Single chip microcomputer power supply circuit and electronic chip with off-chip adjustable power good threshold

Abstract

The embodiments of the present disclosure provide a single-chip microcomputer power supply circuit and an electronic chip with an off-chip adjustable power-good threshold, comprising: an enable signal generation module, which generates a first enable signal to a switch module and an off-chip resistance adjustment module when a startup threshold voltage is different from a preset startup threshold voltage; a switch module, which turns off when receiving the first enable signal; an off-chip resistance adjustment module, which determines an adjustment signal for the first resistance module based on the rated operating voltage, startup threshold voltage, preset startup threshold voltage and initial voltage division of the single-chip microcomputer, and adjusts the first resistance module based on the adjustment signal; the first resistance module, which generates an off-chip resistance sampling voltage based on the output voltage; and a first comparison module, which determines a target level signal output from a power-good node to the single-chip microcomputer based on the off-chip resistance sampling voltage and a first reference voltage.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of integrated circuits and related technical fields, and in particular, to a single-chip microcomputer power supply circuit and an electronic chip suitable for an off-chip adjustable power good threshold. Background Art

[0002] LDO (low dropout regulator) has the advantages of low noise and low quiescent current, and is widely used in the front-end power supply of MCU (Microcontroller Unit, micro control unit, also known as single chip microcomputer or single chip microcomputer). There are 3.3V and 5V MCUs on the market, and the corresponding LDO chip can be selected according to the power supply voltage requirements of the MCU. Currently, the power good pin of the LDO is used to detect whether the front-end power supply voltage has failed, such as Figure 1 As shown, the output VOUT of the LDO provides the power voltage to the MCU. If the MCU works under a 5V power supply voltage, the required LDO output VOUT should also be equal to 5V. The PG (Powergood) pin of the LDO is connected to the MCU through a pull-up resistor R PG Connected to VOUT, if the front-stage LDO causes VOUT to be lower than a certain value due to some fault, for example, when VOUT is lower than 88% of the normal value, the PG pin outputs a low-level signal to the MCU. When the MCU receives the low-level signal, the MCU enters the protection working state to prevent the MCU from malfunctioning and losing system data due to problems with the front-stage power supply, thereby ensuring the stability and security of the MCU. If VOUT is higher than 90% of the normal value, the PG pin outputs a high-level signal to the MCU, and the MCU works normally.

[0003] LDO provides stable output to MCU through OUT pin. Figure 2 An exemplary schematic diagram of a partial structure of an LDO is provided, such as Figure 2 As shown, the sampling voltage VFB of the sampling node = VOUT*RL / (RH+RL). The LDO compares the sampling voltage VFB of the sampling node with a fixed reference voltage VREF_PG through a comparator to determine whether the output voltage VOUT of the LDO output node is higher than 90% of the normal value. If the output voltage VOUT of the output node is higher than 90% of the normal value, the PG node (power good node) of the LDO outputs a high level to the MCU, and the MCU operates normally. If the output voltage VOUT of the output node is lower than 88% of the normal value, the PG node of the LDO outputs a low level to the MCU, and the MCU enters a protection working state.

[0004] However, different MCUs on the market currently have different undervoltage lockout voltages. For example, some MCUs require the system to start when the VOUT of the front-end LDO is higher than 90% or 70% of the rated operating voltage. When the undervoltage lockout voltages of different MCUs are different, it is necessary to adjust the reference voltage output from the reference voltage generation module to the comparison module. Therefore, different MCUs require different front-end LDO chips, which does not have high flexibility. Summary of the Invention

[0005] The embodiments described herein provide a microcontroller power supply circuit and electronic chip with an off-chip adjustable power-good threshold, which ensures the accuracy of the target level signal output from the determined power-good node to the microcontroller when the microcontroller startup threshold voltage changes.

[0006] In a first aspect, according to the present disclosure, there is provided a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold, comprising: an enable signal generation module, a switch module, an off-chip resistance adjustment module, a first resistance module, and a first comparison module;

[0007] The enable signal generating module is configured to collect a startup threshold voltage of a single-chip microcomputer electrically connected to the low-voltage difference linear voltage regulator circuit, and generate a first enable signal to the switch module and the off-chip resistance adjustment module when the startup threshold voltage is different from a preset startup threshold voltage, and generate a second enable signal to the switch module when the startup threshold voltage is the same as the preset startup threshold voltage;

[0008] The switch module is configured to be turned off when receiving a first enable signal, and turned on when receiving a second enable signal;

[0009] The off-chip resistance adjustment module is configured to, upon receiving a first enable signal, determine an adjustment signal for the first resistance module based on the rated operating voltage of the single-chip microcomputer, the startup threshold voltage, the preset startup threshold voltage, and an initial voltage division of the first resistance module, and adjust the first resistance module according to the adjustment signal;

[0010] The first resistor module is configured to collect the output voltage of the output node of the low voltage difference linear voltage regulator circuit and generate an off-chip resistor sampling voltage according to the output voltage;

[0011] The first comparison module is configured to determine, when in an enabled state, a target level signal output from the power good node to the single chip microcomputer based on the off-chip resistor sampling voltage and a first reference voltage.

[0012] In some embodiments of the present disclosure, the enable signal generation module, the off-chip resistance adjustment module and the first comparison module are integrated on a chip of a low voltage difference linear voltage regulator circuit, and the switch module and the first resistance module are located outside the chip.

[0013] In some embodiments of the present disclosure, the first resistor module includes a first resistor and a second resistor, the first end of the first resistor is electrically connected to the output node of the low voltage difference linear voltage regulator circuit, the second end of the first resistor and the first end of the second resistor are both electrically connected to the off-chip resistor sampling voltage node, and the second end of the second resistor is electrically connected to the ground node.

[0014] In some embodiments of the present disclosure, the switch module includes a switch, a first end of the switch is electrically connected to the off-chip resistor sampling voltage node, a second end of the switch is electrically connected to the ground node, and a control end of the switch receives the enable signal generated by the enable signal generation module.

[0015] In some embodiments of the present disclosure, the circuit further includes a second comparison module and a third comparison module;

[0016] The second comparison module is configured to output a level signal to the first comparison module and the third comparison module according to the off-chip resistor sampling voltage and the second reference voltage;

[0017] The first comparison module is further configured to be in an enabled state when the level signal output by the second comparison module is a first level signal;

[0018] The third comparison module is configured to be in an enabled state when the level signal output by the second comparison module is a second level signal, and when in the enabled state, determine the target level signal output by the power good node to the microcontroller based on the on-chip resistor sampling voltage and the third reference voltage.

[0019] In some embodiments of the present disclosure, a second resistance module is further included;

[0020] The second resistance module is configured to collect the output voltage of the output node of the low voltage difference linear voltage regulator circuit and generate an on-chip resistance sampling voltage according to the output voltage.

[0021] In some embodiments of the present disclosure, the second resistor module includes a third resistor and a fourth resistor, the first end of the third resistor is electrically connected to the output node of the low voltage difference linear voltage regulator circuit, the second end of the third resistor and the first end of the fourth resistor are both electrically connected to the on-chip resistor sampling voltage node, and the second end of the fourth resistor is electrically connected to the ground node.

[0022] In some embodiments of the present disclosure, the first comparison module includes a first comparator, the second comparison module includes a second comparator, and the third comparison module includes a third comparator. The positive input terminal of the first comparator receives an off-chip resistor sampling voltage, the reverse input terminal of the first comparator receives a first reference voltage, the enable terminal of the first comparator is electrically connected to the output terminal of the second comparator, the positive input terminal of the second comparator receives an off-chip resistor sampling voltage, the reverse input terminal of the second comparator receives a second reference voltage, the positive input terminal of the third comparator receives an on-chip resistor sampling voltage, the reverse input terminal of the third comparator receives a third reference voltage, and the enable terminal of the third comparator is electrically connected to the output terminal of the second comparator.

[0023] In some embodiments of the present disclosure, a reference voltage generating module is further included;

[0024] The reference voltage generating module is configured to generate a first reference voltage, a second reference voltage and a third reference voltage.

[0025] In a second aspect, according to the content of the present disclosure, an electronic chip is provided, comprising a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold as described in any one of the first aspects.

[0026] The embodiment of the present disclosure provides a single-chip microcomputer power supply circuit and an electronic chip with an off-chip adjustable power-good threshold. First, when the startup threshold voltage of the single-chip microcomputer is collected and is different from the preset startup threshold voltage, the enable signal generation module generates a first enable signal to the switch module and the off-chip resistance adjustment module. The switch module is turned off after receiving the first enable signal. After receiving the first enable signal, the off-chip resistance adjustment module determines the adjustment signal of the first resistance module based on the rated operating voltage, startup threshold voltage, preset startup threshold voltage and initial voltage division of the single-chip microcomputer, and adjusts the first resistance adjustment module so that the off-chip resistance sampling voltage generated by the adjusted first resistance adjustment module based on the collected output voltage of the output node matches the startup threshold voltage and the first reference voltage, thereby ensuring the accuracy of the target level signal output from the power-good node to the single-chip microcomputer determined by the first comparison module based on the off-chip resistance sampling voltage and the first reference voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below. It should be noted that the drawings described below only relate to some embodiments of the present disclosure and are not intended to limit the present disclosure.

[0028] Figure 1 It is a schematic diagram of the structure of the electrical connection between the low voltage difference linear voltage regulator circuit and the single chip microcomputer in the prior art;

[0029] Figure 2 It is a circuit structure diagram of a low voltage difference linear voltage regulator circuit in the prior art;

[0030] Figure 3 This is a structural diagram of a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold provided by an embodiment of the present disclosure;

[0031] Figure 4 This is a schematic structural diagram of another single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold provided by an embodiment of the present disclosure;

[0032] Figure 5 This is a structural schematic diagram of another single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also fall within the scope of protection of the present disclosure.

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal manner unless otherwise explicitly defined herein. As used herein, a statement that two or more parts are "connected" or "coupled" together shall mean that the parts are joined together either directly or through one or more intermediate components.

[0035] In all embodiments of the present disclosure, terms such as “first” and “second” are used only to distinguish one component (or a part of a component) from another component (or another part of a component).

[0036] Unless the context clearly indicates otherwise, as used herein and in the appended claims, the singular includes the plural, and vice versa. Thus, when referring to the singular, the plural of the corresponding term is generally included. Similarly, the words "include" and "comprising" are to be interpreted as inclusive rather than exclusive. Likewise, the terms "include" and "or" should be interpreted as inclusive unless such interpretation is expressly prohibited herein. Where the term "example" is used herein, particularly when it follows a group of terms, the "example" is merely exemplary and illustrative and should not be considered exclusive or comprehensive.

[0037] Based on the problems existing in the prior art, the present invention provides a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold. Figure 3 FIG. 1 is a schematic diagram of a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold provided by an embodiment of the present disclosure. Figure 3 As shown, a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold comprises: an enable signal generating module 10, a switch module 20, an off-chip resistance adjusting module 30, a first resistance module 40 and a first comparison module 50; the enable signal generating module 10 is configured to collect a startup threshold voltage of a single-chip microcomputer electrically connected to a low voltage difference linear voltage regulator circuit, and when the startup threshold voltage is different from a preset startup threshold voltage, generates a first enable signal to the switch module 20 and the off-chip resistance adjusting module 30, and when the startup threshold voltage is the same as the preset startup threshold voltage, generates a second enable signal to the switch module; the switch module 20 is configured to turn off the switch module when receiving the first enable signal, and turn off the switch module when receiving the second enable signal. When the enable signal is received, the switch module is turned on; the off-chip resistance adjustment module 30 is configured to determine the adjustment signal of the first resistance module 40 according to the rated operating voltage, start-up threshold voltage, preset start-up threshold voltage and initial voltage division of the first resistance module 40 of the single-chip microcomputer when the first enable signal is received, and adjust the first resistance module 40 according to the adjustment signal; the first resistance module 40 is configured to collect the output voltage of the output node of the low-voltage difference linear voltage regulator circuit, and generate an off-chip resistance sampling voltage according to the output voltage; the first comparison module 50 is configured to determine the target level signal output from the power-good node to the single-chip microcomputer according to the off-chip resistance sampling voltage and the first reference voltage when in the enabled state.

[0038] Specifically, the low voltage difference linear voltage regulator circuit provides a power supply voltage for the single-chip microcomputer, and the startup threshold voltage of the single-chip microcomputer electrically connected to the low voltage difference linear voltage regulator circuit is not fixed. For example, some single-chip microcomputers start up when the output voltage of the output node of the low voltage difference linear voltage regulator circuit is higher than 90% of the rated working voltage, and some single-chip microcomputers start up when the output voltage of the output node of the low voltage difference linear voltage regulator circuit is higher than 70% of the rated working voltage. Corresponding to different startup threshold voltages, when the first reference voltage received by the first comparison module 50 is a fixed value, it is necessary to adjust the voltage division of the first resistance module 40, so that the off-chip resistance sampling voltage generated by the first resistance module 40 according to the collected output voltage of the output node matches the startup threshold voltage and the first reference voltage.

[0039] Based on the problems existing in the prior art, in the microcontroller power supply circuit with an off-chip adjustable power-good threshold provided by the embodiment of the present disclosure, an enable signal generation module 10 is provided. The enable signal generation module 10 collects the startup threshold voltage of the microcontroller electrically connected to the low-voltage difference linear voltage regulator circuit, and generates a first enable signal to the switch module 20 and the off-chip resistance adjustment module 30 when the startup threshold voltage is different from the preset startup threshold voltage. The first enable signal is used to control the switch module 20 to be turned off, and the off-chip resistance adjustment module 30 is used to adjust the voltage division of the first resistance module 40, so that the off-chip resistance sampling voltage generated by the first resistance module 40 according to the collected output voltage of the output node matches the startup threshold voltage and the first reference voltage. Finally, the first comparison module 50 determines the target level signal outputted from the power-good node to the microcontroller by comparing the relationship between the off-chip resistance sampling voltage generated by the first resistance module 40 and the first reference voltage.

[0040] In a specific example, the rated operating voltage of the single-chip microcomputer electrically connected to the low-voltage difference linear voltage regulator circuit is 5V. The single-chip microcomputer starts to work when the output voltage of the output node of the low-voltage difference linear voltage regulator circuit is higher than 90% of the rated operating voltage of the single-chip microcomputer (the preset startup threshold voltage is 90% of the rated operating voltage of the single-chip microcomputer). If the initial voltage division of the first resistor module 40 is 0.4:0.6, the first reference voltage of the first comparison module 50 satisfies: Vref1=5*0.6*0.9=2.7V, that is, when the output node is in the state of the voltage division of the first resistor module 40 being 0.4:0.6, When the output voltage of the point is greater than the first reference voltage through the off-chip resistor sampling voltage generated by the first resistor module 40, the first comparison module 50 outputs a high level. At this time, the target level signal output from the power-good node to the single-chip microcomputer is a high level, and the single-chip microcomputer works normally. When the voltage division of the first resistor module 40 is 0.4:0.6, when the output voltage of the output node is less than the first reference voltage through the off-chip resistor sampling voltage generated by the first resistor module 40, the first comparison module 50 outputs a low level. At this time, the target level signal output from the power-good node to the single-chip microcomputer is a low level, and the single-chip microcomputer enters the protection working state.

[0041] When the startup threshold voltage corresponding to the single-chip microcomputer changes, an exemplary single-chip microcomputer starts to start working when the output voltage of the output node of the low-voltage difference linear voltage regulator circuit is higher than 70% of the rated operating voltage of the single-chip microcomputer (the startup threshold voltage is 70% of the rated operating voltage of the single-chip microcomputer). At this time, the off-chip resistance adjustment module 30 determines the adjustment signal of the first resistance module 40 through the rated operating voltage of the single-chip microcomputer, the startup threshold voltage, the preset startup threshold voltage and the initial voltage division of the first resistance module 40, and adjusts the resistance value of the first resistance module 40 according to the adjustment signal. Specifically, according to the rated operating voltage of the single-chip microcomputer, the preset startup threshold voltage and the initial voltage division of the first resistance module 40, in the scenario where the first reference voltage is 2.7V, the first resistor module 40 is The off-chip resistance sampling voltage generated by the resistance module after dividing the output voltage of the output node should meet the following requirements: 2.7 / 0.7=3.85V, that is, when the off-chip resistance sampling voltage generated by the first resistance module according to the collected output voltage of the output node of the low-voltage difference linear voltage regulator circuit is greater than 3.85V, the first comparison module 50 outputs a high level. At this time, the target level signal output by the power-good node to the single-chip microcomputer is a high level, and the single-chip microcomputer works normally. When the off-chip resistance sampling voltage generated by the first resistance module according to the collected output voltage of the output node of the low-voltage difference linear voltage regulator circuit is less than 3.85V, the first comparison module 50 outputs a low level. At this time, the target level signal output by the power-good node to the single-chip microcomputer is a low level, and the single-chip microcomputer enters the protection working state. Combined with the off-chip resistor sampling voltage and the rated operating voltage of the microcontroller, it can be determined that the target voltage divider of the first resistor module is 0.23:0.77. According to the target voltage divider of the first resistor module, the adjustment signal of the off-chip resistor adjustment module to the first resistor module can be determined (that is, the first resistor module is adjusted from the initial voltage divider to the target voltage divider based on the adjustment signal). After determining the adjustment signal of the first resistor module, the resistance value of the first resistor module is adjusted so that the voltage divider of the first resistor module meets 0.23:0.77, so that when the startup threshold voltage of the microcontroller changes from 90% of the rated operating voltage of the microcontroller to 70% of the rated operating voltage of the microcontroller, the first comparison module can determine the target level signal output by the power-good node to the microcontroller based on the received off-chip resistor sampling voltage and the first reference voltage, thereby ensuring the accuracy of the target level signal output through the power-good node.

[0042] The embodiment of the present disclosure provides a single-chip microcomputer power supply circuit with an off-chip adjustable power-good threshold. First, when the startup threshold voltage of the single-chip microcomputer collected is different from the preset startup threshold voltage, the enable signal generation module generates a first enable signal to the switch module and the off-chip resistance adjustment module. The switch module is turned off after receiving the first enable signal. After receiving the first enable signal, the off-chip resistance adjustment module determines the adjustment signal of the first resistance module based on the rated operating voltage, startup threshold voltage, preset startup threshold voltage and initial voltage division of the single-chip microcomputer, and adjusts the first resistance adjustment module so that the off-chip resistance sampling voltage generated by the adjusted first resistance adjustment module based on the collected output voltage of the output node matches the startup threshold voltage and the first reference voltage, thereby ensuring the accuracy of the target level signal output from the power-good node to the single-chip microcomputer determined by the first comparison module based on the off-chip resistance sampling voltage and the first reference voltage.

[0043] In a specific implementation, the enable signal generation module, the off-chip resistance adjustment module and the first comparison module are integrated on a chip of the low voltage difference linear voltage regulator circuit, and the switch module and the first resistance module are located outside the chip.

[0044] By arranging the switch module and the first resistor module outside the chip corresponding to the low-voltage difference linear voltage regulator circuit, when the startup threshold voltage of the microcontroller electrically connected to the low-voltage difference linear voltage regulator circuit changes, the switch module is controlled to be turned off, and the voltage division of the first resistor module is adjusted, so that the off-chip resistor sampling voltage generated by the voltage division of the first resistor module matches the startup threshold voltage and the first reference voltage.

[0045] It should be noted that the enable signal generation module and the off-chip resistance adjustment module can be the modules originally included in the low-voltage difference linear voltage regulator circuit. By burning the program code input into the low-voltage difference linear voltage regulator circuit, the enable signal generation module can be added to generate the enable signal to the switch module and the off-chip resistance adjustment module, and the off-chip resistance adjustment module can be added to output the adjustment signal to the first resistance module. Therefore, there is no need to change the circuit structure of the original low-voltage difference linear voltage regulator circuit.

[0046] In a specific embodiment, combined with Figure 4 The first resistor module 40 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is electrically connected to the output node OUT of the low voltage difference linear voltage regulator circuit, the second end of the first resistor R1 and the first end of the second resistor R2 are both electrically connected to the off-chip resistor sampling voltage node PGADJ, and the second end of the second resistor R2 is electrically connected to the ground node.

[0047] The switch module 20 includes a switch Switch, a first end of the switch Switch is electrically connected to the off-chip resistor sampling voltage node PGADJ, a second end of the switch Switch is electrically connected to the ground node, and a control end of the switch Switch receives the enable signal generated by the enable signal generation module 10.

[0048] like Figure 4 As shown, when the startup threshold voltage of the single-chip microcomputer electrically connected to the low-voltage difference linear voltage regulator circuit is different from the preset startup threshold voltage, the enable signal generation module 10 generates a first enable signal to the switch Switch, and the switch Switch is turned off under the action of the first enable signal. At this time, the off-chip resistance adjustment module 30, upon receiving the first enable signal, determines the adjustment signal of the first resistance module 40 according to the rated operating voltage of the single-chip microcomputer, the startup threshold voltage, the preset startup threshold voltage and the initial voltage division of the first resistance module 40, and adjusts the first resistance module 40 according to the adjustment signal; after the off-chip resistance adjustment module 40 adjusts the resistance values ​​of the first resistor R1 and the second resistor R2 Through the voltage division of the first resistor R1 and the second resistor R2, the first resistor module 40 generates an off-chip resistor sampling voltage to the first comparison module 50. After comparing the off-chip resistor sampling voltage VPGADJ with the first reference voltage Vref1, the first comparison module 50 determines the target level signal output by the power-good node to the microcontroller. Specifically, when the off-chip resistor sampling voltage VPGADJ is greater than the first reference voltage Vref1, the power-good node PG outputs a high level to the microcontroller, and the microcontroller operates normally. When the off-chip resistor sampling voltage VPGADJ is less than the first reference voltage Vref1, the power-good node PG outputs a low level to the microcontroller, and the microcontroller enters a protection working state.

[0049] In an exemplary embodiment, the rated operating voltage of the single-chip microcomputer is 5V, the preset startup threshold voltage is 90% of the rated operating voltage of the single-chip microcomputer, the initial voltage division ratio of the first resistor R1 and the second resistor R2 of the first resistor module 40 is 0.4:0.6, the first reference voltage Vref1 is 2.7V, and the first resistor module 40 collects the output voltage of the output node of the low-voltage difference linear voltage regulator circuit and divides the collected output voltage by the first resistor R1 and the second resistor R2 to obtain the off-chip resistor sampling voltage VPGADJ. That is, the off-chip resistor sampling voltage of the off-chip resistor sampling node satisfies: The first comparison module 50 determines the target level signal output from the power-good node to the microcontroller by comparing the first reference voltage Vref1 with the off-chip resistor sampling voltage VPGADJ. When the microcontroller's startup threshold voltage changes from 90% of the microcontroller's rated operating voltage to 70% of the microcontroller's rated operating voltage, while the first reference voltage remains unchanged and the output voltage of the output node is 5V, it is necessary to ensure that the voltage divider between the first resistor R1 and the second resistor R2 satisfies the following conditions: 0.23:0.77, and the off-chip resistor sampling voltage at the off-chip resistor sampling node satisfies the following conditions: At this time, the first reference voltage (2.7V) matches the relationship between the off-chip resistor sampling voltage and the startup threshold voltage. Therefore, the target voltage division ratio of the first resistor R1 and the second resistor R2 is 0.23:0.77. As the output voltage of the output node gradually increases, the first resistor module 40 collects the output voltage of the output node of the low-voltage difference linear voltage regulator circuit, and divides the collected output voltage by the first resistor R1 and the second resistor R2 to obtain the off-chip resistor sampling voltage. That is, the off-chip resistor sampling voltage of the off-chip resistor sampling node changes with the change of the output node voltage, specifically satisfying: The first comparison module determines a target level signal outputted from the power good node to the single chip microcomputer by comparing the first reference voltage and the off-chip resistor sampling voltage.

[0050] Based on the above embodiments, Figure 5 As shown, the microcontroller power supply circuit with an off-chip adjustable power-good threshold provided by the embodiment of the present disclosure further includes a second comparison module 60 and a third comparison module 70. The second comparison module 60 is configured to output a level signal to the first comparison module 50 and the third comparison module 70 based on the off-chip resistor sampling voltage VPGADJ and the second reference voltage Vref2; the first comparison module 50 is further configured to enable the first comparison module 50 when the level signal output by the second comparison module 60 is a first level signal; the third comparison module 70 is further configured to enable the third comparison module 70 when the level signal output by the second comparison module 60 is a second level signal, and in the enabled state, determine the target level signal output from the power-good node to the microcontroller based on the on-chip resistor sampling voltage VFB and the third reference voltage Vref3.

[0051] And a second resistance module 80; the second resistance module 80 is configured to collect the output voltage of the output node of the low voltage difference linear voltage regulator circuit, and generate an on-chip resistance sampling voltage VFB according to the output voltage.

[0052] Among them, the first comparison module 50 includes a first comparator Comp1, the second comparison module 60 includes a second comparator Comp2, and the third comparison module 70 includes a third comparator Comp2. The positive input terminal of the first comparator Comp1 receives the off-chip resistor sampling voltage VPGADJ, the inverting input terminal of the first comparator Comp1 receives the first reference voltage Vref1, the enable terminal of the first comparator Comp1 is electrically connected to the output terminal of the second comparator Comp2, the positive input terminal of the second comparator Comp2 receives the off-chip resistor sampling voltage VPGADJ, the inverting input terminal of the second comparator Comp2 receives the second reference voltage Vref2, the positive input terminal of the third comparator Comp3 receives the on-chip resistor sampling voltage VFB, the inverting input terminal of the third comparator Comp3 receives the third reference voltage Vref3, and the enable terminal of the third comparator Comp3 is electrically connected to the output terminal of the second comparator Comp2.

[0053] The second resistor module 80 includes a third resistor R3 and a fourth resistor R4, the first end of the third resistor R3 is electrically connected to the output node of the low voltage difference linear voltage regulator circuit, the second end of the third resistor R3 and the first end of the fourth resistor R4 are both electrically connected to the on-chip resistor sampling voltage node, and the second end of the fourth resistor R4 is electrically connected to the ground node.

[0054] In a specific embodiment, the microcontroller power supply circuit with an off-chip adjustable power-good threshold value is further configured to include a second comparison module 60, a third comparison module 70, and a second resistance module 80. The second comparison module 60 determines whether the first comparison module 50 or the third comparison module 70 is enabled. The second resistance module 80 generates an on-chip resistor sampling voltage VFB based on the output voltage of the output node of the low-voltage difference linear voltage regulator circuit. When the third comparison module 70 is in the enabled state, it determines the target level signal output from the power-good node to the microcontroller based on the on-chip resistor sampling voltage VFB and the third reference voltage Vref3.

[0055] That is, when the startup threshold voltage of the microcontroller electrically connected to the low-voltage difference linear voltage regulator circuit is different from the preset startup threshold voltage, the second comparison module 60 enables the first comparison module 50, and the first comparison module 50 compares the off-chip resistor sampling voltage VPGADJ with the first reference voltage Vref1 to determine the target level signal output from the power good node PG to the microcontroller. When the startup threshold voltage of the microcontroller electrically connected to the low-voltage difference linear voltage regulator circuit is the same as the preset startup threshold voltage, the second comparison module 60 enables the third comparison module 70, and the third comparison module 70 compares the on-chip resistor sampling voltage VFB with the third reference voltage Vref3 to determine the target level signal output from the power good node PG to the microcontroller.

[0056] Specific, combined Figure 5When the enable signal generation module 10 generates a first enable signal to the switch module 20, the switch module 20 is turned off. At this time, the off-chip resistor sampling voltage node PGADJ is electrically connected to the second end of the first resistor R1. When there is an output voltage at the output node of the low-voltage difference linear voltage regulator circuit, the off-chip resistor sampling voltage of the off-chip resistor sampling voltage node is greater than zero. When the enable signal generation module 10 generates a second enable signal to the switch module 20, the switch module 20 is turned on. At this time, the off-chip resistor sampling voltage node PGADJ is electrically connected to the ground node through the switch Switch. The off-chip resistor sampling voltage VPGADJ of the off-chip resistor sampling voltage node PGADJ is equal to zero. The second comparator Comp2 generates a level signal to the first comparator Comp1 and the third comparator Comp3 by comparing the off-chip resistor sampling voltage VPGADJ of the off-chip resistor sampling voltage node with the second reference voltage Vref2. The enable state of the first comparator Comp1 and the third comparator Comp3 is determined based on the output level signal.

[0057] Specifically, when the off-chip resistor sampling voltage VPGADJ is greater than the second reference voltage Vref2, the second comparator Comp2 outputs a first level signal (high level) to the first comparator Comp1 and the third comparator Comp3; when the off-chip resistor sampling voltage VPGADJ is less than the second reference voltage Vref2, the second comparator Comp2 outputs a second level signal (low level) to the first comparator Comp1 and the third comparator Comp3; the first comparator Comp1 is in an enabled state when the second comparator Comp2 outputs a high level, and is in a disabled state when the second comparator Comp2 outputs a low level; the third comparator Comp3 is in an enabled state when the second comparator Comp2 outputs a low level, and is in a disabled state when the second comparator Comp2 outputs a high level.

[0058] When the switch module 20 is turned off, the off-chip resistor sampling voltage VPGADJ is greater than the second reference voltage Vref2. When the switch module 20 is turned on, the off-chip resistor sampling voltage VPGADJ is less than the second reference voltage Vref2. The on and off of the switch module 20 is determined based on the enable signal generated by the enable signal generation module 10. Whether the enable signal generation module 10 generates the first enable signal or the second enable signal is related to the relationship between the startup threshold voltage of the single chip microcomputer and the preset startup threshold voltage. Therefore, when the startup threshold voltage of the single chip microcomputer is different from the preset startup threshold voltage, the enable signal The generation module 10 generates a first enable signal to the switch module 20, the switch module 20 is turned off, the off-chip resistor sampling voltage VPGADJ is greater than the second reference voltage Vref2, and the second comparator Comp2 outputs a first level signal to the first comparator Comp1 and the third comparator Comp3. The first comparator Comp1 is in an enabled state and the third comparator Comp3 is in a disabled state. The first comparator Comp1 determines the target level signal output by the power good node PG to the microcontroller by comparing the off-chip resistor sampling voltage VPGADJ with the first reference voltage Vref1. When the startup threshold voltage of the single-chip microcomputer is the same as the preset startup threshold voltage, the enable signal generation module 10 generates a second enable signal to the switch module 20, the switch module 20 is turned on, the off-chip resistor sampling voltage VPGADJ is less than the second reference voltage Vref2, and the second comparator Comp2 outputs a second level signal to the first comparator Comp1 and the third comparator Comp3. The third comparator Comp3 is in the enabled state, and the first comparator Comp1 is in the disabled state. The third comparator Comp3 determines the target level signal output by the power-good node to the single-chip microcomputer by comparing the on-chip resistor sampling voltage VFB with the third reference voltage Vref3.

[0059] Based on the above embodiment, the microcontroller power supply circuit with an off-chip adjustable power good threshold further includes a reference voltage generation module 90; the reference voltage generation module 90 is configured to generate a first reference voltage Vref1, a second reference voltage Vref2 and a third reference voltage Vref3.

[0060] The first reference voltage Vref1 is determined based on the rated operating voltage of the single chip microcomputer, the initial divided voltage of the first resistance module, and a preset startup threshold voltage.

[0061] The second reference voltage Vref2 is a fixed voltage value, generally set to 100 mV.

[0062] The third reference voltage Vref3 is determined based on the rated operating voltage of the single chip microcomputer, the divided voltage of the second resistance module and the preset startup threshold voltage.

[0063] The embodiments of the present disclosure further provide an electronic chip, which includes a single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold provided by the embodiments of the present disclosure.

[0064] An embodiment of the present disclosure further provides an electronic device. The electronic device includes an electronic chip according to an embodiment of the present disclosure. The electronic device is, for example, a smart terminal device such as a tablet computer, a smart phone, or the like.

[0065] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0066] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned steps / processes does not mean the order of execution, and the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In addition, the serial numbers of the embodiments of the present application mentioned above are only for description and do not represent the advantages and disadvantages of the embodiments.

[0067] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0068] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A single-chip microcomputer power supply circuit with an off-chip adjustable power good threshold, characterized in that: include: An enabling signal generating module, a switching module, an off-chip resistance adjusting module, a first resistance module and a first comparing module; The enable signal generating module is configured to collect a startup threshold voltage of a single-chip microcomputer electrically connected to the low-voltage difference linear voltage regulator circuit, and generate a first enable signal to the switch module and the off-chip resistance adjustment module when the startup threshold voltage is different from a preset startup threshold voltage, and generate a second enable signal to the switch module when the startup threshold voltage is the same as the preset startup threshold voltage; The switch module is configured to be turned off when receiving a first enable signal, and turned on when receiving a second enable signal; The off-chip resistance adjustment module is configured to, upon receiving a first enable signal, determine an adjustment signal for the first resistance module based on the rated operating voltage of the single-chip microcomputer, the startup threshold voltage, the preset startup threshold voltage, and an initial voltage division of the first resistance module, and adjust the first resistance module according to the adjustment signal; The first resistor module is configured to collect the output voltage of the output node of the low voltage difference linear voltage regulator circuit and generate an off-chip resistor sampling voltage according to the output voltage; The first comparison module is configured to determine, when in an enabled state, a target level signal outputted from the power good node to the single chip microcomputer based on the off-chip resistor sampling voltage and a first reference voltage; The circuit further includes a second comparison module and a third comparison module; The second comparison module is configured to output a level signal to the first comparison module and the third comparison module according to the off-chip resistor sampling voltage and the second reference voltage; The first comparison module is further configured to be in an enabled state when the level signal output by the second comparison module is a first level signal; The third comparison module is configured to be in an enabled state when the level signal output by the second comparison module is a second level signal, and when in the enabled state, determine the target level signal output by the power good node to the microcontroller based on the on-chip resistor sampling voltage and the third reference voltage.

2. The circuit according to claim 1, wherein: The enable signal generating module, the off-chip resistance adjusting module and the first comparing module are integrated on a chip of a low voltage difference linear voltage stabilizing circuit, and the switch module and the first resistance module are located outside the chip.

3. The circuit according to claim 1, wherein: The first resistor module includes a first resistor and a second resistor, the first end of the first resistor is electrically connected to the output node of the low voltage difference linear voltage regulator circuit, the second end of the first resistor and the first end of the second resistor are both electrically connected to the off-chip resistor sampling voltage node, and the second end of the second resistor is electrically connected to the ground node.

4. The circuit according to claim 3, characterized in that The switch module includes a switch, a first end of the switch is electrically connected to the off-chip resistor sampling voltage node, a second end of the switch is electrically connected to the ground node, and a control end of the switch receives the enable signal generated by the enable signal generation module.

5. The circuit according to claim 1, wherein: Also includes a second resistance module; The second resistance module is configured to collect the output voltage of the output node of the low voltage difference linear voltage regulator circuit and generate an on-chip resistance sampling voltage according to the output voltage.

6. The circuit according to claim 5, characterized in that The second resistor module includes a third resistor and a fourth resistor, the first end of the third resistor is electrically connected to the output node of the low voltage difference linear voltage regulator circuit, the second end of the third resistor and the first end of the fourth resistor are both electrically connected to the on-chip resistor sampling voltage node, and the second end of the fourth resistor is electrically connected to the ground node.

7. The circuit according to claim 1, wherein: The first comparison module includes a first comparator, the second comparison module includes a second comparator, and the third comparison module includes a third comparator. The positive input terminal of the first comparator receives an off-chip resistor sampling voltage, the inverting input terminal of the first comparator receives a first reference voltage, the enable terminal of the first comparator is electrically connected to the output terminal of the second comparator, the positive input terminal of the second comparator receives the off-chip resistor sampling voltage, the inverting input terminal of the second comparator receives a second reference voltage, the positive input terminal of the third comparator receives an on-chip resistor sampling voltage, the inverting input terminal of the third comparator receives a third reference voltage, and the enable terminal of the third comparator is electrically connected to the output terminal of the second comparator.

8. The circuit according to claim 1, wherein: Also included is a reference voltage generation module; The reference voltage generating module is configured to generate a first reference voltage, a second reference voltage and a third reference voltage.

9. An electronic chip, characterized in that: The invention comprises the circuit according to any one of claims 1 to 8.

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