WO2024112045A1 - Voltage generating circuit, oscillator circuit, and integrated circuit - Google Patents

Abstract

The present invention relates to a voltage generating circuit, an oscillator, and an integrated circuit, the oscillator comprising: a first circuit for outputting a reference voltage; a second circuit that is connected to the first circuit and comprises a resistor of which the resistance value changes in response to changes in temperature; and a third circuit for generating a signal at a frequency corresponding to the reference voltage outputted from the first circuit, wherein the value of the reference voltage outputted from the first circuit is adjusted by the second circuit in response to changes in temperature.　According to an embodiment, the oscillator may provide a stable oscillation frequency by reverse-compensating the reference signal, inputted to a core oscillator circuit, for the changes in temperature.

Description

Voltage generation circuits, oscillator device circuits, and integrated circuits

Embodiments relate to voltage generation circuits, oscillator devices, and integrated circuits.

The electronic device may be equipped with an oscillator that generates a signal of a set frequency. For example, an oscillator generates a clock signal corresponding to a set frequency, and an electronic device can operate based on the oscillator's clock signal. Oscillators must produce accurate and stable clock signals for the reliability of electronic devices.

The oscillator device includes a reference voltage generator circuit that generates a reference voltage (or driving voltage) and a core oscillator circuit that generates a signal with a frequency corresponding to the reference voltage. The frequency of the signal generated in the core oscillator circuit, that is, the oscillation frequency, can be controlled according to the reference voltage and can be changed by various other factors. Various factors include, for example, temperature, threshold voltage of the transistor, mobility, etc. For example, as the temperature increases, the mobility can decrease and the frequency can decrease, and the threshold voltage can decrease and the frequency can increase.

As such, the oscillation frequency of the signal output from the core oscillator circuit changes due to various factors such as temperature changes, etc., so the set frequency may not be stably provided. Therefore, there is a need to develop technology that can provide a stable frequency even if the temperature changes in the oscillator device.

One purpose of the embodiment is to provide a voltage generator circuit, an oscillator device, and an integrated circuit that can provide a stable oscillation frequency by reverse-compensating a reference signal input to an oscillator according to temperature changes.

Another purpose of the embodiment is to provide an oscillator device that can provide a stable oscillation frequency even when the temperature changes by connecting a resistor whose resistance value changes depending on temperature to a reference signal generation circuit that generates a reference signal input to the oscillator. To provide a generator circuit and an integrated circuit.

According to an embodiment, the oscillator device includes: a first circuit that outputs a reference voltage; a second circuit including a resistor whose resistance value changes according to temperature changes and connected to the first circuit; and a third circuit that generates a signal with a frequency corresponding to the reference voltage output from the first circuit, wherein the reference voltage output from the first circuit is generated by the second circuit according to a change in temperature. The voltage value is adjusted.

The reference voltage may decrease as the temperature increases.

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.

Based on the combination ratio between the resistance value of the first resistor and the resistance value of the second resistor, the rate of change for the temperature of the reference voltage output from the first circuit may be set.

The second circuit includes a fourth circuit configured such that the resistance value of the first resistor and the resistance value of the second resistor have a first combination 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 combination ratio.

The third circuit includes a plurality of inverters connected in series, and may have a circular structure in which the output of the last inverter is input to the first inverter.

According to an embodiment, the voltage generation circuit includes: an amplifier that receives a first reference voltage and outputs a second reference voltage; a transistor controlled by a second reference voltage output from the amplifier; and a first circuit connected in series to the transistor and including 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. Includes.

The voltage value of the second reference voltage output from the amplifier may be adjusted by the first resistor and the second resistor according to temperature changes.

The second reference voltage may decrease as the temperature increases.

Based on the combination ratio between the resistance value of the first resistor and the resistance value of the second resistor, the rate of change for the temperature of the second reference voltage output from the amplifier may be set.

The first circuit includes a second circuit connected to the transistor and configured to have a resistance value of the first resistor and a resistance value of the second resistor having a first combination 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 combination ratio.

According to an embodiment, the integrated circuit includes: a first circuit that outputs a reference voltage; and a resistor whose resistance value changes according to temperature changes, and a second circuit connected to the first circuit, wherein the reference voltage output from the first circuit is connected to the second circuit according to temperature changes. The voltage value is adjusted by .

The reference voltage may decrease as the temperature increases.

The second circuit includes: 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.

According to an embodiment, a stable oscillation frequency can be provided by reverse-compensating the reference signal input from the oscillator device to the core oscillator circuit according to temperature changes.

According to an embodiment, a resistor whose resistance value changes depending on temperature is connected to a reference signal generation circuit that generates a reference signal input from the oscillator device to the core oscillator circuit, thereby providing a stable oscillation frequency even when the temperature changes.

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

Figure 2 is a graph showing the relationship between a reference signal, temperature, and frequency according to one embodiment.

Figure 3 is a graph showing the relationship between a reference signal, temperature, and frequency according to one embodiment.

Figure 4 is a block diagram showing circuits constituting an oscillator device according to an embodiment.

Figure 5 is a graph showing the relationship between temperature and frequency for each voltage according to one embodiment.

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

Figure 7 is a block diagram showing the core oscillator circuit of an oscillator device according to an embodiment.

Figure 8 is a graph showing the relationship between temperature and reference voltage according to one embodiment.

Figure 9 is a graph showing experimental results between temperature and error rate according to one embodiment.

Figure 10 is a graph showing experimental results between frequency and error rate according to one embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being “connected” or “coupled” to another component, that component may be directly connected or connected to that other component, but there is no “other component” between each component. It should be understood that they may be “connected,” “coupled,” or “connected.”

Hereinafter, reference signal and reference voltage may be used interchangeably.

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

Referring to FIG. 1, the oscillator device may include a reference voltage generation circuit 110, a linear regulator 120, a ring oscillator 130, etc. The reference voltage generator circuit 110 may generate a reference voltage based on externally applied power. The linear regulator 120 can adjust the reference voltage to a constant constant voltage and output it. The ring oscillator 130 may oscillate based on the adjusted reference voltage to generate a pulse train.

The reference voltage generator circuit 110 may include an amplifier that receives an external power supply voltage and amplifies it. A reference voltage can be generated by the output value of the amplifier.

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 constant rate.

The ring oscillator 130 may include a plurality of (eg, odd number) inverters connected to each other in the form of a loop. The ring oscillator 130 is driven by a constant voltage (VDDOSC) transmitted from the linear regulator 120 and can output a pulse train with a constant frequency.

Figure 2 is a graph showing the relationship between a reference signal, temperature, and frequency according to one embodiment.

Referring to FIG. 2, the constant voltage (eg, driving voltage or power supply voltage (VDDOSC)) generated based on the reference signal may be supplied to an oscillator (eg, ring oscillator or core oscillator circuit). The oscillator may generate a signal with a frequency (eg, oscillation frequency) corresponding to the constant voltage. For example, the frequency of the signal generated in the core oscillator circuit may vary linearly in proportion to the size of the power supply voltage (VDDOSC).

According to an embodiment, the power supply voltage VDDOSC having a constant voltage can be generated as a constant voltage even if the temperature changes. When the power supply voltage (VDDOSC) increases, the frequency of the signal generated by the oscillator may increase proportionally, as described above. For example, the frequency of a signal generated by an oscillator (eg, a ring oscillator) may be determined by Equation 1 below.

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

Referring to <Equation 2>, as the temperature increases, the mobility (μ) may decrease, and as the mobility (μ) decreases, the frequency may decrease according to <Equation 1>. Referring to <Equation 3>, as the temperature increases, the threshold voltage (V _TH ) may decrease, and as the threshold voltage (V _TH ) decreases, the frequency may increase according to <Equation 1>.

Referring to <Equation 1>, as the voltage level of the power supply voltage VDDOSC increases, the frequency may increase. The voltage level of the power supply voltage (VDDOSC) can be set low for low-power circuit design. In this way, for low-power circuit design, the voltage level of the power supply voltage (VDDOSC) is continuously lowered, and as a result, the influence of the threshold voltage (V _TH ) when the temperature rises becomes an important factor in frequency variation.

Referring again to FIG. 2, even if a constant power voltage (VDDOSC) is supplied to the oscillator depending on temperature, the mobility (μ) and threshold voltage (V _TH ) of the transistor change with temperature, so that the signal output from the oscillator changes. Frequency can 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 ) becomes relatively larger, and as the temperature increases, the frequency may increase as shown in FIG. 2. there is.

As described above, even if the voltage level of the power supply voltage VDDOSC is kept constant, the frequency may change depending on temperature changes. To solve this problem, according to an embodiment, the voltage level of the power supply voltage VDDOSC can be adjusted so that a signal with a constant frequency is output even if the temperature changes. For example, in various embodiments described later, instead of supplying the power supply voltage VDDOSC at a constant rate, the power supply voltage VDDOSC may be set to be inversely proportional to temperature to offset frequency changes due to temperature changes.

Figure 3 is a graph showing the relationship between a reference signal, temperature, and frequency according to one embodiment.

Referring to FIG. 3, when the temperature rises as described above, even if the voltage level of the power supply voltage VDDOSC is supplied at a constant level, the frequency may increase due to other factors (e.g., threshold voltage V _TH ). . Accordingly, as the temperature rises, the power supply voltage (VDDOSC) can be lowered. If the voltage level of the power supply voltage (VDDOSC) is lowered as the temperature rises, the increase in frequency due to other factors (eg, threshold voltage (V _TH )) can be offset. By doing this, even if the temperature in the oscillator increases as shown in FIG. 3, the frequency (eg, oscillation frequency) of the signal output from the oscillator can be maintained constant.

Figure 4 is a block diagram showing circuits constituting an oscillator device according to an embodiment.

Referring to FIG. 4, the oscillator device may include a voltage rectifier circuit 410 and a core oscillator circuit 420 that generate a constant voltage from an externally applied power supply voltage.

The voltage rectification circuit 410 may include a reference voltage generator circuit 411, a linear regulator 413, a temperature compensation circuit 412, etc. The reference voltage generator circuit 411 may generate a reference voltage with power applied from the outside. The linear regulator 413 may adjust the reference voltage to a constant constant voltage and output the adjusted reference voltage. The temperature compensation circuit 412 can adjust the reference voltage according to temperature. The core oscillator circuit 420 may include a ring oscillator 421 that oscillates based on the adjusted reference voltage to generate a pulse train.

The reference voltage generator circuit 411 may include an amplifier that receives an external power supply voltage and amplifies it. A reference voltage can be generated by the output value of this amplifier.

The linear regulator 413 may receive the reference voltage generated by the reference voltage generator circuit 411 and output the reference voltage as a constant voltage at a constant rate. Since the constant voltage can be used as the power supply voltage of the ring oscillator 421, the constant voltage will be referred to as the power supply voltage.

The temperature compensation circuit 412 is connected to the reference voltage generation circuit 411 and can control the reference voltage output from 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 depending on temperature changes. As the resistance value of the resistor included in the temperature compensation circuit 412 changes according to the temperature change, the reference voltage output from the reference voltage generator circuit 411 may be adjusted according to the temperature and the adjusted reference voltage may be output. For example, the reference voltage output from the reference voltage generation circuit 411 may decrease as the temperature increases.

The ring oscillator 421 may include a plurality of (eg, odd number) inverters connected to each other in the form of a loop. The ring oscillator 421 is driven by a constant voltage transmitted from the linear regulator 413 and can output a pulse train with a constant frequency. Since the constant voltage input to the ring oscillator 421 is generated in response to the reference voltage, the constant voltage may rise or fall as the reference voltage rises or falls. 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 oscillator circuit 420 can generate a signal of a constant frequency regardless of temperature changes by receiving a constant voltage adjusted according to temperature changes.

Figure 5 is a graph showing the relationship between temperature and frequency for each voltage according to one embodiment.

Referring to FIG. 5, as the power supply voltage VDDOSC (eg, constant voltage) increases, the frequency of the signal output from the oscillator may increase, as described above in Equation 1.

Meanwhile, as described above in FIG. 2, even if a constant power voltage (VDDOSC) is supplied, the frequency of the signal output from the oscillator may increase as the temperature increases.

For example, when the power supply voltage (VDDOSC) is 0.9V (501), 1.0V (502), and 1.1V (503), the frequency increases proportionally as the temperature increases from -50℃ to 150℃, respectively. You can check that. When the power supply voltage (VDDOSC) is 0.9V (501), the frequency increase rate according to the temperature increase is 0.263MHz/℃, and when the power supply voltage (VDDOSC) is 1.0V (502), the frequency increase rate according to the temperature increase is 0.248. It can be expressed as MHz/℃. When the power supply voltage (VDDOSC) is 1.1V, the frequency increase rate according to temperature in 503 can be 0.184MHz/°C. Additionally, at -50°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) may be 282.35 MHz/V, and at 0°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) may be 292.88 MHz/V. At 25℃, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 279.15 MHz/V. At 100°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 246.35 MHz/V. At 150°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 279.15 MHz/V. The rise rate can be shown as 220.62MHz/V.

The graph shown in FIG. 5 can be expressed as <Equation 4> and <Equation 5> below.

In <Equation 4>, freq0 may mean the frequency of the signal output from the oscillator when the temperature is 25°C and the power supply voltage (VDDOSC) is 1V. α may refer to the slope of frequency that increases with an increase in temperature, and the unit is Hz/°C. β may refer to the slope of frequency that increases as the power supply voltage (VDDOSC) increases, and the unit is HzV. am. In Equation 5, VDD0 may mean the power supply voltage (VDDOSC) at a temperature of 25°C. γ may refer to the slope of the power supply voltage (VDDOSC) that increases as the temperature increases, and the unit is V/°C. By substituting <Equation 5> for the power supply voltage (VDDOSC) in <Equation 4>, it can be summarized as <Equation 6> below.

According to an embodiment, referring to Equation 6, in order to consistently output freq0, which is the frequency at 25°C (e.g., room temperature) even if the temperature changes, “α+βγ must be 0 and VDD0 must be 1V. Accordingly, the slope γ of the power supply voltage VDDOSC according to temperature change can be determined as shown in Equation 7 below.

According to an embodiment, referring to <Equation 7>, the power supply voltage (VDDOSC) is set to decrease by γ as the temperature increases as shown in <Equation 7>, so that the frequency of the signal output from the oscillator is independent of the temperature. It can be kept constant. γ can be set by α and β as in <Equation 7>. According to an embodiment, α and β may be determined from simulation results as shown in FIG. 5. The simulation can set the optimal slope by measuring the frequency at two points at arbitrary temperatures.

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

Referring to FIG. 6, a voltage rectification circuit 600 (e.g., the voltage rectification circuit 410 of FIG. 4) that generates a constant voltage (e.g., power supply voltage VDDOSC) supplied to an oscillator (e.g., core oscillator circuit) (or The voltage generation circuit) may include a reference voltage generation circuit 610, a temperature compensation circuit 620, a linear regulator 630, and a first controller 640.

According to an embodiment, the reference voltage generator 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 the first reference voltage (REF_OSC) as a reference voltage at the inverting input terminal (-).

The output of the first amplifier 611 may be input to the gate terminal of the first transistor (M1) and the gate terminal of the second transistor (M2). One terminal (eg, source terminal) of the first transistor M1 may be connected to a line of VDDI, and the other terminal (eg, drain terminal) may be connected to the temperature compensation circuit 620. The other terminal of the first transistor (M1) may be fed back and connected to the non-inverting input terminal (+) of the first amplifier 611. One terminal (eg, source terminal) of the second transistor (M2) may be connected to the line of VDDI, and the other terminal (eg, drain terminal) may be connected to the third resistor (R3).

Current may flow in the first transistor (M1) and the second transistor (M2) by the output signal of the first amplifier 611. The size of the current flowing through the first transistor M1 (for example, the current flowing from the source terminal to the drain terminal) may be adjusted by the resistance value set in the temperature compensation circuit 620.

The temperature compensation circuit 620 may include a plurality of temperature compensation circuits connected in parallel. For example, the first temperature compensation circuit, the second temperature compensation circuit, ..., the Nth temperature compensation circuit may be connected in parallel. The first controller 640 controls the switching circuit (e.g., transistor) included in each temperature compensation circuit, so that at least one of the plurality of temperature compensation circuits is connected to the first transistor of the reference voltage generation circuit 610. It can be connected to (M1).

Each temperature compensation circuit may include a switching circuit and a resistor (eg, a first resistor and a second resistor). For example, the first temperature compensation circuit may include a first switching circuit 621-A, a 1-1 resistor 622-A, and a 2-1 resistor 623A. The second temperature compensation circuit may include a second switching circuit (621-B), a 1-2 resistor (622-B), and a 2-2 resistor (623B). The N-th temperature compensation circuit may include an N-th switching circuit (621-N), a 1-N resistor (622-N), and a 2-N resistor (623N).

Each temperature compensation circuit can set the change in resistance value depending on temperature differently by combining two resistors. Each switching circuit (621-A, 621-B, ..., 621-N) may be turned on/off by a control signal from the first controller 640. Each switching circuit (621-A, 621-B, ..., 621-N) may be composed of a transistor (eg, MOSFET), but is not limited thereto.

The first resistors (622-A, 622-B, ..., 622-N) and second resistors (623-A, 623-B, ..., 623-N) constituting each temperature compensation circuit are connected to each other. Can have different temperature coefficients. For example, each resistor may have characteristics as shown in <Table 1> below.

Type	Rsh	TC1
Salicide P + Diffusion	20.834	1.4835m
Salicide N + Diffusion	22.490	1.4690m
Non-Salicide N+Diffusion	147.510	1.2919m
Non-Salicide P + Diffusion	300.000	1.4330m
HiR Resistor	600	0.21175m
MV Salicide N + Diffusion	22.500	1.3m
MV Salicide P + Diffusion	24.600	1.43m
MV Non-Salicide N + Diffusion	112.000	1.24m
MV Non-Salicide P + Diffusion	293.000	1.28m

In <Table 1>, Rsh represents the sheet resistance value for each resistor type. TC1 represents the temperature coefficient for each resistor type. For example, the change in resistance value of each resistor depending on temperature may vary depending on the value of TC1, and the unit of TC1 may be 1/°C. First resistors (622-A, 622-B, ..., 622-N) and second resistors (623-A, 623-B, . .., 623-N) can be configured. For example, by adjusting the combination ratio of the two types of resistors, the voltage (VREFA) output from the reference voltage generation circuit 610 (hereinafter referred to as the second reference voltage) or the constant voltage (or power supply) output from the voltage generation circuit 600. The characteristic slope of voltage (VDDOSC)) can be adjusted with respect to temperature. According to various embodiments, the first resistors (622-A, 622-B, ..., 622-N) are configured as diffusion resistors, and the second resistors (623-A, 623-B, ..., 623) -N) may be configured as a poly resistor, but embodiments described later are not limited thereto.

For example, according to the control signal of the first controller 640, the first switching circuit 621-A included in the first temperature compensation circuit is controlled to be in the on state, and the switching circuit 621-B included in the remaining temperature compensation circuit is controlled to be in the on state. to 621-N) can be controlled in the off state. In this case, the first temperature compensation circuit may be connected to the first transistor M1 of the reference voltage generator circuit 610. In this way, when the first temperature compensation circuit is connected to the first transistor (M1) of the reference voltage generation circuit 610, the sheet resistance of the 1-1 resistor (622-A) and the 2-1 resistor (623-A) Depending on the value and the temperature coefficient TC1, the rate of change (or slope) according to the temperature change of the second reference voltage VREFA output from the reference voltage generation circuit 610 may be determined as the first value.

According to the control signal of the first controller 640, the second switching circuit 621-B included in the second temperature compensation circuit is controlled to be in the on state, and the remaining temperature compensation circuits 621-A, 621-C to 621- The switching circuit included in N) can be controlled to be in the off state. In this case, a second temperature compensation circuit may be connected to the first transistor M1 of the reference voltage generation circuit 610. In this way, when the second temperature compensation circuit is connected to the first transistor (M1) of the reference voltage generation circuit 610, the sheet resistance of the 1-2 resistor (622-B) and the 2-2 resistor (623-B) Depending on the value and the temperature coefficient TC1, the rate of change (or slope) according to the temperature change of the second reference voltage VREFA output from the reference voltage generation circuit 610 may be determined as the second value.

According to the control signal of the first controller 640, the N-th switching circuit (621-N) included in the N-th temperature compensation circuit is controlled to be in the on state, and the switching circuits (621-A to 621) included in the remaining temperature compensation circuits are switched on. -(N-1)) can be controlled to be in the off state. In this case, the Nth temperature compensation circuit may be connected to the first transistor (M1) of the reference voltage generation circuit 610. In this way, when the N-th temperature compensation circuit is connected to the first transistor (M1) of the reference voltage generation circuit 610, the sheet resistance of the 1-N resistor (622-N) and the 2-N resistor (623-N) Depending on the value and the temperature coefficient TC1, the rate of change (or slope) according to the temperature change of the second reference voltage VREFA output from the reference voltage generation circuit 610 may be determined as the Nth value.

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

The gate terminals of the first transistor M1 and the second transistor M2 included in the reference voltage generator circuit 610 are commonly connected to the output of the first amplifier 611, thereby forming a current mirror circuit. For example, the first transistor M1 and the second transistor M2 are commonly connected to each other through a gate terminal, so that a mirrored current may flow through the second transistor M2.

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

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 generator circuit 610, may be applied to the inverting input terminal (-) of the second amplifier 631. A fourth resistor (R4) and a 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.

Accordingly, the voltage of the output signal of the second amplifier 631 (hereinafter referred to as the third reference voltage or power supply voltage VDDOSC) is divided by the fourth resistor R4 and the fifth resistor R5. 2 It can be applied to the non-inverting input terminal (+) of the amplifier 631. For example, when the second reference voltage (VREFA) of 0.5V is input to the second amplifier 631 as 0.5V, if the fourth resistor (R4) and the fifth resistor (R5) are set to the same resistance value, the linear regulator (630) can output a power supply voltage (VDDOSC) of 1V.

A power supply voltage (VDDOSC) of a certain magnitude may be output by the linear regulator 630. The power supply voltage VDDOSC may decrease with a constant slope as temperature increases, based on the connection of the temperature compensation circuit 630 described above. According to various embodiments, a resistor (R _ESD ) and a capacitor (C _OUT ) for electrostatic discharge (ESD) may be connected in parallel to the output terminal of the linear regulator 630.

Figure 7 is a block diagram showing the core oscillator circuit of an oscillator device according to an embodiment.

Referring to FIG. 7, the core oscillator circuit 700 of the oscillator device (e.g., the core oscillator circuit 420 in FIG. 4) includes a ring oscillator 710 (e.g., the ring oscillator 421 in FIG. 4) and a second controller. It may include (720). According to an embodiment, the core oscillator circuit 700 may 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 fourth transistor M4 may be PMOS transistors, and the fifth transistor M5 and sixth transistor M6 may be NMOS transistors, but are not limited thereto.

According to an embodiment, the source terminal of the third transistor (M3) may be connected to the output terminal of the voltage generation circuit (600 in FIG. 6) to provide the power supply voltage (VDDOSC), and the drain terminal of the fourth transistor (M4) It can be connected to the source terminal of . The source terminal of the fourth transistor M3 may be connected to the drain terminal of the third transistor M3, and the drain terminal may be connected to the drain terminal of the fifth transistor M5. The source terminal of the fifth transistor M5 may be connected to the drain terminal of the sixth transistor M6, and the drain terminal may be connected to the drain terminal of the fourth transistor M4. The source terminal of the sixth transistor M6 may be connected to the output terminal of the voltage generation circuit (600 in FIG. 6), and the drain terminal may be connected to the source terminal of the fifth transistor M5.

The voltage input to the gate terminals of the fourth transistor M4 and the fifth transistor M5 may 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 from the first inverter 701 and output a PDB signal. can be output. The PD signal output from the first inverter 701 may be supplied to the gate terminal of the fourth transistor (M4), and the PDB signal output from the second inverter 702 may be supplied to the gate terminal of the fifth transistor (M5). It can be.

Although two inverters 701 and 702 are shown in the drawing, more inverters may be provided.

A terminal between the drain terminal of the fourth transistor M4 and the drain terminal of the fifth transistor M5 may be connected to the input terminal of the third inverter 703. The output terminal of the third inverter 703 may be connected to the input terminal of the fourth inverter 704. The output terminal of the fourth inverter 704 may be connected to a variable resistor (R _TRIM ). The first terminal of the variable resistor (R _TRIM ) may be connected to the output terminal of the fourth inverter 704, and the second terminal may be connected to the gate terminal of the third transistor (M3). A node between the output terminal of the third inverter 703 and the input terminal of the fourth inverter 704 may be connected to the first terminal of the first capacitor C1. Although two inverters 703 and 704 are shown in the drawing, more inverters may be provided.

The third inverter 703 and the fourth inverter 704 are connected in series, and may have a circulation structure in which the output of the fourth inverter 704 is input to the third inverter 703.

The second terminal of the first capacitor C1 may be connected to a 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 may be connected to the variable capacitor C _TRIM . The second controller 720 may adjust the frequency of the signal D_OSCCLK output from 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 ).

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 form. The drawing shows four inverters (711, 712, 713, and 714), but more inverters may be provided.

The ring oscillator 710 is driven by the voltage provided from the input terminal of the third inverter 703 and can output a signal (D_OSCCLK) having a constant frequency. The voltage input to the ring oscillator 710 is generated in response to the reference voltage (e.g., VDDOSC) output from the above-described voltage generation circuit 600, so as the reference voltage (VDDSOC) rises or falls, the ring oscillator 710 The input voltage may rise or fall. The reference voltage (VDDSOC) can be adjusted according to temperature changes as described above. Accordingly, the ring oscillator 710 of the core oscillator circuit 700 can generate a signal with a constant frequency regardless of temperature changes in response to the constant voltage VDDOSC adjusted according to temperature changes.

Figure 8 is a graph showing the relationship between temperature and reference voltage according to one embodiment.

Referring to FIG. 8, when the first controller 640 of FIG. 6 described above outputs a control signal corresponding to a code value of 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 the first controller 640 in FIG. 6 outputs a control signal corresponding to 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) can be generated as 1.0584V at -40℃ and 0.859V at 145℃.

Referring to FIG. 8, when comparing the first temperature compensation circuit and the 64th temperature compensation circuit, it can be confirmed that the change in voltage according to temperature is greater in the 64th temperature compensation circuit than in the first temperature compensation circuit. For example, a specific integrated circuit or an oscillator device that outputs a specific frequency can be controlled to select a specific temperature compensation circuit by considering changes in voltage depending on temperature.

As a first example, if the oscillator device wants to generate a signal of the first frequency (eg, 165.0 MHz), the code value 38 can be set to select (or connect) the 39th temperature compensation circuit. As a second example, when it is desired to generate a signal of a second frequency (eg, 139.5 MHz), the code value 43 can be set to select (or connect) the 44th temperature compensation circuit. As a third example, if you want to generate a signal of a third frequency (eg, 109.5 MHz), you can set the code value 49 to select (or connect) the 50th temperature compensation circuit.

Figure 9 is a graph showing experimental results between temperature and error rate according to one embodiment. Figure 10 is a graph showing experimental results between frequency and error rate according to one embodiment.

Referring to Figures 9 and 10, according to the above-described embodiment, it can be seen that errors due to temperature changes are canceled by inversely compensating the reference voltage according to temperature. For example, when the frequency of the signal output from the oscillator device is 113 MHz (901), 116 MHz (902), 140 MHz (903), and 164 MHz (904), the error is reduced despite temperature changes and the desired frequency is reached. can be output consistently.

According to an embodiment, a stable oscillation frequency can be provided by reverse-compensating the reference signal input from the oscillator device to the core oscillator circuit according to temperature changes.

In addition, according to an embodiment, by connecting a resistor whose resistance value changes depending on temperature to the reference signal generation circuit that generates the reference signal input from the oscillator device to the core oscillator circuit, a stable oscillation frequency can be provided even if the temperature changes. there is.

Claims (14)

1. a first circuit that outputs a reference voltage;

   a second circuit including a resistor whose resistance value changes according to temperature changes and connected to the first circuit; and

   It includes a third circuit that generates a signal with a frequency corresponding to the reference voltage output from the first circuit,

   The reference voltage output from the first circuit is,

   An oscillator device whose voltage value is adjusted by the second circuit according to temperature changes.
2. According to paragraph 1,

   An oscillator device wherein the reference voltage falls as the temperature rises.
3. According to paragraph 1,

   The second circuit is,

   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.
4. According to paragraph 3,

   An oscillator device in which a rate of change with respect to the temperature of the reference voltage output from the first circuit is set based on a combination ratio between the resistance value of the first resistor and the resistance value of the second resistor.
5. According to paragraph 4,

   The second circuit is,

   a fourth circuit configured such that the resistance value of the first resistor and the resistance value of the second resistor have a first combination 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 combination ratio.
6. According to paragraph 1,

   The third circuit is,

   An oscillator device that includes a plurality of inverters connected in series and has a circular structure in which the output of the last inverter is input to the first inverter.
7. An amplifier that receives a first reference voltage and outputs a second reference voltage;

   a transistor controlled by a second reference voltage output from the amplifier; and

   A first resistor connected in series to the transistor and having a first temperature coefficient, and

   A first circuit connected in series with the first resistor and including a second resistor having a second temperature coefficient different from the first temperature coefficient.
8. In clause 7,

   The second reference voltage output from the amplifier is,

   A voltage generation circuit in which the voltage value is adjusted by the first resistor and the second resistor according to temperature changes.
9. According to clause 8,

   The second reference voltage falls as the temperature rises.
10. In clause 7,

    A voltage generation circuit in which a rate of change in temperature of the second reference voltage output from the amplifier is set based on a combination ratio between the resistance value of the first resistor and the resistance value of the second resistor.
11. According to clause 10,

    The first circuit is,

    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 combination ratio; and

    A third circuit connected to the transistor and configured so that the resistance value of the first resistor and the resistance value of the second resistor have a second combination ratio.
12. a first circuit that outputs a reference voltage; and

    It includes a resistor whose resistance value changes according to temperature changes, and a second circuit connected to the first circuit,

    The reference voltage output from the first circuit is,

    An integrated circuit in which the voltage value is adjusted by the second circuit according to temperature changes.
13. According to clause 12,

    The integrated circuit wherein the reference voltage falls as temperature rises.
14. According to clause 12,

    The second circuit is,

    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.

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