Crystal oscillator, clock generation circuit, chip and electronic equipment

Abstract

The invention discloses a crystal oscillator, a clock generation circuit, a chip and electronic equipment, and belongs to the technical field of integrated circuits, the crystal oscillator comprises a current generation circuit, an amplification circuit and a crystal oscillator circuit; the current generating circuit is electrically connected with the input end of the amplifying circuit and is used for providing a first current signal for the amplifying circuit and switching to provide a second current signal for the amplifying circuit after oscillation starting of the crystal oscillation circuit; wherein the current value of the first current signal is greater than that of the second current signal; the output end of the amplifying circuit is electrically connected with the crystal oscillator circuit, and the amplifying circuit is used for providing a first feedback signal for the crystal oscillator circuit according to the first current signal so as to enable the crystal oscillator circuit to start oscillation and providing a second feedback signal for the crystal oscillator circuit according to the second current signal so as to enable the crystal oscillator circuit to stably oscillate after oscillation starting; wherein the amplitude of the first feedback signal is greater than that of the second feedback signal. The low-power-consumption crystal oscillator can start oscillation quickly, and the starting time is shortened.

Description

Technical Field

[0001] The present application belongs to the technical field of integrated circuits, and specifically relates to a crystal oscillator, a clock generating circuit, a chip and an electronic device. Background Art

[0002] Crystal oscillators can be used in clock generation fields such as real-time clocks (RTCs). Crystal oscillators can generate independent and stable sinusoidal oscillation signals, which can be used as reference clock signals after conversion.

[0003] At present, crystal oscillators can adopt a current bias type oscillation circuit structure, which includes a bias current source, an amplifier composed of a transistor and a resistor, and a crystal oscillator circuit composed of an external crystal and a load capacitor connected to both ends of the resistor. The bias current source can provide a smaller bias current signal, so that the crystal oscillator has low power consumption performance.

[0004] However, the smaller bias current signal leads to a smaller transconductance of the amplifier of the crystal oscillator, that is, a smaller feedback loop gain, which is not conducive to the starting of the crystal oscillator, resulting in problems such as slow starting speed and long startup time of the crystal oscillator. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a crystal oscillator, a clock generating circuit, a chip and an electronic device, which can solve the problems of slow start-up speed and long startup time of the current low-power crystal oscillator.

[0006] In a first aspect, an embodiment of the present application provides a crystal oscillator, the crystal oscillator comprising: a current generating circuit, an amplifying circuit, and a crystal oscillator circuit;

[0007] The current generating circuit is electrically connected to the input end of the amplifier circuit, and is used to provide a first current signal to the amplifier circuit, and is switched to provide a second current signal to the amplifier circuit after the crystal oscillator circuit starts oscillating; wherein the current value of the first current signal is greater than the current value of the second current signal;

[0008] The output end of the amplifier circuit is electrically connected to the crystal oscillator circuit, and is used to provide a first feedback signal to the crystal oscillator circuit according to the first current signal to start the crystal oscillator circuit, and to provide a second feedback signal to the crystal oscillator circuit according to the second current signal to enable the crystal oscillator circuit to oscillate stably after starting; wherein the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal.

[0009] Optionally, the crystal oscillator further includes a power supply terminal; the current generating circuit includes a first resistance module, a second resistance module and a first switch module;

[0010] The first resistor module is connected in series with the first switch module to serve as a first branch; the first resistor module and the first switch module connected in series are also connected in parallel with the second resistor module; the second resistor module serves as a second branch; wherein the resistance of the first branch is less than the resistance of the second branch;

[0011] The power supply end is electrically connected to the input end of the first branch and the input end of the second branch respectively; the input end of the amplifier circuit is electrically connected to the output end of the first branch and the output end of the second branch respectively; wherein the first switch module is used to disconnect the first branch after the crystal oscillator circuit starts oscillating.

[0012] Optionally, the first switch module includes a first transistor; the first resistor module includes a first resistor; the second resistor module includes a second resistor;

[0013] The first electrode of the first transistor is electrically connected to the power supply terminal, and the second electrode is electrically connected to the first end of the first resistor; the second end of the first resistor is electrically connected to the input end of the amplifier circuit;

[0014] The first end of the second resistor is electrically connected to the power supply end, and the second end is electrically connected to the input end of the amplifier circuit; wherein the resistance value of the first resistor is smaller than the resistance value of the second resistor.

[0015] Optionally, the current generating circuit further includes a first current mirror; the first current mirror is arranged between the output end of the first branch and the input end of the amplifier circuit, and between the output end of the second branch and the input end of the amplifier circuit;

[0016] The input end of the first current mirror is electrically connected to the output end of the first branch and the output end of the second branch respectively, and the output end of the first current mirror is electrically connected to the input end of the amplifier circuit, for respectively mirroring the first current signal and the second current signal to the amplifier circuit.

[0017] Optionally, the crystal oscillator further includes a delay switch circuit;

[0018] The output end of the delay switch circuit is electrically connected to the control end of the current generating circuit, and is used to send a first control signal to the current generating circuit and start timing, and switch to sending a second control signal to the current generating circuit after the timing duration reaches a preset duration;

[0019] Among them, the preset time length is not less than the time length required for the crystal oscillator circuit to start up quickly; the first control signal is used to control the current generating circuit to output the first current signal; the second control signal is used to control the current generating circuit to switch to output the second current signal.

[0020] Optionally, the crystal oscillator further includes a ground terminal; the delay switch circuit includes a capacitor module and a transistor module;

[0021] The input end of the capacitor module is electrically connected to the power supply end, and the output end of the capacitor module is electrically connected to the input end of the transistor module;

[0022] The output end of the transistor module is electrically connected to the ground end, and is used to provide a leakage current signal to charge the capacitor module;

[0023] An intermediate node is provided between the capacitor module and the transistor module; the intermediate node is electrically connected to the control end of the current generating circuit.

[0024] Optionally, the delay switch circuit further includes an inverter module; the inverter module is arranged between the intermediate node and the control end of the current generating circuit;

[0025] The input end of the inverter module is electrically connected to the intermediate node, and the output end is electrically connected to the control end of the current generating circuit.

[0026] Optionally, the transistor module includes a second transistor;

[0027] The first electrode of the second transistor is electrically connected to the output end of the capacitor module and the input end of the inverter module respectively; the second electrode of the second transistor is short-circuited with the control electrode and then connected to the ground end.

[0028] Optionally, the crystal oscillator further comprises a gain enhancement circuit;

[0029] The gain enhancement circuit is arranged between the current generating circuit and the amplifier circuit, and is electrically connected to the current generating circuit and the amplifier circuit respectively, and is used to amplify the first current signal and the second current signal according to a preset amplification ratio and then input them into the amplifier circuit.

[0030] Optionally, the gain enhancement circuit comprises a feedback module and a second current mirror;

[0031] The second current mirror is electrically connected to the current generating circuit and the amplifying circuit respectively; wherein the amplification ratio is the mirror amplification ratio of the second current mirror;

[0032] The feedback module is arranged between the amplifier circuit and the second current mirror, and is electrically connected to the amplifier circuit and the second current mirror respectively, and is used to transmit the first feedback signal and the second feedback signal to the second current mirror, so that the second current mirror amplifies the first feedback signal and the second feedback signal and then inputs them into the amplifier circuit.

[0033] Optionally, the second current mirror is coupled to the first current mirror, and is used to receive the first current signal and the second current signal after mirror copying by the first current mirror, and respectively perform mirror amplification according to the amplification ratio and then input them into the amplifier circuit.

[0034] Optionally, the amplifier circuit includes a bias current module, a third resistor module and an amplifier tube module;

[0035] The input end of the bias current module is electrically connected to the output end of the current generating module, and the output end of the bias current module is electrically connected to the first end of the third resistor module and the input end of the amplifier module, respectively, for transmitting the first current signal and the second current signal to the first resistor module and the amplifier module;

[0036] The second end of the third resistor module is electrically connected to the control end of the amplifier module; the first end and the second end of the third resistor module are electrically connected to the crystal oscillator circuit respectively, serving as the output end of the amplifier circuit;

[0037] The output end of the amplifier module is electrically connected to the ground end of the crystal oscillator, and is used to generate the first feedback signal according to the first current signal, and to generate the second feedback signal according to the second current signal.

[0038] Optionally, the bias current module includes a third transistor;

[0039] The first electrode of the third transistor is electrically connected to the power supply terminal of the crystal oscillator, and the second electrode is electrically connected to the first end of the third resistor module; wherein, when the third transistor is turned on, the first electrode and the second electrode of the third transistor form a third branch;

[0040] The control electrode of the third transistor is electrically connected to the control electrode of the fourth transistor in the second current mirror to form a third current mirror; the third current mirror is used to mirror the first current signal amplified by the second current mirror and the second current signal amplified to the third branch.

[0041] Optionally, the output end of the first current mirror is electrically connected to the first end of the third resistor module and the input end of the amplifier module respectively;

[0042] The first current mirror is further used to send the first current signal and the second current signal to the amplifier tube module respectively, so that the amplifier tube module can perform current multiplexing on the first current signal and the second current signal.

[0043] Optionally, the amplifier module includes a fifth transistor; the feedback module includes a sixth transistor;

[0044] A first electrode of the fifth transistor is electrically connected to the first end of the third resistor module, and a second electrode is electrically connected to the ground end;

[0045] The control electrode of the fifth transistor is electrically connected to the control electrode of the sixth transistor to form a fourth current mirror; the fourth current mirror is used to mirror the first feedback signal and the second feedback signal generated by the fifth transistor to the second current mirror.

[0046] In a second aspect, an embodiment of the present application provides a clock generation circuit, wherein the clock generation circuit includes the crystal oscillator as described in the first aspect.

[0047] In a third aspect, an embodiment of the present application provides a chip, wherein the chip includes the crystal oscillator as described in the first aspect.

[0048] In a fourth aspect, an embodiment of the present application provides an electronic device, wherein the electronic device includes the chip as described in the third aspect.

[0049] A crystal oscillator, clock generation circuit, chip and electronic device provided by the embodiment of the present application have at least the following advantages: the current generation circuit provides a first current signal to the amplifier circuit, so that the amplifier circuit provides a first feedback signal to the crystal oscillator circuit according to the first current signal, so that the crystal oscillator circuit starts oscillating under the action of the first feedback signal. After the crystal oscillator circuit starts oscillating, the current generation circuit switches to provide a second current signal to the amplifier circuit, so that the amplifier circuit provides a second feedback signal to the crystal oscillator circuit according to the first current signal, so that the crystal oscillator circuit oscillates stably after starting. Since the current value of the first current signal is greater than the current value of the second current signal, the amplifier circuit can provide a larger feedback signal, namely the first feedback signal, to the crystal oscillator circuit according to the first current signal, and the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal, which is conducive to the rapid oscillation of the crystal oscillator circuit and can shorten the startup time of the crystal oscillator. After the crystal oscillator circuit starts oscillating, the current generation circuit can reduce the current value of the bias current signal provided to the amplifier circuit, that is, by providing the second current signal, the power consumption of the amplifier circuit and the crystal oscillator circuit is reduced, so that the crystal oscillator circuit oscillates stably at lower power consumption. In this way, the low-power crystal oscillator can start oscillating quickly and the startup time can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1is a structural schematic diagram of a crystal oscillator provided in an embodiment of the present application;

[0051] Figure 2 is a structural schematic diagram of a delay switch circuit provided in an embodiment of the present application;

[0052] Figure 3 is a structural schematic diagram of a gain improvement circuit provided in an embodiment of the present application;

[0053] Figure 4 is a structural schematic diagram of a current generating circuit provided in an embodiment of the present application;

[0054] Figure 5 is a structural schematic diagram of an amplifier circuit provided in an embodiment of the present application;

[0055] Figure 6 is a structural schematic diagram of a crystal oscillator circuit provided in an embodiment of the present application;

[0056] Figure 7 It is a structural schematic diagram of a Pierce crystal oscillator circuit in the related art;

[0057] Figure 8 It is a schematic diagram of the structure of another crystal oscillator provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0059] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or at least two. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0060] First, the background technology involved in the embodiments of the present application is described.

[0061] At present, low-power RTC can be applied to the field of low-power clock generation. For example, low-power RTC can be used as a clock module of a low-power system to provide a reference clock signal for the low-power system. For example, in the field of low-power IoT applications, clock modules such as RTC are generally powered by batteries. Even if the system is powered off, the clock module continues to work. Therefore, the lower the power consumption of the RTC, the longer the service life of the device or the fewer times the battery needs to be replaced. RTC can be composed of a crystal oscillator, a low-dropout regulator, and a digital logic circuit. Therefore, if each module of the RTC has low power consumption performance, a low-power RTC can be obtained.

[0062] In conjunction with the accompanying drawings, a crystal oscillator 10, a clock generating circuit, a chip and an electronic device provided in an embodiment of the present application are described in detail through specific embodiments and their application scenarios.

[0063] Figure 1 is a structural diagram of a crystal oscillator 10 provided in an embodiment of the present application, such as Figure 1 As shown, the crystal oscillator 10 includes: a current generating circuit 101, an amplifying circuit 102, and a crystal oscillator circuit 103;

[0064] The current generating circuit 101 is electrically connected to the input end of the amplifier circuit 102, and is used to provide a first current signal to the amplifier circuit 102, and is switched to provide a second current signal to the amplifier circuit 102 after the crystal oscillator circuit 103 starts oscillating; wherein the current value of the first current signal is greater than the current value of the second current signal;

[0065] The output end of the amplifier circuit 102 is electrically connected to the crystal oscillator circuit 103, and is used to provide a first feedback signal to the crystal oscillator circuit 103 according to the first current signal to start the crystal oscillator circuit 103, and to provide a second feedback signal to the crystal oscillator circuit 103 according to the second current signal to enable the crystal oscillator circuit 103 to oscillate stably after starting; wherein the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal.

[0066] In some embodiments, the crystal oscillator 10 can be applied to a low-power clock generation circuit such as an RTC, which helps the clock generation circuit achieve low power consumption and fast startup performance. The current generation circuit 101 is used to generate a bias current signal required by the amplifier circuit 102. The amplifier circuit 102 can be an amplifier composed of a bias current source, a resistor and a transistor. The crystal oscillator circuit 103 may include a crystal and a load capacitor, such as a quartz crystal. The quartz crystal can start to vibrate under the action of an external electric field and generate an oscillation signal. This property is called "piezoelectricity".

[0067] In some embodiments, the current generating circuit 101, the amplifier circuit 102, and the crystal oscillator circuit 103 are connected in sequence. The current generating circuit 101 provides the first current signal or the second current signal to the amplifier circuit 102 as a bias current signal of the amplifier circuit 102. The amplifier circuit 102 outputs the first feedback signal or the second feedback signal to the crystal oscillator circuit 103 according to the bias current signal. The crystal oscillator circuit 103 starts to vibrate, i.e., starts to oscillate, under the action of the first feedback signal, and then stabilizes the oscillation under the action of the second feedback signal.

[0068] Among them, since the current value of the first current signal is greater than the current value of the second current signal, when the crystal oscillator 10 is powered on and started, the amplifier circuit 102 can provide a larger first feedback signal to the crystal oscillator circuit 103 according to the larger bias current signal, i.e., the first current signal, so that the crystal oscillator circuit 103 can start oscillating quickly, and the starting speed of the crystal oscillator 10 can be improved. After the crystal oscillator 10 is started, when the crystal oscillator circuit 103 can oscillate stably, the current value of the bias current signal output by the current generation is reduced, i.e., the current generation circuit 101 provides the second current signal to the amplifier circuit 102, and the amplifier circuit 102 can provide the second feedback signal to the crystal oscillator circuit 103 according to the smaller bias current signal, i.e., the second current signal, and the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal, so that the power consumption of the amplifier circuit 102 and the crystal oscillator circuit 103 can be reduced, so that the crystal oscillator 10 achieves low power consumption performance, and by improving the starting speed of the crystal oscillator circuit 103, the crystal oscillator 10 can start quickly.

[0069] In the embodiment of the present application, the current generating circuit 101 provides a first current signal to the amplifier circuit 102, so that the amplifier circuit 102 provides a first feedback signal to the crystal oscillator circuit 103 according to the first current signal, so that the crystal oscillator circuit 103 starts to oscillate under the action of the first feedback signal. After the crystal oscillator circuit 103 starts to oscillate, the current generating circuit 101 switches to provide a second current signal to the amplifier circuit 102, so that the amplifier circuit 102 provides a second feedback signal to the crystal oscillator circuit 103 according to the first current signal, so that the crystal oscillator circuit 103 oscillates stably after starting. Since the current value of the first current signal is greater than the current value of the second current signal, the amplifier circuit 102 can provide a larger feedback signal, namely the first feedback signal, to the crystal oscillator circuit 103 according to the first current signal, and the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal, which is conducive to the rapid oscillation of the crystal oscillator circuit 103 and can shorten the startup time of the crystal oscillator 10. After the crystal oscillator circuit 103 starts oscillating, the current generating circuit 101 can reduce the current value of the bias current signal provided to the amplifier circuit 102, that is, by providing the second current signal, the power consumption of the amplifier circuit 102 and the crystal oscillator circuit 103 is reduced, so that the crystal oscillator circuit 103 can oscillate stably at a lower power consumption. In this way, the low-power crystal oscillator 10 can start oscillating quickly and shorten the startup time.

[0070] Optionally, the crystal oscillator 10 further includes a power supply terminal; the current generating circuit 101 includes a first resistance module 1011, a second resistance module 1012 and a first switch module 1013;

[0071] The first resistor module 1011 and the first switch module 1013 are connected in series to serve as a first branch; the first resistor module 1011 and the first switch module 1013 connected in series are also connected in parallel to the second resistor module 1012; the second resistor module 1012 serves as a second branch; wherein the resistance value of the first branch is less than the resistance value of the second branch;

[0072] The power supply end is electrically connected to the input end of the first branch and the input end of the second branch respectively; the input end of the amplifier circuit 102 is electrically connected to the output end of the first branch and the output end of the second branch respectively; wherein the first switch module 1013 is used to disconnect the first branch after the crystal oscillator circuit 103 starts oscillating.

[0073] In some embodiments, the power supply terminal of the crystal oscillator 10 can be electrically connected to an external power supply to receive a power supply signal input by the external power supply. For example, the crystal oscillator 10 belongs to a clock generating circuit, and the power supply terminal of the crystal oscillator 10 can be electrically connected to a power supply module in the clock generating circuit. The power supply module of the clock generating circuit can be a battery, or the power supply module can be connected to an external power supply of the clock generating circuit. This is only an example, and the embodiments of the present application are not limited to this.

[0074] In some embodiments, the current generating circuit 101 includes a first branch formed by a first resistor module 1011 and a first switch module 1013 connected in series, and a second branch where a second resistor module 1012 is located, and the first branch and the second branch are connected in parallel to each other. The input ends of the first branch and the second branch are respectively electrically connected to the input end of the crystal oscillator 10, and the output ends of the first branch and the second branch are respectively electrically connected to the input end of the amplification branch.

[0075] Specifically, when the crystal oscillator 10 is started, the power supply end is connected to the input end of the amplifier circuit 102 via the first branch and the second branch. Since the resistance of the first branch is smaller than the resistance of the second branch, the total resistance of the current generating circuit 101 is smaller than the resistance of the first branch, and the current generating circuit 101 outputs a larger bias current signal, i.e., the first current signal. After the crystal oscillator circuit 103 starts oscillating, the first switch module 1013 disconnects the first branch, so that only the second branch is connected between the power supply end and the input end of the amplifier circuit 102, and the current generating circuit 101 outputs a smaller bias current signal, i.e., the second current signal.

[0076] In some embodiments, the first resistor module 1011 may include one or more resistors, and the multiple resistors may be connected in series and / or in parallel, and the same is true for the second resistor module 1012. The first switch module 1013 may include a controllable switch element, such as a triode, a field effect transistor, etc. This is only an example, and the embodiments of the present application are not limited to this.

[0077] In the embodiment of the present application, since the resistance of the first branch is smaller than the resistance of the second branch, the first branch is disconnected by the first switch module 1013 after the crystal oscillator circuit 103 starts oscillating, so that the resistance of the current generating circuit 101 can be conveniently changed, so that the current generating circuit 101 switches from the first current signal to the second current signal with a smaller output current value, thereby improving the practicality of the crystal oscillator 10.

[0078] Optionally, the first switch module 1013 includes a first transistor; the first resistor module 1011 includes a first resistor; the second resistor module 1012 includes a second resistor;

[0079] The first electrode of the first transistor is electrically connected to the power supply terminal, and the second electrode is electrically connected to the first end of the first resistor; the second end of the first resistor is electrically connected to the input end of the amplifier circuit 102;

[0080] A first end of the second resistor is electrically connected to the power supply end, and a second end is electrically connected to the input end of the amplifier circuit 102; wherein the resistance value of the first resistor is smaller than the resistance value of the second resistor.

[0081] In some embodiments, in order to reduce the cost of the crystal oscillator 10 and simplify the circuit structure, the current generating circuit 101 can be simply composed of a transistor and two resistors. Specifically, the first transistor is connected in series with the first resistor as a first branch. The first transistor and the first resistor connected in series are then connected in parallel with the second resistor, and the second resistor is used alone as a second branch. The resistance value of the first resistor is less than the resistance value of the second resistor.

[0082] The first transistor may be a metal-oxide-semiconductor (MOS) field effect transistor, i.e., a MOS transistor, the first electrode may be a source electrode or a drain electrode of the MOS transistor, the second electrode may be a drain electrode or a source electrode of the MOS transistor, and the control electrode may be a gate electrode of the MOS transistor. For example, the first transistor is a P-type metal-oxide-semiconductor (PMOS) field effect transistor, i.e., a PMOS transistor, the PMOS transistor is connected in series with the first resistor, the source electrode of the PMOS transistor is connected to the power supply terminal of the crystal oscillator 10, the drain electrode of the PMOS transistor is connected to the first resistor, and the other end of the first resistor is connected to the input end of the amplifier circuit 102.

[0083] Optionally, the current generating circuit 101 further includes a first current mirror 1014; the first current mirror 1014 is arranged between the output end of the first branch and the input end of the amplifier circuit 102, and between the output end of the second branch and the input end of the amplifier circuit 102;

[0084] The input end of the first current mirror 1014 is electrically connected to the output end of the first branch and the output end of the second branch respectively, and the output end of the first current mirror 1014 is electrically connected to the input end of the amplifier circuit 102, for respectively mirroring the first current signal and the second current signal to the amplifier circuit 102.

[0085] In some embodiments, the first current mirror 1014 may be a current mirror simply composed of two transistors, or may be a common-source and common-gate current mirror with a more complex structure, such as a cascode current mirror. The input end of the first current mirror 1014 is electrically connected to the output ends of the first branch and the second branch, respectively. When the first branch and the second branch are both turned on, the first current mirror 1014 receives the first current signal and then copies it to the amplifier circuit 102. When the crystal oscillator circuit 103 starts oscillating, the first branch is disconnected, and the first current mirror 1014 receives the second current signal and then copies it to the amplifier circuit 102. In this way, the bias current signal can be copied to the amplifier circuit 102 by the first current mirror 1014 without changing the direction of the current, so that the amplifier circuit 102 receives the bias current signal and processes it.

[0086] Optionally, the crystal oscillator 10 further includes a delay switch circuit 104;

[0087] The output end of the delay switch circuit 104 is electrically connected to the control end of the current generating circuit 101, and is used to send a first control signal to the current generating circuit 101 and start timing, and switch to sending a second control signal to the current generating circuit 101 after the timing time reaches a preset time;

[0088] The first control signal is used to control the current generating circuit 101 to output the first current signal; the second control signal is used to control the current generating circuit 101 to switch to output the second current signal.

[0089] In some embodiments, the time from when the current generating circuit 101 outputs the first current signal to when it switches to outputting the second current signal can be controlled by controlling the time from when the circuit is powered on to when the first branch is disconnected by the first switch module 1013 in the current generating circuit 101. The first switch module 1013 can be controlled by a control signal sent by an external circuit of the current generating circuit 101. For example, the control signal can come from a control circuit of a clock generating circuit to which the crystal oscillator 10 belongs. This is merely an example, and the embodiments of the present application are not limited thereto.

[0090] In some embodiments, the delay switch circuit 104 can be used to provide a corresponding control signal to the first switch module 1013 of the current generating circuit 101, so that the current generating circuit 101 switches from the first current signal to the second current signal after the crystal oscillator circuit 103 starts oscillating. Specifically, the delay switch circuit 104 outputs the first control signal to the current generating circuit 101 by default after power-on to control the current generating circuit 101 to output the first current signal. At the same time, the delay switch circuit 104 can start timing, and after the timing time reaches a preset time, switch to output the second control signal to the current generating circuit 101 to control the current generating circuit 101 to switch to provide the second current signal to the amplifying circuit 102.

[0091] In some embodiments, the delay switch circuit 104 may include a timing module. When the delay switch circuit 104 outputs the first control signal, the timing module starts timing from zero. When the timing duration reaches a preset duration, the delay switch circuit 104 switches to outputting a second control signal. The timing duration may be determined based on the duration required for the crystal oscillator 10 to start stable operation from power-on, or based on the duration required for the crystal oscillator circuit 103 to start stable oscillation. The control end of the current generating circuit 101 may be the control end of the first switch module 1013, for example, the control electrode of the first transistor in the first switch module 1013. The output end of the delay switch circuit 104 may be electrically connected to the control end of the first switch module 1013, and specifically may be electrically connected to the control electrode of the first transistor.

[0092] In the embodiment of the present application, the time delay switch circuit 104 is used for timing. When the current generating circuit 101 outputs the first current signal and reaches a preset time length, the time delay switch circuit 104 switches from the first control signal to the second control signal, so that the current generating circuit 101 switches from the first current signal to the second current signal under the control of the second control signal. In this way, the time when the current generating circuit 101 switches the current signal can be conveniently controlled by setting the preset time length of the time delay switch circuit 104, ensuring that the current generating circuit 101 switches to output a smaller bias current signal in time after the crystal oscillator circuit 103 starts oscillating, thereby reducing the power consumption of the crystal oscillator 10.

[0093] Optionally, the crystal oscillator 10 further includes a ground terminal; the delay switch circuit 104 includes a capacitor module 1041 and a transistor module 1042;

[0094] The input end of the capacitor module 1041 is electrically connected to the power supply end, and the output end of the capacitor module 1041 is electrically connected to the input end of the transistor module 1042;

[0095] The output terminal of the transistor module 1042 is electrically connected to the ground terminal, and is used to provide a leakage current signal to charge the capacitor module 1041;

[0096] An intermediate node is provided between the capacitor module 1041 and the transistor module 1042 ; the intermediate node is electrically connected to the control terminal of the current generating circuit 101 .

[0097] In some embodiments, the delay switch circuit 104 can realize timing through the charging delay characteristics of the capacitor. The capacitor module 1041 may include one or more capacitor elements, and the transistor module 1042 may also include one or more transistors. Among them, the control electrode of the transistor in the transistor module 1042 is short-circuited with the first electrode so that the transistor is in a cut-off state, and the transistor in the cut-off state generates a leakage current signal, which is used to charge the capacitor in the capacitor module 1041.

[0098] In some embodiments, after the circuit is powered on, the voltage signal at the intermediate node can be sent to the current generating circuit 101 as a first control signal, so that the current generating circuit 101 outputs the first current signal. At the same time, the leakage current signal generated by the transistor module 1042 starts to charge the capacitor module 1041, that is, the delay switch circuit 104 outputs the first control signal and starts timing. When the capacitor module 1041 is full, the voltage signal at the intermediate node can be provided to the current generating circuit 101 as a second control signal, so that the current generating circuit 101 switches to output the second current signal.

[0099] Specifically, the first control signal may be used to control the first switch module 1013 to turn on the first branch, so that the first branch and the second branch together provide the first bias current for the amplifier circuit 102. The second control signal may be used to control the first switch module 1013 to disconnect the first branch, so that the second branch alone provides the second bias current for the amplifier circuit 102. For example, the first control signal may be used to control the first transistor to turn on to turn on the first branch, and the second control signal may be used to control the first transistor to turn off to disconnect the first branch.

[0100] In some embodiments, the charging delay of the capacitor module 1041 is the preset time length of the delay switch circuit 104, and the preset time length of the delay switch circuit 104 can be set by setting the capacitance of the capacitor. The preset time length of the delay switch circuit 104 is not less than the time length required for the crystal oscillator circuit 103 to start oscillation, so as to ensure that the crystal oscillator circuit 103 can start oscillation quickly under the control of the first control signal.

[0101] For example, the capacitance of the capacitor module 1041 is in the picofarad (pF) level, and by setting the size of the transistor so that the transistor module 1042 provides a leakage current signal in the picoampere (pA) level, the delay switch circuit 104 can ultimately achieve a charging delay in the second (s) level.

[0102] In an embodiment of the present application, the delay switch module is composed of a capacitor module 1041 and a transistor module 1042. The capacitor module 1041 and the transistor module 1042 are connected between the power supply terminal and the ground terminal. The intermediate node between the capacitor module 1041 and the transistor module 1042 is electrically connected to the control terminal of the current generating circuit 101. Since the leakage current signal provided by the transistor module 1042 is usually relatively small, the leakage current signal is used to charge the capacitor module 1041. In this way, a smaller charging delay of the capacitor module 1041 can be achieved, so that after the charging time of the capacitor module 1041 reaches the preset time of the delay switch circuit 104, the delay switch circuit 104 switches from outputting the first control signal to outputting the second control signal, thereby improving the practicality of the crystal oscillator 10.

[0103] Optionally, the delay switch circuit 104 further includes an inverter module 1043; the inverter module 1043 is arranged between the intermediate node and the control end of the current generating circuit 101;

[0104] The input end of the inverter module 1043 is electrically connected to the intermediate node, and the output end is electrically connected to the control end of the current generating circuit 101 .

[0105] In some embodiments, the on and off of the first branch in the current generating circuit 101 is controlled by the first transistor, and the level state of the control signal output by the delay switch circuit 104 needs to match the model of the first transistor so that the first transistor is turned on under the control of the first control signal and turned off under the control of the second control signal.

[0106] In some embodiments, since the capacitor module 1041 and the transistor module 1042 are connected between the power supply terminal and the ground terminal of the crystal oscillator 10, the input terminal of the capacitor module 1041 is electrically connected to the power supply terminal, and the output terminal of the transistor module 1042 is electrically connected to the ground terminal, the intermediate node provides a high-level signal when the delay switch circuit 104 is powered on, and the intermediate node provides a low-level signal when the charging time of the capacitor module 1041 reaches a preset time. If the low level of the first transistor is effective, the voltage signal of the intermediate node needs to be inverted to obtain the first control signal and the second control signal.

[0107] In some embodiments, the inverter module 1043 may be an inverter composed of a PMOS tube and an N-type metal-oxide-semiconductor (NMOS) field effect tube, that is, an NMOS tube, wherein the PMOS tube and the NMOS tube are connected in series and connected between the power supply terminal and the ground terminal. Specifically, the gates of the PMOS tube and the NMOS tube in the inverter module 1043 are electrically connected as the input terminal of the inverter module 1043, and the drains of the PMOS tube and the NMOS tube are electrically connected as the output terminal of the inverter module 1043. If the first transistor is a PMOS tube, the source of the PMOS tube is electrically connected to the power supply terminal, and the source of the NMOS tube is electrically connected to the ground terminal.

[0108] Among them, when the delay switch circuit 104 is powered on, the middle node is in a high level state, the PMOS tube is turned off and the NMOS tube is turned on, and the control electrode of the first transistor is pulled low. When the capacitor module 1041 is fully charged, the middle node is in a low level state, the PMOS tube is turned on and the NMOS tube is turned off, and the control electrode of the first transistor is pulled high. If the first transistor is a PMOS tube, the low level is turned off and the high level is turned on, that is, the first transistor is turned on first after the delay switch circuit 104 is powered on, and after the charging time of the capacitor module 1041 reaches the preset time, the first transistor is turned off.

[0109] In an embodiment of the present application, by setting an inverter module 1043 between the intermediate node and the control end of the current generating circuit 101, the signal output by the capacitor module 1041 can be inverted, so that the level state of the output signal of the inverter module 1043 matches the level state required for controlling the current generating circuit 101 to switch the current, thereby improving the practicality of the crystal oscillator 10.

[0110] Optionally, the transistor module 1042 includes a second transistor;

[0111] The first electrode of the second transistor is electrically connected to the output end of the capacitor module 1041 and the input end of the inverter module 1043 respectively; the second electrode of the second transistor is short-circuited with the control electrode and then connected to the ground end.

[0112] In some embodiments, when the gate-source voltage of the transistor is less than the threshold voltage, the transistor will not be cut off immediately, but will enter the subthreshold region to generate a very small leakage current. The size of the leakage current is related to the size of the transistor, and the size of the leakage current can be adjusted by modifying the size of the transistor. The leakage current is used to charge a small capacitor, and a short-term charging delay can be achieved. For example, when the gate and source of the NMOS tube are short-circuited, Vgs is 0V. According to the subthreshold model of the MOS tube, the leakage current generated by the NMOS tube at this time is generally in the range of tens of picoamperes (pA) to hundreds of pA. This pA-level leakage current charges a small capacitor of the picofarad (pF) level, which can achieve a charging delay of seconds.

[0113] In some embodiments, the leakage current generated when the transistor is short-circuited can be used as a leakage current signal provided by the transistor module 1042 in this embodiment to charge the capacitor module 1041. In this embodiment, the second transistor provides a leakage current signal to the capacitor module 1041, and the leakage current signal is generated after the second electrode of the second transistor is short-circuited with the control electrode. The leakage current signal can charge the capacitor module 1041 in the branch where the capacitor module 1041 and the second transistor are located. For example, the second transistor is an NMOS tube, the first electrode of the second transistor is the drain of the NMOS tube, the second electrode is the source of the NMOS tube, the control electrode is the gate of the NMOS tube, and the gate and source of the NMOS tube are short-circuited and electrically connected to the ground terminal.

[0114] In some embodiments, the capacitor module 1041 includes a first capacitor, a first end of the first capacitor is electrically connected to the power supply end of the crystal oscillator 10, and a second end is electrically connected to the first electrode of the second transistor and the input end of the inverter module 1043. The order of magnitude corresponding to the capacitance of the first capacitor matches the order of magnitude corresponding to the leakage current signal generated by the second transistor, for example, a pA leakage current signal charges the pF first capacitor.

[0115] Figure 2 is a structural diagram of a delay switch circuit 104 provided in an embodiment of the present application, such as Figure 2As shown, VDD is the power supply terminal of the crystal oscillator 10, VSS is the ground terminal of the crystal oscillator 10, and the delay switch circuit 104 includes a first capacitor C1, a second transistor MN2, and an inverter module 1043 composed of a PMOS tube MP1 and an NMOS tube MN2. The gate and source of the NMOS tube MN1 are short-circuited, and the NMOS tube MN1 can provide a leakage current signal of the pA level. The capacitance of the first capacitor C1 is pF level, and the delay switch circuit 104 can achieve a charging delay of up to seconds.

[0116] Among them, Figure 2 The power consumption of the delay switch circuit 104 is low and can be ignored for the overall circuit power consumption of the crystal oscillator 10. In addition, since the capacitance of the first capacitor C1 is small, only a small circuit area is required to achieve a charging delay of seconds, which can reduce circuit costs.

[0117] Optionally, the crystal oscillator 10 further includes a gain enhancement circuit 105;

[0118] The gain enhancement circuit 105 is disposed between the current generating circuit 101 and the amplifier circuit 102 , and is electrically connected to the current generating circuit 101 and the amplifier circuit 102 , respectively, for amplifying the first current signal and the second current signal according to a preset amplification ratio and then inputting the amplification circuit 102 .

[0119] In some embodiments, since the oscillation speed of the crystal oscillator circuit 103 is positively correlated with the feedback loop gain of the amplifier circuit 102 and the crystal oscillator circuit 103, the feedback loop gain may be increased to improve the oscillation speed of the crystal oscillator circuit 103. The feedback loop gain is related to the magnitude of the bias current signal in the amplifier circuit 102. The larger the bias current signal, the larger the amplifier transconductance, and thus the larger the feedback loop gain.

[0120] In this embodiment, the first current signal and the second current signal output by the current generating circuit 101 are amplified by the gain improvement circuit 105 and then input into the amplifier circuit 102, which can increase the current value of the bias current signal in the amplifier circuit 102, thereby improving the starting speed of the crystal oscillator circuit 103 when the crystal oscillator 10 is powered on, and the resistance value of the second branch in the current generating circuit 101 can be increased so that after the current generating circuit 101 switches to outputting the second current signal, the current value of the second current signal is reduced, thereby reducing the circuit power consumption, so that the crystal oscillator 10 can achieve lower power consumption.

[0121] In some embodiments, the gain enhancement circuit 105 may include only a second current mirror 1052, and the preset amplification ratio may be the mirror amplification ratio of the second current mirror 1052. In this way, the first current signal and the second current signal may be mirror-amplified according to the preset amplification ratio and then input into the amplifier circuit 102, thereby increasing the feedback loop gain by increasing the bias current signal of the amplifier circuit 102, and the starting speed of the crystal oscillator 10 may be increased.

[0122] Optionally, the gain improvement circuit 105 includes a feedback module 1051 and a second current mirror 1052;

[0123] The second current mirror 1052 is electrically connected to the current generating circuit 101 and the amplifying circuit 102 respectively; wherein the amplification ratio is the mirror amplification ratio of the second current mirror 1052;

[0124] The feedback module 1051 is arranged between the amplifier circuit 102 and the second current mirror 1052, and is electrically connected to the amplifier circuit 102 and the second current mirror 1052 respectively, and is used to transmit the first feedback signal and the second feedback signal to the second current mirror 1052, so that the second current mirror 1052 amplifies the first feedback signal and the second feedback signal and then inputs them into the amplifier circuit 102.

[0125] In some embodiments, the gain improvement circuit 105 introduces a feedback loop via the feedback module 1051, and improves the feedback loop gain by amplifying the first feedback signal and the second feedback signal transmitted by the feedback module 1051 through the second current mirror 1052. Specifically, the input end of the feedback module 1051 can be electrically connected to the output end of the amplifier circuit 102, and the output end of the feedback module 1051 can be electrically connected to the input end of the second current mirror 1052, so as to transmit the first feedback signal and the second feedback signal to the second current mirror 1052.

[0126] In some embodiments, the amplifier circuit 102 is an amplifier composed of a bias current source, a resistor, and an amplifier tube, and the feedback module 1051 includes a sixth transistor, and the control electrode of the sixth transistor can be electrically connected to the control electrode of the amplifier tube in the amplifier circuit 102 to form a current mirror, which can mirror the oscillating small signal at the input end of the amplifier tube to the second current mirror 1052 according to a certain ratio. The oscillating small signal includes the first feedback signal and the second feedback signal in this embodiment.

[0127] In some embodiments, the gain improvement circuit 105 works together through the second current mirror 1052 and the feedback module 1051 to improve the feedback loop gain as a whole, and can enable the crystal oscillator 10 to achieve lower power consumption. Among them, the mirror amplification ratio of the second current mirror 1052 can be determined according to the size of the transistor in the second current mirror 1052, and the mirror amplification ratio of the second current mirror 1052 can be adjusted by modifying the size of the transistor. The second current mirror 1052 can be a current mirror simply composed of two transistors, or it can be a more complex common source and common gate current mirror, such as a Cascode current mirror. This is only an example, and the embodiments of the present application are not limited to this.

[0128] In an embodiment of the present application, the first feedback signal and the second feedback signal output by the amplifier circuit 102 can be introduced into the gain improvement circuit 105 through the feedback module 1051, and the second current mirror 1052 performs mirror amplification according to a preset amplification ratio and then outputs the amplification signal to the amplifier circuit 102, thereby improving the feedback loop gain and further improving the starting speed of the crystal oscillator circuit 103.

[0129] Optionally, the second current mirror 1052 is coupled to the first current mirror 1014 to receive the first current signal and the second current signal after mirror copying by the first current mirror 1014 , and input the first current signal and the second current signal into the amplifier circuit 102 after mirror amplification according to the amplification ratio.

[0130] In some embodiments, the second current mirror 1052 is disposed between the first current mirror 1014 and the input terminal of the amplifier circuit 102. The first current mirror 1014 and the second current mirror 1052 are respectively composed of transistors, and the control electrodes of the transistors in the second current mirror 1052 are electrically connected to the control electrodes of the transistors in the first current mirror 1014, so that the second current mirror 1052 is coupled with the first current mirror 1014. The first current mirror 1014 is used to respectively mirror-copy the first current signal and the second current signal to the second current mirror 1052 in a 1:1 manner, and the second current mirror 1052 is used to respectively mirror-amplify the first current signal and the second current signal according to a preset amplification ratio and then input them to the amplifier circuit 102.

[0131] Figure 3 is a schematic diagram of a gain enhancement circuit 105 provided in an embodiment of the present application. Figure 3As shown, the second current mirror 1052 is composed of a PMOS tube MP5, a PMOS tube MP6, an NMOS tube MN5, and an NMOS tube MN6, and the feedback module 1051 includes an NMOS tube MN7. The gate of the PMOS tube MP5 can be used to connect the gate of the MOS tube in the first current mirror 1014, so that the second current mirror 1052 is coupled with the first current mirror 1014. The second current mirror 1052 composed of MP5, MN5, MN6, and MP6 can output the first current signal and the second current signal output by the current generating circuit 101 to the amplifier circuit 102 after mirror-amplification according to a preset amplification ratio. The NMOS tube MN7 can be electrically connected to the gate of the amplifier tube in the amplifier circuit 102, and the current of the NMOS tube MN7 can be obtained by copying the bias current signal of the amplifier tube according to a certain ratio.

[0132] Optionally, the amplifier circuit 102 includes a bias current module 1021, a third resistor module 1022 and an amplifier tube module 1023;

[0133] The input end of the bias current module 1021 is electrically connected to the output end of the current generating module, and the output end of the bias current module 1021 is electrically connected to the first end of the third resistor module 1022 and the input end of the amplifier module 1023, respectively, for transmitting the first current signal and the second current signal to the first resistor module 1011 and the amplifier module 1023;

[0134] The second end of the third resistor module 1022 is electrically connected to the control end of the amplifier module 1023; the first end and the second end of the third resistor module 1022 are electrically connected to the crystal oscillator circuit 103 respectively, serving as the output end of the amplifier circuit 102;

[0135] The output end of the amplifier module 1023 is electrically connected to the ground end of the crystal oscillator 10 , and is used to generate a first feedback signal according to the first current signal, and to generate a second feedback signal according to the second current signal.

[0136] In some embodiments, the crystal oscillator 10 can adopt a current biased Pierce crystal oscillator circuit structure, and the current generating circuit 101 and the bias current module 1021 can serve as bias current sources in the Pierce crystal oscillator circuit. The current generating circuit 101 outputs a first current signal and a second current signal, and the bias current module 1021 transmits the first current signal and the second current signal to the first resistor module 1011 and the amplifier tube module 1023 respectively, so that the first current signal and the second current signal serve as bias current signals of the amplifier circuit 102.

[0137] In some embodiments, the input end of the bias current module 1021 can be electrically connected to the output end of the second current mirror 1052 in the gain improvement circuit 105, and the second current mirror 1052 is coupled to the first current mirror 1014 in the current generating circuit 101, so that the first current mirror 1014 mirrors the first current signal and the second current signal to the second current mirror 1052, and the second current mirror 1052 then mirrors and amplifies the first current signal and the second current signal and inputs them into the bias current module 1021.

[0138] In some embodiments, the bias current module 1021, the third resistor module 1022 and the amplifier module 1023 form an amplifier, and the first end and the second end of the third resistor module 1022 are output ends of the amplifier circuit 102, which can be used to connect the crystal oscillator circuit 103 and provide the first feedback signal and the second feedback signal to the crystal oscillator circuit 103. The first end and the second end of the second resistor module 1012 are electrically connected to the input end and the control end of the amplifier module 1023, respectively, and the output end of the amplifier module 1023 is electrically connected to the ground end. The first current signal and the second current signal are provided to the amplifier module 1023, so that the amplifier module 1023 generates a first feedback signal according to the first current signal, and generates a second feedback signal according to the second current signal after the current generating module switches to output the second current signal.

[0139] In some embodiments, the third resistor module 1022 may include a third resistor, a first end of the third resistor being electrically connected to the second electrode of the third transistor and the first electrode of the fifth transistor, and a second end of the third resistor being electrically connected to the control electrode of the fifth transistor and the control electrode of the sixth transistor. The first end and the second end of the third resistor are also electrically connected to the crystal oscillator circuit 103, respectively, as the output end of the amplifier circuit 102.

[0140] In the embodiment of the present application, the bias current module 1021, the third resistor module 1022 and the amplifier module 1023 constitute a current bias type amplifier circuit 102, and the first current signal and the second current signal are transmitted from the bias current module 1021 to the first resistor module 1011 and the amplifier module 1023 as bias current signals. The amplifier module 1023 generates a first feedback signal and a second feedback signal according to the bias current signal, and then outputs them to the crystal oscillator circuit 103 through the first end and the second end of the third resistor module 1022, so that after the current generating circuit 101 provides a larger first current signal, the crystal oscillator circuit 103 is controlled to start oscillation quickly through the first feedback signal, and after the current generating circuit 101 switches to provide a smaller second current signal, the crystal oscillator circuit 103 is controlled to oscillate stably through the second feedback signal, so that the crystal oscillator 10 operates with low power consumption.

[0141] Optionally, the bias current module 1021 includes a third transistor;

[0142] The first electrode of the third transistor is electrically connected to the power supply terminal of the crystal oscillator 10, and the second electrode is electrically connected to the first end of the third resistor module 1022; wherein, when the third transistor is turned on, the first electrode and the second electrode of the third transistor form a third branch;

[0143] The control electrode of the third transistor is electrically connected to the control electrode of the fourth transistor in the second current mirror 1052 to form a third current mirror; the third current mirror is used to mirror the first current signal amplified by the second current mirror 1052 and the second current signal amplified to the third branch.

[0144] In some embodiments, the second current mirror 1052 is composed of transistors, and the second current mirror 1052 includes a fourth transistor. The bias current module 1021 of the amplifier circuit 102 includes a third transistor, the control electrode of the third transistor is electrically connected to the control electrode of the fourth transistor, the first electrode of the fourth transistor is electrically connected to the power supply terminal of the crystal oscillator 10, and the control electrode of the fourth transistor is also electrically connected to the second electrode, so that the third transistor and the fourth transistor form a third current mirror.

[0145] When the third transistor is turned on, the first electrode and the second electrode of the third transistor form a third branch, and the amplified first current signal and the amplified second current signal in the second current mirror 1052 flow through the branch where the fourth transistor is located. In this way, the amplified first current signal and the amplified second current signal in the second current mirror 1052 can be mirror-copied to the third branch through the third current mirror, so that the amplified first current signal and the amplified second current signal in the gain improvement circuit 105 can be mirror-copied to the amplifier circuit 102 as the bias current signal of the amplifier circuit 102.

[0146] In the embodiment of the present application, the control electrode of the third transistor of the bias current module 1021 is electrically connected to the control electrode of the fourth transistor in the second current mirror 1052 to form a third current mirror. The first current signal amplified by the second current mirror 1052 and the amplified second current signal can be conveniently mirrored to the third branch through the third current mirror, thereby transmitting the amplified first current signal and the amplified second current signal from the gain improvement circuit 105 to the amplifier circuit 102, thereby improving the practicality of the crystal oscillator 10.

[0147] Optionally, the output end of the first current mirror 1014 is electrically connected to the first end of the third resistor module 1022 and the input end of the amplifier module 1023 respectively;

[0148] The first current mirror 1014 is further used to send the first current signal and the second current signal to the amplifier module 1023 respectively, so that the amplifier module 1023 can perform current multiplexing on the first current signal and the second current signal.

[0149] In some embodiments, the first current signal and the second current signal in the first current mirror 1014 can be mirror-copied to the second current mirror 1052, mirror-amplified by the second current mirror 1052, and then input into the amplifier circuit 102. In addition, the first current signal and the second current signal in the first current mirror 1014 can also be connected to the amplifier tube module 1023 of the amplifier circuit 102 through the output end, so that the first current signal and the second current signal are directly transmitted to the amplifier tube module 1023, so that the first current signal and the second current signal in the first current mirror 1014 can be current multiplexed.

[0150] Among them, the current signal received by the amplifier module 1023 includes two parts, one part comes from the bias current signal transmitted by the bias current module 1021, and the bias current signal includes the first current signal and the second current signal amplified by the second current mirror 1052, and the other part is the first current signal and the second current signal of the current multiplexing. In this way, the current values ​​of the first current signal and the second current signal output by the current generating circuit 101 can be reduced, and the power consumption of the crystal oscillator 10 can be reduced as a whole, and the purpose of improving the feedback loop gain is achieved by amplifying the first current signal and the second current signal through the gain enhancement circuit 105 and deriving the feedback loop from the amplifier circuit 102.

[0151] Figure 4 is a schematic diagram of the structure of a current generating circuit 101 provided in an embodiment of the present application, such as Figure 4 As shown, the current generating circuit 101 includes a first branch where a first transistor MP2 (PMOS tube) and a first resistor R1 are located, a second branch where a second resistor R2 is located, and a first current mirror 1014 composed of a PMOS tube MP3, a PMOS tube MP4, an NMOS tube MN3 and an NMOS tube MN4. The resistance value of the first resistor R1 is much smaller than the resistance value of the second resistor R2.

[0152] See also Figure 4, the sources of NMOS tubes MN3 and MN4 can be used as the output ends of the first current mirror 1014, and are respectively electrically connected to the first end (XTAL2) of the third resistor module 1022. Since the first end of the third resistor module 1022 is electrically connected to the input end of the amplifier module 1023, the sources of NMOS tubes MN3 and MN4 can be connected to the input end of the amplifier module 1023. In this way, the first current mirror 1014 can directly send the first current signal and the second current signal to the amplifier module 1023 for current multiplexing by the amplifier module 1023. Among them, the drain of the NMOS tube MN3 is electrically connected to the source, and the source of the PMOS tube MP4 is electrically connected to the drain. The gate of the PMOS tube MP4 is also electrically connected to the gate of the PMOS tube MP5 in the gain improvement circuit 105, so that the second current mirror 1052 is coupled with the first current mirror 1014.

[0153] Optionally, the amplifier module 1023 includes a fifth transistor; the feedback module 1051 includes a sixth transistor;

[0154] A first electrode of the fifth transistor is electrically connected to the first end of the third resistor module 1022, and a second electrode of the fifth transistor is electrically connected to the ground end;

[0155] The control electrode of the fifth transistor is electrically connected to the control electrode of the sixth transistor to form a fourth current mirror; the fourth current mirror is used to mirror-copy the first feedback signal and the second feedback signal generated by the fifth transistor to the second current mirror 1052 .

[0156] In some embodiments, the first electrode of the fifth transistor is electrically connected to the first end of the third resistor module 1022, the second electrode is electrically connected to the ground end, and the control electrode is electrically connected to the second end of the third resistor module 1022 and the control electrode of the sixth transistor. The bias current module 1021, the third resistor module 1022 and the amplifier module 1023 in the amplifier circuit 102 form an amplifier, and the fifth transistor can be used as an amplifier of the amplifier. The control electrode of the fifth transistor is electrically connected to the control electrode of the sixth transistor to form a fourth current mirror.

[0157] In some embodiments, the fourth current mirror can mirror the first feedback signal and the second feedback signal generated by the amplifier tube, i.e., the fifth transistor, to the second current mirror 1052 in a certain ratio, and then the second current mirror 1052 amplifies the first feedback signal and the second feedback signal to improve the feedback loop gain. Among them, the mirror ratio of the fourth current mirror can be determined according to the size ratio of the fifth transistor and the sixth transistor. For example, if the size ratio of the fifth transistor and the sixth transistor is 1 / 5, then the mirror ratio of the fifth transistor and the sixth transistor is 1 / 5. This is only an example, and the embodiments of the present application are not limited to this.

[0158] In some embodiments, the first feedback signal and the second feedback signal amplified by the gain improvement circuit 105 can be mirror-copied from the gain improvement circuit 105 to the amplifier circuit 102 through the fourth current mirror, and specifically, can be mirror-copied to the third transistor. Then, in the amplifier circuit 102, the third transistor can be used as an amplifier to amplify the amplified first feedback signal and the amplified second feedback signal again, and superimpose them with the first feedback signal and the second feedback signal generated by the fifth transistor in the amplifier module 1023, so that the overall loop gain of the amplifier circuit 102 is improved.

[0159] Figure 5 is a schematic diagram of the structure of an amplifier circuit 102 provided in an embodiment of the present application, such as Figure 5 As shown, the amplifier circuit 102 includes a third transistor MP7 (PMOS tube), a fifth transistor MN8 (NMOS tube), and a third resistor R3. The PMOS tube MP7, the NMOS tube MN8 and the third resistor R3 form an amplifier. The first end of the third resistor is XTAL2, and the second end of the third resistor is XTAL1. XTAL1 and XTAL2 are respectively connected to the crystal oscillator circuit 103.

[0160] Figure 6 1 is a schematic diagram of the structure of a crystal oscillator circuit 103 provided in an embodiment of the present application. Figure 6 As shown, the crystal oscillator circuit 103 includes an off-chip crystal X1, and load capacitors C2 and C3. The output terminals XTAL1 and XTAL2 of the amplifier circuit 102 are electrically connected to the two ends of the off-chip crystal X1, respectively. The two ends of the off-chip crystal X1 are also connected to the load capacitors C2 and C3, respectively. The other ends of the load capacitors C2 and C3 are grounded.

[0161] Figure 7 This is a schematic diagram of the structure of a Pierce crystal oscillator circuit in the related art. The Pierce crystal oscillator circuit structure is commonly used in RTC crystal oscillators. The Pierce crystal oscillator circuit structure includes: Figure 7 The current bias type circuit structure shown in the figure is composed of a specific bias current source, an NMOS tube and a resistor to form an amplifier, and XTAL1 and XTAL2 are connected to the crystal and load capacitors respectively. Among them, the bias current source can be a current source that provides a nanoampere (nA) level bias current signal, which is beneficial for the crystal oscillator to achieve a smaller circuit power consumption. However, the smaller bias current signal leads to a smaller amplifier transconductance, that is, a smaller feedback loop gain, which is not conducive to the crystal oscillator starting, resulting in a longer startup time for the crystal oscillator.

[0162] Figure 8 is a schematic diagram of the structure of another crystal oscillator 10 provided in an embodiment of the present application. Figure 8As shown, the crystal oscillator 10 at least includes a delay switch circuit 104, a current generating circuit 101, a gain increasing circuit 105 and an amplifying circuit 102. Figure 8 The crystal oscillator 10 shown may also include Figure 6 The crystal oscillator circuit 103 shown here is only an example, and the present application embodiment does not limit this. Figure 8 As shown, in the delay switch circuit 104, the drain of the PMOS tube MP1 is connected to the source of the NMOS tube MN2 and serves as the output end of the inverter module 1043, and the gate of the PMOS tube MP2 in the current generating circuit 101 is electrically connected to the output end of the inverter module 1043. The gate of the PMOS tube MP4 in the current generating circuit 101 is also electrically connected to the gate of the PMOS tube MP5 in the gain increasing circuit 105, so that the second current mirror 1052 is coupled with the first current mirror 1014, and the sources of the NMOS tubes MN3 and MN4 can serve as the output ends of the first current mirror 1014, and are respectively electrically connected to the first end (XTAL2) of the resistor R3 in the amplifier circuit 102. The gate of the PMOS tube MP6 in the gain increasing circuit 105 is electrically connected to the gate of the PMOS tube MP7 in the amplifier circuit 102, and the gate of the NMOS tube MN7 is respectively electrically connected to the second end of the resistor R3 in the amplifier circuit 102 and the gate of the NMOS tube MN8.

[0163] The crystal oscillator 10 provided in the embodiment of the present application can have a high starting speed at the initial stage of powering on the circuit. After the circuit completes the rapid starting, the bias current signal of the amplifier circuit 102 in the crystal oscillator 10 can be reduced by current switching, so that the circuit works at a lower power consumption. The gain improvement circuit 105 of this embodiment adopts a loop gain improvement method, which can increase the starting speed of the circuit at the initial stage of starting the crystal oscillator 10, and the circuit can achieve lower power consumption after the bias current switching. In this embodiment, the working current of the current generating circuit 101 can be fully injected into the amplifier circuit 102, that is, the crystal oscillator 10 has low power consumption performance through current multiplexing.

[0164] An embodiment of the present application provides a clock generating circuit, which includes the crystal oscillator 10 as described in the above embodiment.

[0165] The clock generating circuit has the same advantages as those of the crystal oscillator 10 in the related art and the aforementioned embodiment, which will not be described in detail here.

[0166] An embodiment of the present application provides a chip, which includes the crystal oscillator 10 as described in the above embodiment.

[0167] The advantages of this chip compared to the related art and the crystal oscillator 10 of the aforementioned embodiment are the same, and will not be described in detail here.

[0168] An embodiment of the present application provides an electronic device, and the electronic device includes a chip as described in the above embodiment.

[0169] The electronic device has the same advantages as those of the crystal oscillator 10 of the aforementioned embodiment compared to the related art, and will not be described in detail here.

[0170] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0171] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A crystal oscillator, characterized in that: The crystal oscillator comprises: a current generating circuit, an amplifying circuit, and a crystal oscillator circuit; The current generating circuit is electrically connected to the input end of the amplifier circuit, and is used to provide a first current signal to the amplifier circuit, and is switched to provide a second current signal to the amplifier circuit after the crystal oscillator circuit starts oscillating; wherein the current value of the first current signal is greater than the current value of the second current signal; The output end of the amplifier circuit is electrically connected to the crystal oscillator circuit, and is used to provide a first feedback signal to the crystal oscillator circuit according to the first current signal to start the crystal oscillator circuit, and to provide a second feedback signal to the crystal oscillator circuit according to the second current signal to enable the crystal oscillator circuit to oscillate stably after starting; wherein the amplitude of the first feedback signal is greater than the amplitude of the second feedback signal.

2. The crystal oscillator according to claim 1, characterized in that The crystal oscillator also includes a power supply terminal; the current generating circuit includes a first resistance module, a second resistance module and a first switch module; The first resistor module is connected in series with the first switch module to serve as a first branch; the first resistor module and the first switch module connected in series are also connected in parallel with the second resistor module; the second resistor module serves as a second branch; wherein the resistance of the first branch is less than the resistance of the second branch; The power supply end is electrically connected to the input end of the first branch and the input end of the second branch respectively; the input end of the amplifier circuit is electrically connected to the output end of the first branch and the output end of the second branch respectively; wherein the first switch module is used to disconnect the first branch after the crystal oscillator circuit starts oscillating.

3. The crystal oscillator according to claim 2, characterized in that: The first switch module includes a first transistor; the first resistor module includes a first resistor; the second resistor module includes a second resistor; The first electrode of the first transistor is electrically connected to the power supply terminal, and the second electrode is electrically connected to the first end of the first resistor; the second end of the first resistor is electrically connected to the input end of the amplifier circuit; The first end of the second resistor is electrically connected to the power supply end, and the second end is electrically connected to the input end of the amplifier circuit; wherein the resistance value of the first resistor is smaller than the resistance value of the second resistor.

4. The crystal oscillator according to claim 2, characterized in that: The current generating circuit further includes a first current mirror; the first current mirror is arranged between the output end of the first branch and the input end of the amplifier circuit, and between the output end of the second branch and the input end of the amplifier circuit; The input end of the first current mirror is electrically connected to the output end of the first branch and the output end of the second branch respectively, and the output end of the first current mirror is electrically connected to the input end of the amplifier circuit, for respectively mirroring the first current signal and the second current signal to the amplifier circuit.

5. The crystal oscillator according to any one of claims 1 to 4, characterized in that: The crystal oscillator also includes a delay switch circuit; The output end of the delay switch circuit is electrically connected to the control end of the current generating circuit, and is used to send a first control signal to the current generating circuit and start timing, and switch to sending a second control signal to the current generating circuit after the timing duration reaches a preset duration; Among them, the preset time length is not less than the time length required for the crystal oscillator circuit to start up quickly; the first control signal is used to control the current generating circuit to output the first current signal; the second control signal is used to control the current generating circuit to switch to output the second current signal.

6. The crystal oscillator according to claim 5, characterized in that: The crystal oscillator also includes a ground terminal; the delay switch circuit includes a capacitor module and a transistor module; The input end of the capacitor module is electrically connected to the power supply end, and the output end of the capacitor module is electrically connected to the input end of the transistor module; The output end of the transistor module is electrically connected to the ground end, and is used to provide a leakage current signal to charge the capacitor module; An intermediate node is provided between the capacitor module and the transistor module; the intermediate node is electrically connected to the control end of the current generating circuit.

7. The crystal oscillator according to claim 5, characterized in that: The delay switch circuit further includes an inverter module; the inverter module is arranged between the intermediate node and the control end of the current generating circuit; The input end of the inverter module is electrically connected to the intermediate node, and the output end is electrically connected to the control end of the current generating circuit.

8. The crystal oscillator according to claim 6, characterized in that: The transistor module includes a second transistor; The first electrode of the second transistor is electrically connected to the output end of the capacitor module and the input end of the inverter module respectively; the second electrode of the second transistor is short-circuited with the control electrode and then connected to the ground end.

9. The crystal oscillator according to any one of claims 1 to 4, characterized in that: The crystal oscillator also includes a gain enhancement circuit; The gain enhancement circuit is arranged between the current generating circuit and the amplifier circuit, and is electrically connected to the current generating circuit and the amplifier circuit respectively, and is used to amplify the first current signal and the second current signal according to a preset amplification ratio and then input them into the amplifier circuit.

10. The crystal oscillator according to claim 9, characterized in that: The gain improvement circuit includes a feedback module and a second current mirror; The second current mirror is electrically connected to the current generating circuit and the amplifying circuit respectively; wherein the amplification ratio is the mirror amplification ratio of the second current mirror; The feedback module is arranged between the amplifier circuit and the second current mirror, and is electrically connected to the amplifier circuit and the second current mirror respectively, and is used to transmit the first feedback signal and the second feedback signal to the second current mirror, so that the second current mirror amplifies the first feedback signal and the second feedback signal and then inputs them into the amplifier circuit.

11. The crystal oscillator according to claim 10, characterized in that: The second current mirror is coupled to the first current mirror, and is used to receive the first current signal and the second current signal after being mirror-copied by the first current mirror, and to input the first current signal and the second current signal into the amplifier circuit after mirror-amplifying them according to the amplification ratio.

12. The crystal oscillator according to any one of claims 1 to 4, characterized in that: The amplifier circuit includes a bias current module, a third resistor module and an amplifier tube module; The input end of the bias current module is electrically connected to the output end of the current generating module, and the output end of the bias current module is electrically connected to the first end of the third resistor module and the input end of the amplifier module, respectively, for transmitting the first current signal and the second current signal to the first resistor module and the amplifier module; The second end of the third resistor module is electrically connected to the control end of the amplifier module; the first end and the second end of the third resistor module are electrically connected to the crystal oscillator circuit respectively, serving as the output end of the amplifier circuit; The output end of the amplifier module is electrically connected to the ground end of the crystal oscillator, and is used to generate the first feedback signal according to the first current signal, and to generate the second feedback signal according to the second current signal.

13. The crystal oscillator according to claim 12, characterized in that: The bias current module includes a third transistor; The first electrode of the third transistor is electrically connected to the power supply terminal of the crystal oscillator, and the second electrode is electrically connected to the first end of the third resistor module; wherein, when the third transistor is turned on, the first electrode and the second electrode of the third transistor form a third branch; The control electrode of the third transistor is electrically connected to the control electrode of the fourth transistor in the second current mirror to form a third current mirror; the third current mirror is used to mirror the first current signal amplified by the second current mirror and the second current signal amplified to the third branch.

14. The crystal oscillator according to claim 12, characterized in that: The output end of the first current mirror is electrically connected to the first end of the third resistor module and the input end of the amplifier module respectively; The first current mirror is further used to send the first current signal and the second current signal to the amplifier tube module respectively, so that the amplifier tube module can perform current multiplexing on the first current signal and the second current signal.

15. The crystal oscillator according to claim 12, characterized in that: The amplifier module includes a fifth transistor; the feedback module includes a sixth transistor; The first electrode of the fifth transistor is electrically connected to the first end of the third resistor module, and the second electrode is electrically connected to the ground end; The control electrode of the fifth transistor is electrically connected to the control electrode of the sixth transistor to form a fourth current mirror; the fourth current mirror is used to mirror the first feedback signal and the second feedback signal generated by the fifth transistor to the second current mirror.

16. A clock generating circuit, characterized in that: The clock generating circuit comprises a crystal oscillator as claimed in any one of claims 1-15.

17. A chip, characterized in that: The chip comprises a crystal oscillator as claimed in any one of claims 1-15.

18. An electronic device, characterized in that: The electronic device comprises the chip as claimed in claim 17.

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