscillation frequency from the oscillator and the corner wafer characteristics. When the plurality of temperature compensation circuits are set to 64 temperature compensation circuits, the first controller 640 may be controlled to select one temperature compensation circuit by setting a 6-bit (2 6 ^6 = 64) control signal.

[0101] The gate terminals of the first transistor M1 and the second transistor M2 included in the reference voltage generation circuit 610 may be commonly connected to the output of the first amplifier 611, thereby configuring a current mirror circuit. For example, the first transistor M1 and the second transistor M2 may be commonly connected to each other through the gate terminals such that the mirror current may flow to the second transistor M2.

[0102] Accordingly, the voltage between the second transistor M2 and the third resistor R3 (e.g., the second reference voltage VREFA) may have a temperature-dependent slope characteristic determined by a specific temperature compensation circuit selectively connected according to the control signal of the first controller 640. For example, as the temperature increases, the second reference voltage VREFA for the constant current output by the reference voltage generation circuit 600 may decrease. For example, the rate (e.g., slope) at which the second reference voltage VREFA decreases as the temperature increases may change according to the selection of the temperature compensation circuit.

[0103] The linear regulator 630 may include a second amplifier 631, a fourth resistor R4, a fifth resistor R5, etc. The second reference voltage VREFA, which is the output voltage of the reference voltage generation circuit 610, may be applied to the inverting input terminal (-) of the second amplifier 631. The fourth resistor R4 and the fifth resistor R5 may be connected to the output terminal of the second amplifier 631. The terminal between the fourth resistor R4 and the fifth resistor R5 may be connected to the non-inverting input terminal (+) of the second amplifier 631.

[0104] Accordingly, the voltage obtained by dividing the voltage of the output signal of the second amplifier 631 (hereinafter referred to as the third reference voltage or the power supply voltage VDDOSC) by the fourth resistor R4 and the fifth resistor R5 may be applied to the non-inverting input terminal (+) of the second amplifier 631. For example, when the second reference voltage VREFA of 0.5V is input to the second amplifier 631 as 0.5V, when the fourth resistor R4 and the fifth resistor R5 are set to the same resistance, the linear regulator 630 may output a power supply voltage VDDOSC of 1V.

[0105] A power supply voltage VDDOSC with a constant amplitude can be output by the linear regulator 630. Based on the connection of the temperature compensation circuit 630 described above, the power supply voltage VDDOSC can decrease with a constant slope as the temperature increases. According to various embodiments, a resistor R for electrostatic discharge (ESD) ESD and a capacitor C OUT can be connected in parallel to the output terminal of the linear regulator 630.

[0106] Figure 7 is a block diagram showing a core oscillation circuit of an oscillator device according to an embodiment.

[0107] Referring to Figure 7 , the core oscillation circuit 700 of the oscillator device (e.g., Figure 4 's core oscillation circuit 420) can include a ring oscillator 710 (e.g., Figure 4 's ring oscillator 421) and a second controller 720. According to an embodiment, the core oscillation circuit 700 can include a plurality of transistors (a third transistor M3, a fourth transistor M4, a fifth transistor M5, and a sixth transistor M6). For example, the third transistor M3 and the fourth transistor M4 can be PMOS transistors, and the fifth transistor M5 and the sixth transistor M6 can be NMOS transistors, but the present disclosure is not limited thereto.

[0108] According to an embodiment, the source terminal of the third transistor M3 can be connected to the output terminal of a voltage generation circuit ( Figure 6 's 600) such that the power supply voltage VDDOSC can be provided, and the drain terminal of the third transistor M3 can be connected to the source terminal of the fourth transistor M4. The source terminal of the fourth transistor M3 can be connected to the drain terminal of the third transistor M3, and the drain terminal of the fourth transistor M4 can be connected to the drain terminal of the fifth transistor M5. The source terminal of the fifth transistor M5 can be connected to the drain terminal of the sixth transistor M6, and the drain terminal of the fifth transistor M5 can be connected to the drain terminal of the fourth transistor M4. The source terminal of the sixth transistor M6 can be connected to the output terminal of the voltage generation circuit ( Figure 6 's 600), and the drain terminal of the sixth transistor M6 can be connected to the source terminal of the fifth transistor M5.

[0109] The voltages input to the gate terminals of the fourth transistor M4 and the fifth transistor M5 can be generated based on the oscillator enable signal A_OSC_EN. For example, the first inverter 701 can receive the oscillator enable signal A_OSC_EN and output a PD signal, and the second inverter 702 can receive the PD signal output by the first inverter 701 and output a PDB signal. The PD signal output by the first inverter 701 can be provided to the gate terminal of the fourth transistor M4, and the PDB signal output by the second inverter 702 can be provided to the gate terminal of the fifth transistor M5.

[0110] Although two inverters 701 and 702 are shown, more inverters can be provided.

[0111] The terminal between the drain terminal of the fourth transistor M4 and the drain terminal of the fifth transistor M5 can be connected to the input terminal of the third inverter 703. The output terminal of the third inverter 703 can be connected to the input terminal of the fourth inverter 704. The output terminal of the fourth inverter 704 can be connected to the variable resistor R TRIM . The variable resistor R TRIM 's first terminal can be connected to the output terminal of the fourth inverter 704, and the variable resistor R TRIM 's second terminal can be connected to the gate terminal of the third transistor M3. The node between the output terminal of the third inverter 703 and the input terminal of the fourth inverter 704 can be connected to the first terminal of the first capacitor C1. Although two inverters 703 and 704 are shown, more inverters can be provided.

[0112] The third inverter 703 and the fourth inverter 704 are connected in series and can have a loop structure in which the output of the fourth inverter 704 is input to the third inverter 703.

[0113] The second terminal of the first capacitor C1 can be connected to the node between the second terminal of the variable resistor R TRIM and the gate terminal of the third transistor M3. The second terminal of the first capacitor C1 can be connected to the variable capacitor C TRIM . The second controller 720 can adjust the frequency of the signal D_OSCCLK output by the core oscillator circuit 700 by adjusting the resistance value of the variable resistor R TRIM or the capacitance of the variable capacitor C TRIM .

[0114] The input terminal of the third inverter 703 may be connected to the input terminal of the ring oscillator 710. The ring oscillator 710 may include a plurality of inverters 711, 712, 713, and 714 connected to each other in a loop shape. Although four inverters 711, 712, 713, and 714 are shown, more inverters may be provided.

[0115] The ring oscillator 710 may be driven by the voltage provided from the input terminal of the third inverter 703, and may output a signal D_OSCCLK having a constant frequency. Since the voltage input to the ring oscillator 710 is generated corresponding to the reference voltage (e.g., VDDOSC) output by the above voltage generation circuit 600, the voltage input to the ring oscillator 710 may increase or decrease as the reference voltage VDDSOC increases or decreases. As described above, the reference voltage VDDSOC may be adjusted according to the temperature change. Therefore, the ring oscillator 710 of the core oscillation circuit 700 may generate a signal having a constant frequency corresponding to the constant voltage VDDOSC adjusted according to the temperature change, regardless of the temperature change.

[0116] Figure 8 is a graph showing the relationship between temperature and reference voltage according to an embodiment.

[0117] Referring to Figure 8 when the first controller 640 of the above Figure 6 outputs a control signal corresponding to the code value 0, the first temperature compensation circuit may be selected. Depending on the selection of the first temperature compensation circuit, the reference voltage VDDOSC may be generated as 1.014V at -40°C and 0.942V at 145°C. When Figure 6 the first controller 640 of the above

[0118] outputs a control signal corresponding to the code value 63, the 64th temperature compensation circuit may be selected. Depending on the selection of the 64th temperature compensation circuit, the reference voltage VDDOSC may be generated as 1.0584V at -40°C and 0.859V at 145°C. Figure 8 Referring to

[0119] As a first example, when the oscillator device generates a signal of a first frequency (e.g., 165.0 MHz), the code value 38 can be set to select (or connect) the 39th temperature compensation circuit. As a second example, when generating a signal of a second frequency (e.g., 139.5 MHz), the code value 43 can be set to select (or connect) the 44th temperature compensation circuit. As a third example, when generating a signal of a third frequency (e.g., 109.5 MHz), the code value 49 can be set to select (or connect) the 50th temperature compensation circuit.

[0120] Figure 9 is a graph showing the test results between temperature and error rate according to an embodiment. Figure 10 is a graph showing the test results between frequency and error rate according to an embodiment.

[0121] Referring to Figure 9 and Figure 10 , it can be confirmed that, according to the above embodiment, by reversely compensating the reference voltage according to temperature, the error caused by temperature change is offset. For example, when the frequency of the signal output by the oscillator device is 113 MHz (901), 116 MHz (902), 140 MHz (903), or 164 MHz (904), the error can be reduced, and the desired frequency can be output consistently regardless of temperature change.

[0122] According to an embodiment, a stable oscillation frequency can be provided by reversely compensating the reference signal input from the oscillator device to the core oscillation circuit according to temperature change.

[0123] In addition, according to an embodiment, by connecting a resistor whose resistance value changes according to temperature to the reference signal generation circuit, a stable oscillation frequency can be provided even when the temperature changes, wherein the reference signal generation circuit generates a reference signal to be input to the core oscillation circuit of the oscillator device.

Claims

1. An oscillator device, the oscillator device comprising: A first circuit configured to output a reference voltage; A second circuit connected to the first circuit and including a resistor, the resistance value of the resistor varying according to temperature; And A third circuit configured to generate a signal having a frequency corresponding to the reference voltage output by the first circuit, wherein the second circuit adjusts the voltage value of the reference voltage output by the first circuit according to the temperature change.

2. The oscillator device according to claim 1, wherein, The reference voltage decreases as the temperature increases.

3. The oscillator device according to claim 1, wherein, The second circuit includes: A first resistor having a first temperature coefficient; and A second resistor connected in series to the first resistor and having a second temperature coefficient different from the first temperature coefficient.

4. The oscillator device according to claim 3, wherein, Based on the combined ratio between the resistance value of the first resistor and the resistance value of the second resistor, the rate of change of the reference voltage output by the first circuit according to the temperature is set.

5. The oscillator device according to claim 4, wherein, The second circuit includes: A fourth circuit configured to make the resistance values of the first resistor and the second resistor have a first combined ratio; and A fifth circuit configured to make the resistance values of the first resistor and the second resistor have a second combined ratio.

6. The oscillator device according to claim 1, wherein, The third circuit has a loop structure in which a plurality of inverters connected in series are included and the output of the last inverter is input to the first inverter.

7. A voltage generation circuit, the voltage generation circuit comprising: An amplifier configured to receive a first reference voltage and output a second reference voltage; A transistor controlled by the second reference voltage output by the amplifier; And A first circuit including a first resistor and a second resistor, the first resistor connected in series to the transistor and having a first temperature coefficient, the second resistor connected in series to the first resistor and having a second temperature coefficient different from the first temperature coefficient.

8. The voltage generation circuit according to claim 7, wherein The voltage value of the second reference voltage output by the amplifier is adjusted by the first resistor and the second resistor according to temperature change.

9. The voltage generation circuit according to claim 8, wherein, The second reference voltage decreases as the temperature increases.

10. The voltage generation circuit according to claim 7, wherein, Based on the combined ratio between the resistance value of the first resistor and the resistance value of the second resistor, the rate of change of the second reference voltage output by the amplifier according to the temperature is set.

11. The voltage generation circuit according to claim 10, wherein, The first circuit includes: A second circuit connected to the transistor and configured to make the resistance values of the first resistor and the second resistor have a first combined ratio; and A third circuit connected to the transistor and configured to make the resistance values of the first resistor and the second resistor have a second combined ratio.

12. An integrated circuit, the integrated circuit comprising: A first circuit configured to output a reference voltage; And A second circuit, the second circuit being connected to the first circuit and including a resistor whose resistance value changes according to temperature, wherein the second circuit adjusts a voltage value of the reference voltage output by the first circuit according to the temperature change.

13. The integrated circuit according to claim 12, wherein, The reference voltage decreases as the temperature increases.

14. The integrated circuit according to claim 12, wherein, The second circuit includes: a first resistor having a first temperature coefficient; and a second resistor connected in series to the first resistor and having a second temperature coefficient different from the first temperature coefficient.

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