Oscillation circuit and current compensation circuit for oscillator

Abstract

The invention discloses an oscillation circuit and a current compensation circuit for an oscillator. The current compensation circuit comprises a current generating circuit and a current generating circuit. A first node of the current generating circuit is coupled to an input signal. A second node of the current generating circuit is coupled to a process-dependent current. The current generating circuit is configured to provide a compensation current according to the input signal and the process-dependent current. The signal generator is configured to couple a supply voltage to the first node to provide the input signal. A signal level of the input signal changes in response to a change in the power supply voltage. A power supply node of the oscillator is configured to receive a supply current to drive the oscillator. The current generating circuit is configured to draw the compensation current from the power supply node to compensate for a variation in the power supply current generated in response to a variation in the power supply voltage. The current compensation circuit can improve the power supply rejection ratio performance.

Description

TECHNICAL FIELD

[0001] The present application relates to an oscillator circuit, and more particularly to a current compensation circuit for an oscillator, and an oscillator circuit with high power supply variation immunity. BACKGROUND

[0002] A system-on-chip (SoC) is an integrated circuit (IC) that integrates components of an entire electronic system on a single platform. A power supply is used to drive numerous functional blocks that are tightly integrated on the same chip. A SoC can reduce a design that normally requires multiple chips into a single processor, thereby reducing energy waste and saving space occupied by a large system. However, a high operating frequency of a SoC can cause a power supply to drive a rapidly varying load, thereby generating noise in a power supply bus. This noise can reduce a power supply rejection ratio (PSRR) and propagate inside a chip, thereby generating jitter that reduces a dynamic range of sensitive functional blocks, such as a phase-locked loop (PLL). In a SoC design at an advanced technology node, the degradation of the PSRR is more severe due to a reduction in a supply voltage. Therefore, there is a need in the art for an improvement to reduce adverse effects caused by power supply variation. SUMMARY

[0003] Embodiments of the present application disclose a current compensation circuit for an oscillator, and an oscillator circuit with high power supply variation immunity.

[0004] Certain embodiments of the present application include a current compensation circuit for an oscillator. The current compensation circuit includes a current generation circuit and a current generation circuit. The current generation circuit has a first node and a second node. The first node is coupled to an input signal. The second node is coupled to a current having process dependency. The current generation circuit is configured to provide a compensation current based on the input signal and the current having process dependency. A signal generator is coupled to the first node and configured to couple a supply voltage to the first node to provide the input signal. A signal level of the input signal varies in response to variations in the supply voltage. A supply node of the oscillator is configured to receive a supply current to drive the oscillator. The current generation circuit is configured to draw the compensation current from the supply node of the oscillator to compensate for variations in the supply current in response to variations in the supply voltage.

[0005] Certain embodiments of the present application include an oscillator circuit. The oscillator circuit includes a current generator, an oscillator, and a current compensation circuit. The current generator is powered by a supply voltage to output a supply current. The oscillator has a supply node configured to receive the supply current. The oscillator is configured to generate an oscillation signal based on a drive current. A first portion of the supply current flows from the supply node of the oscillator to the oscillator as the drive current. The current compensation circuit is coupled to the supply node of the oscillator and configured to generate a first portion of a compensation current based on the supply voltage and a reference signal, and to generate a second portion of the compensation current based on a first current having process dependency. A signal level of the reference signal is independent of variations in the supply voltage, and the first portion of the compensation current varies in response to variations in the supply voltage. The current compensation circuit is configured to draw the compensation current from the supply node of the oscillator to compensate for variations in the supply current in response to variations in the supply voltage.

[0006] With the current compensation schemes disclosed herein, an oscillator circuit can generate an oscillation signal having a stable (or substantially fixed) frequency under supply variations. The current compensation schemes disclosed herein can enable an oscillator circuit to improve its immunity to supply noise. In addition, an oscillator circuit can be used to implement a phase-locked loop having less jitter and phase noise. The current compensation schemes disclosed herein can improve the power supply rejection ratio performance without increasing the voltage headroom of the phase-locked loop. BRIEF DESCRIPTION OF DRAWINGS

[0007] The implementations described herein can be implemented in connection with any computer system. Figure 1 illustrates an example computer system 100 that can be used to implement the described implementations. As shown in Figure 1, computer system 100 includes a bus 102 or other communication mechanism for communicating information, and a processor 104 coupled with bus 102 for processing information. Computer system 100 also includes a main memory, such as a random access memory (RAM) or other dynamic storage device 106 coupled to bus 102 for storing information and instructions to be executed by processor 104. Main memory 106 also can be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 104. Computer system 100 further includes a read only memory (ROM) 108 or other static storage device coupled to bus 102 for storing static information and instructions for processor 104. Data storage device 110, such as a magnetic disk or optical disk, coupled to bus 102 for storing information and instructions.

[0008] Figure 1 is a schematic diagram of an exemplary oscillation circuit according to certain embodiments of the present application.

[0009] Figure 2 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0010] Figure 3 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0011] Figure 4 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0012] Figure 5 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0013] Figure 6 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0014] Figure 7 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0015] Figure 8 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0016] Figure 9 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0017] Figure 10 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0018] Figure 11 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1

[0019] Figure 12 is an implementation of an oscillation circuit according to certain embodiments of the present application. Figure 1 DETAILED DESCRIPTION

[0020] ​​​​​​​​​​​The following disclosure discloses various implementations or examples that can be used to implement different features of the present disclosure. Specific examples of components and configurations described below are intended to simplify the present disclosure. When possible, the same reference designators are used in the various drawings and the same terminology is used to describe the same features. As such, the description need not be limited to the specific examples described herein. For example, the present disclosure can be repeated in embodiments using components and / or nomenclature different from those described herein. Such repetition is not to be interpreted as a limitation on the different embodiments and / or configurations discussed.

[0021] Also, if a component is described as being "connected to" or "coupled to" another component, it can be directly connected or coupled to the other component, or intervening components can be present.

[0022] To enhance the ability to suppress power supply ripple, a phase-locked loop can utilize a high-impedance path to reduce variations in the supply current injected into a current-controlled oscillator. For example, a cascode circuit composed of two transistors in series can be provided between the power supply and the current-controlled oscillator to reduce the ripple in the supply current. However, in some processes, the transistors used in the cascode circuit exhibit relatively low output resistance. Connecting the cascode circuit between the power supply and the current-controlled oscillator is not sufficient to provide good jitter performance.

[0023] One approach is to add a gain boosting stage at the output of the cascode circuit to increase the output impedance looking into the output of the cascode circuit. However, one or more transistors of the gain boosting stage are in series with the transistors of the cascode circuit, resulting in increased voltage headroom. This approach is not suitable for circuit design in advanced technology nodes.

[0024] This application discloses exemplary current compensation circuits, each capable of generating a compensation current by emulating / simulating the effects of process, voltage, and / or temperature variations on the supply current (which is injected into the oscillator's supply node). The current compensation circuit can draw compensation current from the supply node to compensate for variations in the supply current. For example, the compensation current may be sourced from the supply current and may represent a portion of the supply current that changes with process, voltage, and / or temperature variations. Another portion of the supply current unaffected (or almost unaffected) by process, voltage, and / or temperature variations can flow through the supply node into the oscillator as a drive current, which is used to control the oscillator's oscillation frequency. Therefore, the oscillation frequency can be unaffected or almost unaffected by power supply variations.

[0025] This application also discloses an exemplary oscillator circuit with high power supply variability immunity. Each oscillator circuit can be applied in a phase-locked loop to reduce phase noise and jitter. Further details are provided below.

[0026] Figure 1 This is a schematic diagram of an exemplary oscillation circuit according to certain embodiments of this application. The oscillation circuit 100 can be used to implement a phase-locked loop with high power supply noise immunity. However, this is not intended to limit the scope of this application. Those skilled in the art will understand that the oscillation circuit 100 can be applied to other circuits or devices without departing from the scope of this application. Furthermore, the oscillator in the oscillation circuit 100 can be implemented as a current-controlled oscillator, wherein the oscillation frequency is controlled by a control current injected into the current-controlled oscillator. This embodiment is for illustrative purposes and is not intended to limit the scope of this application. The current compensation scheme disclosed in this application can be applied to other types of oscillators (such as voltage-controlled oscillators or hybrid controlled oscillators) without departing from the scope of this application.

[0027] The oscillation circuit 100 may include (but is not limited to) a current generator 102, an oscillator 104, and a current compensation circuit 110. The current generator 102 is powered by the power supply voltage VCC to output a power supply current I. S The oscillator 104 can generate an oscillation signal CK based on the control current injected into the oscillator 104. OSC For example, oscillator 104 has a supply node N. OSC It is used to receive the power supply current I.S Power supply current I S Can flow into power supply node N OSC To drive oscillator 104. From power supply current I S The driving current I D It can be used as the control current for oscillator 104. For example, the oscillation signal CK. OSC The frequency can be determined by the driving current I D control.

[0028] The current compensation circuit 110 is coupled to the power supply node N. OSC Used for self-powered node N OSC Draw current I C This compensates for the impact of power supply noise on the power supply current I. S The effects of variations in power supply voltage (VCC) can, for example, cause changes in power supply current (I). S The change in current I. C This can be achieved by simulating / simulating power supply noise to control the power supply current I. S The compensation current generated by the influence of [the system / mechanism]. Drive current I D It can maintain a constant or approximately constant level under power supply fluctuations. Therefore, the oscillation signal CK OSC The frequency can remain constant or approximately constant under power supply fluctuations.

[0029] For example (but not limited thereto), the current generator 102 may employ a voltage V B Biased transistor M B This can be implemented using a ring oscillator, and the combination of oscillator 104 and current generator 102 can be considered a voltage-controlled oscillator. Figure 2 In the example shown, oscillator 104 may include N inverters A1-AN connected in series, where N is an integer greater than 1. Note that current generator 102 and / or oscillator 104 may be implemented using other circuit structures without departing from the scope of this application.

[0030] When the power supply voltage VCC rises due to power supply noise, the power supply current I... S The current will also increase accordingly. The current compensation circuit 110 can generate a current I. C (For example, compensation current), which can reflect the effect of power supply noise on power supply current I. S The effect of current I. C It can be the power supply current I S Part of it, its self-powered node N OSC The current flows to the current compensation circuit 110. The power supply current I... S The other part (from power supply node N) OSCThe power supply current I flowing to the oscillator 104 S It can be used as the driving current I. D Please note the drive current I. D It is the power supply current I S Deduct current I C As a result, the power supply current I can therefore be maintained at a constant or approximately constant level. This is achieved through simulation / modeling of power supply noise affecting the power supply current I. S The current compensation circuit 110 can reduce / eliminate the impact of power supply noise on the frequency stability of the oscillator 104.

[0031] In some embodiments, process and / or temperature variations in the current generator 102 and oscillator 104 may cause power supply current I to change. S The response to power supply noise differs. The current compensation circuit 110 can also simulate / analyze the effects of process and / or temperature variations to generate current I. C Noise compensation is performed.

[0032] For example, consider a scenario where both the first and second circuits employ the same structure comprised of a current generator 102 and an oscillator 104. When subjected to the same power supply noise or voltage fluctuations, the first and second circuits may exhibit different current responses due to process variations. Furthermore / or, the first / second circuits may exhibit different current responses when subjected to the same power supply noise or voltage fluctuations at different temperatures. In other words, power supply current fluctuations caused by power supply noise may differ due to process and / or temperature variations. The current compensation scheme disclosed in this application can compensate for power supply current fluctuations caused by process, voltage, and / or temperature variations.

[0033] Figure 3 According to certain embodiments of this application Figure 1 The illustrated embodiment of the oscillation circuit 100. The current compensation circuit 110 includes (but is not limited to) a signal generator 120 and a current generation circuit 130. The signal generator 120 can be used to couple the power supply voltage VCC to node N of the current generation circuit 130. M1 Thus providing the input signal S IN Input signal S IN The signal level can change with variations in the power supply voltage VCC. That is, the input signal S... IN It can be related to voltage fluctuations. In some cases, the input signal S IN It can be a current signal, which indicates the effect of changes in the power supply voltage VCC on the power supply current I. S The influence of the input signal S. In some cases, the input signal S INIt can be a voltage signal that carries information about the variation of the power supply voltage VCC (or information about the noise component of the power supply voltage VCC).

[0034] Node N of current generating circuit 130 M1 With N M2 It can be coupled to the input signal S respectively. IN With process-dependent current I PT The current generating circuit 130 can generate current based on the input signal S. IN and process-dependent current I PT Provide compensation current (i.e., current I) C Please note that the current I C It can be obtained from power supply node N OSC Outflow to compensate for power supply current I caused by process, voltage and / or temperature variations. S Changes.

[0035] Process-dependent current I PT This can be related to process variations. For example, if the current compensation scheme disclosed in this application is not applied to the oscillator 104, then the power supply current I... S This will change in response to variations in transistor manufacturing processes. To compensate for these variations, the current generation circuit 130 can simulate / analyze the process variations to adjust the power supply current I. S The influence of this provides a process-dependent current I PT In some embodiments, the process-dependent current I... PT It may also be temperature-dependent. The process-dependent current I... PT The current generation circuit 130 can be controlled to either flow in or out, thereby compensating for process and temperature variations.

[0036] During operation, the power supply current I S It can supply power to power node N OSC To drive oscillator 104. Signal generator 120 can provide input signal S. IN It can change in response to variations in the power supply voltage VCC. The process-related current I, which is associated with process and / or temperature variations, is... PT Flowable through node N M2 The current generating circuit 130 can generate current based on the input signal S. IN With process-dependent current I PT Self-powered node N OSC Draw current I C This compensates for the power supply current I generated in response to changes in the power supply voltage VCC. SThe supply current IS, which changes in response to variations in the supply voltage VCC, may vary due to process and / or temperature variations. C (It is not only related to the power supply noise on the power supply current I) S The influence is related to the effect of process and / or temperature variations on the power supply current I. S (Related to the influence of factors), the current generating circuit 130 can compensate for the power supply current I caused by process, voltage and / or temperature variations. S Variation. The oscillator 104 can be driven by a drive current I having a constant (or approximately constant) level. D , generating oscillation signal CK OSC .

[0037] The current compensation scheme disclosed in this application enables the oscillation circuit to generate an oscillation signal with a stable frequency (or a roughly fixed frequency) under power supply fluctuations. The current compensation scheme also improves the oscillation circuit's immunity to power supply noise. Furthermore, the oscillation circuit can be used to implement a phase-locked loop (PLL) that reduces jitter and phase noise.

[0038] To facilitate understanding of the content of this application, certain embodiments are given below to further illustrate the current compensation scheme disclosed in this application. Those skilled in the art should understand that other methods employing… Figure 1 or Figure 2 All embodiments of the circuit structures shown fall within the scope of this application.

[0039] Figure 2 According to certain embodiments of this application Figure 2 The illustrated embodiment of the oscillation circuit 100. The oscillation circuit 300 may include a current generator 302, an oscillator 304, and a current compensation circuit 310. The current generator 302 and the oscillator 304 may respectively employ… Figure 2 The current generator 302 and oscillator 304 shown are used for implementation. Both the current generator 302 and oscillator 304 can be represented by current source symbols. Furthermore, the current compensation circuit 310 can be... Figure 3 The illustrated embodiment of the current compensation circuit 110. The current compensation circuit 310 may include a signal generator 320 and a current generation circuit 330, which may respectively serve as... Figure 3 The illustrated embodiment of the signal generator 120 and the current generation circuit 130.

[0040] In this embodiment, Figure 3 The input signal S shown IN It can be the inflow node N M1 Input current I IN For example, the current generating circuit 330 can be used at node N. M1 Provide node voltage VN The voltage level of node voltage VN is independent (or nearly independent) of variations in the supply voltage VCC. Signal generator 320 has a power supply node N coupled to the supply voltage VCC. CG The signal generator 320 can generate signals based on the power supply voltage VCC and the node voltage V. N The voltage difference between them provides the input current I. IN Input current I IN Inflow node N M1 As Figure 3 The input signal S shown IN Examples of implementations.

[0041] The signal generator 320 can utilize a signal generator to provide input current I. IN It is implemented using a current source. Figure 4 In the example shown, the signal generator 320 can be implemented using a resistive current source, which includes components coupled to the power supply node N. CG With node N M1 The resistive element R1 is between the input current I and the input current I. IN The magnitude can be equal to (or approximately equal to) the power supply voltage VCC and the node voltage V. N The voltage difference between them is divided by the resistance value of the resistive element R1.

[0042] The current generating circuit 330 may include (but is not limited to) a current mirror 332 and a current generator 336. The current mirror 332 is connected to node N. M1 Coupled to signal generator 320, and having a connection to power supply node N OSC node N C1 The current mirror 332 is used at node N. M1 Provide node voltage V N , self-node N M1 Draw input current I IN The first part (i.e., current I) M1 ), and the mirror input current I IN The first part is to provide current I C Current I C From node N C1 Current flows into mirror 332.

[0043] For example (but not limited thereto), the current mirror 332 may include an amplifier 334 and a transistor M. 41 With M 42 Amplifier 334 has an input terminal T. I1 Input terminal T I2 With output terminal TO Input terminal T I1 Coupled to reference voltage V REF Input terminal T I2 Coupled to node N M1 Used to determine the reference voltage V REF At node N M1 Provide node voltage V N Reference voltage V REF It can be insensitive to or unaffected by variations in process, voltage, and temperature (PVT). For example, the reference voltage V... REF This can be provided by a bandgap voltage reference. Additionally, the node voltage V... N It can be equal to (or approximately equal to) the reference voltage V. REF .exist Figure 1 In the example shown, amplifier 334 can be implemented using an operational amplifier with a fairly large (or almost infinite) gain, thereby forming a virtual short circuit in which the voltages at the inverting and non-inverting terminals are equal or approximately equal to each other.

[0044] transistor M 41 With M 42 Each of their control terminals is coupled to the output terminal T. O Transistor M 41 The first connection end is coupled to node N M1 And current I M1 From transistor M 41 The first connection terminal flows into transistor M 41 Transistor M 42 The first connection end is coupled to node N C1 And current I C From transistor M 42 The first connection terminal flows into transistor M 42 Furthermore, transistor M 41 With M 42 Each of their second connection terminals can be coupled to a reference voltage VSS, such as ground voltage.

[0045] Furthermore, the current generator 336 is connected via node N M2 Coupled to the power supply voltage VCC, and having a coupling to node N M1 node N C2 The current generator 336 can generate a process-dependent current I based on the current I. PT From node N M1 Draw input current I IN The second part (i.e., current I) M2The current generator 336 may include (but is not limited to) a current mirror 338 and a resistive element R2. The current mirror 338 can be used to mirror a process-dependent current I. PT , from node N M2 Draw current I M2 (i.e., input current I) IN (Part Two). Current I M2 It can be considered as a process-dependent current.

[0046] Process-dependent current I PT With current I M2 All of these can be related to the impact of process variations on the power supply current IS. For example (but not limited to this application), the current generator 302 or oscillator 304 can be a MOS-based circuit, which is a circuit developed using a metal-oxide-semiconductor field-effect transistor (MOSFET). The process-dependent current I... PT The transistor can flow through the current mirror 338, thus allowing correlation with the transistor's current response to process variations. The response to the process-dependent current I... PT The generated current I M2 This can also be related to the transistor's current response to process variations. Note that the transistor in the current mirror 338 can exhibit temperature dependence. Process-dependent current I... PT With current I M2 It can also be related to the current response of a transistor to temperature changes.

[0047] exist Figure 3 In the example shown, the current mirror 338 may include a transistor M. 31 With M 32 Transistor M 31 The first connection terminal is coupled to transistor M 31 The control terminal is used to receive process-dependent current I. PT Transistor M 32 The control terminal is coupled to transistor M 31 The control terminal. Transistor M 32 The first connection end is coupled to node N C2 Used to receive current I M2 In other words, from node N M1 Outflowing current I M2 It can be obtained from transistor M 32 The first connection terminal flows into transistor M 32 Furthermore, transistor M 31 With M 32Each of their second terminals is coupled to the reference voltage VSS. Note that transistor M... 31 With M 32 Both can be implemented using an n-channel transistor. If the oscillator 304 (or current generator 302) is NMOS (n-channel metal-oxide-semiconductor field-effect transistor) dominant, then the current I... M2 It may be related to the effects of process variations in oscillator 304 (or current generator 302).

[0048] One end of resistor R2 passes through node N. M2 The other end of resistor R2 is coupled to the power supply voltage VCC, and the other end of resistor R2 is coupled to transistor M. 31 The first connection terminal. The process-dependent current I. PT Transistors that can flow through current mirror 338 (e.g., transistor M) 31 And resistor R2. Note that the resistance of resistor R2 can vary with temperature. For process-dependent current I... PT By controlling the flow to (or out of) resistor R2, better temperature compensation can be achieved. For example, resistor R2 can reduce or prevent overcompensation due to temperature variations.

[0049] During operation, the current generator 302 generates the power supply current I based on the power supply voltage VCC. S Output to power supply node N OSC The signal generator 320 can provide input current I. IN Its value varies with the power supply voltage VCC. Input current I IN It can be used with a constant or nearly constant voltage (i.e., node voltage V) N ) node N M1 It is divided into different parts.

[0050] For example, the voltage difference across resistor R1 causes the input current I to... IN Inflow node N M1 The voltage difference across resistor R2 causes a process-dependent current I to... PT Inflow node N M2 Due to the process-dependent current I PT The current flows through the resistor R2 and the transistor M 31 Therefore, the process-dependent current I PT It can exhibit process and temperature dependence. The current mirror 338 can reflect process-dependent currents I... PT Guided to transistor M 31 And mirror process-dependent current I PTTo provide current I M2 It is the input current I IN A portion flows into transistor M 32 Input current I IN Another portion flows into transistor M 41 As current I M1 It can be related to the impact of PVT changes.

[0051] In addition, the current mirror 332 can mirror current I. M1 To provide current I C (That is, compensation current). Current I C It can be obtained from power supply node N OSC Outflow to compensate for the power supply current I S The oscillator 304 can adjust according to the drive current I. D This generates an oscillation signal CK with a stable (or approximately fixed) frequency. OSC .

[0052] Please note that due to the process-dependent current I PT This can be correlated with the transistor's current response to process variations; therefore, the oscillator circuit 300 can achieve a high power supply rejection ratio at different process corners. Furthermore, by utilizing the process-dependent current I... PT Due to its temperature response, the oscillator circuit 300 can have a low temperature coefficient. For example, when the power supply current I... S As the temperature rises, the flow increases through the resistor R2 and the transistor M. 31 Process-dependent current I PT It can be reduced. Current I M2 With process-dependent current I PT The decrease is due to the reduction of current I. M1 It can be adjusted according to the current I M2 The decrease leads to an increase, resulting in a compensation current I. C The increase in driving current I. D It can be maintained at a constant (or approximately constant) level. That is, the oscillator circuit 300 can have a low temperature coefficient.

[0053] Figure 3 The circuit structures shown are for illustrative purposes and are not intended to limit the scope of this application. In some embodiments, the node voltage V NThis can be provided by other circuitry or devices (which can generate a voltage unaffected by variations in the supply voltage VCC). In some embodiments, the signal generator 320 can be implemented using other circuit structures, each of which can output a current that varies with the supply voltage VCC. In some embodiments, other circuitry / devices capable of generating temperature-dependent currents can be used instead of the resistive element R2.

[0054] Figure 3 According to certain embodiments of this application Figure 4 An embodiment of the oscillation circuit 100 is shown. The oscillation circuit 400 may include... Figures 1 to 3 The current generator 302 and oscillator 304 shown may also include a current compensation circuit 410. Except for the current generator 436 included in the current generation circuit 430, the structure of the current compensation circuit 410 is similar to... Figure 4 The current compensation circuit 310 shown has a similar / identical structure.

[0055] The current generator 436 may include a current mirror 438, a resistive element R3, and Figure 5 The current mirror 338 is shown. Current mirror 438 passes through node N. M3 Coupled to current mirror 338. Current mirror 438 is coupled to node N. M2 It can also mirror process-dependent current I. PT To provide flow through node N M3 The intermediate current (i.e., current I) M3 The current mirror 338 passes through node N. M3 Coupled to current mirror 438, used to mirror current I M3 With self-node N M1 Draw current I M2 Please note the current I. M3 It can adjust the power supply current I according to process changes. S The influence is related. For example, current generator 302 or oscillator 304 can be a metal-oxide-semiconductor (MODS) based circuit. The process-dependent current I... PT The transistor that can flow through the current mirror 438 therefore has a process-dependent current I. PT With current I M3 All of these are related to the current response of transistors to process variations.

[0056] exist Figure 1 In the example shown, the current mirror 438 may include a transistor M. 33 With M 34 Transistor M 33 With M 34 Each of their control terminals is coupled to transistor M. 33The first connection terminal. Transistor M 33 With M 34 Each transistor's first connection terminal is coupled to the power supply voltage VCC. 33 With M 34 Their respective second connection terminals are coupled to resistor R3 and node N. M3 Please note that transistor M 33 With M 34 Both can be implemented as p-channel transistors. If the oscillator 304 (or current generator 302) is PMOS (p-channel metal-oxide-semiconductor field-effect transistor) dominant, then the process-dependent current I... PT It may be related to the effects of process variations in oscillator 304 (or current generator 302).

[0057] One end of resistor R3 is coupled to transistor M. 33 The second connection terminal, the other end of resistor R3, is coupled to the reference voltage VSS. The process-dependent current I... PT Transistors that can flow through current mirror 438 (e.g., transistor M) 33 ( ) and resistor R3. Note that the resistance of resistor R3 can vary with temperature. For a process-dependent current I PTT By controlling the flow to (or out of) resistor R3, better temperature compensation can be achieved. For example, resistor R3 can reduce or prevent overcompensation for temperature variations.

[0058] Because those skilled in the art will understand the above regarding Figure 3 After the paragraph explanation, it should be clear that... Figure 3 The operational details of the oscillator circuit 400 shown are omitted here.

[0059] Figures 1 to 4 According to certain embodiments of this application Figure 5 An embodiment of the oscillation circuit 100 is shown. The oscillation circuit 500 may include... Figure 6 The current generator 302 and oscillator 304 shown may also include a current compensation circuit 510. Except for the current generator 536 included in the current generation circuit 530, the structure of the oscillator circuit 500 is similar to... Figure 1 The structure of the oscillator circuit 300 shown is similar to / identical to that of the circuit shown.

[0060] In this embodiment, transistor M 31 The control terminal and the first connection terminal are both coupled to the power supply voltage VCC. The current mirror 338 can mirror process-dependent currents I. PT To provide current I M2Through the current compensation circuit 510, the oscillation circuit 500 can achieve a high power supply rejection ratio at different process corners. As those skilled in the art will understand from the above description... Figure 3 After the paragraph explanation, it should be clear that... Figure 4 The operational details of the oscillator circuit 500 shown are omitted here.

[0061] Figures 1 to 5 According to certain embodiments of this application Figure 6 An embodiment of the oscillating circuit 100 is shown. The oscillating circuit 600 may include... Figure 7 The current generator 302 and oscillator 304 shown may also include a current compensation circuit 610. Except for the current generator 636 included in the current generation circuit 630, the structure of the oscillator circuit 600 is similar to... Figure 1 The structure of the oscillator circuit 400 shown is similar to / identical to that of the circuit shown.

[0062] In this embodiment, transistor M 33 The second connection terminal is coupled to the reference voltage VSS. The current mirror 438 can mirror process-dependent currents I. PT To provide current I M3 Through the current compensation circuit 610, the oscillation circuit 600 can achieve a high power supply rejection ratio at different process corners. As those skilled in the art will understand from the above description... Figure 3 After the paragraph explanation, it should be clear that... Figures 1 to 6 The operational details of the oscillator circuit 600 shown are omitted here.

[0063] Figure 7 According to certain embodiments of this application Figure 8 The embodiment of the oscillation circuit 100 shown. Except for the current compensation circuit 710, the structure of the oscillation circuit 700 is similar to... Figure 1 The oscillation circuit 300 shown has a similar / identical structure. In this embodiment, the injection node N... M1 Input current I IN Can be used as an input to transistor M 41 Current I M1 Through the current compensation circuit 710, the oscillation circuit 700 can achieve a high power supply rejection ratio. As those skilled in the art will understand from the above description... Figure 3 After the paragraph explanation, it should be clear that... Figure 2 The operational details of the oscillator circuit 700 shown are omitted here.

[0064] Figure 2 According to certain embodiments of this application Figure 8The embodiment of the oscillation circuit 100 shown is similar to that of the oscillation circuit 800, except for the current compensation circuit 810. Figure 8 The oscillation circuit 300 shown has a similar / identical structure. In this embodiment, Figure 8 The input signal S shown IN It can be applied to node N M1 The voltage signal. For example, signal generator 820 can capacitively couple the power supply voltage VCC to node N. M1 This provides the input voltage V. IN Input voltage V IN Can be used as Figure 9 The input signal S shown IN Examples of implementations.

[0065] The signal generator 820 can utilize a voltage source (which provides the input voltage V) IN To implement this. Figure 1 In the example shown, the signal generator 820 may include a capacitor element C1, which may be coupled to the power supply node N. CG With node N M1 The voltage source between them. Input voltage V IN It can carry information about the variation of the power supply voltage VCC (or the alternating current (AC) component of the power supply voltage VCC).

[0066] The current generating circuit 830 may include (but is not limited to) a current source 834 and a transistor M. 81 With transistor M 82 In this embodiment, the current source 834 may be associated with the current generator 302. For example, the current source 834 may be associated with node N. M2 Coupled to the power supply voltage VCC, and used to provide a process-dependent current I PT It can be related to the effect of process variations on the power supply current I. S The impact is related to this.

[0067] In addition, transistor M 81 The connection terminal is coupled to transistor M. 81 The control terminal is also coupled to the current source 834 to receive a process-dependent current I. PT Transistor M 82 The connection end is coupled to node N C1 Transistor M 82 The control terminal is coupled to node N M1 And electrically connected to transistor M 81 The control terminal. In Figure 8 In the example shown, transistor M 82The control terminal can be electrically connected to transistor M via resistor R4. 81 The control terminal.

[0068] In operation, the current generating circuit 830 can act as a current mirror to mirror a process-dependent current I. PT To provide compensation current I C The first part (with current I) CP (To be represented). Node voltage V N The first component (e.g., the direct current (DC) component) can respond to a process-dependent current I. PT And built on node N M1 Furthermore, the power supply noise or voltage ripple presented by the power supply voltage VCC can be capacitively coupled to node N. M1 This generates an input voltage V. IN It can be used as the node voltage V N The second component (e.g., the alternating current component). Current I C The second part (with current I) CV (To represent) the responsive node voltage V N The second component flows into transistor M 82 Therefore, the current I C This can be related to the impact of PVT variations. The 810 current compensation circuit is self-powered at node N. OSC Draw current I C To compensate for the power supply current I S The oscillator 304 can adjust according to the drive current I. D This generates an oscillation signal CK with a stable (or approximately fixed) frequency. OSC .

[0069] Through the current compensation circuit 810, the oscillation circuit 800 can achieve a high power supply rejection ratio at different process corners. Please note that... Figure 3 The circuit structures shown are for illustrative purposes and are not intended to limit the scope of this application. In some embodiments, the node voltage V N The first component can be derived from other circuits (which can provide process-dependent current I). PT It is generated by [method name missing]. In some embodiments, the resistor element R4 may be omitted.

[0070] Figure 8 According to certain embodiments of this application Figures 1 to 8 The embodiment of the oscillation circuit 100 shown is similar to that of the oscillation circuit 900, except for the current generating circuit 930. Figure 9 The oscillation circuit 800 shown has a similar / identical structure. In this embodiment, the current generating circuit 930 includes (but is not limited to) a current mirror 932 and...Figure 10 The current generator 336 is shown. The current mirror 932 may include... Figure 1 The resistor R4 and transistor M shown are shown. 81 With M 82 And including the reference current I REF The current source is 934. Reference current I. REF The current level can be unaffected by changes in the power supply voltage VCC, or be insensitive to changes in the power supply voltage VCC.

[0071] The current mirror 932 can be used to mirror the reference current I. REF The first part (i.e., current I) P1 ), to provide compensation current I C The first part (with current I) C1 (To represent). Current I P1 This can be related to process and / or temperature variations. For example, current generator 336 via node N C2 Coupled to current mirror 932, and used to determine the process-dependent current I. PT From node N C2 Draw reference current I REF The second part (i.e., current I) P2 Process-dependent current I PT With current I P2 Both can be related to process and / or temperature variations. Therefore, the current I P1 (i.e., reference current I) REF Subtract current I P2 The results can be related to process and / or temperature variations.

[0072] During operation, the current mirror 932 reflects the current I. P1 To provide compensation current I C The first part (i.e., the current I related to process and / or temperature variations) C1 The power supply noise or voltage ripple presented by the power supply voltage VCC can be capacitively coupled to node N. M1 This generates a compensation current I. C The second part (with current I) C2 (to represent), its flow into transistor M 82 Current I C2 This is related to voltage fluctuations. Therefore, the current flows into node N. C1 Current I C It can be related to the effects of PVT variations. The current compensation circuit 910 can self-power node N. OSC Draw current I C To compensate for the power supply current I S The oscillator 304 can adjust according to the drive current I.D This generates an oscillation signal CK with a stable (or approximately fixed) frequency. OSC .

[0073] Through the current compensation circuit 910, the oscillation circuit 800 can achieve a high power supply rejection ratio and a low temperature coefficient at different process corners. As those skilled in the art will understand from the above description... Figure 4 After the paragraph explanation, it should be clear that... Figure 9 The operational details of the oscillator circuit 900 shown are omitted here.

[0074] Figure 9 According to certain embodiments of this application Figure 4 The embodiment of the oscillation circuit 100 shown. Except for the current compensation circuit 1010 utilizing... Figures 1 to 9 Besides the current generator 436 shown to compensate for process and temperature variations, the structure of the oscillation circuit 1000 is similar to... Figure 10 The oscillation circuit 900 shown has a similar / identical structure. In this embodiment, the current generation circuit 1030 in the current compensation circuit 1010 includes... Figure 11 The current mirror 932 shown and Figure 1 The current generator 436 is shown. In some embodiments, the resistor R3 may be omitted. As those skilled in the art will understand from the above description... Figure 9 After the paragraph explanation, it should be clear that... Figure 8 The operational details of the oscillator circuit 1000 shown are omitted here.

[0075] Figure 9 According to certain embodiments of this application Figure 11 The embodiment of the oscillation circuit 1100 shown is similar to that of the oscillation circuit 1100, except for the current compensation circuit 1110. Figure 4 The oscillation circuit 900 shown has a similar / identical structure. In this embodiment, the current compensation circuit 1110 includes a current generation circuit 1130 and... Figures 1 to 10 The signal generator 820 shown is shown.

[0076] The current generating circuit 1130 includes (but is not limited to) a current generator 1136 and Figure 11 The current mirror 932 is shown. Figure 12 In the example shown, the current generator 1136 includes Figure 1 The current mirror 438 and the resistor R3 are shown. The current mirror 438 is coupled to node N. C2 And used to mirror process-dependent current I PT To provide inflow to node N C2 Current I P3 Current IP3 The power supply current I can be adjusted according to process and / or temperature variations. S The influence is related. The current mirror 932 can reflect current I. P4 (i.e., reference current I) REF With current I P3 The sum of both provides compensation current I. C The first part (which is related to process and / or temperature variations). The current mirror 932 can also be capacitively coupled to node N. M1 To reduce power supply noise, provide compensation current I C The second part. Therefore, the inflow to node N. C1 Current I C It may be related to the impact of PVT changes.

[0077] Through the current compensation circuit 1110, the oscillation circuit 1000 can achieve a high power supply rejection ratio and a low temperature coefficient at different process corners. As those skilled in the art will understand from the above description... Figure 8 After the paragraph explanation, it should be clear that... Figure 12 The operational details of the oscillator circuit 1100 shown are omitted here.

[0078] Figure 2 According to certain embodiments of this application Figure 3 The embodiment of the oscillation circuit 100 shown is similar to that of the oscillation circuit 1200, except for the current generating circuit 1230. Figure 2 The structure of the oscillating circuit 800 shown is similar to / identical to that of the oscillating circuit 800. In this embodiment, node N of the current generating circuit 1230... M2 Coupled to power supply node N OSC To determine the current I C The current generating circuit 1230 may include (but is not limited to) a transistor M. 121 With resistor R5. Transistor M 121 The control terminal is coupled to node N M1 transistor M 121 The first connection end is through node N M2 Coupled to power supply node N OSC transistor M 121 The second connection terminal is coupled to the reference voltage VSS. Resistor R5 is used to connect transistor M. 121 The first connection terminal is coupled to transistor M 121 The control terminal.

[0079] During operation, when the power supply voltage VCC is at a constant level, the transistor M is coupled to... 121The resistor R5 between the first connection terminal and the control terminal enables a process-dependent current I. PT Through node N M2 Flow into transistor M 121 Process-dependent current I PT It can adjust the power supply current I according to process changes. S The influence is related. Furthermore, when power supply noise (or voltage ripple) occurs at the power supply voltage VCC, the signal generator 820 can capacitively couple the power supply noise (or voltage ripple) to node N. M1 This generates an input voltage V. IN The current compensation circuit 1210 can be self-powered at node N. OSC Draw current I C To compensate for the power supply current I S The oscillator 304 can adjust according to the drive current I. D This generates an oscillation signal CK with a stable (or approximately fixed) frequency. OSC .exist Figure 8 In the example shown, the current I C Including process-dependent current I PT With current I P0 , where the current I P0 Response input voltage V IN Flow into transistor M 121 node N M2 .

[0080] Please note that at least a portion of the compensation current provided by the current compensation scheme of this application can be generated based on the power supply voltage and a reference signal. At least a portion of the compensation current can correspond to the effects of power supply noise or voltage fluctuations on the power supply current. The signal level of the reference signal is independent of power supply voltage variations.

[0081] Please refer to it again. Figure 2 The current compensation circuit 110 can be configured to adjust the current based on the power supply voltage VCC and the reference signal S. REF To generate current I C At least a portion of it. Reference signal S REF The signal level is independent of the power supply voltage VCC variation, and the current I C At least a portion of it changes in response to variations in the power supply voltage VCC. For example (but not limited to this application), the reference signal S REF This could be a reference voltage unaffected by changes in the power supply voltage VCC. In another example, the reference signal S... REF This can be a reference current unaffected by fluctuations in the power supply voltage VCC. Furthermore, the current compensation circuit 110 can be configured to compensate for process-dependent currents (e.g., process-dependent current I).PT To generate current I C The other part.

[0082] For example, please refer to [link / reference] again. Figure 9 , Figure 2 The reference signal S shown REF It can be coupled to node N C2 node voltage V N To implement this, signal generator 320 and current mirror 332 can be included as part of current generator 316. Current generator 316 can be configured to operate based on supply voltage VCC and node voltage V. N To generate input current I IN And according to the input current I IN And applied to node N M1 Process-dependent current (i.e., current I) M2 From power supply node N OSC Draw current I C Furthermore, the current generator 336 is used to generate a process-dependent current I. PT And based on the process-dependent current I PT Provide current I M2 Input current I IN and current I M2 Combinations (e.g., input current I) IN Subtract current I M2 This can be used as the compensation current generated by the current compensation circuit 310. The current compensation circuit 310 can adjust the current based on the input current I. IN With current I M2 The combination of self-powered nodes N OSC Draw compensation current (i.e., current I) C ).

[0083] Please refer to it again. Figure 2 In another example, Figure 3 The reference signal S shown REF This can be implemented using a reference voltage VSS, the voltage level of which is unaffected by fluctuations in the supply voltage VCC. The capacitor C1 and transistor M... 82 It can be used as part of current generator 816. Current generator 816 can be used to generate input current (i.e., current I) based on power supply voltage VCC and reference voltage VSS. CV ), and based on the input current and node N M1 node voltage V N The first component (e.g., the DC component) originates from power supply node N. OSC Draw current I C Additionally / or, resistor R4, current source 834, and transistor M...81 It can be used as part of current generator 836. Current generator 836 can be used to generate a process-dependent current I. PT And based on the process-dependent current I PT Provide node voltage V N The first component (e.g., the DC component). Current I CP (That is, the response node voltage V) N The first component (such as the DC component) flows into transistor M 82 Current I C (part of) with current I CV (That is, the response node voltage V) N The second component (such as the AC component) flows into transistor M 82 Current I C The combination of the two (part of the total) can serve as the compensation current (i.e., current I) provided by the current compensation circuit 810. C ).

[0084] See again Figure 8 In another example, Figure 3 The reference signal S shown REF This can be implemented using a reference voltage VSS. Signal generator 820 and current mirror 932 can be used as part of current generator 916. Current generator 916 can operate based on a reference current I. REF Subtract current I P2 (That is, a process-dependent current) as a result, a current I is generated. C1 The current generator 916 can also adjust the current based on the power supply voltage VCC and the node voltage V. N Generate current I C2 .

[0085] The circuit structure described above is for illustrative purposes and is not intended to limit the scope of this application. For example, in some embodiments, Figure 8 The current compensation circuit 110 shown can be implemented as including a first current generator and a second current generator. The first current generator can generate current based on the power supply voltage VCC and the reference signal S. REF (For example, Figure 3 The node voltage V shown N or Figure 8 The reference voltage VSS shown is used to generate the input current (e.g., Figure 12 The input current I shown IN or Figure 2 The current I shown CV ), and can be based on the input current and applied to node N M1 Electrical signals (e.g.) Figures 1 to 12 The current I shown M2 ,or​ The node voltage V shown N (DC component) self-powered node N OSC Draw current I C The first current generator and / or the second current generator may be implemented using other circuit structures without departing from the scope of this application.

[0086] In addition, refer again ​ , ​ The reference signal S shown REF This can be implemented using a reference voltage VSS (which has a voltage level unaffected by fluctuations in the supply voltage VCC). Capacitor C1 is used to couple the supply voltage VCC to transistor M. 121 The control terminal, so that the compensation current I C The first part (i.e., current I) P0 ) Flow into transistor M 121 Resistor R5 is used to power transistor M. 121 The first connection terminal is coupled to transistor M 121 The control terminal, so that the compensation current I C The second part (i.e., the process-dependent current I) PT ) Flow into transistor M 121 .

[0087] Because those skilled in the art will understand the above regarding ​ After the paragraph description, one should understand the operational details of the current compensation circuit configured to generate a first part of the compensation current based on the power supply voltage and reference signal, and a second part of the compensation current based on the process-dependent current. Therefore, further explanation will not be repeated here.

[0088] The current compensation scheme disclosed in this application enables the oscillation circuit to generate an oscillation signal with a stable (or approximately fixed) frequency under power supply fluctuations. This scheme also improves the oscillation circuit's immunity to power supply noise. Furthermore, the oscillation circuit can be used to implement a phase-locked loop (PLL) with less jitter and phase noise. The current compensation scheme also improves the power supply rejection ratio (PSRR) without increasing the PLL's voltage margin.

[0089] The term "approximately" as used in this application is used to describe and illustrate minor variations. When these terms are used in conjunction with an event or situation, they can cover examples of the event or situation occurring precisely or very close to occurring. For example, when the term "approximately" is used with a given value or range, it generally means ±10%, ±5%, ±1%, or ±0.5% of the given value or range. In this application, a numerical range is expressed as a range from one endpoint to another or between two endpoints. Unless otherwise stated, numerical ranges described in this application may include endpoints. Furthermore, when multiple values ​​or characteristics are mentioned as "approximately" the same, it can cover situations where these values ​​are all within ±10%, ±5%, ±1%, or ±0.5% of the average of these values.

[0090] The foregoing description briefly outlines the features of certain embodiments of this application, enabling those skilled in the art to gain a more comprehensive understanding of the various forms of this application. Those skilled in the art will understand that they can readily utilize the content of this application as a basis to design or modify other processes and structures to achieve the same objectives and / or advantages as the embodiments described herein. Those skilled in the art should understand that these equivalent embodiments still fall within the spirit and scope of this application, and that various changes, substitutions, and modifications can be made without departing from the spirit and scope of this application.

Claims

1. A current compensation circuit for an oscillator, comprising: A current generating circuit has a first node and a second node, the first node being coupled to an input signal and the second node being coupled to a process-dependent current, the current generating circuit being used to provide a compensation current based on the input signal and the process-dependent current; as well as A signal generator, coupled to the first node, is used to couple a power supply voltage to the first node to provide the input signal, wherein the signal level of the input signal varies in response to variations in the power supply voltage; The power supply node of the oscillator is used to receive power supply current to drive the oscillator, and the current generation circuit is used to draw the compensation current from the power supply node of the oscillator to compensate for the variation in power supply current caused by the variation in power supply voltage.

2. The current compensation circuit according to claim 1, wherein the current generating circuit is used to provide a node voltage at the first node, the node voltage being independent of variations in the power supply voltage; the signal generator is used to provide an input current based on the voltage difference between the power supply voltage and the node voltage, and the input current flows into the first node as the input signal.

3. The current compensation circuit according to claim 2, wherein the power supply node of the signal generator is coupled to the power supply voltage; the signal generator includes a resistive element coupled between the first node and the power supply node of the signal generator.

4. The current compensation circuit according to claim 2, wherein the current generating circuit comprises: A first current mirror, coupled to the first node and the power supply node of the oscillator, is used to provide the node voltage at the first node, draw a first portion of the input current from the first node, and mirror the first portion of the input current to provide the compensation current. as well as A current generator, coupled to the first node and the second node, is used to draw a second portion of the input current from the first node based on the process-dependent current.

5. The current compensation circuit according to claim 4, wherein the first current mirror comprises: An amplifier, wherein a first input terminal of the amplifier is coupled to a reference voltage; The second input terminal of the amplifier is coupled to the first node and is used to provide the node voltage at the first node according to the reference voltage; A first transistor, wherein the control terminal of the first transistor is coupled to the output terminal of the amplifier, the connection terminal of the first transistor is coupled to the first node, and a first portion of the input current flows into the first transistor from the connection terminal of the first transistor. as well as The second transistor has a control terminal coupled to the output terminal of the amplifier, a connection terminal coupled to the power supply node of the oscillator, and the compensation current flowing into the second transistor from the connection terminal.

6. The current compensation circuit according to claim 5, wherein the node voltage is equal to the reference voltage.

7. The current compensation circuit according to claim 4, wherein the current generator comprises: A second current mirror is used to mirror the process-dependent current to draw a second portion of the input current from the first node, wherein the process-dependent current flows through the transistor of the second current mirror.

8. The current compensation circuit of claim 7, wherein the current generator further comprises a resistive element coupled to the transistor, and the process-dependent current flows through the transistor and the resistive element.

9. The current compensation circuit according to claim 4, wherein the current generator comprises: A second current mirror is used to mirror the intermediate current to draw a second portion of the input current from the first node; A third current mirror is coupled to the second current mirror. It is used to mirror the process-dependent current to provide the intermediate current. as well as A resistive element is coupled to the third current mirror, wherein a process-dependent current flows through the transistor of the third current mirror and the resistive element.

10. The current compensation circuit of claim 1, wherein the signal generator is used to capacitively couple the power supply voltage to the first node to provide an input voltage at the first node; the input voltage serves as the input signal.

11. The current compensation circuit according to claim 10, wherein the current generating circuit comprises: A current source, coupled to the second node, is used to provide the process-dependent current; A first transistor, wherein the connection terminal of the first transistor is coupled to the control terminal of the first transistor and coupled to the current source to receive the process-dependent current; as well as The second transistor has a connection terminal coupled to the power supply node of the oscillator, and a control terminal coupled to the first node and electrically connected to the control terminal of the first transistor.

12. The current compensation circuit according to claim 10, wherein the current generating circuit comprises: A current source for providing a reference current, wherein the current level of the reference current is independent of variations in the power supply voltage; A first transistor, wherein the connection terminal of the first transistor is coupled to the control terminal of the first transistor and coupled to the current source to receive a first portion of the reference current; The second transistor has a connection terminal coupled to the power supply node of the oscillator to receive the compensation current, and a control terminal of the second transistor is coupled to the first node and electrically connected to the control terminal of the first transistor. as well as A current generator, coupled to the second node, is used to draw a second portion of the reference current from the current source based on the process-dependent current.

13. The current compensation circuit of claim 10, wherein the second node is coupled to the power supply node of the oscillator to determine the compensation current, and the current generating circuit comprises: A transistor, wherein the control terminal of the transistor is coupled to the first node, the first connection terminal of the transistor is coupled to the power supply node of the oscillator through the second node, and the second connection terminal of the transistor is coupled to a reference voltage; A first portion of the compensation current flows through the second node in response to the input voltage provided by the signal generator; as well as A resistive element is used to couple the first connection terminal to the second connection terminal so that a second portion of the compensation current flows through the second node, wherein the second portion of the compensation current is the process-dependent current.

14. An oscillating circuit, comprising: A current generator is powered by the power supply voltage to output power supply current; An oscillator having a power supply node for receiving the power supply current, the oscillator being configured to generate an oscillation signal based on a drive current, wherein a first portion of the power supply current flows into the oscillator from the power supply node of the oscillator as the drive current; as well as A current compensation circuit, coupled to the power supply node of the oscillator, is used to generate a first portion of the compensation current based on the power supply voltage and a reference signal, and a second portion of the compensation current based on a first process-dependent current. The reference signal level is independent of the power supply voltage variation, and the first portion of the compensation current changes in response to the power supply voltage variation; the current compensation circuit draws the compensation current from the power supply node of the oscillator to compensate for the variation in the power supply current caused by the power supply voltage variation.

15. The oscillation circuit according to claim 14, wherein the current compensation circuit comprises: A first current generator is coupled to the power supply node of the oscillator and has a first node. The first current generator is configured to generate an input current based on the power supply voltage and the reference signal, and to draw a compensation current from the power supply node of the oscillator based on the input current and an electrical signal applied to the first node. as well as A second current generator, coupled to the first node, is used to generate the first process-dependent current and to provide the electrical signal to the first node based on the first process-dependent current.

16. The oscillation circuit of claim 15, wherein the electrical signal provided by the second current generator is a second process-dependent current, and the first current generator comprises: A current mirror, coupled to the first node and the power supply node of the oscillator, is used to provide a node voltage at the first node, draw a first portion of the input current from the first node, and mirror the first portion of the input current to provide the compensation current, wherein the node voltage of the first node serves as the reference signal, and the voltage level of the node voltage is independent of the variation of the power supply voltage. as well as A current source, coupled to the first node and having a power supply node coupled to the power supply voltage, is used to provide the input current based on the voltage difference between the power supply voltage and the node voltage.

17. The oscillation circuit of claim 16, wherein the second current generator comprises: A current mirror is used to mirror a first process-dependent current to provide a second process-dependent current, wherein the first process-dependent current flows through a transistor of the current mirror.

18. The oscillation circuit of claim 15, wherein the reference signal is a reference voltage whose voltage level is independent of the variation of the power supply voltage; the electrical signal provided by the second current generator is a first component of the node voltage of the first node; The first current generator includes: A capacitor element for capacitively coupling the power supply voltage to the first node to provide a second component of the node voltage at the first node; and A first transistor, wherein a first connection terminal of the first transistor is coupled to a power supply node of the oscillator to receive the compensation current, a control terminal of the first transistor is coupled to the first node, and a second connection terminal of the first transistor is coupled to the reference voltage; The first portion of the compensation current flows into the first transistor in response to a first component of the node voltage; the second portion of the compensation current flows into the first transistor in response to a second component of the node voltage, serving as the input current.

19. The oscillation circuit of claim 18, wherein the second current generator comprises: A resistive element, wherein a first end of the resistive element is coupled to the first node; A current source is used to provide the first process-dependent current; as well as A second transistor, wherein the connection terminal of the second transistor is coupled to the current source to receive the first process-dependent current; The control terminal of the second transistor is coupled to the connection terminal of the second transistor and to the second terminal of the resistive element to provide the first component of the node voltage to the first node.

20. The oscillation circuit of claim 15, wherein the reference signal is a reference voltage whose voltage level is independent of variations in the power supply voltage; the current compensation circuit comprises: A transistor, wherein a first connection terminal of the transistor is coupled to a power supply node of the oscillator, and a second connection terminal of the transistor is coupled to the reference voltage; A capacitor element is used to couple the power supply voltage to the control terminal of the transistor so that a first portion of the compensation current flows into the transistor; as well as A resistive element is used to couple the first connection terminal to the control terminal so that a second portion of the compensation current flows into the transistor, wherein the second portion of the compensation current serves as the first process-dependent current.

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