An oscillator circuit

Abstract

The present invention discloses an oscillation circuit. The oscillation circuit includes a charge and discharge module, an energy storage module, a self-zeroing comparison module, and an output module; the self-zeroing comparison module includes a storage unit and an output unit; the charge and discharge module is connected to the energy storage module, and the charge and discharge module is configured to charge and discharge the energy storage module according to a power supply voltage so that the energy storage module outputs a triangular wave signal; the storage unit is connected to a first threshold voltage, a second threshold voltage, and an offset voltage of the output unit, and the output unit is configured to output a comparison signal based on a comparison result between the triangular wave signal and the first threshold voltage when a feedback voltage is at a second level, and output a comparison signal based on a comparison result between the triangular wave signal and the second threshold voltage when the feedback voltage is at a first level; the output module is connected to the self-zeroing comparison module, the output module is connected to the feedback voltage, and the output module is configured to output an oscillation signal according to the comparison signal and the feedback voltage. The technical solution of the present invention improves the reliability and stability of the oscillation circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of oscillation circuits, and in particular to an oscillation circuit. Background Art

[0002] An oscillation circuit can generate an oscillating signal with periodic changes. The oscillation circuit can be an inductor-capacitor LC oscillation circuit or a resistor-capacitor RC oscillation circuit.

[0003] In an RC oscillation circuit, a current source is used to charge and discharge a capacitor. For example, the power supply voltage is connected to the first end of the capacitor through a first current source, and the second end of the capacitor is grounded through a second current source. When charging the capacitor with the power supply voltage, the voltage at the first end of the capacitor increases from zero to the power supply voltage. When discharging the capacitor, the voltage at the first end of the capacitor drops from the power supply voltage to zero. Thus, a triangular wave voltage is output at the first end of the capacitor.

[0004] In the existing RC oscillation circuit, a first comparator compares the triangular wave voltage with a high voltage threshold. When the triangular wave voltage is greater than the high voltage threshold, a high level is output, and the latch outputs a high level. A second comparator compares the triangular wave voltage with a low voltage threshold. When the triangular wave voltage is less than the low voltage threshold, the first comparator outputs a low level, the second comparator outputs a high level, and the latch outputs a low level, thereby outputting an oscillating signal with high and low levels.

[0005] However, in the existing RC oscillation circuit, two comparators are provided to generate an oscillating signal, resulting in a large offset voltage of the oscillation circuit, causing the output frequency of the oscillation circuit to vary greatly with temperature, and the stability and reliability of the oscillation circuit are poor. Summary of the Invention

[0006] The present invention provides an oscillation circuit to solve the problem of poor stability and reliability of the oscillation circuit.

[0007] The present invention provides an oscillation circuit, which includes a charge and discharge module, an energy storage module, a self-zeroing comparison module, and an output module; the self-zeroing comparison module includes a storage unit and an output unit;

[0008] The charge and discharge module is connected to a power supply voltage, the charge and discharge module is connected to the energy storage module, and the charge and discharge module is used to charge and discharge the energy storage module according to the power supply voltage so that the energy storage module outputs a triangular wave signal;

[0009] The energy storage module is connected to the self - zeroing comparison module. The storage unit accesses the first threshold voltage, the second threshold voltage, and the offset voltage of the output unit. The output unit is configured to output a comparison signal based on the comparison result between the triangular wave signal and the first threshold voltage when the feedback voltage is at the second level, and output a comparison signal based on the comparison result between the triangular wave signal and the second threshold voltage when the feedback voltage is at the first level. Wherein, the feedback voltage is the voltage of the oscillation signal output by the output module in the previous time.

[0010] The output module is connected to the self - zeroing comparison module. The output module accesses the feedback voltage and is configured to output an oscillation signal according to the comparison signal and the feedback voltage.

[0011] Optionally, the charge - discharge module includes a first selector, at least two first switches, and at least two first resistors. The power supply voltage includes a first power supply voltage and a second power supply voltage. The first power supply voltage is greater than the second power supply voltage.

[0012] The enable terminal of the first selector accesses the feedback voltage. The first input terminal of the first selector accesses the first power supply voltage. The second input terminal of the first selector accesses the second power supply voltage.

[0013] The first end of the first switch is connected to the output terminal of the first selector. The second end of the first switch is connected to the first end of the energy storage module through the first resistor. The second end of the energy storage module accesses the second power supply voltage.

[0014] Optionally, the storage unit is configured to, based on the first level of the inverted voltage,

[0015] store the first difference between the voltage of the triangular wave signal and the second threshold voltage; based on the second level of the inverted voltage, store the second difference between the first threshold voltage and the voltage of the triangular wave signal. Wherein, the inverted voltage and the feedback voltage are inversely - phase to each other.

[0016] The output unit is connected to the storage unit and is configured to, when the self - zeroing comparison module is in the working state, output the comparison signal according to the first difference based on the first level of the inverted voltage; output the comparison signal according to the second difference based on the second level of the inverted voltage.

[0017] Optionally, the oscillation circuit further includes a first input module, a second input module, a third input module, and a fourth input module.

[0018] The control terminal of the first input module is connected to the inverted voltage, the first input terminal of the first input module is connected to the second power supply voltage, the second input terminal of the first input module is connected to the first end of the energy storage module, and the first input module is configured to output the voltage of the triangular wave signal based on the first level of the inverted voltage; output the second power supply voltage based on the second level of the inverted voltage;

[0019] The control terminal of the second input module is connected to the inverted voltage, the first input terminal of the second input module is connected to the first end of the energy storage module, the second input terminal of the second input module is connected to the second power supply voltage, and the second input module is configured to output the second power supply voltage based on the first level of the inverted voltage; output the voltage of the triangular wave signal based on the second level of the inverted voltage;

[0020] The control terminal of the third input module is connected to the inverted voltage, the first input terminal of the third input module is connected to the second power supply voltage, the second input terminal of the third input module is connected to the second threshold voltage, and the third input module is configured to output the second threshold voltage based on the first level of the inverted voltage; output the second power supply voltage based on the second level of the inverted voltage;

[0021] The control terminal of the fourth input module is connected to the inverted voltage, the first input terminal of the fourth input module is connected to the first threshold voltage, the second input terminal of the fourth input module is connected to the second power supply voltage, and the fourth input module is configured to output the second power supply voltage based on the first level of the inverted voltage; output the first threshold voltage based on the second level of the inverted voltage;

[0022] The storage unit is respectively connected to the output terminals of the first input module, the second input module, the third input module and the fourth input module.

[0023] Optionally, the storage unit includes a first storage capacitor, a second storage capacitor, a second switch, a third switch, a fourth switch and a fifth switch;

[0024] The second switch is connected between the output terminal of the first input module and the first end of the first storage capacitor;

[0025] The third switch is connected between the output terminal of the second input module and the first end of the second storage capacitor, and the second switch and the third switch are configured to be turned on when the auto-zero comparison module is in the working state and turned off when the auto-zero comparison module is in the reset state;

[0026] The fourth switch is connected between the output terminal of the third input module and the first end of the first storage capacitor;

[0027] The fifth switch is connected between the output end of the fourth input module and the first end of the second storage capacitor. The fourth switch and the fifth switch are used to conduct when the auto-zero comparison module is in a reset state and turn off when the auto-zero comparison module is in an operating state.

[0028] Optionally, the output unit includes: a first transistor, a second transistor, a second resistor, a third resistor, a sixth switch, a seventh switch, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, and a NOR device;

[0029] The control end of the first transistor is connected to the second end of the second storage capacitor. The first end of the first transistor is connected to a first power supply voltage through the second resistor, and the second end of the first transistor is connected to a second power supply voltage;

[0030] The sixth switch is connected between the control end and the first end of the first transistor;

[0031] The control end of the second transistor is connected to the first end of the first storage capacitor. The first end of the second transistor is connected to the first power supply voltage through the third resistor, and the second end of the second transistor is connected to the second power supply voltage;

[0032] The seventh switch is connected between the control end and the first end of the second transistor. The sixth switch and the seventh switch are used to conduct when the auto-zero comparison module is in a reset state and turn off when the auto-zero comparison module is in an operating state;

[0033] The control end of the third transistor is connected to the first end of the second transistor. The first end of the third transistor is connected to the control end and the first end of the fifth transistor. The second end of the fifth transistor is connected to the first power supply voltage, and the second end of the third transistor is connected to the second power supply voltage;

[0034] The control end of the fourth transistor is connected to the first end of the first transistor. The first end of the fourth transistor is connected to the first end of the sixth transistor. The second end of the sixth transistor is connected to the first power supply voltage. The control end of the sixth transistor is connected to the control end of the fifth transistor. The second end of the fourth transistor is connected to the second power supply voltage;

[0035] The first input terminal of the NOR device is connected to the first terminal of the sixth transistor. The second input terminal of the NOR device is used to receive the status control signal of the self - zeroing comparison module. The NOR device is configured to output the comparison signal based on the voltage at the first terminal of the sixth transistor and the voltage of the status control signal.

[0036] Optionally, the self - zeroing comparison module further includes a status control unit;

[0037] The status control unit receives the triangular wave signal, the third threshold voltage, and the feedback voltage. The status control unit is connected to the self - zeroing comparison module and is configured to output a status control signal to the self - zeroing comparison module based on the triangular wave signal, the third threshold voltage, and the feedback voltage, so that the self - zeroing comparison module is in a working state or a reset state.

[0038] Optionally, the status control unit includes: a comparator and an XOR device;

[0039] The first input terminal of the comparator is connected to the first terminal of the energy storage module. The second input terminal of the comparator receives the third threshold voltage;

[0040] The first input terminal of the XOR device receives the feedback voltage. The second input terminal of the XOR device is connected to the output terminal of the comparator. The output terminal of the XOR device is connected to the self - zeroing comparison module.

[0041] Optionally, the output module includes a second selector, a third selector, and a latch;

[0042] The first input terminal of the second selector receives a second power supply voltage. The second input terminal of the second selector is connected to the output unit. The enable terminal of the second selector receives an inverted voltage;

[0043] The first input terminal of the third selector receives the second power supply voltage. The second input terminal of the third selector is connected to the output unit. The enable terminal of the third selector receives the feedback voltage;

[0044] The first input terminal of the latch is connected to the output terminal of the second selector. The second input terminal of the latch is connected to the output terminal of the third selector. The first output terminal of the latch outputs the oscillation signal. The second output terminal of the latch outputs the inverted signal of the oscillation signal;

[0045] The control terminal of the latch receives the inverted signal of the reset signal.

[0046] Optionally, the oscillation circuit further includes a reset module;

[0047] The control terminal of the reset module is connected to a reset signal, the first end of the reset module is connected to the first end of the energy storage module, and the second end of the reset module is connected to a second power supply voltage; the reset module is configured to reset the first end of the energy storage module in response to a first level of the reset signal.

[0048] In the technical solution of the embodiment of the present invention, the oscillation circuit includes: a charge and discharge module, an energy storage module, a self-zeroing comparison module, and an output module; the charge and discharge module charges and discharges the energy storage module, so that the energy storage module outputs a triangular wave signal. The self-zeroing comparison module can receive the triangular wave signal, and the storage unit of the self-zeroing comparison module can load a first threshold voltage and a second threshold voltage. When the feedback voltage is at the second level, the output unit compares the triangular wave signal with the first threshold voltage and outputs a comparison signal. When the feedback voltage is at the first level, the output unit compares the triangular wave signal with the second threshold voltage and outputs a comparison signal. So that the output module can output an oscillation signal according to the comparison signal. In this way, a comparison signal can be output through one output unit, without setting two comparators, reducing the offset voltage in the oscillation circuit. And when the storage unit in the self-zeroing comparison module loads the first threshold voltage and the second threshold voltage, it can load the offset voltage of the output unit, further reducing the influence of the offset voltage of the output unit on the comparison signal, and then avoiding the influence of the offset voltage of the output unit on the oscillation signal, improving the stability and reliability of the oscillation circuit.

[0049] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0051] Figure 1 is a schematic structural diagram of an oscillation circuit provided by an embodiment of the present invention;

[0052] Figure 2 is a schematic structural diagram of another oscillation circuit provided by an embodiment of the present invention;

[0053] Figure 3 is a schematic circuit diagram of a self-zeroing comparison module provided by an embodiment of the present invention;

[0054] Figure 4It is a schematic diagram of the circuit structure of a comparator provided by an embodiment of the present invention;

[0055] Figure 5 It is a timing diagram of an oscillation circuit provided by an embodiment of the present invention. Detailed implementation manners

[0056] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0058] An embodiment of the present invention provides an oscillation circuit, Figure 1 It is a schematic diagram of the structure of an oscillation circuit provided by an embodiment of the present invention. Refer to Figure 1 , the oscillation circuit includes: a charge and discharge module 110, an energy storage module 120, a self-zeroing comparison module 130, and an output module 140; the self-zeroing comparison module 130 includes a storage unit 131 and an output unit 132;

[0059] The charge and discharge module 110 is connected to the power supply voltage V0. The charge and discharge module 110 is connected to the energy storage module 120. The charge and discharge module 110 is used to charge and discharge the energy storage module 120 according to the power supply voltage so that the energy storage module 120 outputs a triangular wave signal Vosc;

[0060] The energy storage module 120 is connected to the self-zeroing comparison module 130. The storage unit 131 is connected to the first threshold voltage V1, the second threshold voltage V2, and the offset voltage of the output unit 132. The output unit 132 is used to output a comparison signal based on the comparison result of the triangular wave signal Vosc and the first threshold voltage V1 when the feedback voltage V Q1 is at the second level, and output a comparison signal based on the comparison result of the triangular wave signal Vosc and the second threshold voltage V2 when the feedback voltage VQ1 When at the first level, a comparison signal is output based on the comparison result between the triangular wave signal Vosc and the second threshold voltage V2; wherein, the feedback voltage V Q1 is the voltage of the oscillation signal output by the output module 140 in the previous time;

[0061] The output module 140 is connected to the auto - zero comparison module 130, and the output module 140 is connected to the feedback voltage V Q1 , and the output module 140 is used to output the oscillation signal Vout according to the comparison signal Vosc and the feedback voltage V Q1 Output the oscillation signal Vout.

[0062] Wherein, the power supply voltage V0 may include a first power supply voltage and a second power supply voltage. The first power supply voltage may be a positive voltage, and the second power supply voltage is grounded or a negative voltage. Therefore, the charge - discharge module 110 can charge the energy storage module 120 through the first power supply voltage and discharge the energy storage module 120 through the second power supply voltage.

[0063] For example, if the first end of the energy storage module 120 is connected to the charge - discharge module 110 and the second end of the energy storage module 120 is grounded to GND, then during the charging process of the energy storage module 120, the voltage at the second end of the energy storage module 120 remains unchanged, and the voltage at the first end of the energy storage module 120 rises from zero to the first power supply voltage. During the discharging process of the energy storage module 120, the voltage at the first end of the energy storage module 120 drops from the first power supply voltage to zero, so that the first end of the energy storage module 120 outputs the triangular wave signal Vosc.

[0064] Specifically, the energy storage module 120 is connected to the auto - zero comparison module 130, so that the auto - zero comparison module 130 can obtain the triangular wave signal Vosc generated by the energy storage module 120. For example, the storage unit 131 can store the triangular wave signal Vosc and the threshold voltages (the first threshold voltage V1 and the second threshold voltage V2) in a time - sharing manner. In this way, it is convenient for the output unit 132 to compare the triangular wave signal Vosc with the first threshold voltage V1 or compare the triangular wave signal Vosc with the second threshold voltage V2. For example, the first threshold voltage V1 is less than the second threshold voltage V2.

[0065] For example, when the feedback voltage is at the second level, the output unit 132 compares the triangular wave signal Vosc with the first threshold voltage V1. When the output unit 132 determines that the voltage value of the triangular wave signal Vosc is greater than the first threshold voltage V1, the output unit 132 outputs the first level; when the feedback voltage is at the second level and the output unit 132 outputs the first level, the output module 140 outputs the first - level signal. Therefore, the feedback voltage V Q1When it becomes the first level, the output unit 132 compares the triangular wave signal Vosc with the second threshold voltage V2. When the output unit 132 determines that the triangular wave signal Vosc is less than the second threshold voltage V2, the output unit 132 outputs a first-level signal. When the feedback voltage V Q1 is at the first level and the output unit 132 outputs the first level, a second-level signal is output. In this way, the alternating output of the first-level signal and the second-level signal is realized. By repeating this, the output of the oscillation signal Vout is realized. Among them, for example, the first level is a high level and the second level is a low level; in some other embodiments, the first level can also be a low level and the second level is a high level, which is not limited in this embodiment.

[0066] Therefore, by using one output unit 132, it is possible to compare the triangular wave signal Vosc with the first threshold voltage V1 or the second threshold voltage V2, without the need to set two comparators, which can reduce the problem of oscillation signal fluctuations caused by the output delay and offset voltage of the comparator. Moreover, during the process of loading the first threshold voltage V1 and the second threshold voltage V2, the storage unit 131 can load the offset voltage of the output unit 132, which can further reduce the influence of the offset voltage of the output unit 132 on the comparison signal, and thus avoid the influence of the offset voltage of the output unit 132 on the oscillation signal Vout, improving the stability and reliability of the oscillation circuit.

[0067] In the technical solution of this embodiment, the oscillation circuit includes: a charge and discharge module, an energy storage module, a self-zeroing comparison module, and an output module; the charge and discharge module charges and discharges the energy storage module so that the energy storage module outputs a triangular wave signal. The self-zeroing comparison module can receive the triangular wave signal, and the storage unit of the self-zeroing comparison module can load the first threshold voltage and the second threshold voltage. When the feedback voltage is at the second level, the output unit compares the triangular wave signal with the first threshold voltage and outputs a comparison signal. When the feedback voltage is at the first level, the output unit compares the triangular wave signal with the second threshold voltage and outputs a comparison signal. Thus, the output module can output an oscillation signal according to the comparison signal. In this way, by using one output unit, the comparison signal can be output without setting two comparators, reducing the offset voltage in the oscillation circuit. Moreover, when the storage unit in the self-zeroing comparison module loads the first threshold voltage and the second threshold voltage, it can load the offset voltage of the output unit, further reducing the influence of the offset voltage of the output unit on the comparison signal, and thus avoiding the influence of the offset voltage of the output unit on the oscillation signal, improving the stability and reliability of the oscillation circuit.

[0068] Based on the above technical solution, Figure 2 is a schematic structural diagram of another oscillation circuit provided by an embodiment of the present invention. Optionally, referring to Figure 2, the charge and discharge module 110 includes a first selector U1, at least two first switches S1, and at least two first resistors R1; the power supply voltage V0 includes a first power supply voltage VDD and a second power supply voltage; the first power supply voltage VDD is greater than the second power supply voltage;

[0069] The enable terminal of the first selector U1 is connected to the feedback voltage V Q1 , the first input terminal of the first selector U1 is connected to the first power supply voltage VDD, and the second input terminal of the first selector U1 is connected to the second power supply voltage;

[0070] The first end of the first switch S1 is connected to the output terminal of the first selector U1, the second end of the first switch S1 is connected to the first end of the energy storage module 120 through the first resistor R1, and the second end of the energy storage module 120 is connected to the second power supply voltage.

[0071] Among them, the second power supply voltage can be a negative voltage or ground GND, Figure 2 The case where the second power supply voltage is ground GND is shown in, and this embodiment is not limited. The first selector U1 is a two-to-one multiplexer.

[0072] Specifically, the first selector U1 can output the first power supply voltage VDD or the second power supply voltage according to the feedback voltage V Q1 For example, when the feedback voltage V Q1 is at the second level, the first selector U1 outputs the first power supply voltage VDD, and the first power supply voltage VDD charges the energy storage module 120 through at least two first switches S1 and the first resistor R1, so that the voltage at the first end of the energy storage module 120 increases from zero until it approaches the first power supply voltage VDD. When the feedback voltage V Q1 is at the first level, the first selector U1 outputs the second power supply voltage, so that the energy storage module 120 discharges through at least two first resistors R1 and the first switch S1, and the voltage at the first end of the energy storage module 120 decreases to zero. In this way, a triangular wave signal Vosc is generated at the first end of the energy storage module 120.

[0073] By setting at least two first switches S1 and at least two first resistors R1, multiple resistor paths are formed. By controlling the number of first switches S1 that are turned on, the number of first resistors R1 connected to the circuit can be controlled, thereby controlling the charging and discharging current of the energy storage module 120, and further controlling the charging rate and discharging rate of the energy storage module 120. In this way, the frequency of the triangular wave signal Vosc can be controlled, thereby controlling the frequency of the comparison signal, and further controlling the frequency of the oscillation signal. In this way, there is no need to set a constant current source, and there is no need to adjust the current value of the constant current source to adjust the frequency of the oscillation signal, which can avoid the problem that the constant current source is greatly affected by temperature and the frequency of the oscillation signal is greatly affected by temperature, so that a stable oscillation signal can be output, further improving the reliability and stability of the oscillation circuit.

[0074] Among them, the first switch S1 can be controlled by a controller or by a user, and this embodiment does not make a limitation.

[0075] Based on the above technical solutions, optionally, the storage unit 131 is configured to store a first difference between the voltage of the triangular wave signal Vosc and the second threshold voltage V2 based on the first level of the inverted voltage; store a second difference between the first threshold voltage V1 and the voltage of the triangular wave signal Vosc based on the second level of the inverted voltage; wherein, the inverted voltage and the feedback voltage V Q1 are inverted with each other;

[0076] The output unit 132 is connected to the storage unit 131. When the self-zeroing comparison module 130 is in the working state, the output unit 132 is configured to output a comparison signal based on the first level of the inverted voltage according to the first difference; output a comparison signal based on the second level of the inverted voltage according to the second difference.

[0077] Among them, the inverted voltage and the feedback voltage V Q1 are inverted with each other, that is, when the feedback voltage V Q1 is at a high level, the inverted voltage is at a low level; when the feedback voltage V Q1 is at a low level, the inverted voltage is at a high level.

[0078] Specifically, the storage unit 131 can receive the triangular wave signal Vosc and the second threshold voltage V2 in a time-sharing manner when the inverted voltage is at the first level, so that the voltage stored in the storage unit 131 is the difference between the voltage of the triangular wave signal Vosc and the second threshold voltage V2, which is the first difference. Similarly, the storage unit 131 can receive the first threshold voltage V1 and the triangular wave signal Vosc in a time-sharing manner when the inverted voltage is at the second level, so as to store the second difference between the first threshold voltage V1 and the voltage of the triangular wave signal Vosc.

[0079] Thus, the output unit 132 can compare the triangular wave signal Vosc with the first threshold voltage V1 or compare the triangular wave signal Vosc with the second threshold voltage V2, so as to output a comparison signal.

[0080] Based on the above technical solution, optionally, referring to Figure 2 , the oscillation circuit further includes a first input module 133, a second input module 134, a third input module 135, and a fourth input module 136;

[0081] The control terminal of the first input module 133 is connected to an inverted voltage The first input terminal of the first input module 133 is connected to the second power supply voltage, the second input terminal of the first input module 133 is connected to the first terminal of the energy storage module 120, and the first input module 133 is configured to output the voltage of the triangular wave signal Vosc based on the first level of the inverted voltage ; output the second power supply voltage based on the second level of the inverted voltage ;

[0082] The control terminal of the second input module 134 is connected to an inverted voltage The first input terminal of the second input module 134 is connected to the first terminal of the energy storage module 120, the second input terminal of the second input module 134 is connected to the second power supply voltage, and the second input module 134 is configured to output the second power supply voltage based on the first level of the inverted voltage ; output the voltage of the triangular wave signal Vosc based on the second level of the inverted voltage ;

[0083] The control terminal of the third input module 135 is connected to an inverted voltage The first input terminal of the third input module 135 is connected to the second power supply voltage, the second input terminal of the third input module 135 is connected to the second threshold voltage V2, and the third input module 135 is configured to output the second threshold voltage V2 based on the first level of the inverted voltage ; output the second power supply voltage based on the second level of the inverted voltage ;

[0084] The control terminal of the fourth input module 136 is connected to an inverted voltage The first input terminal of the fourth input module 136 is connected to the first threshold voltage V1, the second input terminal of the fourth input module 136 is connected to the second power supply voltage, and the fourth input module 136 is configured to output the second power supply voltage based on the first level of the inverted voltage ; output the first threshold voltage V1 based on the second level of the inverted voltage ;

[0085] The storage unit 131 is respectively connected to the output terminals of the first input module 133, the second input module 134, the third input module 135, and the fourth input module 136.

[0086] Among them, the storage unit 131 is respectively connected to the output terminal vinp of the first input module 133, the output terminal vinm of the second input module 134, the output terminal voffp of the third input module 135, and the output terminal voffm of the fourth input module 136.

[0087] Specifically, when the inverted voltage is at the first level, the first input module 133 outputs a triangular wave signal Vosc to the storage unit 131, the second input module 134 outputs a second power supply voltage to the storage unit 131, the third input module 135 outputs a second threshold voltage V2 to the storage unit 131, and the fourth input module 136 outputs a second power supply voltage to the storage unit 131, so that the storage unit 131 stores the difference between the voltage of the triangular wave signal Vosc and the second threshold voltage V2.

[0088] When the inverted voltage is at the second level, the first input module 133 outputs a second power supply voltage to the storage unit 131, the second input module 134 outputs a triangular wave signal Vosc to the storage unit 131, the third input module 135 outputs a second power supply voltage to the storage unit 131, and the fourth input module 136 outputs a first threshold voltage V1 to the storage unit 131, so that the storage unit 131 stores the difference between the first threshold voltage V1 and the voltage of the triangular wave signal Vosc.

[0089] Optionally, referring to Figure 2 , the first input module 133 includes a fourth selector U4, and the control terminal of the fourth selector U4 is connected to the inverted voltage The first input terminal of the fourth selector U4 is connected to a second power supply voltage, and the second input terminal of the fourth selector U4 is connected to the first terminal of the energy storage module 120;

[0090] The second input module 134 includes a fifth selector U5, and the control terminal of the fifth selector U5 is connected to the inverted voltage The first input terminal of the fifth selector U5 is connected to the first terminal of the energy storage module 120, and the second input terminal of the fifth selector U5 is connected to a second power supply voltage;

[0091] The third input module 135 includes a sixth selector U6, and the control terminal of the sixth selector U6 is connected to the inverted voltage The first input terminal of the sixth selector U6 is connected to a second power supply voltage, and the second input terminal of the sixth selector U6 is connected to the second threshold voltage V2;

[0092] The fourth input module 136 includes a seventh selector U7, and the control terminal of the seventh selector U7 is connected to an inverted voltage. The first input terminal of the seventh selector U7 is connected to a first threshold voltage V1, and the second input terminal of the seventh selector U7 is connected to a second power supply voltage. Among them, the fourth selector U4, the fifth selector U5, the sixth selector U6, and the seventh selector U7 can all be two-to-one multiplexers.

[0093] Based on the above technical solutions, the circuit structure of the self-zeroing comparison module 130 will be described below, but it is not a limitation to this application.

[0094] Figure 3 It is a schematic diagram of the circuit structure of a self-zeroing comparison module provided by an embodiment of the present invention. Optionally, referring to Figure 3 , the storage unit 131 includes a first storage capacitor C1, a second storage capacitor C2, a second switch S2, a third switch S3, a fourth switch S4, and a fifth switch S5;

[0095] The second switch S2 is connected between the output terminal vinp of the first input module 133 and the first end of the first storage capacitor C1;

[0096] The third switch S3 is connected between the output terminal vinm of the second input module 134 and the first end of the second storage capacitor C2. The second switch S2 and the third switch S3 are used to conduct when the self-zeroing comparison module 130 is in the working state and turn off when the self-zeroing comparison module 130 is in the reset state;

[0097] The fourth switch S4 is connected between the output terminal voffp of the third input module 135 and the first end of the first storage capacitor C1;

[0098] The fifth switch S5 is connected between the output terminal voffm of the fourth input module 136 and the first end of the second storage capacitor C2. The fourth switch S4 and the fifth switch S5 are used to conduct when the self-zeroing comparison module 130 is in the reset state and turn off when the self-zeroing comparison module 130 is in the working state.

[0099] Specifically, when the self-zeroing comparison module 130 is in the working state, the second switch S2 and the third switch S3 conduct, so that the first storage capacitor C1 can receive the voltage output by the first input module 133, and the second storage capacitor C2 can receive the voltage output by the second input module 134. When the inverted voltage is at the first level, the first storage capacitor C1 can receive the triangular wave signal Vosc output by the first input module 133. When the inverted voltage is at the second level, the first storage capacitor C1 can receive the second power supply voltage output by the first input module 133. When the inverted voltage When at the first level, the second storage capacitor C2 can receive the second power supply voltage output by the second input module 134, and during the inverted voltage When at the second level, the second storage capacitor C2 can receive the triangular wave signal Vosc output by the second input module 134.

[0100] When the auto-zeroing comparison module 130 is in the reset state, the fourth switch S4 and the fifth switch S5 are turned on, so that the first storage capacitor C1 can receive the voltage output by the third input module 135, and the second storage capacitor C2 can receive the voltage output by the fourth input module 136. During the inverted voltage When at the first level, the first storage capacitor C1 can receive the second threshold voltage V2 output by the third input module 135, and during the inverted voltage When at the second level, the first storage capacitor C1 can receive the second power supply voltage output by the third input module 135. During the inverted voltage When at the first level, the second storage capacitor C2 can receive the second power supply voltage output by the fourth input module 136, and during the inverted voltage When at the second level, the second storage capacitor C2 can receive the first threshold voltage output by the fourth input module 136.

[0101] Thus, when the inverted voltage is at the first level, if the auto-zeroing comparison module 130 is in the reset state, the first storage capacitor C1 receives the second threshold voltage V2, and the second storage capacitor C2 receives the second power supply voltage; when the auto-zeroing comparison module 130 switches to the working state, the first storage capacitor C1 receives the triangular wave signal Vosc, and the second storage capacitor C2 receives the second power supply voltage. Then the first storage capacitor C1 stores the first difference between the voltage of the triangular wave signal Vosc and the second threshold voltage V2, enabling the output unit 132 to determine whether the first difference between the voltage of the triangular wave signal Vosc and the second threshold voltage V2 is greater than 0, realizing the comparison of the triangular wave signal Vosc and the second threshold voltage V2, and outputting a comparison signal VO1.

[0102] During the inverted voltage When at the second level, if the auto - zero comparison module 130 is in the reset state, the second storage capacitor C2 stores the first threshold voltage V1, and the first storage capacitor C1 stores the second power supply voltage; when the auto - zero comparison module 130 switches to the working state, the second storage capacitor C2 stores the triangular wave signal Vosc, and the first storage capacitor C1 stores the second power supply voltage. Then the second storage capacitor C2 stores the second difference between the first threshold voltage V1 and the triangular wave signal Vosc, enabling the output unit 132 to determine whether the second difference between the voltage of the first threshold voltage V1 and the triangular wave signal Vosc is greater than 0, realizing the comparison of the triangular wave signal Vosc and the first threshold voltage V1, and outputting a comparison signal VO1.

[0103] Optionally, referring to Figure 3 , the control terminals of the second switch S2 and the third switch S3 are connected to the state control signal PH1, and the control terminals of the fourth switch S4 and the fifth switch S5 are connected to the inverted signal of the state control signal The state control signal PH1 can control the state of the auto - zero comparison module 130. For example, when the state control signal PH1 is at a high level, the auto - zero comparison module 130 is in the working state; when the state control signal PH1 is at a low level, the auto - zero comparison module 130 is in the reset state. In this way, the second switch S2 and the third switch S3 can be turned on when the auto - zero comparison module 130 is in the reset state, and the fourth switch S4 and the fifth switch S5 can be turned on when the auto - zero comparison module 130 is in the working state.

[0104] Optionally, referring to Figure 3 , the output unit 132 includes: a first transistor M1, a second transistor M2, a second resistor R2, a third resistor R3, a sixth switch S6, a seventh switch S7, a third transistor M3, a fourth transistor M4, a fifth transistor M5, a sixth transistor M6, and a NOR device U8;

[0105] The control terminal of the first transistor M1 is connected to the second terminal of the second storage capacitor C2. The first terminal of the first transistor M1 is connected to the first power supply voltage VDD through the second resistor R2, and the second terminal of the first transistor M1 is connected to the second power supply voltage;

[0106] The sixth switch S6 is connected between the control terminal and the first terminal of the first transistor M1;

[0107] The control terminal of the second transistor M2 is connected to the first terminal of the first storage capacitor C1. The first terminal of the second transistor M2 is connected to the first power supply voltage VDD through the third resistor R3, and the second terminal of the second transistor M2 is connected to the second power supply voltage;

[0108] The seventh switch S7 is connected between the control terminal of the second transistor M2 and the first terminal of the second transistor M2. The sixth switch S6 and the seventh switch S7 are used to conduct when the auto - zero comparison module 130 is in the reset state and turn off when the auto - zero comparison module 130 is in the working state;

[0109] The control terminal of the third transistor M3 is connected to the first terminal of the second transistor M2. The first terminal of the third transistor M3 is connected to the control terminal and the first terminal of the fifth transistor M5. The second terminal of the fifth transistor M5 is connected to the first power supply voltage VDD, and the second terminal of the third transistor M3 is connected to the second power supply voltage;

[0110] The control terminal of the fourth transistor M4 is connected to the first terminal of the first transistor M1. The first terminal of the fourth transistor M4 is connected to the first terminal of the sixth transistor M6. The second terminal of the sixth transistor M6 is connected to the first power supply voltage VDD. The control terminal of the sixth transistor M6 is connected to the control terminal of the fifth transistor M5, and the second terminal of the fourth transistor M4 is connected to the second power supply voltage;

[0111] The first input terminal of the NOR device U8 is connected to the first terminal of the sixth transistor M6, and the second input terminal of the NOR device U8 is used to receive the inverted signal of the state control signal of the auto - zero comparison module 130 The NOR device U8 is used to output a comparison signal VO1 based on the voltage at the first terminal of the sixth transistor M6 and the voltage of the state control signal.

[0112] Among them, the control terminal of the sixth switch S6 receives the inverted signal of the state control signal The control terminal of the seventh switch S7 receives the inverted signal of the state control signal

[0113] Specifically, when the state control signal PH1 is at a low level, the inverted signal of the state control signal is at a high level. The auto - zero comparison module 130 is in the reset state, and the sixth switch S6 and the seventh switch S7 conduct, so that the offset voltage of the first transistor M1 and the second resistor R2 can be loaded onto the second storage capacitor C2 through the sixth switch S6, and the offset voltage of the second transistor M2 and the third resistor R3 can be loaded onto the first storage capacitor C1 through the seventh switch S7. Thus, the first storage capacitor C1 and the second storage capacitor C2 can load the offset voltage of the output unit 132 while loading the threshold voltage. Thereby, the influence of the offset voltage on the comparison signal of the output unit 132 is avoided, and further the influence on the oscillation signal is avoided.

[0114] When the auto - zero comparison module 130 is in the reset state, the inverted signal of the state control signal is at a high level, the fourth switch S4 and the fifth switch S5 are turned on, the first capacitor C1 is loaded with the voltage voffp output from the output terminal voffp of the third input module 135, and the second capacitor C2 is loaded with the voltage voffm output from the output terminal voffm of the fourth input module 136. When the auto-zero comparison module 130 is in the working state, the state control signal PH1 is at a high level, the second switch S2 and the third switch S3 are turned on, the first capacitor C1 is loaded with the voltage vinp output from the output terminal vinp of the first input module 133, and the second capacitor C2 is loaded with the voltage vinm output from the output terminal vinm of the second input module 134. Then the voltage at the control terminal of the second transistor M2 is vinp - voffp, and the voltage at the control terminal of the first transistor M1 is vinm - voffm. The first transistor M1 and the second transistor M2 form a differential transistor, which can compare whether (vinp - voffp) - (vinm - voffm) is greater than 0, that is, it can compare whether (vinp - vinm) - (voffp - voffm) is greater than 0. In this way, the auto-zero comparison module 130 can achieve multi-input comparison.

[0115] When the feedback voltage is at a low level, the inverted voltage is at a high level, the first input module 133 outputs a triangular wave signal Vosc, the second input module 134 outputs a second power supply voltage, the third input module 135 outputs a second threshold voltage V2, and the fourth input module 136 outputs a second power supply voltage. For example, if the second power supply voltage is grounded GND, then the auto-zero comparison module 130 can compare whether (Vosc - GND) - (V2 - GND) is greater than 0, that is, it can compare the voltage of the triangular wave signal Vosc with the second threshold voltage V2. When the voltage of the triangular wave signal Vosc is greater than the second threshold voltage V2, the first difference is greater than zero, the second transistor M2 is turned on, and the first end of the second transistor M2 is at a low level. The first transistor M1 is turned off, and the first end of the first transistor M1 is at a high level. Then the fourth transistor M4 is turned on, and the first end of the fourth transistor M4 is at a low level. The inverted signal of the state control signal is at a low level, and the NOR device U8 outputs a high-level signal. In this way, when the voltage of the triangular wave signal Vosc is greater than the second threshold voltage V2, a high-level comparison signal is output.

[0116] When the first difference is less than zero, the first transistor M1 is not turned on, the second transistor M2 is not turned on, the first end of the second transistor M2 is at a high level, the third transistor M3 is turned on, then the first end of the third transistor M3 is at a low level, the fifth transistor M5 and the sixth transistor M6 are turned on, the first end of the sixth transistor M6 is at a high level, and then the NOR device U8 outputs a low-level signal. In this way, when the voltage of the triangular wave signal Vosc is less than the second threshold voltage V2, a low-level comparison signal is output.

[0117] When the feedback voltage is at a high level, the first input module 133 outputs a second power supply voltage, the second input module 134 outputs a triangular wave signal Vosc, the third input module 135 outputs a second power supply voltage, and the fourth input module 136 outputs a first threshold voltage V1. For example, if the second power supply voltage is grounded GND, the auto-zero comparison module 130 can compare whether (GND - Vosc) - (GND - V1) is greater than 0, that is, it can compare whether V1 - Vosc is greater than 0, and thus can compare the voltage of the triangular wave signal Vosc with the second threshold voltage V2. When the voltage of the triangular wave signal Vosc is less than the first threshold voltage V1, the second transistor M2 is turned on, then the first end of the second transistor M2 is at a low level, then the fourth transistor M4 is turned on, and the first end of the fourth transistor M4 is at a low level. The inverted signal of the status control signal is at a low level, and the NOR device U8 outputs a high-level signal. In this way, when the voltage of the triangular wave signal Vosc is less than the first threshold voltage V1, a high-level comparison signal is output. Similarly, when the voltage of the triangular wave signal Vosc is greater than the first threshold voltage V1, the NOR device U8 can output a low-level signal, thereby outputting a low-level comparison signal.

[0118] Optionally, referring to Figure 3 , the output unit 132 further includes a first current source I1 and a second current source I2. The second ends of the first transistor M1 and the second transistor M2 are connected to the second power supply voltage through the first current source I1, and the second ends of the third transistor M3 and the fourth transistor M4 are connected to the second power supply voltage through the second current source I2. In this way, by setting the first current source I1 and the second current source I2, the current in the output unit 132 is made more stable, thereby improving the stability of the comparison signal.

[0119] Optionally, referring to Figure 2 , the oscillation circuit further includes a status control module 150;

[0120] The status control module 150 accesses the triangular wave signal Vosc, the third threshold voltage V3, and the feedback voltage V Q1 , the status control module 150 is connected to the auto-zero comparison module 130, and the status control module 150 is configured to output a status control signal PH1 to the auto-zero comparison module 130 based on the triangular wave signal Vosc, the third threshold voltage V3, and the feedback voltage V Q1 , so that the auto-zero comparison module 130 is in a working state or a reset state.

[0121] Specifically, the state control module 150 can compare the triangular wave signal Vosc with the third threshold voltage V3. According to the comparison result between the voltage of the triangular wave signal Vosc and the third threshold voltage V3, combined with the level of the feedback voltage, it outputs a state control signal PH1 to control the state of the auto-zeroing comparison module 130. For example, when the feedback voltage V Q1 is at a low level, if the triangular wave signal Vosc is less than the third threshold voltage V3, the state control signal PH1 is at a low level, causing the auto-zeroing comparison module 130 to be in a reset state, facilitating the storage unit 131 to load the threshold voltage (such as the second threshold voltage) and the offset voltage. When the triangular wave signal Vosc rises to be greater than the third threshold voltage V3, the state control signal PH1 is at a high level, causing the auto-zeroing comparison module 130 to be in an operating state, enabling the output unit 132 to compare the triangular wave signal Vosc with the second threshold voltage V2 and output a comparison signal. When the feedback voltage V Q1 is at a high level, if the triangular wave signal Vosc is greater than the third threshold voltage V3, the state control signal PH1 is at a low level, causing the auto-zeroing comparison module 130 to be in a reset state, facilitating the storage unit 131 to load the threshold voltage (such as the first threshold voltage) and the offset voltage. When the triangular wave signal Vosc drops to be less than the third threshold voltage V3, the state control signal PH1 is at a high level, causing the auto-zeroing comparison module 130 to be in an operating state, enabling the output unit 132 to compare the triangular wave signal Vosc with the first threshold voltage V1 and output a comparison signal VO1.

[0122] Optionally, referring to Figure 2 , the state control module 150 includes: a comparator 151 and an XOR device 152;

[0123] The first input terminal of the comparator 151 is connected to the first end of the energy storage module 120, and the second input terminal of the comparator 151 is connected to the third threshold voltage V3;

[0124] The first input terminal of the XOR device 152 is connected to the feedback voltage V Q1 , the second input terminal of the XOR device 152 is connected to the output terminal VO2 of the comparator 151, and the output terminal of the XOR device 152 is connected to the auto-zeroing comparison module 130.

[0125] Specifically, the comparator 151 can compare the triangular wave signal Vosc with the third threshold voltage V3. When the voltage of the triangular wave signal Vosc is less than the third threshold voltage V3, the comparator 151 outputs a low level; when the voltage of the triangular wave signal Vosc is greater than the third threshold voltage V3, the comparator 151 outputs a high level.

[0126] The XOR device 152 can, according to the signal output by the comparator 151 and the feedback voltage V Q1Output a status control signal PH1. When the feedback voltage is at a high level and the comparator 151 outputs a high level, the XOR device 152 outputs a low level; when the feedback voltage is at a high level and the comparator 151 outputs a low level, the XOR device 152 outputs a high level; when the feedback voltage is at a low level and the comparator 151 outputs a low level, the XOR device 152 outputs a low level; when the feedback voltage is at a low level and the comparator 151 outputs a high level, the XOR device 152 outputs a high level. In this way, the output status control signal can be implemented to control the status of the auto-zeroing comparison module 130. Moreover, the comparator 151 does not participate in the frequency adjustment of the oscillation signal. Therefore, the offset voltage of the comparator 151 does not affect the frequency of the oscillation signal, enabling the use of devices with lower precision for the comparator 151, which is beneficial for reducing costs and the difficulty of circuit design.

[0127] Based on the above technical solution, Figure 4 is a schematic circuit diagram of a comparator provided by an embodiment of the present invention. As Figure 4 described, the comparator 151 includes: a seventh transistor M7, an eighth transistor M8, a ninth transistor M9, a tenth transistor M10, an eleventh transistor M11, a twelfth transistor M12, a fourth resistor R4, a fifth resistor R5, an inverter U9, a third current source I3, and a fourth current source I4; the control terminal of the seventh transistor M7 is connected to the third threshold voltage V3, the control terminal of the eighth transistor M8 is connected to the first end of the energy storage module 120, the first end of the seventh transistor M7 is connected to the first power supply voltage VDD through the fourth resistor R4, and the second end of the seventh transistor M7 is connected to the second power supply voltage through the third current source I3; the first end of the eighth transistor M8 is connected to the first power supply voltage VDD through the fifth resistor R5, and the second end of the eighth transistor M8 is connected to the second power supply voltage through the third current source I3; the control terminal of the ninth transistor M9 is connected to the first end of the eighth transistor M8, the first end of the ninth transistor M9 is connected to the first end and the control terminal of the eleventh transistor M11, the second end of the eleventh transistor M11 is connected to the first power supply voltage VDD, and the second end of the ninth transistor M9 is connected to the second power supply voltage through the fourth current source I4; the control terminal of the tenth transistor M10 is connected to the first end of the seventh transistor M7, the first end of the tenth transistor M10 is connected to the first end of the twelfth transistor M12, the second end of the twelfth transistor M12 is connected to the first power supply voltage VDD, the control terminal of the twelfth transistor M12 is connected to the control terminal of the eleventh transistor M11, and the second end of the tenth transistor M10 is connected to the second power supply voltage through the fourth current source I4; the first end of the twelfth transistor M12 is connected to the input terminal of the inverter U9, and the output terminal VO2 of the inverter U9 is connected to the second input terminal of the XOR device 152.

[0128] Specifically, when the voltage of the triangular wave signal Vosc is greater than the third threshold voltage V3, the eighth transistor M8 is turned on and the seventh transistor M7 is turned off. Then, the first end of the eighth transistor M8 is at a low level, the first end of the seventh transistor M7 is at a high level, the ninth transistor M9 is not turned on, the tenth transistor M10 is turned on, the first end of the tenth transistor M10 is at a low level, and after passing through the inverter U9, a high level is output. Thus, when the voltage of the triangular wave signal Vosc is greater than the third threshold voltage V3, a high level signal is output.

[0129] When the voltage of the triangular wave signal Vosc is less than the third threshold voltage V3, the eighth transistor M8 is turned off and the seventh transistor M7 is turned on. Then, the first end of the seventh transistor M7 is at a low level, the first end of the eighth transistor M8 is at a high level, the ninth transistor M9 is turned on, the tenth transistor M10 is not turned on, the first end of the ninth transistor M9 is at a low level, the eleventh transistor M11 and the twelfth transistor M12 are turned on, making the first end of the twelfth transistor M12 at a high level, and after passing through the inverter U9, a low level is output. Thus, when the voltage of the triangular wave signal Vosc is less than the third threshold voltage V3, a low level signal is output.

[0130] Optionally, referring to Figure 2 , the output module 140 includes a second selector U2, a third selector U3, and a latch U10;

[0131] The first input terminal of the second selector U2 is connected to the second power supply voltage, the second input terminal of the second selector U2 is connected to the output unit 132, and the enable terminal of the second selector U2 is connected to the inverted voltage

[0132] The first input terminal of the third selector U3 is connected to the second power supply voltage, the second input terminal of the third selector U3 is connected to the output unit 132, and the enable terminal of the third selector U3 is connected to the feedback voltage V Q1 ;

[0133] The first input terminal of the latch U10 is connected to the output terminal of the second selector U2, the second input terminal of the latch U10 is connected to the output terminal of the third selector U3, the first output terminal of the latch U10 outputs the oscillation signal Vout, and the second output terminal of the latch U10 outputs the inverted signal Vout1 of the oscillation signal;

[0134] The control terminal of the latch U10 is connected to the inverted signal of the reset signal

[0135] Among them, the latch U10 can be an RS latch. When a high level is applied to the first input terminal of the latch U10, the first output terminal of the latch U10 outputs a high level, and the second output terminal of the latch U10 outputs a low level. When a high level is applied to the second input terminal of the latch U10, the first output terminal of the latch U10 outputs a low level, and the second output terminal of the latch U10 outputs a high level.

[0136] Specifically, when the feedback voltage is at a low level, the second selector U2 outputs the comparison signal of the auto - zeroing comparison module 130, and the third selector U3 outputs the second power supply voltage. If the voltage of the triangular wave signal Vosc is greater than the second threshold voltage V2, the second selector U2 outputs a high - level comparison signal, and then the first output terminal of the latch U10 outputs a high level. Therefore, the feedback voltage switches to a high level, the second selector U2 outputs the second power supply voltage, the third selector U3 outputs the comparison signal of the auto - zeroing comparison module 130. If the triangular wave signal Vosc is less than the first threshold voltage V1, the third selector U3 outputs a high - level comparison signal, and then the first output terminal of the latch U10 outputs a low level. Repeating this way, the first output terminal of the latch U10 outputs an oscillating signal of high and low levels, and the second output terminal of the latch U10 outputs an inverted signal of the oscillating signal.

[0137] Moreover, the control terminal of the latch U10 is connected to the inverted signal of the reset signal When the inverted signal of the reset signal is at a low level, the latch U10 is reset.

[0138] Optionally, refer to Figure 2 , the oscillation circuit further includes a reset module 160;

[0139] The control terminal of the reset module 160 is connected to the reset signal RST. The first terminal of the reset module 160 is connected to the first terminal of the energy storage module 120, and the second terminal of the reset module 160 is connected to the second power supply voltage. The reset module 160 is used to reset the first terminal of the energy storage module 120 in response to the first level of the reset signal RST.

[0140] Specifically, when the reset signal RST is at the first level, the reset module 160 is turned on, so that the reset module 160 transmits the second power supply voltage to the first terminal of the energy storage module 120 to reset the first terminal of the energy storage module 120. The second power supply voltage is, for example, grounded. In some other embodiments, the second power supply voltage can be a negative voltage.

[0141] Optionally, refer to Figure 2 , the energy storage module 120 includes an energy storage capacitor C0. The first terminal of the energy storage capacitor C0 is connected to the charge - discharge module 110, and the second terminal of the energy storage capacitor C0 is connected to the second power supply voltage.

[0142] Optionally, with reference to Figure 2 , the reset module 160 includes a reset transistor 161. The control terminal of the reset transistor 161 is connected to a reset signal RST. The first terminal of the reset transistor 161 is connected to the first terminal of the energy storage module 120. The second terminal of the reset transistor 161 is connected to a second power supply voltage. For example, if the reset transistor 161 is an N-type transistor, the first level is a high level; if the reset transistor 161 is a P-type transistor, the first level is a low level. Figure 2 The case where the reset transistor 161 is an N-type transistor is shown in

[0143] Exemplarily, Figure 5 is a timing diagram of an oscillation circuit provided by an embodiment of the present invention. Optionally, as shown in Figure 5 , in the t1 stage, the reset signal RST is at a high level, and the inverted signal of the reset signal is at a low level. The energy storage module 120 and the latch U10 are reset. The oscillation signal is at a low level, that is, the feedback voltage is at a low level, and the state control signal PH1 is at a low level. In the t2 stage, the charge and discharge module 110 charges the energy storage module 120, so that the triangular wave signal Vosc gradually increases. The state control signal PH1 is at a low level, the auto-zeroing comparison module 130 is in a reset state, and the first storage capacitor C1 is loaded with a second threshold voltage V2. In the t3 stage, the voltage of the triangular wave signal Vosc increases to be greater than a third threshold voltage V3, and the voltage at the output terminal VO2 of the comparator 151 is at a high level, so that the state control signal PH1 is at a high level, the auto-zeroing comparison module 130 is in an operating state. After the output unit 132 determines that the voltage of the triangular wave signal Vosc is greater than the second threshold voltage V2, after a delay time td, in the t4 stage, a high-level comparison signal is output. The second selector U2 outputs a high-level comparison signal, and the latch U10 outputs a high-level oscillation signal, so that the feedback voltage becomes high. In the t5 stage, the voltage of the triangular wave signal Vosc is greater than a first threshold voltage V1, and the third selector U3 outputs a low-level comparison signal, so that the latch U10 maintains the output of a high level. In the t6 stage, the voltage of the triangular wave signal Vosc is less than the first threshold voltage V1, and the third selector U3 outputs a high-level comparison signal, so that the latch U10 outputs a low-level oscillation signal. In the t7 stage, the voltage of the triangular wave signal Vosc is less than the second threshold voltage V2, and the second selector U2 outputs a low-level comparison signal, and the latch U10 maintains the output of a low level. Repeat this way to realize the output of the oscillation signal.

[0144] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An oscillator circuit, characterized in that: include: A charging and discharging module, an energy storage module, a self-zeroing comparison module and an output module; the self-zeroing comparison module includes a storage unit and an output unit; The charging and discharging module is connected to the power supply voltage, and the charging and discharging module is connected to the energy storage module. The charging and discharging module is used to charge and discharge the energy storage module according to the power supply voltage, so that the energy storage module outputs a triangular wave signal; The energy storage module is connected to the self-zero comparison module, the storage unit is connected to the first threshold voltage, the second threshold voltage and the offset voltage of the output unit, and the output unit is used to output a comparison signal based on the comparison result between the triangular wave signal and the first threshold voltage when the feedback voltage is at the second level, and output a comparison signal based on the comparison result between the triangular wave signal and the second threshold voltage when the feedback voltage is at the first level; wherein the feedback voltage is the voltage of the oscillation signal outputted by the output module last time; The output module is connected to the self-zero comparison module, the output module is connected to the feedback voltage, and the output module is used to output an oscillation signal according to the comparison signal and the feedback voltage; The storage unit is used to store a first difference between the voltage of the triangular wave signal and a second threshold voltage based on a first level of the inverted voltage; and to store a second difference between the first threshold voltage and the voltage of the triangular wave signal based on a second level of the inverted voltage; wherein the inverted voltage and the feedback voltage are in opposite phases to each other; The output unit is connected to the storage unit, and is used to output the comparison signal according to the first difference based on the first level of the inverting voltage when the self-return-to-zero comparison module is in a working state; and output the comparison signal according to the second difference based on the second level of the inverting voltage.

2. The oscillation circuit according to claim 1, characterized in that: The charging and discharging module includes a first selector, at least two first switches and at least two first resistors; the power supply voltage includes a first power supply voltage and a second power supply voltage; the first power supply voltage is greater than the second power supply voltage; The enable terminal of the first selector is connected to the feedback voltage, the first input terminal of the first selector is connected to the first power supply voltage, and the second input terminal of the first selector is connected to the second power supply voltage; The first end of the first switch is connected to the output end of the first selector, the second end of the first switch is connected to the first end of the energy storage module through the first resistor, and the second end of the energy storage module is connected to the second power supply voltage.

3. The oscillation circuit according to claim 1, characterized in that: The oscillation circuit further comprises a first input module, a second input module, a third input module and a fourth input module; The control end of the first input module is connected to the inverted voltage, the first input end of the first input module is connected to the second power supply voltage, the second input end of the first input module is connected to the first end of the energy storage module, and the first input module is used to output the voltage of the triangular wave signal based on the first level of the inverted voltage; outputting the second power supply voltage based on the second level of the inverted voltage; The control end of the second input module is connected to the inverted voltage, the first input end of the second input module is connected to the first end of the energy storage module, the second input end of the second input module is connected to the second power supply voltage, and the second input module is used to output the second power supply voltage based on the first level of the inverted voltage; outputting a voltage of the triangular wave signal based on a second level of the inverted voltage; The control end of the third input module is connected to the inverting voltage, the first input end of the third input module is connected to the second power supply voltage, the second input end of the third input module is connected to the second threshold voltage, and the third input module is used to output the second threshold voltage based on the first level of the inverting voltage; outputting the second power supply voltage based on the second level of the inverted voltage; The control end of the fourth input module is connected to the inverting voltage, the first input end of the fourth input module is connected to the first threshold voltage, the second input end of the fourth input module is connected to the second power supply voltage, and the fourth input module is used to output the second power supply voltage based on the first level of the inverting voltage; outputting the first threshold voltage based on a second level of the inverted voltage; The storage unit is connected to output ends of the first input module, the second input module, the third input module and the fourth input module respectively.

4. The oscillation circuit according to claim 3, characterized in that: The storage unit includes a first storage capacitor, a second storage capacitor, a second switch, a third switch, a fourth switch and a fifth switch; The second switch is connected between the output terminal of the first input module and the first terminal of the first storage capacitor; The third switch is connected between the output end of the second input module and the first end of the second storage capacitor, and the second switch and the third switch are used to be turned on when the self-zero comparison module is in a working state, and turned off when the self-zero comparison module is in a reset state; The fourth switch is connected between the output end of the third input module and the first end of the first storage capacitor; The fifth switch is connected between the output end of the fourth input module and the first end of the second storage capacitor. The fourth switch and the fifth switch are used to be turned on when the self-zero comparison module is in a reset state, and turned off when the self-zero comparison module is in a working state.

5. The oscillation circuit according to claim 4, characterized in that: The output unit includes: a first transistor, a second transistor, a second resistor, a third resistor, a sixth switch, a seventh switch, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor and a NOR device; The control end of the first transistor is connected to the second end of the second storage capacitor, the first end of the first transistor is connected to the first power supply voltage through the second resistor, and the second end of the first transistor is connected to the second power supply voltage; The sixth switch is connected between the control terminal of the first transistor and the first terminal of the first transistor; The control end of the second transistor is connected to the first end of the first storage capacitor, the first end of the second transistor is connected to the first power supply voltage through the third resistor, and the second end of the second transistor is connected to the second power supply voltage; The seventh switch is connected between the control terminal of the second transistor and the first terminal of the second transistor, and the sixth switch and the seventh switch are used to be turned on when the self-zero comparison module is in a reset state, and turned off when the self-zero comparison module is in a working state; The control end of the third transistor is connected to the first end of the second transistor, the first end of the third transistor is connected to the control end of the fifth transistor and the first end of the fifth transistor, the second end of the fifth transistor is connected to the first power supply voltage, and the second end of the third transistor is connected to the second power supply voltage; The control end of the fourth transistor is connected to the first end of the first transistor, the first end of the fourth transistor is connected to the first end of the sixth transistor, the second end of the sixth transistor is connected to the first power supply voltage, the control end of the sixth transistor is connected to the control end of the fifth transistor, and the second end of the fourth transistor is connected to the second power supply voltage; The first input terminal of the OR-NON device is connected to the first terminal of the sixth transistor, the second input terminal of the OR-NON device is used to access the inverted signal of the state control signal of the self-return-to-zero comparison module, and the OR-NON device is used to output the comparison signal based on the voltage of the first terminal of the sixth transistor and the voltage of the inverted signal of the state control signal.

6. The oscillation circuit according to claim 1, characterized in that: The oscillation circuit also includes a state control module; The state control module is connected to the triangular wave signal, the third threshold voltage and the feedback voltage, and is connected to the self-zero comparison module. The state control module is used to output a state control signal to the self-zero comparison module based on the triangular wave signal, the third threshold voltage and the feedback voltage, so that the self-zero comparison module is in a working state or a reset state.

7. The oscillation circuit according to claim 6, characterized in that: The state control module includes: a comparator and an XOR device; The first input terminal of the comparator is connected to the first terminal of the energy storage module, and the second input terminal of the comparator is connected to the third threshold voltage; The first input terminal of the XOR device is connected to the feedback voltage, the second input terminal of the XOR device is connected to the output terminal of the comparator, and the output terminal of the XOR device is connected to the self-zero comparison module.

8. The oscillation circuit according to claim 1, characterized in that: The output module includes a second selector, a third selector and a latch; The first input terminal of the second selector is connected to the second power supply voltage, the second input terminal of the second selector is connected to the output unit, and the enable terminal of the second selector is connected to the reverse voltage; The first input terminal of the third selector is connected to the second power supply voltage, the second input terminal of the third selector is connected to the output unit, and the enable terminal of the third selector is connected to the feedback voltage; The first input end of the latch is connected to the output end of the second selector, the second input end of the latch is connected to the output end of the third selector, the first output end of the latch outputs the oscillation signal, and the second output end of the latch outputs an inverted signal of the oscillation signal; The control terminal of the latch is connected to the inverted signal of the reset signal.

9. The oscillation circuit according to claim 1, characterized in that: The oscillation circuit also includes a reset module; The control end of the reset module is connected to a reset signal, the first end of the reset module is connected to the first end of the energy storage module, and the second end of the reset module is connected to a second power supply voltage; the reset module is used to reset the first end of the energy storage module in response to the first level of the reset signal.

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