KR20240077994A - Oscillator device, reference volatage generating circuit for oscillator, and integrated circuit - Google Patents

Abstract

One embodiment relates to an oscillator, and includes a reference voltage generator circuit that outputs a reference voltage, and an oscillator that generates a signal with a frequency corresponding to the reference voltage output from the reference voltage generator circuit. According to this embodiment, the oscillator device can provide a stable oscillation frequency by performing compensation processing according to temperature changes.

Description

Oscillator device, voltage generating circuit and integrated circuit for oscillator {OSCILLATOR DEVICE, REFERENCE VOLATAGE GENERATING CIRCUIT FOR OSCILLATOR, AND INTEGRATED CIRCUIT}

This embodiment relates to an oscillator device, a voltage generation circuit for an oscillator, and an integrated circuit.

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

According to one embodiment, the oscillator device may be comprised of a reference voltage generator circuit that generates a reference voltage (or driving voltage) and a core oscillator that generates a signal with a frequency corresponding to the reference voltage. The frequency (e.g., oscillation frequency) of the signal generated in the core oscillator can be controlled according to the reference voltage, and various other factors (e.g., temperature, threshold voltage of the transistor, mobility, etc.) It may be changed by . 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.

In this way, the oscillator device may change the frequency (eg, oscillation frequency) of the signal output from the core oscillator due to various factors depending on temperature changes, and accordingly, it may not be able to stably provide the set frequency. Therefore, there is a need to develop technology that can provide a stable frequency even if the temperature changes in the oscillator device.

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

Another purpose of this embodiment is an oscillator device, an oscillator, 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 voltage generating circuit and integrated circuit for.

To achieve the above-described object, one embodiment 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. An oscillator device whose voltage value is adjusted is provided.

Another embodiment 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 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. Provides a voltage generating circuit including;

Another embodiment 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. An integrated circuit whose voltage value is adjusted is provided.

As described above, according to this embodiment, a stable oscillation frequency can be provided by reverse-compensating the reference signal input from the oscillator device to the core oscillator according to temperature changes.

In addition, according to this embodiment, a resistor whose resistance value changes depending on temperature is connected to the reference signal generation circuit that generates the reference signal input from the oscillator device to the core oscillator, 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 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, in 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,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there is another component between each component. It will be understood that elements may be “connected,” “combined,” or “connected.”

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

Referring to FIG. 1, the oscillator device includes a reference voltage generator circuit 110 that generates and provides a reference voltage with an externally applied power source, a linear regulator 120 that adjusts the reference voltage to a constant constant voltage and outputs it, and an adjusted It may be configured to include a ring oscillator 130 that oscillates based on a reference voltage to generate a pulse train.

The reference voltage generating circuit 110 is provided with an amplifying stage that receives and amplifies an external power supply voltage, and can generate a reference voltage (VREFA) by the output value of this amplifying stage.

The linear regulator 120 may receive the reference voltage VREFA generated by the reference voltage generator circuit 110 and output the reference voltage VREFA as a constant voltage VDDOSC at a constant rate. .

The ring oscillator 130 is configured by connecting a plurality (e.g., an odd number) of inverters in the form of a loop, and is driven by a constant voltage (VDDOSC) transmitted from the linear regulator 120 to maintain a constant frequency. A pulse train with can be generated and output.

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

Referring to FIG. 2, a constant voltage (e.g., a driving voltage or a power supply voltage (VDDOSC)) generated based on a reference signal may be supplied to an oscillator (e.g., a ring oscillator or a core oscillator), and the oscillator corresponds to the constant voltage. A signal of a frequency (eg, oscillation frequency) can be generated. For example, the frequency of the signal generated by the core oscillator may vary linearly in proportion to the size of the power supply voltage (VDDOSC).

According to one embodiment, the constant voltage power supply voltage VDDOSC may be generated at a constant level 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> above, the frequency of the signal generated by the oscillator can be determined by the power supply voltage (VDDOSC), the mobility of the transistor (μ), and the threshold voltage (V _TH ). . The mobility and threshold voltage may increase or decrease according to changes in temperature, as shown in Equation 2 and Equation 3 below, respectively.

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

According to one embodiment, referring to Equation 1 above, as the voltage level of the power supply voltage VDDOSC increases, the frequency may increase. The voltage level of the power supply voltage VDDOSC may 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 according to temperature, the mobility (μ) and threshold voltage (V _TH ) of the transistor change according to 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.

According to one embodiment, even if the voltage level of the power supply voltage (VDDOSC) is kept constant, the frequency may change depending on temperature changes. Therefore, in an embodiment described later, the power supply voltage (VDDOSC) is adjusted so that a signal of a constant frequency is output even if the temperature changes. The voltage level can be adjusted. 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., the threshold voltage (V _TH )), 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, as shown in FIG. 3, even if the temperature in the oscillator increases, the frequency (eg, oscillation frequency) of the output signal 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 410 and a core oscillator 420 that generate a constant voltage from an externally applied power source. The voltage rectifier 410 includes a reference voltage generator circuit 411 that generates and provides a reference voltage with an externally applied power source, a linear regulator 413 that adjusts the reference voltage to a constant constant voltage and outputs it, and a reference voltage according to temperature. It may include a temperature compensation circuit 412 that adjusts the voltage. The core oscillator 420 may be configured to include a ring oscillator 421 that oscillates based on an adjusted reference voltage to generate a pulse train.

The reference voltage generating circuit 411 is provided with an amplifying stage that receives and amplifies an external power supply voltage, and can generate a reference voltage (VREFA) by the output value of this amplifying stage.

The linear regulator 413 receives the reference voltage (VREFA) generated by the reference voltage generator circuit 411, and outputs the reference voltage (VREFA) as a constant voltage (VDDOSC) 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 so that the reference voltage output from the reference voltage generation circuit 411 is 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. The resistance value of the resistor included in the temperature compensation circuit 412 changes according to temperature changes, so that the reference voltage output from the reference voltage generator circuit 411 can be adjusted and output according to temperature. For example, the reference voltage output from the reference voltage generator circuit 411 may decrease as the temperature increases.

The ring oscillator 421 is configured by connecting a plurality (e.g., an odd number) of inverters in the form of a loop, and is driven by a constant voltage (VDDOSC) transmitted from the linear regulator 413 to maintain a constant frequency. A pulse train with can be generated and output. Since the constant voltage VDDOSC input to the ring oscillator 421 is generated in response to the reference voltage, the constant voltage VDDOSC may rise or fall as the reference voltage rises or falls. Since the reference voltage VDDSOC can be adjusted according to temperature changes as described above, the constant voltage VDDOSC can be adjusted according to temperature changes. The ring oscillator 421 of the core oscillator 420 can generate a signal with a constant frequency regardless of the temperature change by receiving a constant voltage (VDDOSC) adjusted according to the temperature change.

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 voltage 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 in proportion as the temperature increases from -50℃ to 150℃, respectively. You can see that it is increasing. At this time, when the power supply voltage (VDDOSC) is 0.9V (501), the frequency increase rate according to the temperature increase is 0.263 MHz / ℃, and when the power supply voltage (VDDOSC) is 1.0V (502), the frequency increase rate according to the temperature increase is 0.263 MHz / ℃. The frequency increase rate is shown as 0.248MHz/°C, and when the power supply voltage (VDDOSC) is 1.1V (503), the frequency increase rate according to temperature can be shown as 0.184MHz/°C. In addition, at -50°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 282.35 MHz/V, at 0°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 292.88 MHz/V, and at 25°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 282.35 MHz/V. ), the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 279.15MHz/V, and at 100℃, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 246.35MHz/V, and at 150°C, the rate of increase in frequency compared to the power supply voltage (VDDOSC) is 220.62MHz/V. It may appear as

If the graph shown in FIG. 5 is expressed as a mathematical equation, it can be expressed as <Equation 4> and <Equation 5> below.

In Equation 4 above, freq0 may mean the frequency of the signal output from the oscillator when the temperature is 25°C and 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 above, VDD0 may mean 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> above, it can be summarized as <Equation 6> below.

According to one embodiment, referring to Equation 6 above, 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 should 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 one 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 adjusted to the temperature. It can be kept constant regardless. At this time, γ can be set by α and β as in <Equation 7>. According to one embodiment, α and β may be determined as a simulation result as shown in FIG. 5. At this time, 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 rectifier 600 (e.g., the voltage rectifier 410 of FIG. 4) that generates a constant voltage (e.g., power supply voltage VDDOSC) supplied to an oscillator (e.g., core oscillator) (or a voltage generator circuit) ) may be configured to include a reference voltage generation circuit 610, a temperature compensation circuit 620, a linear regulator 630, and a first control unit 640.

According to one embodiment, the reference voltage generator circuit 610 may include a first amplifier 611, a first transistor (M1), a second transistor (M2), and a fourth resistor (R4). 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 VDDI, and the other terminal (eg, drain terminal) may be connected to the temperature compensation circuit 620. Additionally, the other terminal of the first transistor (M1) may be fed back and input 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 VDDI, and the other terminal (eg, drain terminal) may be connected to the third resistor (R3). According to one embodiment, current may flow in the first transistor (M1) and the second transistor (M2) by the output signal of the first amplifier 611. At this time, the size of the current flowing through the first transistor M1 (for example, the current flowing from the source terminal to the drain terminal) can be adjusted by the resistance value set in the temperature compensation circuit 620.

According to one embodiment, the temperature compensation circuit 620 may be configured as 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 control unit 640 controls the switch unit (e.g., transistor) included in each temperature compensation circuit, so that any one of the plurality of temperature compensation circuits operates as the first control unit of the reference voltage generation circuit 610. 1 It can be connected to transistor (M1).

According to one embodiment, each temperature compensation circuit among the plurality of temperature compensation circuits may include a switch unit and a resistor (eg, a first resistor and a second resistor). For example, the first temperature compensation circuit may include a first switch unit 621-A, a 1-1 resistor 622-A, and a 2-1 resistor 623A. The second temperature compensation circuit may include a second switch unit 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 switch unit (621-N), a 1-N resistor (622-N), and a 2-N resistor (623N). Each temperature compensation circuit of the plurality of temperature compensation circuits can set a different change in resistance value depending on temperature by combining two resistors. According to one embodiment, each of the switch units 621-A, 621-B,..., 621-N may be turned on/off by a control signal from the first control unit 640. Each of the switch units 621-A, 621-B,..., 621-N may be composed of a transistor (eg, MOSFET), but is not limited thereto.

According to one embodiment, first resistors 622-A, 622-B,..., 622-N and second resistors 623-A, 623-B,..., constituting each temperature compensation circuit. 623-N) can be configured to 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 for each resistance type, and TC1 represents the temperature coefficient for each resistance 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.

According to one embodiment, the first resistors (622-A, 622-B,..., 622-N) and second resistors (623-) constituting each temperature compensation circuit in consideration of the sheet resistance value and temperature coefficient. 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 output from the voltage generation circuit 600 (or The characteristic slope of the power supply voltage (VDDOSC) with respect to temperature can be adjusted. According to various embodiments, the first resistors 622-A, 622-B,..., 622-N are composed of 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 control unit 640, the first switch unit 621-A included in the first temperature compensation circuit is controlled to be in the on state, and the switches included in the remaining temperature compensation circuit are controlled to be in the off state. In case of control, 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 1-1 resistor 622-A and the 2-1 resistor 623-A According to the sheet resistance 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 control unit 640, the second switch unit 621-B included in the second temperature compensation circuit is controlled to be in the on state, and the switch units included in the remaining temperature compensation circuit are controlled to be in the off state. In this case, the second temperature compensation circuit may be connected to the first transistor M1 of the reference voltage generator 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 1-2 resistor 622-B and the 2-2 resistor 623-B According to the sheet resistance 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 control unit 640, the Nth switch unit 621-N included in the Nth temperature compensation circuit is controlled to be in the on state, and the switch units included in the remaining temperature compensation circuit are 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 generator 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 1-N resistor 622-N and the 2-N resistor 623-N According to the sheet resistance 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 control unit 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. According to one embodiment, when the plurality of temperature compensation circuits are set to 64, the first control unit 640 can be controlled to select any one temperature compensation circuit by setting a control signal of 6 bits (2 ⁶ = 64). You can.

According to one embodiment, the gate terminal of the first transistor (M1) and the second transistor (M2) included in the reference voltage generator circuit 610 is commonly connected to the output of the first amplifier 611, thereby forming a current mirror circuit. can be formed. For example, the first transistor M1 and the second transistor M2 are connected to each other through a gate so that a mirrored current can 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 adjusted by a specific temperature compensation circuit connected according to the control signal of the first control unit 640. It may have slope characteristics depending on temperature. 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, and the second reference voltage (VREFA) may decrease as the temperature increases. The ratio (eg, slope) can be changed depending on the selection of the temperature compensation circuit.

According to one embodiment, the linear regulator 630 may include a second amplifier 631, a fourth resistor (R4), and a fifth resistor (R5). A 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. A 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 applied to the non-inverting input terminal (+) of the second amplifier 631. A divided voltage may be applied to the fourth resistor R4 and the fifth resistor R5. For example, when VREFA is input as 0.5V, if the fourth resistor (R4) and the fifth resistor (R5) are set to the same resistance value, the power supply voltage (VDDOSC) output by the linear regulator 630 is 1V. It can be. A power supply voltage (VDDOSC) of a certain magnitude may be output by the linear regulator 630, and the power supply voltage (VDDOSC) has a constant slope as temperature increases based on the connection of the temperature compensation circuit 630 described above. It can be reduced. 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 of an oscillator device according to an embodiment.

Referring to FIG. 7, the core oscillator 700 of the oscillator device (e.g., the core oscillator 420 in FIG. 4) includes a ring oscillator 710 (e.g., the ring oscillator 421 in FIG. 4) and a second control unit 720. ) may include. According to one embodiment, the core oscillator 700 may further include a plurality of transistors (a third transistor (M3), a fourth transistor (M4), a fifth transistor (M5), and a sixth transistor (M6). You can. 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 one embodiment, the source terminal of the third transistor (M3) may be connected to the power supply voltage (VDDOSC) output from the voltage generator circuit 600 described above in FIG. 6, and the drain terminal may be connected to 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 VSSOSC and the drain terminal may be connected to the source terminal of the fifth transistor M5.

According to one embodiment, 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. PDB signals 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). can be supplied to

According to one embodiment, the 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 ). One end of the variable resistor (R _TRIM ) may be connected to the output terminal of the fourth inverter 704, and the other end may be connected to the gate terminal of the third transistor (M3). A terminal between the output terminal of the third inverter 703 and the input terminal of the fourth inverter 704 may be connected to one end of the first capacitor C1. The other end of the first capacitor C1 may be connected between the other end of the variable resistor R _TRIM and the gate terminal of the third transistor M3. Additionally, the other end of the first capacitor C1 may be connected to the variable capacitor C _TRIM . According to one embodiment, the second control unit 720 adjusts the resistance value of the variable resistor (R _TRIM ) or the capacitance of the variable capacitor (C _TRIM ) to adjust the frequency of the signal (D_OSCCLK) output from the core oscillator 700. can be adjusted.

According to one embodiment, the input terminal of the third inverter 703 may be connected to the input terminal of the ring oscillator 710. The ring oscillator 710 is constructed by connecting a plurality of inverters 711, 712, 713, and 714 in the form of a loop, and is driven by a voltage provided from the input terminal of the third inverter 703 to generate a signal ( D_OSCCLK) can be generated and output. Since 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, as the reference voltage rises or falls, the ring oscillator 710 The input voltage may rise or fall. The reference voltage (VDDSOC) may be adjusted according to temperature changes as described above. Accordingly, the ring oscillator 710 of the core oscillator 700 can generate a signal with a constant frequency regardless of the temperature change in response to the constant voltage VDDOSC adjusted according to the temperature change.

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

Referring to FIG. 8, when the first control unit 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) can be generated as 1.014V at -40°C and 0.942V at 145°C. When the first control unit 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 an example, if you want to generate a signal of the first frequency (e.g., 165.0 MHz) in the oscillator device, you can set the code value 38 to select (or connect) the 39th temperature compensation circuit, and select (or connect) the 39th temperature compensation circuit. If you want to generate a signal of 139.5MHz), you can set the code value 43 to select (or connect) the 44th temperature compensation circuit, and if you want to generate a signal of a third frequency (e.g. 109.5MHz), the code The value 49 can be set 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, if 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 can be maintained. It can be output consistently.

As described above, according to this embodiment, a stable oscillation frequency can be provided by reverse-compensating the reference signal input from the oscillator device to the core oscillator according to temperature changes.

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

Claims (14)

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. According to paragraph 1,
An oscillator device wherein the reference voltage falls as the temperature rises. According to paragraph 1,
The second circuit is,
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. According to paragraph 3,
An oscillator device in which a rate of change in 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. According to clause 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. 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. 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 with the transistor and including 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; A voltage generating circuit comprising: In clause 7,
The second reference voltage output from the amplifier is,
A voltage generating circuit in which a voltage value is adjusted by the first resistor and the second resistor according to temperature changes. According to clause 8,
A voltage generation circuit wherein the second reference voltage falls as temperature rises. 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. According to clause 10,
The first circuit is,
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 so that the resistance value of the first resistor and the resistance value of the second resistor have a second combination ratio. 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. According to clause 12,
The integrated circuit wherein the reference voltage falls as temperature rises. 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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