CN117254773A

CN117254773A - MEMS oscillator

Info

Publication number: CN117254773A
Application number: CN202311386174.1A
Authority: CN
Inventors: 雷永庆; 廖德文; 高楷渊; 黄寿
Original assignee: Mestar Microelectronics Shenzhen Co ltd
Current assignee: Mestar Microelectronics Shenzhen Co ltd
Priority date: 2023-10-24
Filing date: 2023-10-24
Publication date: 2023-12-19

Abstract

The present invention provides a MEMS oscillator comprising: a MEMS resonator for vibrating to generate an oscillation signal; the oscillating module comprises a transimpedance amplifying unit, the transimpedance amplifying unit is electrically connected with the MEMS resonator and used for maintaining the vibration of the MEMS resonator, the oscillating module receives an oscillating signal to output a frequency signal, and the control module is configured to generate a corresponding control signal based on the preset oscillating frequency of the MEMS resonator, wherein the control module is electrically connected with the oscillating module, and the oscillating module receives the control signal to adjust the bandwidth of the transimpedance amplifying unit in the oscillating module to be matched with the preset oscillating frequency. The bandwidth of the oscillating unit is regulated by the control module, so that the transimpedance amplifying unit can be ensured to have enough bandwidth to receive the oscillating signal for processing, and the overlarge bandwidth can be avoided, thereby effectively inhibiting the waste of power consumption.

Description

MEMS oscillator

Technical Field

The invention relates to the field of circuit manufacturing, in particular to a MEMS oscillator.

Background

In recent years, microelectromechanical systems (Microelectromechanical Systems, MEMS) resonators have become the best choice for replacing traditional quartz crystal oscillators due to their small size, low failure rate, good compatibility with integrated circuit fabrication processes, and the like. MEMS oscillators typically comprise two parts, a first part being a resonant circuit that mainly produces oscillation and a second part being a Trans-amp (Trans-Impedance Amplifier, TIA) oscillator sub-circuit that mainly ensures that the oscillation can continue to operate. After the resonant circuit is connected with the TIA oscillator sub-circuit, the preset oscillation frequency can be sampled and used as a clock signal to be output.

The MEMS resonator may operate at different frequency points to vibrate at different frequencies, causing the MEMS resonator to output different frequency signals, such as MHz level frequency signals and KHz level frequency signals. However, in the existing MEMS oscillator, the TIA oscillator subcircuit has a single operation mode, and if the MEMS oscillator is used to generate a MHz-level frequency signal, in order to match the MHz-level frequency signal, the TIA oscillator subcircuit tends to operate in a high power state; however, if the MEMS resonator is used to generate a KHz-level frequency signal, the TIA oscillator subcircuit can still only operate in a high power state due to the fixed mode of operation, resulting in unnecessary power consumption.

Based on the above, the invention provides a novel MEMS oscillator, which controls the working mode of a TIA oscillator subcircuit, thereby reducing the power consumption of the MEMS oscillator.

It should be noted that the foregoing description of the background art is only for the purpose of facilitating a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background section of the present application.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a MEMS oscillator 1, which is used for solving the problem that the power consumption of the MEMS oscillator is unnecessarily wasted due to the single operation mode of the TIA oscillator sub-circuit in the prior art.

To achieve the above and other related objects, the present invention provides

A MEMS oscillator, comprising: a MEMS resonator for vibrating to generate an oscillation signal; the oscillating module comprises a transimpedance amplifying unit, the transimpedance amplifying unit is electrically connected with the MEMS resonator and used for maintaining the vibration of the MEMS resonator, the oscillating module receives the oscillating signal to output a frequency signal, and the control module is configured to generate a corresponding control signal based on the preset oscillating frequency of the MEMS resonator, wherein the control module is electrically connected with the oscillating module, and the oscillating module receives the control signal to adjust the bandwidth of the transimpedance amplifying unit in the oscillating module to be matched with the preset oscillating frequency.

Optionally, the oscillation module further comprises a gain adjusting unit and a level converting unit; the transimpedance amplifying unit is used for receiving the oscillation signal and performing gain conversion to generate a voltage driving signal, the gain adjusting unit is respectively and electrically connected with the transimpedance amplifying unit and the control module, and the gain adjusting unit is used for receiving the control signal and adjusting and controlling the bandwidth of the transimpedance amplifying unit based on the control signal; the level conversion unit is electrically connected with the transimpedance amplification unit, and receives the voltage driving signal to convert the voltage driving signal into the frequency signal.

Optionally, the gain adjustment unit receives the voltage driving signal and processes the voltage driving signal based on the control signal to generate an adjustment current, and the adjustment current is used for adjusting and controlling the bandwidth of the transimpedance amplification unit.

Optionally, the transimpedance amplifying unit includes an inverting amplifier, a feedback resistor and a bias current source, the feedback resistor is connected in parallel with the inverting amplifier, the bias current source is electrically connected with the inverting amplifier and the gain adjusting unit respectively, and the bias current source receives the adjusting current and provides bias current for the inverting amplifier based on the adjusting current so as to adjust the gain and bandwidth of the transimpedance amplifying unit.

Optionally, the gain adjusting unit adopts an automatic gain control circuit, and the level converting unit adopts a level converter.

Optionally, the MEMS oscillator further comprises a vibration regulation module, wherein the vibration regulation module is used for regulating the vibration state of the MEMS resonator.

Optionally, the vibration regulation module is disposed between the oscillation module and the MEMS resonator, and the voltage driving signal output by the oscillation module is output to the MEMS resonator via the vibration regulation module.

Optionally, when the MEMS resonator and the oscillation module stably operate, the oscillation regulation module is turned off or standby, and the voltage driving signal output by the oscillation module is directly provided to the MEMS resonator, so as to maintain the MEMS resonator to operate in a current oscillation state.

Optionally, the vibration regulation module is electrically connected with the control module, and the vibration regulation module receives the state regulation signal sent by the control module and outputs a corresponding state driving signal according to the state regulation signal so as to regulate the vibration state of the MEMS resonator.

Optionally, if the vibration state of the MEMS resonator is changed, when the control module sends the state adjustment signal to the vibration adjustment module, the control module also sends a corresponding control signal to the oscillation module, so that the working state of the oscillation module is matched with the vibration state of the MEMS resonator after the change.

As described above, the MEMS oscillator of the present invention has the following advantageous effects: the control module is configured based on the preset oscillation frequency of the MEMS resonator, and the bandwidth of the oscillation unit is adjusted by the control module, so that the transimpedance amplification unit can be ensured to have enough bandwidth to receive oscillation signals for processing, and the overlarge bandwidth can be avoided, so that the waste of power consumption is effectively restrained; the MEMS oscillator is relatively simple in structure and suitable for large-scale production and manufacture.

Drawings

Fig. 1 shows a schematic structure of a MEMS oscillator according to the present invention.

Fig. 2 is a schematic structural diagram of an oscillating module according to the present invention.

Fig. 3 is a schematic diagram of a transimpedance amplifier unit according to the present invention.

Fig. 4 shows a schematic structure of the MEMS resonator of the present invention.

Fig. 5 is a schematic structural view of another oscillation module according to the present invention.

Description of element reference numerals

1 MEMS oscillator

11. Control module

12. Oscillation module

121. Transimpedance amplifying unit

1211. Inverting amplifier

1212. Bias current source

122. Gain adjusting unit

1221. Controllable attenuation subunit

1222. Signal processing subunit

123. Level conversion unit

13 MEMS resonator

131. Driving electrode

132. Sensing electrode

133. Vibrator(s)

14. Bias voltage generating module

15. Vibration control module

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.

Please refer to fig. 1-5. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

In an embodiment of the present application, referring to fig. 1, a MEMS oscillator 1 may include a control module 11, an oscillation module 12, and a MEMS resonator 13. Wherein the MEMS resonator 13 is adapted to vibrate to generate an oscillating signal. The oscillation module 12 may be electrically connected to the MEMS resonator for maintaining the MEMS resonator 13 in oscillation. The oscillating module 12 may receive the oscillating signal to output a frequency signal. The control module 11 is electrically connected to the oscillation module 12, and the control module 11 is configured to provide a control signal for the oscillation module 12 to adjust the working state of the oscillation module 12 so as to match the preset oscillation frequency of the MEMS resonator 13.

In this embodiment, the MEMS resonator 13 may have a plurality of frequency points, and the MEMS resonator 13 may operate at the frequency points to output an oscillation signal more stably. Different frequency points may correspond to different oscillation frequencies. The preset oscillation frequency of the MEMS resonator 13 is determined according to the requirement of the circuit in which the MEMS oscillator 1 is located, and the MEMS resonator 13 may be configured to vibrate at a corresponding frequency point. For example, the MEMS resonator 13 may have a first frequency point corresponding to the MHz level oscillation frequency and a second frequency point corresponding to the KHz level oscillation frequency, and if the preset oscillation frequency of the MEMS resonator 13 is determined to be the MHz level according to the circuit requirement, the MEMS resonator 13 is configured to operate to vibrate at the first frequency point. If the preset oscillation frequency of the MEMS resonator 13 is determined to be in KHz-order according to the circuit requirement, the MEMS resonator 13 is configured to vibrate at a second frequency point.

It will be appreciated that the oscillating frequency of the MEMS resonator 13 is different and the requirements on the oscillating module 12 are also different. The control module 11 may determine to output a corresponding control signal according to the preset oscillation frequency of the MEMS resonator 13, and adjust the oscillation module 12 based on the control signal, so that the oscillation module 12 is in an operating state matched with the preset oscillation frequency, thereby stably outputting a required frequency signal of the MEMS oscillator 1. In this case, the operating state (or operating mode) of the oscillation module 12 is adjusted accordingly, so that it can be better matched to the vibration state of the MEMS resonator 13.

Specifically, the oscillation module 12 may include a transimpedance amplification unit 121. The transimpedance amplification unit 121 is electrically connected to the MEMS resonator 13 for maintaining the MEMS resonator 13 in vibration. The oscillation frequencies of the MEMS resonators 13 are different, and the bandwidths required by the transimpedance amplification unit 121 are also different. The control signal provided by the control module 13 can be used for regulating and controlling the bandwidth of the transimpedance amplification unit 121 so as to enable the bandwidth to be matched with the preset oscillation frequency of the current MEMS resonator 13, and ensure that the MEMS resonator 13 can vibrate normally. In the present embodiment, the larger the oscillation frequency of the MEMS resonator 13, the larger the bandwidth of the transimpedance amplification unit 121 is relatively required to ensure that the MEMS resonator 13 can vibrate at a preset oscillation frequency. According to the required preset oscillation frequency, the transimpedance amplification unit 121 can be controlled by the control module 13 to be configured with matched bandwidths. In this case, different bandwidths are configured for different oscillation frequencies, so that it is possible to ensure that the transimpedance amplifying unit 121 has a sufficient bandwidth to receive the oscillation signal for processing, and to avoid an excessive bandwidth, so as to effectively suppress waste of power consumption.

In the embodiments of the present application, referring to fig. 1 and 4, both the input and output of the mems resonator 13 are connected to the oscillating module 12.

Specifically, the MEMS resonator 13 includes a drive electrode 131 and a sense electrode 132 that are disposed opposite to each other, and a vibrator 133 interposed between the drive electrode 131 and the sense electrode 132. The driving electrode 131 is used as an input end of the MEMS resonator 13, and the sensing electrode 132 is used as an output end of the MEMS resonator 13. When the MEMS oscillator 1 is operated, the driving electrode 131 is applied with an ac driving signal (such as an ac voltage signal), so that an electrostatic force is applied between the opposite or same charges established on the driving electrode 131 and the vibrator 133, and the vibrator 133 vibrates back and forth under the driving of the electrostatic force, so that the capacitance between the sensing electrode 132 and the vibrator 133 changes, so that an ac current signal is generated on the sensing electrode 132, and the ac current is subsequently received by the oscillating module 12 for amplification (or gain) and converted into a voltage driving signal for output. The output end of the oscillating module 12 is electrically connected with the driving electrode 131, and the driving electrode 131 receives the voltage driving signal to maintain the vibrator 113 to vibrate, so that a closed loop circulation system of 'electric energy, mechanical kinetic energy and electric energy' is formed. Accordingly, the MEMS resonator 13 of the MEMS oscillator 1 can perform physical vibration of a fixed frequency to generate a current oscillation signal, i.e., an alternating current signal.

In some embodiments, referring to fig. 1 and 4, the mems oscillator 1 further comprises a bias voltage generating module 14. The bias voltage generating module 14 is connected to the vibrator 133, and is configured to generate a preset bias voltage and apply the preset bias voltage to the vibrator 133, so that the MEMS resonator 13 can start vibrating better, and the phase noise of the MEMS oscillator 1 can be reduced effectively.

In the present embodiment, the bias voltage generating module 14 is provided as a charge pump circuit, by which the set bias voltage is output. In fact, the bias voltage generating module 14 may be configured in any structure, as long as a circuit configuration capable of providing the vibrator 131 with a stable bias voltage is not limited to the present embodiment.

In the embodiment of the present application, referring to fig. 1, an input end of the oscillation module 12 is connected to the sensing electrode 132, and an output end of the oscillation module 12 is connected to the driving electrode 131. The oscillation module 12 is configured to receive the oscillation signal output by the MEMS resonator 13, perform gain amplification, and convert the oscillation signal into a voltage driving signal, where the voltage driving signal may be a sine wave signal; the oscillation module 12 outputs the voltage driving signal to the driving electrode 131 and the subsequent module of the oscillation module 12, respectively. The driving electrode 131 receives the voltage driving signal to maintain the vibrator 113 to vibrate. Subsequent ones of the oscillating modules 12 receive the voltage drive signal and process it to generate a frequency signal.

In the present embodiment, referring to fig. 2, the oscillation module 12 may include a transimpedance amplification unit 121, a gain adjustment unit 122, and a level conversion unit 123.

As an example, the transimpedance amplifying unit 121 receives a current oscillation signal for gain-amplifying and converting the current oscillation signal into a voltage driving signal. In this case, the transimpedance amplification unit 121 gain-amplifies and converts the current oscillation signal into a voltage drive signal output again, thereby achieving energy interaction between the oscillation module 12 and the MEMS resonator 13, so that the MEMS resonator 13 continuously oscillates.

The level conversion unit 123 is connected to an output terminal of the transimpedance amplification unit 121, and is configured to receive a voltage driving signal and convert the voltage driving signal into a frequency signal. It is understood that the Level Shift unit 123 may employ a Level Shifter (LS) to output a frequency signal by performing Level detection adjustment on the voltage driving signal. The frequency signal may be a square wave signal or a sine wave signal.

In some embodiments, referring to fig. 3, the transimpedance amplifying unit 121 may include an inverting amplifier 1211, a feedback resistor R, and a bias current source 1212. The bias current source 1212 is coupled to the inverting amplifier 1211 for providing a bias current to the inverting amplifier 1211 that may be used to adjust the transconductance, gain, bandwidth, etc. of the inverting amplifier 1211. The feedback resistor R is connected in parallel with the inverting amplifier 1211 to convert the current signal into a voltage signal based on ohm's law. The inverting amplifier 1211 taps the oscillation signal and performs gain amplification on the oscillation signal by the bias current source 1212.

It will be appreciated that when the bias current provided by the bias current source 1212 is small, the gain (or bandwidth) of the inverting amplifier 1211, etc. is correspondingly reduced. Accordingly, when the bias current supplied from the bias current source 1212 is large, the gain (or bandwidth) of the inverting amplifier 1211 and the like are also increased accordingly. In this case, if the oscillation frequency of the MEMS resonator 13 is high (e.g., in the MHz range), in order to ensure that the transimpedance amplifying unit 121 is in a matched operation state (e.g., has a suitable bandwidth to determine that an oscillation signal with high oscillation frequency can be received for processing and maintain the oscillation of the MEMS resonator 13), a larger bias current is required to be provided by the bias current source 1212. If the oscillation frequency of the MEMS resonator 13 is low (e.g., in KHz), the bias current source 1212 may provide a smaller bias current to ensure that the transimpedance amplifier unit 121 is in a matched operating state (e.g., has a suitable bandwidth and is not too wide to increase power consumption). That is, by adjusting the magnitude of the bias current provided by the bias current source 1212, the operation state of the transimpedance amplifying unit 121 can be adjusted, which will be described in detail later. In the present embodiment, in order to facilitate better understanding of the arrangement, the high oscillation frequency is the frequency of the Mhz stage, and the low oscillation frequency is the frequency of the Khz stage. In fact, the concept of relatively setting the high and low oscillation frequencies is not limited to the present embodiment.

In the embodiment of the present application, referring to fig. 2, the gain adjusting unit 122 may be electrically connected to the control module 11 and the transimpedance amplifying unit 121, respectively. The gain adjusting unit 122 may receive the control signal, and regulate the working state of the transimpedance amplifying unit 121 based on the control signal. Specifically, the gain adjustment unit 122 may have a first input terminal, a second input terminal, and an output terminal. A first input terminal of the gain adjustment unit 122 may be connected to an output terminal of the transimpedance amplification unit 121, a second input terminal of the gain adjustment unit 122 may be connected to an output terminal of the control module 11, and an output terminal of the gain adjustment unit 122 may be connected to an input terminal of the transimpedance amplification unit 121. The gain adjustment unit 122 may receive the control signal and the voltage driving signal, and the gain adjustment unit 122 processes the voltage driving signal under the control signal to generate the adjustment signal. The transimpedance amplifying unit 121 may receive the adjustment signal and adjust its own operation state based on the adjustment signal, for example, adjust bandwidth and gain.

In this embodiment, the output end of the gain adjustment unit 122 may be electrically connected to the bias current source 1212. The adjustment signal output by gain adjustment unit 122 may be applied to bias current source 1212. After receiving the adjustment signal, the bias current source 1212 may adjust the magnitude of the bias current provided to the inverting amplifier 1211 based on the adjustment signal. In this case, the magnitude of the bias current is adjusted by the adjustment signal, and the transconductance and gain of the inverting amplifier 1211 can be adjusted to affect the gain bandwidth of the inverting amplifier 1211 and the bandwidth of the transimpedance amplifying unit 121.

In some embodiments, the gain adjustment unit 122 may employ an automatic gain control circuit (Automatic Gain Control, AGC). In this embodiment, the gain adjustment unit 122 may also be used to adjust the amplitude of the voltage driving signal output by the transimpedance amplification unit 121. Specifically, the gain adjustment unit 122 may adjust the amplitude of the voltage driving signal output from the transimpedance amplification unit 121 by adjusting the bias current supplied from the bias current source 1212. In this case, it is possible to enable the transimpedance amplification unit 121 to output a voltage drive signal that maintains a fixed amplitude.

In some embodiments, the adjustment signal may be an adjustment current. The gain adjustment unit 122 processes the voltage drive signal under the influence of the control signal to generate an adjustment current. The control signal acts on the gain adjusting unit to regulate the magnitude of the adjusting current.

In some embodiments, referring to fig. 2, the gain adjustment unit 122 may include a controllable attenuation subunit 1221 and a signal processing subunit 1222. The controllable attenuation subunit 1221 is electrically connected to the control module 11 and the transimpedance amplifying unit 121, respectively, to receive the control signal and the voltage driving signal. The controllable damping subunit 1221 processes the voltage driving signal under the adjustment of the control signal to obtain the adjustment signal. The signal processing subunit 1222 is electrically connected to the controllable attenuation subunit 1221, so as to receive the adjustment signal and convert it into an adjustment current, and provide the adjustment current to the transimpedance amplifying unit 121.

In some embodiments, controllable damping subunit 1221 may include a variable attenuator. In this embodiment, the control signal may be a control voltage. The control voltage is input to the control end of the controllable attenuation subunit 1221, the voltage driving signal is input to the input end of the controllable attenuation subunit 1221, and the attenuation degree of the controllable attenuation subunit 1221 is adjusted by adjusting the magnitude of the control voltage so as to adjust the voltage driving signal to obtain an adjustment signal. In some embodiments, the signal processing subunit 1222 may include MOS transistors, resistors, etc. to implement the process conversion of the adjustment signal to obtain the adjustment current.

It should be noted that, if the adjusting current is larger, the bias current will be larger, so that the bandwidth (or called bandwidth) of the transimpedance amplifying unit 121 is larger and is in a high-power mode, and the MHz-level oscillation signal with higher frequency can be received for processing; if the adjustment current is reduced, the bias current will be smaller, resulting in the smaller bandwidth of the transimpedance amplifying unit 121 in the low power mode, and the transimpedance amplifying unit 121 can receive the kHz-level oscillation signal with lower frequency for processing. Based on this, in the present embodiment, the bandwidth of the transimpedance amplifying unit 121 is further regulated by adjusting the magnitude of the adjustment signal input to the transimpedance amplifying unit 121 by the gain adjusting unit 122. Meanwhile, the gain adjusting unit 122 may be further configured to have other circuit structures, and any circuit capable of outputting an adjusting signal based on an input control signal, so that the circuit configuration for adjusting the working state of the transimpedance amplifying unit 121 is within the protection range of the embodiment, for example, the gain adjusting unit 122 may be implemented by using devices such as a current source, a MOS transistor, and a resistor.

In some embodiments, the operating state of the oscillating module 12 corresponds to the oscillating frequency of the MEMS resonator 13. For example, if the oscillation frequency of the MEMS resonator 13 is a high oscillation frequency, the oscillation module 12 needs a large bandwidth to be in a high power mode. If the oscillation frequency of the MEMS resonator 13 is low, the oscillation module 12 needs a smaller bandwidth to be in the low power mode. In fact, the high-low power mode is a concept of relative arrangement, and is not limited to the present embodiment. The control module 11 is regulated to realize the regulation and control of the working state of the oscillating module 12. In this case, by adjusting the operating state (or the operating mode) of the oscillation module 12, it is made possible to better match the vibration state of the MEMS resonator 13.

In the embodiment of the present application, the control module 11 may be configured in advance according to the circuit requirement, so as to implement regulation and control on the oscillating module 12. Specifically, the preset oscillation frequency of the MEMS resonator 13 is known according to the circuit requirement, and the control module 11 is configured based on the preset oscillation frequency, so as to adjust the working state of the oscillation module 12 to match with the preset oscillation frequency.

In some embodiments, the control module 11 adjusts the gain adjusting unit 122 by adjusting the control signal, so as to regulate the bias current source 1212 to affect the working state of the transimpedance amplifying unit 121. In this embodiment, if the oscillating module 12 is in the low power mode, the control module 11 may output a control signal, such as a standby signal, and the control signal acts on the gain adjusting unit 122 to decrease the output adjusting signal, so as to decrease the bias current provided by the bias current source 1212, so that the transimpedance amplifying unit 121 has a smaller bandwidth. If the oscillating module 12 is in the high power mode, the control module 11 may not output the control signal, or the output control signal does not affect the operation of the gain adjusting unit 122, so that the gain adjusting unit 122 may receive the voltage driving signal to normally output the adjusting signal, so that the bias current provided by the bias current source 1212 is larger, and the transimpedance amplifying unit 121 has a larger bandwidth. The example of the present application is not limited thereto, if the oscillating module 12 is in the high power mode, the control signal output by the control module 11 may also increase the adjusting signal output by the gain adjusting unit 122, so that the bias current provided by the bias current source 1212 is larger, and thus the transimpedance amplifying unit 121 has a larger bandwidth. In some embodiments, the control signal is a voltage signal, and the circuit structure of the control module 11 may provide the voltage signal, which is not limited in particular.

In an embodiment of the present application, the MEMS oscillator 1 further comprises a vibration conditioning module 15. The vibration regulation module 15 may be used to regulate the vibration state of the MEMS resonator 13. For example, the MEMS resonator 13 may have a dual mode vibration state, that is, a MHz vibration state vibrating at a MHz-level vibration frequency, and a KHz vibration state vibrating at a KHz-level vibration frequency, respectively. The vibration control module 15 may output a state driving signal to the MEMS resonator 13 to make the MEMS resonator 13 operate in a corresponding vibration state.

In an embodiment of the present application, the vibration modulation module 15 may be disposed between the oscillation module 12 and the MEMS resonator 13, and the voltage driving signal output from the oscillation module 12 is output to the MEMS resonator 13 through the vibration modulation module 15. In this embodiment, the voltage driving signal output by the oscillation module 12 is adjusted by the vibration adjusting module 15 to output a state driving signal, and the state driving signal can adjust the vibration state of the MEMS resonator 13.

In some embodiments, the vibration conditioning module 15 may be a voltage source, in which case, based on the vibration state required by the MEMS resonator 13, the voltage source may provide a corresponding state driving signal to drive the MEMS resonator 13 into operation. For example, the MEMS resonator 13 needs to operate in a MHz vibration state, and the voltage source may provide an ac driving signal of MHz level to the MEMS resonator 13. Or, the MEMS resonator 13 originally works in the MHz vibration state, and at this time, the MEMS resonator 13 needs to be converted into the KHz vibration state, so that the voltage source can suppress the voltage driving signal output by the oscillation module 12, and directly output the ac driving signal of the KHz level to the MEMS resonator 13 or convert the voltage driving signal at this time into the ac driving signal of the KHz level to the MEMS resonator 13. In some embodiments, the voltage source may be a voltage controlled oscillator, or a ring oscillator circuit.

In another embodiment, the vibration modulation module 15 may include a frequency dividing unit and a frequency doubling unit. For example, when the MEMS oscillator 1 is normally operated and the MEMS resonator 13 is operated in the MHz vibration state, and when the MEMS resonator 13 is required to be operated in the KHz vibration state, the voltage driving signal (e.g., the reduced frequency) at that time is reduced by the frequency dividing unit to be converted into a KHz driving signal to the MEMS resonator 13. Or, when the MEMS resonator 13 is operated in KHz vibration state, and when the MEMS resonator 13 is required to be operated in MHz vibration state, the voltage driving signal is converted into a MHz driving signal by increasing the frequency multiplication unit, and the MHz driving signal is supplied to the MEMS resonator 13.

In some embodiments, when the MEMS resonator 13 and the oscillation module 12 stably operate, the oscillation regulation module 15 may be in a closed or standby state, etc., and the voltage driving signal output by the oscillation module 12 may be directly provided to the MEMS resonator 13 to maintain the MEMS resonator 13 to operate in the current oscillation state. Thus, power consumption can be effectively reduced.

In an embodiment of the present application, the vibration control module 15 may be electrically connected to the control module 11, and the vibration control module 15 is controlled by the control module 11. The vibration control module 15 may receive the state adjustment signal sent by the control module 11 and output a corresponding state driving signal according to the state adjustment signal, so as to adjust the vibration state of the MEMS resonator 13. For example, when the MEMS oscillator 1 is operating normally, the MEMS resonator 13 is operating in the MHz vibration state, and when the control module 11 sends a state adjustment signal (corresponding to the KHz frequency), the vibration adjustment module 15 may output a KHz driving signal to the MEMS resonator 13 based on the state adjustment signal, so that the MEMS resonator 13 is operating in the KHz vibration state.

It will be appreciated that if the vibration state of the MEMS resonator 13 changes, the control module 11 sends a state adjustment signal to the vibration control module 15, and the control module 11 also sends a corresponding control signal to the oscillation module 12. Thereby, the vibration state of the MEMS resonator 13 and the working state of the oscillation module 12 can be synchronously switched, and the working state of the oscillation module 12 can be better matched with the vibration state of the MEMS resonator 13.

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A MEMS oscillator, the MEMS oscillator comprising:

a MEMS resonator for vibrating to generate an oscillation signal;

an oscillation module including a transimpedance amplification unit electrically connected with the MEMS resonator for maintaining the MEMS resonator to vibrate, and receiving the oscillation signal to output a frequency signal, an

And the control module is configured to generate a corresponding control signal based on a preset oscillation frequency of the MEMS resonator, wherein the control module is electrically connected with the oscillation module, and the oscillation module receives the control signal to adjust the bandwidth of the transimpedance amplification unit in the oscillation module so as to be matched with the preset oscillation frequency.

2. The MEMS oscillator of claim 1, wherein: the oscillation module further comprises a gain adjusting unit and a level converting unit;

the transimpedance amplifying unit is used for receiving the oscillating signal and performing gain conversion to generate a voltage driving signal;

the gain adjusting unit is respectively and electrically connected with the transimpedance amplifying unit and the control module, receives the control signal and adjusts and controls the bandwidth of the transimpedance amplifying unit based on the control signal;

the level conversion unit is electrically connected with the transimpedance amplification unit, and receives the voltage driving signal to convert the voltage driving signal into the frequency signal.

3. The MEMS oscillator of claim 2, wherein: the gain adjusting unit receives the voltage driving signal and processes the voltage driving signal based on the control signal to generate an adjusting current, wherein the adjusting current is used for adjusting and controlling the bandwidth of the transimpedance amplifying unit.

4. A MEMS oscillator as claimed in claim 3, wherein: the transimpedance amplifying unit comprises an inverting amplifier, a feedback resistor and a bias current source, wherein the feedback resistor is connected with the inverting amplifier in parallel, the bias current source is respectively and electrically connected with the inverting amplifier and the gain adjusting unit, and the bias current source receives the adjusting current and provides bias current for the inverting amplifier based on the adjusting current so as to adjust the gain and the bandwidth of the transimpedance amplifying unit.

5. The MEMS oscillator of claim 2, wherein: the gain adjusting unit adopts an automatic gain control circuit, and the level converting unit adopts a level converter.

6. The MEMS oscillator of claim 1, wherein: the MEMS oscillator further comprises a vibration regulation module, wherein the vibration regulation module is used for regulating the vibration state of the MEMS resonator.

7. The MEMS oscillator of claim 6, wherein: the vibration regulation and control module is arranged between the oscillation module and the MEMS resonator, and a voltage driving signal output by the oscillation module is output to the MEMS resonator through the vibration regulation and control module.

8. The MEMS oscillator of claim 7, wherein: when the MEMS resonator and the oscillation module work stably, the vibration regulation module is closed or standby, and the voltage driving signal output by the oscillation module is directly supplied to the MEMS resonator so as to maintain the MEMS resonator to work in the current vibration state.

9. The MEMS oscillator of claim 6, wherein: the vibration regulation module is electrically connected with the control module, receives the state regulation signal sent by the control module, and outputs a corresponding state driving signal according to the state regulation signal so as to regulate the vibration state of the MEMS resonator.

10. The MEMS oscillator of claim 9, wherein: if the vibration state of the MEMS resonator is changed, when the control module sends the state adjusting signal to the vibration adjusting module, the control module also sends a corresponding control signal to the oscillation module so as to enable the working state of the oscillation module to be matched with the vibration state of the MEMS resonator after the change.