CN116488615A

CN116488615A - Triangular wave generation circuit and method, chip and electronic equipment

Info

Publication number: CN116488615A
Application number: CN202310259425.3A
Authority: CN
Inventors: 应豪; 程立; 张启帆; 张海军
Original assignee: Shanghai Awinic Technology Co Ltd
Current assignee: Shanghai Awinic Technology Co Ltd
Priority date: 2023-03-16
Filing date: 2023-03-16
Publication date: 2023-07-25

Abstract

The application discloses a triangular wave generating circuit, a triangular wave generating method, a chip and electronic equipment, wherein in the triangular wave generating circuit, a charge pump module is used for taking a first clock signal output by a clock generating module as a switch clock to output switch current; the integrator comprises an integrator capacitor, and the integrator capacitor outputs triangular waves when being charged and discharged along with the switching current; the comparison module is used for comparing the amplitude of the triangular wave with a first threshold value, outputting a first comparison result, comparing the amplitude of the triangular wave with a second threshold value and outputting a second comparison result; the clock generation module is used for outputting a first clock signal according to the first comparison result and the second comparison result; the calibration module is used for obtaining the clock frequency of the first clock signal, and adjusting the magnitude of the switching current and the magnitude of the integrator capacitor according to the clock frequency so as to adjust the frequency of the triangular wave. The method and the device can adjust at least part of waveform parameters in real time and accurately control the waveform parameters such as frequency and/or amplitude.

Description

Triangular wave generation circuit and method, chip and electronic equipment

Technical Field

The application relates to the technical field of circuits, in particular to a triangular wave generating circuit and method, a chip and electronic equipment.

Background

The triangle wave generating circuit is an important component of the digital class-D power amplifier. The triangular wave generated by the triangular wave generating circuit is used for comparing with the audio signal in PWM (pulse width modulation), so parameters such as frequency, amplitude, phase and the like of the triangular wave can determine a square wave output signal after PWM modulation.

The inventor researches the traditional triangular wave generation schemes, and found that two constant reference voltages are generated by a voltage generation unit, the two constant reference voltages respectively limit the high peak value and the low peak value of the triangular wave, and then the charge pump charges and discharges the integrator to generate the triangular wave; in addition, an adjustable current source module is added to charge and discharge the large capacitor so as to widen the frequency band and reduce the emitted electromagnetic interference. The above scheme optimizes the generated triangular wave to a certain extent, but it is difficult to adjust the waveform parameters of the triangular wave in real time according to the related output signals of the triangular wave generating circuit.

Disclosure of Invention

In view of this, the present application provides a triangle wave generating circuit and method, a chip, and an electronic device, so as to solve the problem that the conventional scheme is difficult to adjust the triangle wave waveform parameters in real time.

The triangular wave generation circuit comprises a charge pump module, an integrator, a comparison module, a clock generation module and a calibration module;

the charge pump module is used for taking the first clock signal output by the clock generation module as a switch clock and outputting switch current;

the integrator comprises an integrator capacitor, and the integrator capacitor outputs triangular waves when being charged and discharged along with the switching current;

the comparison module is used for comparing the amplitude of the triangular wave with a first threshold value, outputting a first comparison result, comparing the amplitude of the triangular wave with a second threshold value and outputting a second comparison result;

the clock generation module is used for outputting a first clock signal according to the first comparison result and the second comparison result;

the calibration module is used for obtaining the clock frequency of the first clock signal, and adjusting the magnitude of the switching current output by the charge pump module and the magnitude of the integrator capacitor according to the clock frequency so as to adjust the frequency of the triangular wave.

Optionally, the switching current includes a first current in a first direction and a second current in a second direction; the integrator further comprises an operational amplifier; the non-inverting input end of the operational amplifier is connected with the output end of the charge pump module, and is connected with the output end of the operational amplifier through the integrator capacitor, the inverting input end of the operational amplifier is used for being connected with clamping voltage, and the output end of the operational amplifier is used for outputting the triangular wave; the integrator capacitor is charged when the first current is connected, the polar plate voltage close to the equidirectional input end of the operational amplifier rises, the polar plate voltage close to the output end of the operational amplifier falls, the integrator capacitor is charged when the second current is connected, the polar plate voltage close to the equidirectional input end of the operational amplifier falls, and the polar plate voltage close to the output end of the operational amplifier rises, so that the triangular wave is generated at the output end of the operational amplifier.

Optionally, the comparison module includes a first comparator and a second comparator; the positive input end of the first comparator is connected with the output end of the charge pump module, the negative input end is used for being connected with the first threshold value, the output end is used for being connected with the first input end of the clock generation module, the negative input end of the second comparator is connected with the output end of the charge pump module, the positive input end is used for being connected with the second threshold value, and the output end is connected with the second input end of the clock generation module.

Optionally, the first comparison result and the second comparison result are used for representing a magnitude relation among the amplitude of the triangular wave, the first threshold value and the second threshold value; the clock generation module comprises an RS trigger and a first inverter; the first input end of the RS trigger is connected with the first comparison result, the second input end of the RS trigger is connected with the second comparison result, and the output end of the RS trigger is connected with the clock end of the charge pump module and the input end of the calibration module respectively through the first inverter; the RS trigger outputs a high level when the amplitude of the triangular wave is smaller than or equal to the first threshold value, so that the first clock signal output by the inverter is low level; outputting a high level to make the first clock signal output by the inverter be a low level when the amplitude of the triangular wave is greater than the first threshold; outputting a low level to make the first clock signal output by the inverter be a high level when the amplitude of the triangular wave is greater than the second threshold; and outputting a low level when the amplitude of the triangular wave is less than or equal to the second threshold value, so that the first clock signal output by the inverter is in a high level.

Optionally, the RS flip-flop includes a first nand gate and a second nand gate; the first input end of the first NAND gate is used for accessing the first comparison result, the second input end of the first NAND gate is connected with the output end of the second NAND gate, and the output end of the first NAND gate is connected with the input end of the first inverter; the first input end of the second NAND gate is used for accessing the second comparison result, and the second input end is connected with the output end of the first NAND gate.

Optionally, the triangle wave generating circuit further comprises a second inverter, and the charge pump module comprises a third inverter, a first current source, a first switch, a second current source and a second switch; the input end of the second inverter is used for being connected with the first clock signal, the output end of the second inverter is respectively connected with the input end of the third inverter and the control end of the second switch, the output end of the third inverter is connected with the control end of the first switch, the first end of the first switch is connected with an external power supply through a first current source, the second end of the first switch is respectively connected with the input end of the integrator and the first end of the second switch, and the second end of the second switch is grounded through the second current source; when the first clock signal is at a low level, the first switch is opened, the second switch is closed, and the second current source provides current to enable the switch current to be a second current so as to enable the integrator capacitor to discharge; when the first clock signal is at a high level, the first switch is closed, the second switch is opened, and the first current source provides current to enable the switch current to be a first current so as to enable the integrator capacitor to be charged.

Optionally, the calibration module includes a frequency detection unit and a parameter adjustment unit; the input end of the frequency detection unit is connected with the output end of the clock generation module, the output end of the frequency detection unit is connected with the input end of the parameter adjustment unit, the first output end of the parameter adjustment unit is connected with the current control end of the charge pump module, and the second output end of the parameter adjustment unit is connected with the capacitance control end of the integrator; the frequency detection unit is used for detecting the clock frequency of the first clock signal; the parameter adjusting unit is used for adjusting the magnitude of the switching current and/or the magnitude of the integrator capacitor according to the clock frequency.

Optionally, the triangular wave generating circuit further comprises a frequency dividing module and a dual-channel selector; the input end of the frequency division module is used for accessing a system master clock, the output end of the frequency division module is connected with the first input end of the two-channel selector, the second input end of the two-channel selector is connected with the output end of the clock generation module, and the output end of the frequency division module is connected with the clock end of the charge pump module; the frequency division module is used for dividing the system main clock by 2N so as to provide a second clock signal; the dual-channel selector is configured to provide the second clock signal to the charge pump module when the first channel corresponding to the first input end is gated, so that the charge pump module uses the second clock signal as a switching clock, and provide the first clock signal to the charge pump module when the second channel corresponding to the second input end is gated, so that the charge pump module uses the first clock signal as a switching clock.

Optionally, the frequency dividing module comprises a frequency N divider and a frequency divider; the input end of the N frequency divider is connected with the system master clock, the output end of the N frequency divider is connected with the input end of the two frequency dividers, and the output end of the two frequency dividers is connected with the first input end of the two-channel selector.

Optionally, the triangular wave generating circuit further comprises a parameter control module; the first output end of the parameter control module is connected with the control end of the N frequency divider, the second output end of the parameter control module is connected with the current control end of the charge pump module, and the third output end of the parameter control module is connected with the capacitance control end of the integrator; the parameter control module is used for determining a frequency division number N, an initial current value of the switching current and an initial capacitance value of the integrator capacitor according to a preset frequency.

Optionally, the triangle wave generating circuit further comprises a phase synchronization module; the first input end of the phase synchronization module is used for accessing a phase selection signal, the second input end of the phase synchronization module is connected with the first output end of the parameter control module, and the output end of the phase synchronization module is connected with the phase control end of the N frequency divider; the phase synchronization module is used for obtaining a frequency division starting point according to the phase selection signal and the frequency division number N, so that the N frequency divider carries out N frequency division on the system main clock according to the frequency division starting point and the frequency division number N, and phase synchronization processing is achieved.

Optionally, the calibration module is further configured to obtain an amplitude parameter of the first clock signal, and adjust a magnitude of the switching current output by the charge pump module and a magnitude of the integrator capacitor according to the amplitude parameter, so as to adjust an amplitude of the triangular wave.

The application also provides a triangular wave generation method which is applied to any triangular wave generation circuit; the triangular wave generation method comprises the following steps:

determining a switching current by taking the first clock signal as a switching clock;

outputting triangular waves when the integrator capacitor is charged and discharged along with the switching current;

comparing the amplitude of the triangular wave with a first threshold value, determining a first comparison result, comparing the amplitude of the triangular wave with a second threshold value, and determining a second comparison result;

determining the first clock signal according to the first comparison result and the second comparison result;

and acquiring the clock frequency of the first clock signal, and adjusting the magnitude of the switching current output by the charge pump module and the magnitude of the integrator capacitor according to the clock frequency so as to adjust the frequency of the triangular wave.

The application also provides a chip comprising any one of the triangular wave generating circuits.

The application also provides electronic equipment comprising any one of the triangular wave generating circuits or any one of the chips.

In the triangular wave generating circuit, the method, the chip and the electronic equipment provided by the application, the charge pump module can take the first clock signal output by the clock generating module as a switch clock, output switch current, enable the integrator capacitor in the integrator to output triangular waves when the integrator capacitor is charged and discharged along with the switch current, the comparison module can compare the amplitude of the triangular waves with a first threshold value, output a first comparison result, compare the amplitude of the triangular waves with a second threshold value and output a second comparison result, so that the clock generating module can output the first clock signal according to the first comparison result and the second comparison result, enable the first clock signal to correspond to the triangular waves, and the calibration module adjusts the magnitude of the switch current output by the charge pump module and the magnitude of the integrator capacitor according to the clock frequency of the first clock signal, thereby achieving the purpose of adjusting the frequency of the triangular waves in real time according to the output information of the triangular wave generating circuit; and the amplitude of the generated triangular wave is limited between a first threshold value and a second threshold value; therefore, the triangular wave generating circuit can precisely control the frequency and the amplitude of the generated triangular wave in a closed-loop working mode.

Further, the two working modes of an open-loop working mode and a closed-loop working mode are provided through the two-channel selector; in the open-loop working mode, the amplitude of the triangular wave can be adjusted in real time according to the related output information of the triangular wave generating circuit, and the frequency domain of the triangular wave is determined according to the frequency of the system main clock SYS_CLK and the frequency division number N, so that the triangular wave generating circuit in the open-loop working mode can accurately control the frequency and the amplitude of the generated triangular wave.

Therefore, at least part of waveform parameters can be adjusted in real time under each working mode, and the waveform parameters such as frequency and/or amplitude and the like are accurately controlled.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a triangle wave generating circuit according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a triangle wave generating circuit according to another embodiment of the present application;

FIG. 3 is a schematic diagram of a triangle wave generating circuit according to another embodiment of the present application;

fig. 4 is a schematic diagram of a triangle wave generating circuit according to another embodiment of the present application;

fig. 5 is a schematic diagram of a triangle wave generating circuit according to another embodiment of the present application;

fig. 6 is a schematic diagram of a triangle wave generating circuit according to another embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application. The various embodiments described below and their technical features can be combined with each other without conflict.

A first aspect of the present application provides a triangle wave generation circuit, referring to fig. 1, which includes a charge pump module 110, an integrator 120, a comparison module 130, a clock generation module 200, and a calibration module 300. The current control end of the charge pump module 110 is connected with the first output end of the calibration module 300, and the output end is connected with the input end of the integrator 120; the capacitance control end of the integrator 120 is connected with the second output end of the calibration module 300, and the output end is connected with the first input end of the comparison module; the second input end of the comparison module 130 is used for accessing the first threshold value, the third input end is used for accessing the second threshold value, the first output end is connected with the first input end of the clock generation module 200 to output a first comparison result, and the second output end is connected with the second input end of the clock generation module 200 to output a second comparison result; the output terminal of the clock generation module 200 is connected to the clock terminal of the charge pump module 110 and the input terminal of the calibration module 300, respectively.

The charge pump module 110 is configured to output a switching current by using the first clock signal output by the clock generating module 110 as a switching clock.

The integrator 120 includes an integrator capacitor (not shown in fig. 1), and the integrator 120 capacitor outputs a triangular wave when the switching current is charged and discharged.

The comparing module 130 is configured to compare the amplitude of the triangular wave with a first threshold, output a first comparison result, compare the amplitude of the triangular wave with a second threshold, and output a second comparison result; the first comparison result and the second comparison result can be represented by high and low levels respectively; for example, the first comparison result indicates that the amplitude of the triangular wave is larger than a first threshold value for the high level 1, and the amplitude of the triangular wave is smaller than the first threshold value for the low level 0; for another example, the second comparison result indicates that the amplitude of the triangular wave is smaller than the second threshold value for the high level 1 and that the amplitude of the triangular wave is larger than the second threshold value for the low level 0. The first threshold and the second threshold can be set according to parameters such as the frequency and/or the amplitude of the required triangular wave; alternatively, the first threshold is smaller than the second threshold, for example the first threshold may take 1V and the second threshold may take 3V.

The clock generation module 200 is configured to output a first clock signal according to the first comparison result and the second comparison result.

The calibration module 300 is configured to obtain a clock frequency of the first clock signal, and adjust the magnitude of the switching current and the magnitude of the integrator capacitor output by the charge pump module 110 according to the clock frequency, so as to adjust the frequency of the triangular wave in real time according to the output information of the triangular wave generating circuit.

In the above triangle wave generating circuit, the charge pump module 110 may output a switch current by using the first clock signal output by the clock generating module 110 as a switch clock, so that the integrator capacitor in the integrator 120 outputs a triangle wave when charging and discharging along with the switch current, the comparing module 130 may compare the amplitude of the triangle wave with a first threshold value, output a first comparison result, compare the amplitude of the triangle wave with a second threshold value, and output a second comparison result, so that the clock generating module 200 may output the first clock signal according to the first comparison result and the second comparison result, and the first clock signal corresponds to the triangle wave, and the calibrating module 300 adjusts the magnitude of the switch current output by the charge pump module 110 and the magnitude of the integrator capacitor according to the clock frequency of the first clock signal, thereby achieving the purpose of adjusting the frequency of the triangle wave in real time according to the output information of the triangle wave generating circuit; and the amplitude of the generated triangular wave is limited between a first threshold value and a second threshold value; the triangular wave generating circuit can precisely control the frequency and amplitude of the generated triangular wave.

In one embodiment, referring to fig. 2, the switching current includes a first current I1 in a first direction and a second current I1 in a second direction; wherein the first direction may comprise a direction toward the input of the integrator 120, in which case the first current I1 may flow toward the input of the integrator 120; the first direction may include a direction from the input of the integrator 120 to the ground, and the second current I2 may flow from the input of the integrator 120 to the ground.

The integrator 120 includes an integrator capacitor 121 and an operational amplifier 122; the non-inverting input end of the operational amplifier 122 is used as the input end of the integrator 120, connected to the output end of the charge pump module 120, and connected to the output end of the operational amplifier 122 through the integrator capacitor 121, the inverting input end of the operational amplifier 122 is used for accessing the clamp voltage Vcm, and the output end of the operational amplifier 122 is used for outputting the triangular wave.

The integrator capacitor 121 is charged when the first current I1 is connected, the voltage of the electrode plate near the same-directional input end of the operational amplifier 122 increases, the voltage of the electrode plate near the output end of the operational amplifier 122 decreases, and the integrator capacitor is charged when the second current I2 is connected, the voltage of the electrode plate near the same-directional input end of the operational amplifier 122 decreases, and the voltage of the electrode plate near the output end of the operational amplifier increases, so that the triangular wave is generated at the output end of the operational amplifier 122.

Optionally, the integrator capacitor 121 comprises a tunable capacitor bank. The adjustable capacitor bank may include a plurality of unit capacitors, and the components of the calibration module 300 and the like may adjust the size of the integrator capacitor 121 by controlling the number of unit capacitors connected to the circuit.

The integrator 120 provided in this embodiment has a simple structure, and the parameters such as the frequency of the generated triangular wave match the first clock signal CLK1 of the calibration module 300, and can be adjusted according to the first clock signal CLK 1.

In one embodiment, as shown in fig. 2, the comparison module 130 includes a first comparator 131 and a second comparator 132; the positive input end of the first comparator 131 is used as the first input end of the comparison module 130 and connected with the output end of the charge pump module, the negative input end of the first comparator 131 is used as the second input end of the comparison module 130 and connected with the first threshold value, the output end of the first comparator 131 is used as the first output end of the comparison module 130 and connected with the first input end of the clock generation module, the negative input end of the second comparator 132 is connected with the output end of the charge pump module, the positive input end of the second comparator 132 is used as the third input end of the comparison module 130 and connected with the second threshold value, and the output end of the second comparator 132 is used as the second output end of the comparison module 130 and connected with the second input end of the clock generation module.

In one embodiment, the first comparison result and the second comparison result are used to characterize a magnitude relationship between the amplitude of the triangular wave, the first threshold value, and the second threshold value; taking the comparison module 130 shown in fig. 2 as an example, the first comparison result indicates that the amplitude of the high level representation triangular wave is greater than the first threshold VL, and indicates that the amplitude of the low level representation triangular wave is less than the first threshold VL; the second comparison result indicates that the amplitude of the high level representation triangular wave is smaller than the second threshold value VH, and the amplitude of the low level representation triangular wave is larger than the second threshold value VH.

As shown in fig. 2, the clock generation module 200 includes an RS flip-flop 210 and a first inverter 221; the first input terminal of the RS flip-flop 210 is used for accessing the first comparison result, the second input terminal is used for accessing the second comparison result, and the output terminal is respectively connected to the clock terminal of the charge pump module 110 and the input terminal of the calibration module 300 through the first inverter 221. If the triangular wave generating circuit includes the second inverter 141, the output terminal of the first inverter 221 may be connected to the clock terminal of the charge pump module 110 through the second inverter 141.

The RS flip-flop 210 outputs a high level to make the first clock signal CLK1 output from the inverter 221 a low level when the magnitude of the triangular wave is less than or equal to the first threshold VL; outputting a high level to make the first clock signal CLK1 output from the inverter 221 be a low level when the magnitude of the triangular wave is greater than the first threshold VL; outputting a low level such that the first clock signal CLK1 output from the inverter 221 is at a high level when the magnitude of the triangular wave is greater than the second threshold VH; when the amplitude of the triangular wave is less than or equal to the second threshold VH, a low level is output so that the first clock signal CLK1 output from the inverter 221 is at a high level. Further, after the amplitude of the triangular wave falls below or equal to the first threshold VL, the RS flip-flop 210 repeats the above-described operation to cause the inverter 221 to output the stable continuous first clock signal CLK1.

In one example, the RS flip-flop 210 includes a first nand gate 211 and a second nand gate 212; a first input terminal of the first nand gate 211 is used for accessing the first comparison result, a second input terminal is connected to an output terminal of the second nand gate 212, and an output terminal is connected to an input terminal of the first inverter 221; the first input end of the second nand gate 212 is used for accessing the second comparison result, and the second input end is connected to the output end of the first nand gate 211.

In another example, the RS flip-flop 210 may also be formed using other logic devices.

In one embodiment, as shown in fig. 2, the triangle wave generating circuit further includes a second inverter 141, and the charge pump module 110 includes a third inverter 111, a first current source 112, a first switch 113, a second current source 114, and a second switch 115. The input end of the second inverter 141 is used for accessing the first clock signal CLK1, the output end of the second inverter 141 is connected to the input end of the third inverter 111 and the control end of the second switch 115, the output end of the third inverter 111 is connected to the control end of the first switch 113, the first end of the first switch 113 is connected to the external power AVDD through the first current source 112, the second end of the first switch is connected to the input end of the integrator and the first end of the second switch 115, and the second end of the second switch 115 is grounded through the second current source 114.

When the first clock signal CLK1 is low, the first switch 113 is opened, the second switch 115 is closed, and the second current source 114 provides a current to make the switch current be a second current I2 to discharge the integrator capacitor 121; when the first clock signal CLK1 is high, the first switch 113 is closed, the second switch 115 is open, and the first current source 112 provides a current such that the switch current is the first current I1 to charge 121 the integrator capacitor.

In one embodiment, as shown in fig. 2, the calibration module 300 includes a frequency detection unit 310 and a parameter adjustment unit 320; the input end of the frequency detection unit 310 is connected to the output end of the clock generation module 200 to access the first clock signal CLK1, and the output end of the frequency detection unit 310 is connected to the input end of the parameter adjustment unit 320; a first output terminal of the parameter adjusting unit 320 is connected to a current control terminal (not shown in fig. 2) of the charge pump module 110, and specifically, the first output terminal of the parameter adjusting unit 320 may be connected to current control terminals of the first current source 112 and the second current source 114, respectively, so as to control current magnitudes of the first current source 112 and the second current source 114, respectively; a second output terminal of the parameter adjusting unit 320 is connected to a capacitance control terminal (not shown in fig. 2) of the integrator 121, so as to control the capacitance of the integrator capacitor 121.

The frequency detection unit 310 is configured to detect a clock frequency of the first clock signal CLK 1;

the parameter adjustment unit 320 is configured to adjust the magnitude of the switching current according to the clock frequency, for example, the magnitude of the switching current may be adjusted by controlling the current magnitude of the first current source 112 or the second current source 114; and/or the parameter adjusting unit 320 is configured to adjust the size of the integrator capacitor 121 according to the clock frequency, specifically, the integrator capacitor 121 includes an adjustable capacitor set having a plurality of unit capacitors, and the parameter adjusting unit 320 may adjust the size of the integrator capacitor 121 by controlling the number of unit capacitors connected to the circuit.

Alternatively, the frequency detecting unit 310 and the parameter adjusting unit 320 may be implemented by digital circuits such as a counter, where the frequency detecting unit 310 may be implemented in various ways, for example, a high-frequency clock may count in one period of CLK1, the count value is greater than a count threshold, that is, indicates that the triangle wave frequency is lower than the frequency threshold, increasing the magnitude of the switching current or decreasing the magnitude of the integrator capacitor 121 may increase the triangle wave frequency, and otherwise the count value is less than or equal to the count threshold, that is, indicates that the triangle wave frequency is higher than the frequency threshold, and decreasing the magnitude of the switching current or increasing the magnitude of the integrator capacitor 121 may decrease the triangle wave frequency.

In this embodiment, the parameter adjusting unit 320 adjusts the frequency of the triangular wave by adjusting the magnitude of the switching current and/or the magnitude of the integrator capacitor 121.

In one embodiment, referring to fig. 3, the triangle wave generation circuit further includes a frequency division module 150 and a dual channel selector 142; the input end of the frequency dividing module 150 is used for accessing the system master clock sys_clk, the output end is connected to the first input end of the dual-channel selector 142, the second input end of the dual-channel selector 142 is connected to the output end of the clock generating module 200, and the output end is connected to the clock end of the charge pump module 110. Alternatively, if the clock terminal of the charge pump module 110 is provided with the second inverter 141, the output terminal of the dual-channel selector 142 is connected to the clock terminal of the charge pump module 110 through the second inverter 141.

The frequency division module 150 is configured to divide the system master clock sys_clk by 2N to provide the second clock signal CLK0. The frequency division module 150 divides the system master clock sys_clk by 2N here to ensure that the frequency division number is always even, and that the duty cycle of the second clock signal CLK0 is 50%. Where N may be determined according to the system master clock sys_clk, for example, dividing the frequency of the system master clock sys_clk by the frequency of the required triangle wave may obtain a value of 2N.

The dual-channel selector 142 is configured to provide the second clock signal CLK0 to the charge pump module 110 when the first channel corresponding to the first input terminal is gated, so that the charge pump module 110 uses the second clock signal CLK0 as a switching clock, and provide the first clock signal CLK1 to the charge pump module 110 when the second channel corresponding to the second input terminal is gated, so that the charge pump module 110 uses the first clock signal CLK1 as a switching clock. Here, the channels selected by the two-channel selector 142 may be preconfigured, which may be determined according to the application scenario and/or the working clock requirement of the triangular wave generating circuit.

In this embodiment, when the dual-channel selector 142 gates the first channel, the charge pump module 110 is provided with the second clock signal CLK0 determined according to the system master clock sys_clk, and the charge pump module 110 uses the second clock signal CLK0 as the switching clock, so that the triangular wave generating circuit enters the open-loop working mode; when the two-channel selector 142 gates the second channel, the charge pump module 110 is provided with the first clock signal CLK1 corresponding to the triangular wave, and at this time, the charge pump module 110 uses the first clock signal CLK1 as a switching clock, and the triangular wave generating circuit enters a closed-loop working mode. Therefore, the triangular wave generating circuit provided by the embodiment has two working modes, namely an open-loop working mode and a closed-loop working mode.

In one example, as shown in fig. 3, the frequency division module 150 includes a divide-by-N151 and a divide-by-two 152; the input end of the N frequency divider 151 is connected to the system master clock sys_clk, the output end is connected to the input end of the frequency divider 152, and the N frequency divider 151 is used for dividing the system master clock sys_clk by N; the output end of the divide-by-two device 152 is connected to the first input end of the two-channel selector 142, and the divide-by-two device 152 is configured to divide the divided signal output by the divide-by-N device 151 by two, so as to obtain the second clock signal CLK0.

In one embodiment, referring to fig. 4, the triangle wave generation circuit further includes a parameter control module 160; the first output end of the parameter control module 160 is connected to the control end of the N frequency divider 151, the second output end is connected to the current control end of the charge pump module 110, and the third output end is connected to the capacitance control end of the integrator 120.

The parameter control module 160 is configured to determine the frequency division number N, the initial current value of the switching current, and the initial capacitance value of the integrator capacitor 121 according to a preset frequency, so as to set the N value of the N divider 151, and set the initial current value of the switching current (such as the initial current values of the first current source 112 and the second current source 114) and the initial capacitance value of the integrator capacitor 121 when the triangular wave generating circuit starts to operate.

The preset frequency may be a PWM modulation frequency corresponding to the triangular wave generating circuit, the parameter control module 160 may calculate N according to the preset frequency, and may calculate a plurality of corresponding sets of current capacitance values according to the preset frequency, and determine an initial current value of the switching current and an initial capacitance value of the integrator capacitor 121 according to the plurality of sets of current capacitance values.

Optionally, the parameter control module 160 may include a divider and/or other logic device to enable the parameter control module 160 to calculate N, a corresponding initial current value, and an initial capacitance value according to a preset frequency. Further, the parameter control module 160 may calculate an initial current value by mirroring a current mirror or dividing a voltage by a resistor, and set the initial current value of the switching current or adjust the switching current by selecting a different current mirror or changing a voltage resistor.

Further analysis of the triangular wave generating circuit shown in fig. 4 shows that in the open loop operation mode, the clock of the charge pump module 110 is homologous to the system clock, and the problem of phase asynchronization easily occurs in the process of dividing the system clock by N. In view of the above, in one example, referring to fig. 5, the triangle wave generation circuit further includes a phase synchronization module 170; the first input end of the PHASE synchronization module 170 is used for accessing a PHASE selection signal phase_sel, the second input end is connected with the first output end of the parameter control module 160, and the output end is connected with the PHASE control end of the N frequency divider 151; the PHASE synchronization module 170 is configured to obtain a frequency division start point according to the PHASE selection signal phase_sel and the frequency division number N, so that the N frequency divider 151 performs N frequency division on the system master clock sys_clk according to the frequency division start point and the frequency division number N, thereby implementing PHASE synchronization processing and reducing EMI interference (electromagnetic interference). Alternatively, the phase synchronization module 170 may include a phase synchronization circuit formed of at least one logic device. Optionally, the PHASE synchronization module 170 may also access the PHASE select signal phase_sel.

In one embodiment, the calibration module 300 is further configured to obtain an amplitude parameter of the first clock signal CLK1, and adjust the magnitude of the switching current output by the charge pump module 110 and the magnitude of the integrator capacitor according to the amplitude parameter, so as to adjust the amplitude of the triangular wave in real time. Here, the first clock signal CLK1 is a square wave corresponding to a triangular wave, and the amplitude of the first clock signal CLK1 can characterize the amplitude of the corresponding triangular wave; the embodiment can adjust the amplitude of the triangular wave in real time according to the related output information of the triangular wave generating circuit; in the open loop working mode, the frequency domain of the triangular wave is determined according to the frequency of the system main clock SYS_CLK and the frequency division number N, so that the triangular wave generating circuit can accurately control the frequency and the amplitude of the generated triangular wave in the working mode.

Specifically, referring to fig. 6, the calibration module 300 may further include an amplitude detection unit 330, wherein an input terminal of the amplitude detection unit 330 is connected to an output terminal of the clock generation module 200 to be connected to the first clock signal CLK1, and an output terminal of the amplitude detection unit 330 is connected to an input terminal of the parameter adjustment unit 320. The amplitude detection unit 330 is used for detecting an amplitude parameter of the first clock signal CLK 1. Correspondingly, the parameter adjusting unit 320 may calculate a current parameter and/or a capacitance parameter to be adjusted according to the amplitude parameter, and the first output end of the parameter adjusting unit 320 may be connected to the current control ends of the first current source 112 and the second current source 114, respectively, so as to control the current magnitudes of the first current source 112 and the second current source 114, respectively; the second output terminal of the parameter adjusting unit 320 is connected to the capacitance control terminal of the integrator 121, so as to control the capacitance of the integrator capacitor 121. Alternatively, the amplitude detection unit 330 may comprise a flip-flop or the like for acquiring a parameter characterizing the amplitude of the first clock signal CLK 1. Specifically, the amplitude detection unit 330 may perform flip detection on the first clock signal CLK1, so as to modulate the current parameter and/or the capacitance parameter. For example, it may be implemented by a flip-flop, where the first clock signal CLK1 does not flip for a certain period of time, that is, indicates that the magnitude of the triangular wave is lower than a preset magnitude threshold, increasing the magnitude of the switching current or decreasing the magnitude of the integrator capacitor 121 increases the magnitude of the triangular wave, whereas it is higher than the magnitude threshold, and decreasing the magnitude of the switching current or increasing the magnitude of the integrator capacitor 121 decreases the magnitude of the triangular wave.

Specifically, in the triangular wave generating circuit shown in fig. 3 to 6, when the dual-channel selector 142 gates the first channel, the charge pump module 110 uses the second clock signal CLK0 as a switching clock, and the triangular wave generating circuit enters an open-loop working mode, and at this time, the amplitude of the triangular wave can be adjusted in real time by performing flip detection through the first clock signal CLK 1; when the two-channel selector 142 gates the second channel, the charge pump module 110 uses the first clock signal CLK1 as a switching clock, and the triangular wave generating circuit enters a closed-loop operation mode, and at this time, the frequency of the triangular wave can be adjusted in real time by detecting the clock frequency of the first clock signal CLK 1.

In the open loop operation mode, the dual-channel selector 142 selects the channel 0 (the first channel), the parameter control module 160 sets the frequency division number N according to the set PWM modulation frequency, the PHASE synchronization module 170 can obtain an exact frequency division start point according to the frequency division number N and the input PHASE selection signal phase_sel, the N-divider 151 divides the input system master clock sys_clk by N according to the input frequency division number and the frequency division start point, and then obtains the second clock signal CLK0 with a duty ratio of 50% through two division, and outputs the second clock signal CLK0 to the charge pump module 110 as a switching clock of the second clock signal CLK 0. The second clock signal CLK0 charges and discharges the whole integrator capacitor 121 to generate a triangular wave at the output terminal of the integrator 120. Specifically, if the second clock signal CLK0 controls the first current source 112 to be turned off, the second current source 114 is turned on, and an upward slope is generated; when the second clock signal CLK0 turns over, the second clock signal CLK0 controls the first current source 112 to be turned on, and the second current source 114 is turned off, so that the output voltage of the integrator 120 starts to decrease and becomes a downward slope; when CLK0 turns over again, the second clock signal CLK0 controls the first current source 112 to turn off again, and the second current source 114 turns on, so that the output of the integrator 120 starts rising again and becomes an upward slope; … …. The above-described process is repeated with repeated inversion of the second clock signal CLK0, so that the upward and downward slopes together constitute a triangular wave, the frequency of which is determined by the second clock signal CLK0, and thus an accurate triangular wave frequency can be obtained. In addition, the first comparator 131 and the second comparator 132 still operate in the open loop operation mode, the triangular wave at the output end of the integrator 120 is compared with the second threshold VH and the first threshold VL, respectively, and since the output end of the integrator 120 is clamped by the common mode so that the average level (amplitude) of the triangular wave is always kept at the intermediate voltage between the second threshold VH and the first threshold VL, when the amplitude of the triangular wave exceeds VH-VL, the comparator logic of the comparison module 130 will continuously flip as the rising and falling of the triangular wave, outputting the first clock signal CLK1, and when the amplitude of the triangular wave is smaller than VH-VL, the comparator logic will keep the previous state, and no flip occurs, and the first clock signal CLK1 at this time is constantly high or low. The first clock signal CLK1 is sampled by the calibration module 300 at this time, and the charge-discharge current and/or the capacitance value of the integrator capacitor 121 are adjusted through the automatic calibration process, so as to realize self-detection and self-calibration of the amplitude of the triangular wave, so that the amplitude of the triangular wave is compared and calibrated with the set second threshold VH and the first threshold VL, and the peak value of the triangular wave is still kept as the second threshold VH and the first threshold VL, so that the accurate amplitude of the triangular wave can be obtained.

In the closed-loop operation mode, the dual-channel selector 142 selects the channel 1 (the second channel), and the first clock signal CLK1 is directly input to the charge pump module 110, and is used as a switching clock of the charge pump module 110, and the charge pump module 110 charges and discharges the integrator 120 to generate a triangular wave at the output end of the integrator 120. Specifically, if the first clock signal CLK1 controls the first current source 112 to be turned off, the second current source 114 is turned on, and an upward slope is generated; when the ramp signal is greater than the second threshold VH, the first clock signal CLK1 generated by the comparator logic turns over, and at this time, the first current source 112 is controlled to be turned on, and the second current source 114 is turned off, so that the output of the integrator 120 starts to fall and becomes a downward ramp; when the ramp signal is less than the first threshold VL, the first clock signal CLK1 generated by the comparator logic toggles, and at this time, the first current source 112 is controlled to be turned off again, and the second current source 114 is turned on, so that the output of the integrator 120 starts rising again, and becomes an upward increasing ramp; … …. The above-described process is repeated with repeated inversion of the first clock signal CLK1, so that the upward and downward slopes together constitute a triangular wave output signal whose amplitude is limited by the second threshold VH and the first threshold VL, and thus an accurate triangular wave amplitude can be obtained. In addition, the first clock signal CLK1 is sampled by the calibration module 300, and the charging and discharging current and/or the capacitance value of the integrator capacitor 121 are adjusted through the automatic calibration process, so as to realize the self-detection and self-calibration of the triangle wave frequency, so that the triangle wave frequency is compared and calibrated with the set PWM modulation frequency value, and the triangle wave frequency is still kept as the set PWM modulation frequency, so that the accurate triangle wave frequency can be obtained.

The above triangle wave generating circuit, the charge pump module 110 can take the first clock signal output by the clock generating module 110 as a switch clock, output a switch current, so that the integrator capacitor in the integrator 120 outputs a triangle wave when charging and discharging along with the switch current, the comparing module 130 can compare the amplitude of the triangle wave with a first threshold value, output a first comparison result, compare the amplitude of the triangle wave with a second threshold value, and output a second comparison result, so that the clock generating module 200 can output the first clock signal according to the first comparison result and the second comparison result, and the first clock signal corresponds to the triangle wave, and the calibrating module 300 adjusts the magnitude of the switch current output by the charge pump module 110 and the magnitude of the integrator capacitor according to the clock frequency of the first clock signal, thereby achieving the purpose of adjusting the frequency of the triangle wave in real time according to the output information of the triangle wave generating circuit; and the amplitude of the generated triangular wave is limited between a first threshold value and a second threshold value; therefore, the triangular wave generating circuit can precisely control the frequency and the amplitude of the generated triangular wave in a closed-loop working mode. The triangular wave generating circuit also provides two working modes of an open-loop working mode and a closed-loop working mode through a double-channel selector; in the open-loop working mode, the amplitude of the triangular wave can be adjusted in real time according to the related output information of the triangular wave generating circuit, and the frequency domain of the triangular wave is determined according to the frequency of the system main clock SYS_CLK and the frequency division number N, so that the triangular wave generating circuit in the open-loop working mode can accurately control the frequency and the amplitude of the generated triangular wave. Therefore, the triangular wave generating circuit can adjust at least part of waveform parameters in real time under each working mode, and precisely control the waveform parameters such as frequency and/or amplitude.

The present application provides in a second aspect a triangular wave generation method applied to the triangular wave generation circuit described in any one of the above embodiments; the triangular wave generation method comprises the following steps:

The triangular wave generating method is applied to the triangular wave generating circuit in any embodiment, and has all the features and advantages of the triangular wave generating circuit in any embodiment, and are not described herein.

The present application provides a chip in a third aspect, including the triangular wave generating circuit described in any one of the above embodiments, which is capable of adjusting at least part of waveform parameters in real time, and accurately controlling waveform parameters such as frequency and/or amplitude.

In a fourth aspect, the present application provides an electronic device, including the triangular wave generating circuit described in any one of the foregoing embodiments or the chip described in any one of the foregoing embodiments, which is capable of accurately controlling waveform parameters such as frequency and/or amplitude of a triangular wave.

Although the application has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. This application is intended to cover all such modifications and variations, and is limited only by the scope of the appended claims. In particular regard to the various functions performed by the above described components, the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the specification.

That is, the foregoing embodiments are merely examples of the present application, and are not intended to limit the scope of the patent application, and all equivalent structures or equivalent processes using the descriptions and the contents of the present application, such as the combination of technical features of the embodiments, or direct or indirect application to other related technical fields, are included in the scope of the patent protection of the present application.

In addition, the present application may use the same or different reference numerals for structural elements having the same or similar characteristics. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In this application, the term "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The previous description is provided to enable any person skilled in the art to make or use the present application. In the above description, various details are set forth for purposes of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes have not been shown in detail to avoid unnecessarily obscuring the description of the present application. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. The triangular wave generation circuit is characterized by comprising a charge pump module, an integrator, a comparison module, a clock generation module and a calibration module;

2. The triangle wave generation circuit of claim 1, wherein the switching current comprises a first current in a first direction and a second current in a second direction;

The integrator further comprises an operational amplifier; the non-inverting input end of the operational amplifier is connected with the output end of the charge pump module, and is connected with the output end of the operational amplifier through the integrator capacitor, the inverting input end of the operational amplifier is used for being connected with clamping voltage, and the output end of the operational amplifier is used for outputting the triangular wave;

the integrator capacitor is charged when the first current is connected, the polar plate voltage close to the equidirectional input end of the operational amplifier rises, the polar plate voltage close to the output end of the operational amplifier falls, the integrator capacitor is charged when the second current is connected, the polar plate voltage close to the equidirectional input end of the operational amplifier falls, and the polar plate voltage close to the output end of the operational amplifier rises, so that the triangular wave is generated at the output end of the operational amplifier.

3. The triangle wave generation circuit of claim 1, wherein the comparison module comprises a first comparator and a second comparator; the positive input end of the first comparator is connected with the output end of the charge pump module, the negative input end is used for being connected with the first threshold value, the output end is used for being connected with the first input end of the clock generation module, the negative input end of the second comparator is connected with the output end of the charge pump module, the positive input end is used for being connected with the second threshold value, and the output end is connected with the second input end of the clock generation module.

4. The triangle wave generation circuit of claim 1, wherein the first comparison result and the second comparison result are used to characterize a magnitude relationship between the magnitude of the triangle wave, the first threshold value, and the second threshold value;

the clock generation module comprises an RS trigger and a first inverter; the first input end of the RS trigger is connected with the first comparison result, the second input end of the RS trigger is connected with the second comparison result, and the output end of the RS trigger is connected with the clock end of the charge pump module and the input end of the calibration module respectively through the first inverter;

the RS trigger outputs a high level when the amplitude of the triangular wave is smaller than or equal to the first threshold value, so that the first clock signal output by the inverter is low level; outputting a high level to make the first clock signal output by the inverter be a low level when the amplitude of the triangular wave is greater than the first threshold; outputting a low level to make the first clock signal output by the inverter be a high level when the amplitude of the triangular wave is greater than the second threshold; and outputting a low level when the amplitude of the triangular wave is less than or equal to the second threshold value, so that the first clock signal output by the inverter is in a high level.

5. The triangle wave generation circuit of claim 4, wherein the RS flip-flop comprises a first nand gate and a second nand gate;

the first input end of the first NAND gate is used for accessing the first comparison result, the second input end of the first NAND gate is connected with the output end of the second NAND gate, and the output end of the first NAND gate is connected with the input end of the first inverter; the first input end of the second NAND gate is used for accessing the second comparison result, and the second input end is connected with the output end of the first NAND gate.

6. The triangle wave generation circuit of claim 4, further comprising a second inverter, the charge pump module comprising a third inverter, a first current source, a first switch, a second current source, and a second switch;

the input end of the second inverter is used for being connected with the first clock signal, the output end of the second inverter is respectively connected with the input end of the third inverter and the control end of the second switch, the output end of the third inverter is connected with the control end of the first switch, the first end of the first switch is connected with an external power supply through a first current source, the second end of the first switch is respectively connected with the input end of the integrator and the first end of the second switch, and the second end of the second switch is grounded through the second current source;

When the first clock signal is at a low level, the first switch is opened, the second switch is closed, and the second current source provides current to enable the switch current to be a second current so as to enable the integrator capacitor to discharge; when the first clock signal is at a high level, the first switch is closed, the second switch is opened, and the first current source provides current to enable the switch current to be a first current so as to enable the integrator capacitor to be charged.

7. The triangular wave generation circuit according to claim 1, wherein the calibration module includes a frequency detection unit and a parameter adjustment unit; the input end of the frequency detection unit is connected with the output end of the clock generation module, the output end of the frequency detection unit is connected with the input end of the parameter adjustment unit, the first output end of the parameter adjustment unit is connected with the current control end of the charge pump module, and the second output end of the parameter adjustment unit is connected with the capacitance control end of the integrator;

the frequency detection unit is used for detecting the clock frequency of the first clock signal;

the parameter adjusting unit is used for adjusting the magnitude of the switching current and/or the magnitude of the integrator capacitor according to the clock frequency.

8. The triangle wave generation circuit of claim 1, further comprising a frequency division module and a dual channel selector; the input end of the frequency division module is used for accessing a system master clock, the output end of the frequency division module is connected with the first input end of the two-channel selector, the second input end of the two-channel selector is connected with the output end of the clock generation module, and the output end of the frequency division module is connected with the clock end of the charge pump module;

the frequency division module is used for dividing the system main clock by 2N so as to provide a second clock signal;

the dual-channel selector is configured to provide the second clock signal to the charge pump module when the first channel corresponding to the first input end is gated, so that the charge pump module uses the second clock signal as a switching clock, and provide the first clock signal to the charge pump module when the second channel corresponding to the second input end is gated, so that the charge pump module uses the first clock signal as a switching clock.

9. The triangle wave generation circuit of claim 8, wherein the frequency division module comprises a divide-by-N and a divide-by-two; the input end of the N frequency divider is connected with the system master clock, the output end of the N frequency divider is connected with the input end of the two frequency dividers, and the output end of the two frequency dividers is connected with the first input end of the two-channel selector.

10. The triangle wave generation circuit of claim 8, further comprising a parameter control module; the first output end of the parameter control module is connected with the control end of the N frequency divider, the second output end of the parameter control module is connected with the current control end of the charge pump module, and the third output end of the parameter control module is connected with the capacitance control end of the integrator;

the parameter control module is used for determining a frequency division number N, an initial current value of the switching current and an initial capacitance value of the integrator capacitor according to a preset frequency.

11. The triangle wave generation circuit of claim 10, further comprising a phase synchronization module; the first input end of the phase synchronization module is used for accessing a phase selection signal, the second input end of the phase synchronization module is connected with the first output end of the parameter control module, and the output end of the phase synchronization module is connected with the phase control end of the N frequency divider;

the phase synchronization module is used for obtaining a frequency division starting point according to the phase selection signal and the frequency division number N, so that the N frequency divider carries out N frequency division on the system main clock according to the frequency division starting point and the frequency division number N, and phase synchronization processing is achieved.

12. The triangle wave generation circuit of claim 8, wherein the calibration module is further configured to obtain an amplitude parameter of the first clock signal, and adjust a magnitude of the switching current output by the charge pump module and a magnitude of the integrator capacitor according to the amplitude parameter to adjust an amplitude of the triangle wave.

13. A triangular wave generation method, characterized in that the triangular wave generation method is applied to the triangular wave generation circuit of any one of claims 1 to 12; the triangular wave generation method comprises the following steps:

14. A chip comprising the triangular wave generating circuit according to any one of claims 1 to 12.

15. An electronic device comprising the triangular wave generating circuit according to any one of claims 1 to 12 or the chip according to claim 14.