Current comparison circuit, control chip, and master-slave system

Abstract

The present application provides a current comparison circuit, a control chip, and a master-slave system. The current comparison circuit comprises a voltage regulation circuit, a reference voltage circuit, and a comparison circuit. A current receiving terminal of the voltage regulation circuit receives a current to be measured, a floating ground terminal of the voltage regulation circuit generates a floating ground voltage, a voltage detection terminal of the voltage regulation circuit outputs a detected voltage related to the current to be measured, and the voltage regulation circuit is capable of regulating the floating ground voltage. The reference voltage circuit comprises at least two branches, and the comparison circuit comprises at least two comparators, wherein first input terminals of the two comparators are both connected to the voltage detection terminal, and second input terminals of the two comparators receive different reference voltages, thereby achieving two detected voltage measurements on the basis of transition results of the two comparators. In addition, a voltage domain of the voltage regulation circuit is arranged between a high-voltage power supply terminal and a low-voltage power supply terminal, and voltage domains of the reference voltage circuit and the comparison circuit are arranged between the high-voltage power supply terminal and the floating ground terminal, thereby enabling the comparators to operate in a low-voltage domain, and allowing for reduced chip area and increased comparison speed.

Description

Current comparison circuit, control chip and master-slave system

[0001] The present application claims priority to the Chinese patent application No. 202410955544.7, filed on July 16, 2024, and entitled "Current comparison circuit, control chip and master-slave system", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the integrated circuit technology, and in particular to a current comparison circuit, a control chip and a master-slave system. BACKGROUND

[0003] Distributed Systems Interface (DSI) plays a key role in a distributed system, which is a bridge for communication and interaction between devices in the distributed system. Generally, the distributed system includes a master and slaves, and the master and the slaves are connected through a bus. More specifically, when the distributed system includes multiple slaves, the slaves are connected in series, and the slave at the first level is connected to the master through the bus. When the master and the slaves communicate and interact, the master detects the current of the slave. According to the distributed system protocol, the slave sends a signal to the master, which contains two currents, such as 12mA and 24mA, and the master identifies the two currents. More specifically, the master is provided with a comparison circuit, and the detection of the current size is realized through the comparison circuit. Since two currents need to be detected, the bus level is high, and thus the voltage domain in which the device for detecting the two currents works is also high. In order to withstand a large voltage, a high-voltage device needs to be used, which increases the chip area.

[0004] If a low-voltage device is needed, the voltage difference between the supply voltage and the ground needs to be controlled. The fixed setting greatly limits the application scenarios of the circuit. In order to adapt to various voltage differences, the selected device needs to withstand a large voltage, and the best way is to select a high-voltage device. Similarly, the high-voltage device will slow down the response speed of the circuit, increase the chip area, and increase the cost, which is not conducive.

[0005] In other master-slave systems, similar problems also exist. SUMMARY

[0006] In order to enable the master to identify the detection signal sent by the slave and also enable the master to adapt to different supply voltages, the present application proposes a current comparison circuit to solve the problem.

[0007] The present application provides a current comparison circuit, which comprises a voltage adjusting circuit, a reference voltage circuit and a comparison circuit.

[0008] The voltage regulation circuit comprises a current receiving end, a floating ground end and a detection voltage end, the current receiving end is configured to receive a to-be-detected current, the floating ground end is configured to generate a floating ground voltage, and the detection voltage end is configured to output a detection voltage related to the to-be-detected current, the to-be-detected current at least comprises a first to-be-detected current and a second to-be-detected current, the detection voltage corresponding to the first to-be-detected current is a first detection voltage, and the detection voltage corresponding to the second to-be-detected current is a second detection voltage, wherein the current receiving end and the floating ground end are one port or different ports, and the voltage regulation circuit is capable of regulating the floating ground voltage.

[0009] The reference voltage circuit comprises at least two branches, each branch has a reference voltage end, one of the branches of the reference voltage circuit generates a first reference voltage through the reference voltage end, and another branch of the reference voltage circuit generates a second reference voltage through the reference voltage end.

[0010] The comparison circuit comprises at least two comparators, the first input end of each comparator is electrically connected to the detection voltage end, the second input end of one comparator is configured to receive the first reference voltage, and the second input end of another comparator is configured to receive the second reference voltage, and each comparator is configured to compare the detection voltage and the corresponding reference voltage and output a comparison result.

[0011] The voltage domain of the voltage regulation circuit is arranged between a high-voltage power supply end and a low-voltage power supply end, the voltage domain of the reference voltage circuit and the comparison circuit is arranged between the high-voltage power supply end and the floating ground end, and the floating ground voltage is greater than the voltage of the low-voltage power supply end.

[0012] In some embodiments, the voltage regulation circuit comprises a voltage stabilizing circuit, the detection resistance and the voltage dividing resistance are connected to the output end of the voltage stabilizing circuit, the current receiving end and the floating ground end are arranged between the detection resistance and the voltage dividing resistance, one input end of the voltage stabilizing circuit receives the feedback voltage provided by the voltage dividing resistance, another input end of the voltage stabilizing circuit receives an input voltage, and the floating ground voltage is related to the input voltage of the voltage stabilizing circuit.

[0013] In some embodiments, each branch of the reference voltage circuit comprises a current source and a reference resistance, and the reference voltage end is arranged between the current source and the reference resistance.

[0014] The reference resistances of different branches of the reference voltage circuit have different resistance values to generate different reference voltages, or the reference resistances of different branches of the reference voltage circuit have different resistance values and the current sources have the same current to generate different reference voltages.

[0015] In some embodiments, each branch of the reference voltage circuit comprises a current source and a reference resistance, a voltage domain widening component is arranged between the current receiving end and the floating ground end, and / or a voltage domain widening component is arranged between the reference resistance and the floating ground end, and the voltage domain widening component widens the working voltage domain of the reference voltage circuit and the comparison circuit.

[0016] In some embodiments, one of the comparator outputs flips when the detection voltage is greater than or equal to a first reference voltage, and the other comparator output also flips when the detection voltage is greater than or equal to a second reference voltage; wherein the first reference voltage < the first detection voltage < the second reference voltage < the second detection voltage.

[0017] In some embodiments, one of the comparator outputs flips when the detection voltage is greater than or equal to a first reference voltage, and the other comparator output also flips when the detection voltage is greater than or equal to a second reference voltage; wherein the first reference voltage = the first detection voltage < the second reference voltage = the second detection voltage.

[0018] Some embodiments of the present application provide a current comparison circuit, comprising a voltage regulation circuit, a reference voltage circuit and a comparison circuit, the reference voltage circuit at least comprising a first reference voltage circuit and a second reference voltage circuit;

[0019] The first reference voltage circuit provides a first reference voltage, and the second reference voltage circuit provides a second reference voltage, and the voltage domains of the first reference voltage circuit and the second reference voltage circuit are set between a high-voltage power supply end and a floating ground end;

[0020] The voltage regulation circuit comprises a voltage stabilizing circuit, a first resistor, a second resistor and a third resistor;

[0021] The output end of the voltage stabilizing circuit is electrically connected to a low-voltage power supply end through the first resistor, the second resistor and the third resistor, and the floating ground voltage of the floating ground end is adjustable, wherein the current receiving end and the floating ground end are one port or different ports; a feedback node is arranged between the second resistor and the third resistor, and the feedback node is electrically connected to the second input end of the voltage stabilizing circuit, and the first input end of the voltage stabilizing circuit is used for receiving an input voltage; the voltage domain of the voltage stabilizing circuit is set between the high-voltage power supply end and the low-voltage power supply end, the current receiving end is also used for receiving a to-be-measured current, the first resistor is used for detecting the to-be-measured current and outputting a detection voltage related to the to-be-measured current, and the to-be-measured current at least comprises a first to-be-measured current and a second to-be-measured current, the detection voltage corresponding to the first to-be-measured current is a first detection voltage, and the detection voltage corresponding to the second to-be-measured current is a second detection voltage;

[0022] The comparison circuit at least comprises a first comparator and a second comparator, the first input ends of the first comparator and the second comparator are electrically connected to the output end of the voltage stabilizing circuit for receiving the detection voltage, the second input end of the first comparator is used for receiving the first reference voltage, the second input end of the second comparator is used for receiving the second reference voltage, and the voltage domain of the comparison circuit is set between the high-voltage power supply end and the floating ground end.

[0023] In some embodiments, the first detection voltage is Vcp1, the second detection voltage is Vcp2, the first reference voltage is Vcn1, and the second reference voltage is Vcn2, and the relationship satisfies: Vcn1 < Vcp1 < Vcn2 < Vcp2.

[0024] In some embodiments, the first reference voltage circuit includes a first current source and a fourth resistor, and the second reference voltage circuit includes a second current source and a fifth resistor; the first reference voltage is generated between the first current source and the fourth resistor, and the second reference voltage is generated between the second current source and the fifth resistor.

[0025] The first to-be-measured current is I1, the second to-be-measured current is I2, the first current source is Is1, and the second current source is Is2, and the relationship satisfies: Is1*R4 = 1 / 2*I1*R1, Is2*R5 = 2 / 3*I2*R1, wherein R1 is the first resistor, R4 is the fourth resistor, and R5 is the fifth resistor.

[0026] In some embodiments, the fourth resistor and the fifth resistor have different resistance values, or the first current source and the second current source have the same current, and the fourth resistor and the fifth resistor have different resistance values.

[0027] In some embodiments, a voltage domain expansion component is arranged between the current receiving end, the fourth resistor, the fifth resistor, and the floating ground end.

[0028] In some embodiments, the voltage domain expansion component is a diode.

[0029] In some embodiments, the comparator is a five-tube operational amplifier comparator.

[0030] In some embodiments, the supply voltage provides a high-voltage power supply to the voltage regulation circuit, the reference voltage circuit, and the comparison circuit through a diode, and the high-voltage power supply is output through a high-voltage power supply end.

[0031] Some embodiments of the present application provide a control chip including the current comparison circuit involved in the above-mentioned embodiments, and the to-be-measured current is transmitted to the current receiving end through a bus interface.

[0032] Some embodiments of the present application provide a master-slave system including a master and at least one slave, and the master includes the control chip involved in the above-mentioned embodiments, and the master is electrically connected to the at least one slave through a bus interface to receive different to-be-measured currents sent by the slave.

[0033] The current comparison circuit, control chip and master-slave system provided by the application, the current comparison circuit comprises a voltage regulation circuit, a reference voltage circuit and a comparison circuit. The current receiving end of the voltage regulation circuit is used for receiving a to-be-detected current, and the floating ground end is used for generating a floating ground voltage. The detection voltage end of the voltage regulation circuit is used for outputting a detection voltage related to the to-be-detected current. The reference voltage circuit comprises at least two branches, and the comparison circuit comprises at least two comparators. The first input ends of the two comparators are both connected to the detection voltage end of the voltage regulation circuit. The second input end of one of the comparators receives a first reference voltage, and the second input end of the other comparator receives a second reference voltage. In this way, two detection voltages can be detected based on the flipping results of the two comparators, that is, the detection of two different to-be-detected currents can be realized.

[0034] In addition, the voltage domain of the voltage regulation circuit is arranged between the high-voltage power supply end and the low-voltage power supply end, the voltage domains of the reference voltage circuit and the comparison circuit are arranged between the high-voltage power supply end and the floating ground end, the floating ground voltage is greater than the voltage of the low-voltage power supply end, and the floating ground voltage is adjustable. When the supply voltage or the high-voltage power supply becomes larger, the size of the floating ground voltage can be adjusted through the voltage regulation circuit, so as to ensure that the voltages of the high-voltage power supply end and the floating ground end are controllable, so that the comparators can work in a specified low-voltage working range, adapt to the needs of different customers or scenes, be more flexible to use, and no matter how large the high-voltage power supply is, the floating voltage can be adjusted instead of being fixed between the reference grounds. Therefore, the controllable voltage difference can make the working voltage of the comparator always in a controllable low-voltage range, so that the comparator no longer needs to use high-voltage devices, but can use low-voltage devices. The low-voltage devices are used to compare the high-voltage domain voltage, so as to improve the comparison speed and reduce the area and cost of the comparator. BRIEF DESCRIPTION OF DRAWINGS

[0035] FIG. 1 is a structural schematic diagram of a master-slave system according to some embodiments of the application;

[0036] FIG. 2 is a structural schematic diagram of the master-slave system shown in FIG. 1, in which a first comparator is omitted;

[0037] FIG. 3 is a structural schematic diagram of a master-slave system according to some embodiments of the application;

[0038] FIG. 4 is a comparison principle schematic diagram of a comparison circuit in the master-slave system shown in FIG. 1;

[0039] FIG. 5 is a comparison principle schematic diagram of a comparison circuit in the master-slave system shown in FIG. 3;

[0040] FIG. 6 is a setting mode of a first reference signal and a second reference signal;

[0041] FIG. 7 is another setting mode of the first reference signal and the second reference signal.

[0042] 100, voltage regulating circuit; 210, first reference voltage circuit; 220, second reference voltage circuit; 310, first comparator; 320, second comparator; 110, voltage stabilizing circuit; 101, detection voltage terminal; FGND, floating ground terminal; RE, current receiving terminal; 102, feedback voltage terminal; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; M1, first transistor; M2, second transistor; M3, third transistor; M4, fourth transistor; M5, fifth transistor; M6, sixth transistor; M7, seventh transistor; M8, eighth transistor; M9, ninth transistor; M10, tenth transistor; Vcp1, first detection voltage; Vcp2, second detection voltage; Vcn1, first reference voltage; Vcn2, second reference voltage; VDSI, high-voltage power terminal; GND, low-voltage power terminal; D1, first diode; D2, second diode; D3, third diode; 201, reference voltage terminal; GND, low-voltage power terminal; 102, feedback node; Vin, input voltage; Is1, first current source; Is2, second current source. DETAILED DESCRIPTION

[0043] To solve the above problems, some embodiments of the present application provide a current comparison circuit, a control chip and a master-slave system, which can adapt to a larger voltage without increasing the chip area. It should be noted that the current comparison circuit provided by the present application is not limited to be applied in a distributed system, but can also be applied in other applicable scenarios, for example, other use scenarios with similar characteristics, or other arbitrary protocols.

[0044] As shown in FIGS. 1-3, the present application provides a current comparison circuit, which includes a voltage regulating circuit 100, a reference voltage circuit and a comparison circuit.

[0045] The voltage regulation circuit 100 comprises a current receiving end RE, a floating ground end FGND and a detection voltage end 101. The current receiving end RE is configured to receive a current to be measured. The floating ground end FGND is configured to generate a floating ground voltage. The detection voltage end 101 is configured to output a detection voltage related to the current to be measured. The current to be measured comprises at least a first current to be measured and / or a second current to be measured. Correspondingly, as shown in FIG. 4 and FIG. 5, the detection voltage corresponding to the first current to be measured is a first detection voltage Vcp1, and the detection voltage corresponding to the second current to be measured is a second detection voltage Vcp2. As shown in FIG. 1, FIG. 2 and FIG. 4, the current receiving end RE and the floating ground end FGND can be one port. As shown in FIG. 3 and FIG. 5, the current receiving end RE and the floating ground end FGND can be different ports. When the current receiving end RE and the floating ground end FGND are different ports, other components can be arranged between the two ports to achieve other functions, such as the voltage domain widening component described below. The voltage regulation circuit 100 can adjust the size of the floating ground voltage of the floating ground end.

[0046] The reference voltage circuit comprises at least two branches, and each branch has a reference voltage end 201. As shown in FIG. 4 and FIG. 5, one of the branches of the reference voltage circuit generates a first reference voltage Vcn1 through the reference voltage end 201. As shown in FIG. 4 and FIG. 5, another branch of the reference voltage circuit generates a second reference voltage Vcn2 through the reference voltage end 201. In FIG. 1 to FIG. 3, the first reference voltage circuit 210 is one of the branches of the reference voltage circuit, and the second reference voltage circuit 220 is another branch of the reference voltage circuit.

[0047] The comparison circuit comprises at least two comparators. The first input end of each comparator is electrically connected to the detection voltage end 101. The second input end of one of the comparators is configured to receive the first reference voltage Vcn1, and the second input end of another of the comparators is configured to receive the second reference voltage Vcn2. Each comparator is configured to compare the size of the detection voltage and the corresponding reference voltage and output a comparison result. In FIG. 1 to FIG. 3, the first comparator 310 is one of the comparators of the comparison circuit, and the second input end of the first comparator 310 receives the first reference voltage Vcn1. The second comparator 320 is another comparator of the comparison circuit, and the second input end of the second comparator 320 receives the second reference voltage Vcn2.

[0048] More specifically, one of the comparators compares the detection voltage with the first reference voltage Vcn1 and outputs a comparison result which can indicate whether the to-be-measured current is greater than or equal to the first to-be-measured current. The other comparator compares the detection voltage with the second reference voltage Vcn2 and outputs a comparison result which can indicate whether the to-be-measured current is greater than or equal to the second to-be-measured current. When the detection voltage is greater than or equal to the first reference voltage Vcn1, the output of one of the comparators flips. When the detection voltage is greater than or equal to the second reference voltage Vcn2, the output of the other comparator also flips.

[0049] The size of the to-be-measured current at this time can be determined based on the results of the two comparators, by determining whether the detection voltage is the first detection voltage Vcp1 or the second detection voltage Vcp2, and thus determining whether the to-be-measured current is the first to-be-measured current or the second to-be-measured current.

[0050] Here, the first reference voltage Vcn1 is taken as an example which is less than the second reference voltage Vcn2, and the first detection voltage Vcp1 is taken as an example which is less than the second detection voltage Vcp2. If the comparison result of the comparator receiving the first reference voltage Vcn1 flips, but the comparison result of the comparator receiving the second reference voltage Vcn2 does not flip, it is determined that the detection voltage is the first detection voltage Vcp1, and accordingly the to-be-measured current is the first to-be-measured current. If the comparison result of the comparator receiving the first reference voltage Vcn1 flips, and the comparison result of the comparator receiving the second reference voltage Vcn2 also flips, it is determined that the detection voltage is the second detection voltage Vcp2, and accordingly the to-be-measured current is the second to-be-measured current.

[0051] The voltage domain of the voltage adjustment circuit 100 is set between the high-voltage power supply end VDSI and the low-voltage power supply end GND, and the voltage domains of the reference voltage circuit and the comparison circuit are set between the high-voltage power supply end VDSI and the floating ground end FGND. The floating ground voltage is greater than the voltage of the low-voltage power supply end GND. When the voltage of the high-voltage power supply end VDSI needs to be adjusted to a higher level to meet the requirements, the floating ground voltage of the floating ground end FGND can be adjusted by the voltage adjustment circuit 100, so that the voltage between the high-voltage power supply end VDSI and the floating ground end FGND can be kept in a low-voltage range, and thus the selected comparator or reference voltage circuit can be implemented by low-voltage devices, thereby meeting the different or different scene requirements of customers. In one possible way, when the voltage input by the high-voltage power supply end VDSI is a high voltage, the voltage of the floating ground end FGND can be adjusted by the voltage adjustment circuit 100 to be kept in a certain range, so that the voltage of the high-voltage power supply end VDSI and the floating ground end FGND can be controlled in a low-voltage range.

[0052] Therefore, by proper control of the current comparison circuit, different slave currents can be detected, and the voltage domain of the comparator or the reference voltage circuit is controlled in a specified low voltage range, and low voltage devices can meet the demand of different high voltage power supply, so that the chip area is reduced, the processing speed is faster, and the use scene is more flexible.

[0053] In some embodiments, as shown in FIGS. 1-3, the voltage regulation circuit 100 includes a voltage stabilizing circuit 110, and a detection resistor and a voltage dividing resistor are connected to an output end of the voltage stabilizing circuit 110, and a current receiving end RE and a floating ground end FGND are arranged between the detection resistor and the voltage dividing resistor. An input end of the voltage stabilizing circuit 110 receives a feedback voltage provided by the voltage dividing resistor, and another input end of the voltage stabilizing circuit 110 receives an input voltage Vin, and the floating ground voltage is related to the input voltage Vin of the voltage stabilizing circuit 110.

[0054] In some embodiments, as shown in FIGS. 1-3, the first resistor R1 is a detection resistor, the second resistor R2 and the third resistor R3 are voltage dividing resistors, the voltage dividing resistors are used to output a feedback voltage after dividing the floating ground voltage, and the voltage stabilizing circuit 110 adjusts the voltage on the detection resistor and the voltage on the voltage dividing resistors based on the feedback voltage and the input voltage Vin received by the other input end. In this way, the floating ground voltage can be stabilized within a certain range, and more specifically, the parameters of the voltage stabilizing circuit 110, the parameters of the voltage dividing resistors, and the parameters of the detection resistor can be designed to stabilize the floating ground voltage near the input voltage Vin, or to make the ratio of the floating ground voltage to the input voltage Vin within a certain range.

[0055] In the above technical solution, the voltage regulation circuit 100 includes the voltage stabilizing circuit 110, the detection resistor, and the voltage dividing resistor, the feedback voltage is output after the floating ground voltage is divided by the voltage dividing resistor, and the voltage stabilizing circuit 110 adjusts the voltage on the detection resistor and the voltage on the voltage dividing resistors based on the feedback voltage and the input voltage Vin. In this way, the floating ground voltage is stabilized within a certain range, and the working range of the reference voltage circuit and the comparison circuit is ensured within a certain range, which can further reduce the working voltage range of the entire comparator, so that the comparator can work in a low voltage domain, and the chip area is reduced. That is, if the high voltage power supply VDSI needs to be supplied with a higher voltage, the floating ground voltage is controlled at a suitable voltage size through the adjustment of the voltage stabilizing circuit 110, so that the voltage difference between the reference voltage circuit and the comparison circuit is controlled within a low voltage domain. In addition, the voltage stabilizing circuit 110 has a feedback loop, and if the voltage at the connection point between the slave and the current receiving end changes suddenly, the floating ground voltage of the floating ground end FGND can be adjusted in time, so that the floating ground voltage is quickly adjusted to a specified voltage, so that the voltage difference between the reference voltage circuit and the comparison circuit does not exceed the range that can be tolerated, so that the stability of the circuit is stronger and can handle some temporary and short fluctuations.

[0056] In some embodiments, each branch of the reference voltage circuit includes a current source and a reference resistance, and a reference voltage terminal 201 is disposed between the current source and the reference resistance. In FIGS. 1-3, the fourth resistance R4 and the fifth resistance R5 are the reference resistances, and the reference resistances of different branches of the reference voltage circuit have different resistance values to generate different reference voltages. In this way, by setting the resistance values of the reference resistances, the voltage across the reference resistances can be set, and thus the voltage of the reference voltage terminal 201 can be set, so that different branches generate different reference voltages. In a more preferred manner, the reference resistances have different resistance values and the current sources have the same current to generate different reference voltages. In this way, by setting the resistance values of the reference resistances, the voltage across the reference resistances can be set, and thus the voltage of the reference voltage terminal 201 can be set, so that different branches generate different reference voltages. By setting the current sources of each branch to have the same current, the circuit structure can be simplified.

[0057] In some embodiments, each branch of the reference voltage circuit includes a current source and a reference resistance, and a voltage domain expansion component is disposed between the current receiving terminal RE and the floating ground terminal FGND and / or between the reference resistance and the floating ground terminal FGND, and the voltage domain expansion component expands the operating voltage domain of the reference voltage circuit and the comparison circuit. For example, the voltage domain expansion component can be a diode, and of course can also be any other form of device, structure or circuit that can expand the voltage.

[0058] In some embodiments, the first reference voltage Vcn1 = the first detection voltage Vcp1 < the second reference voltage Vcn2 = the second detection voltage Vcp2. When the detection voltage is greater than or equal to the first reference voltage Vcn1, the output of one of the comparators flips, and when the detection voltage is greater than or equal to the second reference voltage Vcn2, the output of the other comparator also flips.

[0059] More specifically, if the current to be measured includes a first current to be measured, the corresponding detection voltage is the first detection voltage Vcp1. Since the first reference voltage Vcn1 = the first detection voltage Vcp1, the output of the comparator receiving the first reference voltage Vcn1 flips. Since the first detection voltage Vcp1 < the second reference voltage Vcn2, the output of the comparator receiving the second reference voltage Vcn2 does not flip.

[0060] If the current to be measured includes a second current to be measured, the corresponding detection voltage is the second detection voltage Vcp2. Since the second reference voltage Vcn2 = the second detection voltage Vcp2, the output of the comparator receiving the second reference voltage Vcn2 flips. The second detection voltage Vcp2 > the first reference voltage Vcn1, and the output of the comparator receiving the first reference voltage Vcn1 also flips.

[0061] As shown in FIG. 6, the oblique line S1 represents the detection voltage corresponding to the to-be-detected current. Taking the first detection current Idsl as 12 mA and the second detection current Idsl as 24 mA as an example. The first detection voltage Vcpl corresponding to 12 mA is set as the first reference voltage Vcnl. The second detection voltage Vcp2 corresponding to 24 mA is set as the second reference voltage Vcn2. In this way, when the detection current is 12 mA, the first comparator 310 flips, and the second comparator 320 does not flip. In this way, when the detection current is 24 mA, the first comparator 310 flips, and the second comparator 320 also flips.

[0062] In this way, based on whether the outputs of the two comparators flip, the determination of the first to-be-detected current and the second to-be-detected current can be realized.

[0063] Under different PVT conditions, the first reference voltage Vcnl and the second reference voltage Vcn2 may fluctuate. If the first detection voltage Vcpl corresponding to the first to-be-detected current is equal to the first reference voltage Vcnl, or the second detection voltage Vcp2 corresponding to the second to-be-detected current is equal to the second reference voltage Vcn2, after the first reference voltage Vcnl and the second reference voltage Vcn2 fluctuate, for example, the first reference voltage Vcnl and the second reference voltage Vcn2 increase, when the current comparison circuit receives the input current as the first to-be-detected current, the two comparators do not flip, and it is considered that the first to-be-detected current does not appear. Similarly, when the current comparison circuit receives the input current as the second to-be-detected current, at least the comparator for receiving the second reference voltage Vcn2 does not flip, and it is considered that the second to-be-detected current does not appear, thereby causing signal misjudgment.

[0064] Based on the above consideration, in some other embodiments, the first reference voltage Vcnl < the first detection voltage Vcpl < the second reference voltage Vcn2 < the second detection voltage Vcp2. In this way, as long as the to-be-detected current reaches the first to-be-detected current, the size of the first detection voltage Vcpl will necessarily be greater than the first reference voltage Vcnl, and therefore, as long as the comparator for detecting the first detection voltage flips, it indicates that the to-be-detected current at this time is the first to-be-detected current. Similarly, as long as the to-be-detected current reaches the second to-be-detected current, the size of the second detection voltage Vcp2 will necessarily be greater than the second reference voltage Vcn2, and therefore, as long as the comparator for detecting the second detection voltage flips, it indicates that the to-be-detected current at this time is the second to-be-detected current.

[0065] More specifically, if the current to be measured includes the first current to be measured, the corresponding detection voltage is the first detection voltage Vcp1. Since the first reference voltage Vcn1 < the first detection voltage Vcp1, even if the first reference voltage Vcn1 rises due to changes in PVT, the changed first reference voltage Vcn1 < the first detection voltage Vcp1 can be guaranteed, and the output of the comparator receiving the first reference voltage Vcn1 flips. Since the first detection voltage Vcp1 < the second reference voltage Vcn2, the output of the comparator receiving the second reference voltage Vcn2 does not flip.

[0066] If the current to be measured includes the second current to be measured, the corresponding detection voltage is the second detection voltage Vcp2. Since the second reference voltage Vcn2 < the second detection voltage Vcp2, even if the second reference voltage Vcn2 rises due to changes in PVT, the changed second reference voltage Vcn2 < the second detection voltage Vcp2 can be guaranteed, and the output of the comparator receiving the second reference voltage Vcn2 flips. The second detection voltage Vcp2 > the first reference voltage Vcn1, and the output of the comparator receiving the first reference voltage Vcn1 also flips.

[0067] As shown in FIG. 7, the oblique line S2 represents the detection voltage corresponding to the current to be measured, and is illustrated by taking the first detection current Idsl of 12 mA and the second detection current Idsl of 24 mA as examples. The first detection voltage Vcp1 corresponding to 12 mA is set to be greater than the first reference voltage Vcn1. The second detection voltage Vcp2 corresponding to 24 mA is set to be greater than the second reference voltage Vcn2. In this way, even if the first reference voltage Vcn1 and the second reference voltage Vcn2 fluctuate, it can still be guaranteed that when the detection current is 12 mA, the first comparator 310 flips, and the second comparator 320 does not flip. It can also be guaranteed that when the detection current is 24 mA, the first comparator 310 flips, and the second comparator 320 also flips.

[0068] By setting in this way, it is guaranteed that when the first current to be measured and the second current to be measured occur, the corresponding comparator is in a flipped state, so that the two currents can be accurately identified.

[0069] As shown in FIGS. 1 to 3, some embodiments of the present application provide a current comparison circuit, which includes a voltage adjustment circuit 100, a reference voltage circuit, and a comparison circuit.

[0070] The reference voltage circuit includes at least a first reference voltage circuit 210 and a second reference voltage circuit 220, the first reference voltage circuit 210 provides a first reference voltage Vcn1, and the second reference voltage circuit 220 provides a second reference voltage Vcn2. The voltage domains of the first reference voltage circuit 210 and the second reference voltage circuit 220 are set between a high-voltage power supply end VDSI and a floating ground end FGND.

[0071] The voltage regulation circuit 100 comprises a voltage stabilizing circuit 110, a first resistor R1, a second resistor R2 and a third resistor R3. The voltage stabilizing circuit 110 comprises a first input end, a second input end and an output end, the output end of the voltage stabilizing circuit 110 is electrically connected with the low-voltage power supply end GND through the first resistor R1, the second resistor R2 and the third resistor R3, the current receiving end RE and the floating ground end FGND are arranged between the first resistor R1 and the second resistor R2, the floating ground voltage of the floating ground end FGND is adjustable, wherein the current receiving end RE and the floating ground end FGND are one port or different ports; the feedback node 102 is arranged between the second resistor R2 and the third resistor R3, the feedback node 102 is electrically connected with the second input end of the voltage stabilizing circuit 110, and the first input end of the voltage stabilizing circuit 110 is used for receiving an input voltage Vin.

[0072] The current receiving end RE is used for receiving a to-be-measured current, the first resistor R1 is used for detecting the to-be-measured current and outputting a detection voltage related to the to-be-measured current, the to-be-measured current at least comprises a first to-be-measured current and a second to-be-measured current, as shown in FIG. 4 and FIG. 5, the detection voltage corresponding to the first to-be-measured current is a first detection voltage Vcp1, and the detection voltage corresponding to the second to-be-measured current is a second detection voltage Vcp2. The voltage domain of the voltage stabilizing circuit 110 is arranged between the high-voltage power supply end VDSI and the low-voltage power supply end GND.

[0073] The comparison circuit at least comprises a first comparator 310 and a second comparator 320, the first input ends of the first comparator 310 and the second comparator 320 are electrically connected with the output end of the voltage stabilizing circuit 110 for receiving the detection voltage, the second input end of the first comparator 310 is used for receiving a first reference voltage Vcn1, the second input end of the second comparator 320 is used for receiving a second reference voltage Vcn2, the first comparator 310 is used for outputting the comparison result of the detection voltage and the first reference voltage Vcn1, the second comparator 320 is used for outputting the comparison result of the detection voltage and the second reference voltage Vcn2, and the voltage domain of the comparison circuit is arranged between the high-voltage power supply end VDSI and the floating ground end FGND.

[0074] Wherein, the detection process of the detection voltage is based on the comparison result of the first comparator 310 and the comparison result of the second comparator 320, which has been described in detail in the above embodiment, and will not be repeated here.

[0075] The first resistor R1 is a detection resistor, and the second resistor R2 and the third resistor R3 are voltage division resistors. The current receiving end RE and the floating ground end FGND are arranged between the first resistor R1 and the second resistor R2, the current receiving end RE and the floating ground end FGND are one port or different ports (the arrangement of the same port and different ports is described in detail in the above embodiment, which will not be described again here), and the voltage of the floating ground end FGND is a floating ground voltage. The feedback node 102 is arranged between the second resistor R2 and the third resistor R3, that is, the feedback voltage is the floating ground voltage multiplied by a voltage division coefficient. When the floating ground voltage becomes larger, the feedback voltage also becomes larger. The floating ground voltage of the floating ground end FGND can become larger due to an increase in the voltage on the high-voltage power supply end VDSI or due to a sudden change in the voltage on the current receiving end RE. The second input end of the voltage stabilizing circuit 110 receives the feedback voltage, and the first input end of the voltage stabilizing circuit 110 receives the input voltage Vin. When the feedback voltage becomes larger, the voltage difference between the two input ends of the voltage stabilizing circuit 110 becomes larger, and then the voltage stabilizing circuit 110 reduces the output voltage. The floating ground voltage is adjusted through the first resistor R1 and the second resistor R2, and then the floating ground voltage is stabilized within a certain range. In other embodiments, the voltage stabilizing circuit 110 is an operational amplifier.

[0076] More specifically, the input voltage of the first input end of the voltage stabilizing circuit 110 is Vin, the feedback voltage between the second resistor R2 and the third resistor R3 is Vf, and the floating ground voltage between the first resistor R1 and the second resistor R2 is Vfloat. The formula of the feedback voltage is:

[0077] Vf = Vfloat*(R3 / (R2+R3)

[0078] The voltage stabilizing circuit 110 finally realizes that the input voltage Vin of the first input end is equal to the feedback voltage of the second input end, that is, Vin = Vf,

[0079] Therefore, the relationship between the floating ground voltage and the input voltage Vin is:

[0080] Vfloat = Vin*(1+R2 / R3)

[0081] That is, after being adjusted by the voltage stabilizing circuit 110, the floating ground voltage is related to the input voltage Vin, and is not a fixed low voltage such as GND, so that it becomes feasible to adjust the floating ground voltage.

[0082] In addition, the voltage domain of the voltage regulating circuit 100 is arranged between the high-voltage power supply end VDSI and the low-voltage power supply end GND, the voltage domain of the reference voltage circuit and the comparison circuit is arranged between the high-voltage power supply end VDSI and the floating ground end FGND, and the floating ground voltage is greater than the voltage of the low-voltage power supply end GND.

[0083] When the voltage of the high-voltage power supply end VDSI needs to be adjusted to a higher level to meet the requirements, the voltage of the floating ground end can be adjusted by the voltage stabilizing circuit, so that the voltage between the high-voltage power supply end VDSI and the floating ground end FGND can be kept in a low-voltage range, so that the comparator or the reference voltage circuit selected can be implemented by low-voltage devices, thereby meeting the different or different scene requirements of customers. In one possible way, when the voltage input by the high-voltage power supply end VDSI is high voltage, the voltage of the floating ground end FGND can be adjusted to a certain range by controlling the voltage stabilizing circuit, so that the voltage of the high-voltage power supply end VDSI and the floating ground end FGND is controlled in a low-voltage range.

[0084] Therefore, by properly controlling the current comparison circuit, different slave currents can be detected, and the voltage domain of the comparator or the reference voltage circuit can be controlled in a specified low-voltage range, and low-voltage devices can be selected to meet the requirements of different high-voltage power supplies, so that the chip area is reduced, the processing speed is faster, and the use scene is more flexible.

[0085] In some embodiments, the first reference voltage circuit 210 includes a first current source Is1 and a fourth resistor R4, and the second reference voltage circuit 220 includes a second current source Is2 and a fifth resistor R5; a first reference voltage Vcn1 is generated between the first current source Is1 and the fourth resistor R4, and a second reference voltage Vcn2 is generated between the second current source Is2 and the fifth resistor R5.

[0086] More specifically, the input end of the first current source Is1 and the input end of the second current source Is2 are connected to the high-voltage power supply end VDSI, the output end of the first current source Is1 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the floating ground end FGND, the output end of the second current source Is2 is connected to the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is connected to the floating ground end FGND. A reference voltage end 201 is provided between the first current source Is1 and the fourth resistor R4 for providing a first reference voltage Vcn1, and another reference voltage end 201 is provided between the second current source Is2 and the fifth resistor R5 for providing a second reference voltage Vcn2.

[0087] The detection voltage is Vcp (not shown in the figure), and the formula of the detection voltage is: Vcp=R1*IDSI+Vfloat

[0088] Where IDSI is the current to be measured.

[0089] The first reference voltage is Vcn1, and the formula of the first reference voltage Vcn1 is: Vcn1=R4*Is1+Vfloat

[0090] The second reference voltage is Vcn2, and the formula of the second reference voltage Vcn2 is: Vcn2 = R5 * Is2 + Vfloat

[0091] If Vcp≥Vcn1, that is, R1*IDSI≥R4*Is1, the first comparator 310 flips. If Vcp≥Vcn2, that is, R1*IDSI≥R5*Is2, the second comparator 320 also flips.

[0092] The parameters of the first resistor R1, the fourth resistor R4, the fifth resistor R5, the first current source Is1, and the second current source Is2 can be set, and when the to-be-measured current is the first to-be-detected current, the first comparator 310 flips, and the second comparator 320 does not flip. When the to-be-measured current is the second to-be-detected current, the first comparator 310 and the second comparator 320 both flip.

[0093] In some embodiments, the first detection voltage is Vcp1, the second detection voltage is Vcp2, the first reference voltage is Vcn1, and the second reference voltage is Vcn2, and the relationship satisfies: Vcn1

[0094] Under different PVT conditions, the first reference voltage Vcn1 and the second reference voltage Vcn2 may fluctuate. If the first detection voltage Vcp1 corresponding to the first to-be-measured current is equal to the first reference voltage Vcn1, or the second detection voltage Vcp2 corresponding to the second to-be-measured current is equal to the second reference voltage Vcn2, if the first reference voltage Vcn1 and the second reference voltage Vcn2 fluctuate, for example, the first reference voltage Vcn1 and the second reference voltage Vcn2 increase, then when the current comparison circuit receives the input current as the first to-be-measured current, the two comparators do not flip, and it is considered that the first to-be-measured current does not appear. Similarly, when the current comparison circuit receives the input current as the second to-be-measured current, the comparator receiving the second reference voltage Vcn2 does not flip, and it is considered that the second to-be-measured current does not appear, thereby causing signal misjudgment. Therefore, Vcn1

[0095] In some embodiments, the first reference voltage circuit 210 includes the first current source Is1 and the fourth resistor R4, and the second reference voltage circuit 220 includes the second current source Is2 and the fifth resistor R5; the first reference voltage Vcn1 is generated between the first current source Is1 and the fourth resistor R4, and the second reference voltage Vcn2 is generated between the second current source Is2 and the fifth resistor R5.

[0096] The first to-be-measured current is I1, the second to-be-measured current is I2, the first current source Is1 is Is1, and the second current source Is2 is Is2, and the relationship satisfies: Is1*R4=1 / 2*I1*R1, Is2*R5=2 / 3*I2*R1, wherein R1 is the first resistor R1, R4 is the fourth resistor R4, and R5 is the fifth resistor R5.

[0097] That is, the formula of the first reference voltage Vcn1 is: Vcn1=Is1*R4+Vfloat=1 / 2*I1*R1+Vfloat

[0098] The formula of the first to-be-measured current Vcp1 is: Vcp1=I1*R1+Vfloat

[0099] In this way, Vcn1Vcp1.

[0100] That is, the formula of the second reference voltage Vcn2 is: Vcn2=Is2*R5+Vfloat=2 / 3*I2*R1+Vfloat

[0101] The formula of the first to-be-measured current Vcp1 is: Vcp2=I2*R1+Vfloat

[0102] In this way, Vcn2Vcp2.

[0103] When the first to-be-measured current is 12 mA and the second to-be-measured current is 24 mA, if Is1=Is2=6 uA, then R4=1000*R1 and R5=3000*R1.

[0104] After the setting, different PVT conditions can meet the requirements, and the first to-be-measured current and the second to-be-measured current can be accurately identified. It is a relatively appropriate proportional relationship. Of course, the present application is not limited to the above proportion, and other appropriate proportional relationships can be set according to specific circuits.

[0105] In some embodiments, the fourth resistor R4 and the fifth resistor R5 have different resistance values, and the embodiments have been described in detail in the foregoing embodiments, and thus will not be described here.

[0106] In some embodiments, the first current source Is1 and the second current source Is2 have the same current, and the fourth resistor R4 and the fifth resistor R5 have different resistance values, and the embodiments have been described in detail in the foregoing embodiments, and thus will not be described here.

[0107] In some embodiments, the first resistor R1, the fourth resistor R4, and the fifth resistor R5 are provided with a voltage domain expansion component between the first resistor R1 and the floating ground terminal FGND, and the working voltage range of the comparison circuit is widened through the voltage domain expansion component.

[0108] In some embodiments, the voltage domain expansion component is a diode.

[0109] More specifically, a first diode D1 is arranged between the current detection end RE (if the current detection end RE and the floating ground end FGND are different ports, it can be considered that a first diode D1 is arranged between the first resistor R1 and the second resistor R2) and the second resistor R2, the anode of the first diode D1 is connected to the current detection end RE, the cathode of the first diode D1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the third resistor R3.

[0110] A second diode D2 is arranged between the fourth resistor R4 and the floating ground end FGND, the anode of the second diode D2 is connected to the second end of the fourth resistor R4, and the cathode of the second diode D2 is connected to the floating ground end FGND.

[0111] A third diode D3 is arranged between the fifth resistor R5 and the floating ground end FGND, the anode of the third diode D3 is connected to the second end of the fifth resistor R5, and the cathode of the third diode D3 is connected to the floating ground end FGND.

[0112] The voltage of the first reference signal Vcn1 = Vfloat + Is1*R4 + Vdiode, the voltage of the second reference signal Vcn2 = Vfloat + Is2*R5 + Vdiode, and the detection voltage Vcp = Vfloat + IdsI*R1 + Vdiode.

[0113] The voltage difference between the two ends of the first comparator 310 Vcp-Vcn1 = IDSI*R1-Is1*R4, and the voltage difference between the two ends of the second comparator 320 Vcp-Vcn2 = IDSI*R1-Is1*R5.

[0114] Therefore, the voltage domain expansion component is arranged between the first resistor R1, the fourth resistor R4, the fifth resistor R5 and the floating ground end FGND, which does not affect the identification of the first signal, and the second diode D2 can prevent the reverse flow of current. In addition, the arrangement of the voltage domain expansion component can prevent the problem that the working range of the corresponding circuit is too small to cause the device to not work normally, which is a redundant design.

[0115] In some embodiments, the first comparator 310 and the second comparator 320 are five-tube operational amplifier comparators.

[0116] More specifically, as shown in FIG. 1, the first comparator 310 includes a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, and a fifth transistor M5.

[0117] The first end of the first transistor M1 is connected to a high-voltage power supply end VDSI, the second end of the first transistor M1 is connected to the first end of the second transistor M2, the second end of the first transistor M1 is connected to the first end of the third transistor M3, and the control end of the first transistor M1 receives a first control signal.

[0118] The second end of the second transistor M2 is connected to the first end of the fourth transistor M4, the first end of the fourth transistor M4 is connected to the control end of the fourth transistor M4, the second end of the fourth transistor M4 is connected to a floating ground end FGND, and the control end of the fourth transistor M4 is connected to the control end of the fifth transistor M5.

[0119] The second end of the third transistor M3 is connected to the first end of the fifth transistor M5, the second end of the fifth transistor M5 is connected to the control end of the fifth transistor M5, and the second end of the fifth transistor M5 is connected to the floating ground end FGND.

[0120] The control end of the second transistor M2 serves as a first input end of the first comparator 310, the control end of the third transistor M3 serves as a second input end of the first comparator 310, and the second end of the second transistor M2 and the second end of the third transistor M3 serve as an output end of the first comparator 310.

[0121] In some embodiments, as shown in FIG. 2, the second comparator 320 includes a sixth transistor M6, a seventh transistor M7, an eighth transistor M8, a ninth transistor M9, and a tenth transistor M10.

[0122] The first end of the sixth transistor M6 is connected to the high-voltage power supply end VDSI, the second end of the sixth transistor M6 is connected to the first end of the seventh transistor M7, the second end of the sixth transistor M6 is connected to the first end of the eighth transistor M8, and the control end of the sixth transistor M6 receives a second control signal.

[0123] The second end of the seventh transistor M7 is connected to the first end of the ninth transistor M9, the first end of the ninth transistor M9 is connected to the control end of the ninth transistor M9, the second end of the ninth transistor M9 is connected to the floating ground end FGND, and the control end of the ninth transistor M9 is connected to the control end of the tenth transistor M10.

[0124] The second end of the eighth transistor M8 is connected to the first end of the tenth transistor M10, the second end of the tenth transistor M10 is connected to the control end of the tenth transistor M10, and the second end of the tenth transistor M10 is connected to the floating ground end FGND.

[0125] The control end of the seventh transistor M7 serves as a first input end of the second comparator 320, the control end of the eighth transistor M8 serves as a second input end of the second comparator 320, and the second end of the seventh transistor M7 and the second end of the eighth transistor M8 serve as an output end of the second comparator 320.

[0126] In some embodiments, as shown in FIGS. 1-3, the supply voltage VLD0 provides a high voltage source to the voltage regulation circuit 100, the reference voltage circuit, and the comparison circuit through the diode, and the high voltage source is output through the high voltage source end VDSI.

[0127] Some embodiments of the present application provide a control chip including the current comparison circuit involved in the above-mentioned embodiments, and the to-be-measured current is transmitted to the current receiving end through the bus interface.

[0128] In some embodiments, the bus is a distributed system interface (DSI) bus. The present application only takes DSI as an example, and is mainly used in the master-slave mode of DSI, but is not limited to the mode of DSI, and any other protocol and interface that need to detect the current signal of the slave and the current signal at least contains two kinds are applicable.

[0129] Each branch of the reference voltage circuit includes a current source and a reference resistance, and a voltage domain expansion component is arranged between the current receiving end and the floating ground end FGND, and / or a voltage domain expansion component is arranged between the reference resistance and the floating ground end FGND, and the voltage domain expansion component expands the working voltage domain of the reference voltage circuit and the comparison circuit. When negative voltage appears on the bus, the low voltage source end GND can be prevented from flowing back to the bus through the voltage dividing resistance, and the currents of the first current source Is1 and the second current source Is2 can also not flow back to the bus, so that the currents of the first current source Is1 and the second current source Is2 can be discharged to the low voltage source end GND through the voltage dividing resistance.

[0130] Based on the above settings, the detection of different currents sent by the slave is completed, the detection circuit has simple structure and good detection effect, the working voltage of the comparator is controlled within a certain range, the working voltage range of the comparator is reduced, and thus the comparator can work in a low voltage domain or adopt a low voltage device, thereby saving chip area.

[0131] Some embodiments of the present application provide a master-slave system including a master and at least one slave, and the master includes the control chip involved in the above-mentioned embodiments, and the master is electrically connected with the at least one slave through the bus interface to receive different to-be-measured currents sent by the slave. When the master-slave system includes a plurality of slaves, the plurality of slaves are connected in series, and the slave at the first end is connected with the master through the bus.

[0132] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A current comparison circuit, characterized by, The voltage regulating circuit, the reference voltage circuit, and the comparison circuit are provided. The voltage regulating circuit comprises a current receiving end, a floating ground end, and a detection voltage end. The current receiving end is configured to receive a to-be-detected current. The floating ground end is configured to generate a floating ground voltage. The detection voltage end is configured to output a detection voltage related to the to-be-detected current. The to-be-detected current comprises at least a first to-be-detected current and a second to-be-detected current. The first to-be-detected current corresponds to a first detection voltage. The second to-be-detected current corresponds to a second detection voltage. The current receiving end and the floating ground end are one port or different ports. The voltage regulating circuit is capable of regulating the floating ground voltage. The reference voltage circuit comprises at least two branches. Each branch has a reference voltage end. One of the branches of the reference voltage circuit generates a first reference voltage through the reference voltage end. Another branch of the reference voltage circuit generates a second reference voltage through the reference voltage end. The comparison circuit comprises at least two comparators. The first input end of each comparator is electrically connected to the detection voltage end. The second input end of one comparator is configured to receive the first reference voltage. The second input end of another comparator is configured to receive the second reference voltage. Each comparator is configured to compare the detection voltage and the corresponding reference voltage and output a comparison result. The voltage domain of the voltage regulating circuit is arranged between a high-voltage power supply end and a low-voltage power supply end. The voltage domains of the reference voltage circuit and the comparison circuit are arranged between the high-voltage power supply end and the floating ground end. The floating ground voltage is greater than the voltage of the low-voltage power supply end.

2. The current comparison circuit according to claim 1, characterized in that, The voltage regulating circuit comprises a voltage stabilizing circuit. The output end of the voltage stabilizing circuit is connected to a detection resistor and a voltage dividing resistor. The current receiving end and the floating ground end are arranged between the detection resistor and the voltage dividing resistor. One input end of the voltage stabilizing circuit receives a feedback voltage provided by the voltage dividing resistor. Another input end of the voltage stabilizing circuit receives an input voltage. The floating ground voltage is related to the input voltage of the voltage stabilizing circuit.

3. The current comparison circuit of claim 1, wherein, Each branch of the reference voltage circuit comprises a current source and a reference resistor. The current source and the reference resistor are arranged between the reference voltage end. The reference resistors of different branches of the reference voltage circuit have different resistance values to generate different reference voltages. Alternatively, the reference resistors of different branches of the reference voltage circuit have different resistance values and the current sources have the same current to generate different reference voltages.

4. The current comparison circuit of claim 2, wherein, Each branch of the reference voltage circuit comprises a current source and a reference resistor. A voltage domain expansion component is arranged between the current receiving end and the floating ground end and / or between the reference resistor and the floating ground end. The voltage domain expansion component expands the working voltage domain of the reference voltage circuit and the comparison circuit.

5. The current comparison circuit according to any one of claims 1 to 4, characterized in that, When the detection voltage is greater than or equal to the first reference voltage, one of the comparator outputs flips; when the detection voltage is greater than or equal to the second reference voltage, the other comparator output also flips; wherein the first reference voltage < the first detection voltage < the second reference voltage < the second detection voltage.

6. The current comparison circuit according to any one of claims 1 to 4, characterized in that, When the detection voltage is greater than or equal to the first reference voltage, one of the comparator outputs flips; when the detection voltage is greater than or equal to the second reference voltage, the other comparator output also flips; wherein the first reference voltage = the first detection voltage < the second reference voltage = the second detection voltage.

7. A current comparison circuit, characterized by comprising: The voltage regulation circuit, the reference voltage circuit and the comparison circuit are included; the reference voltage circuit at least includes a first reference voltage circuit and a second reference voltage circuit; The first reference voltage circuit provides a first reference voltage, and the second reference voltage circuit provides a second reference voltage; the voltage domains of the first reference voltage circuit and the second reference voltage circuit are set between a high-voltage power supply end and a floating ground end; The voltage regulation circuit includes a voltage stabilizing circuit, a first resistor, a second resistor and a third resistor; The output end of the voltage stabilizing circuit is electrically connected with a low-voltage power supply end through the first resistor, the second resistor and the third resistor; a current receiving end and the floating ground end are arranged between the first resistor and the second resistor; the floating ground voltage of the floating ground end is adjustable; the current receiving end and the floating ground end are one port or different ports; a feedback node is arranged between the second resistor and the third resistor; the feedback node is electrically connected with the second input end of the voltage stabilizing circuit; the first input end of the voltage stabilizing circuit is used for receiving an input voltage; the voltage domain of the voltage stabilizing circuit is set between the high-voltage power supply end and the low-voltage power supply end; the current receiving end is used for receiving a to-be-detected current; the first resistor is used for detecting the to-be-detected current and outputting a detection voltage related to the to-be-detected current; the to-be-detected current at least includes a first to-be-detected current and a second to-be-detected current; the detection voltage corresponding to the first to-be-detected current is a first detection voltage, and the detection voltage corresponding to the second to-be-detected current is a second detection voltage; The comparison circuit at least includes a first comparator and a second comparator; the first input ends of the first comparator and the second comparator are electrically connected with the output end of the voltage stabilizing circuit and used for receiving the detection voltage; the second input end of the first comparator is used for receiving the first reference voltage; the second input end of the second comparator is used for receiving the second reference voltage; the voltage domain of the comparison circuit is set between the high-voltage power supply end and the floating ground end.

8. The current comparison circuit of claim 7, wherein, The first detection voltage is Vcp1, the second detection voltage is Vcp2, the first reference voltage is Vcn1, and the second reference voltage is Vcn2; the relationship satisfies: Vcn1 < Vcp1 < Vcn2 < Vcp2.

9. The current comparison circuit of claim 8, wherein, The first reference voltage circuit comprises a first current source and a fourth resistor, and the second reference voltage circuit comprises a second current source and a fifth resistor; a first reference voltage is generated between the first current source and the fourth resistor, and a second reference voltage is generated between the second current source and the fifth resistor; The first to-be-measured current is I1, the second to-be-measured current is I2, the first current source is Is1, and the second current source is Is2, and the relationship satisfies: Is1*R4=1 / 2*I1*R1 and Is2*R5=2 / 3*I2*R1, wherein R1 is the first resistor, R4 is the fourth resistor, and R5 is the fifth resistor.

10. A current comparison circuit as claimed in any one of claims 7 to 9, characterized in that, The fourth resistor and the fifth resistor have different resistance values, or the first current source and the second current source have the same current and the fourth resistor and the fifth resistor have different resistance values.

11. The current comparison circuit according to any one of claims 7 to 9, characterized in that, The current receiving end, the fourth resistor, and the fifth resistor are provided with a voltage domain expansion component between the current receiving end and the floating ground end.

12. The current comparison circuit of claim 11, wherein, The voltage domain expansion component is a diode.

13. The current comparison circuit of claim 7, wherein, The comparator is a five-tube operational amplifier comparator.

14. The current comparison circuit according to any one of claims 7 to 9, characterized by A power supply voltage provides a high-voltage power supply for the voltage regulation circuit, the reference voltage circuit, and the comparison circuit through a diode, and the high-voltage power supply is output through the high-voltage power supply end.

15. A control chip, characterized by The current comparison circuit comprises a current receiving end, a reference voltage circuit, a comparison circuit, and a power supply circuit, wherein the current receiving end is connected to a bus interface; the reference voltage circuit comprises a first reference voltage circuit and a second reference voltage circuit; the comparison circuit comprises a comparator; and the power supply circuit comprises a voltage regulation circuit and a reference voltage circuit.

16. A master-slave system, characterized by comprising: The current comparison circuit comprises a current receiving end, a reference voltage circuit, a comparison circuit, and a power supply circuit, wherein the current receiving end is connected to a bus interface; the reference voltage circuit comprises a first reference voltage circuit and a second reference voltage circuit; the comparison circuit comprises a comparator; and the power supply circuit comprises a voltage regulation circuit and a reference voltage circuit. The current comparison circuit comprises a current receiving end, a reference voltage circuit, a comparison circuit, and a power supply circuit, wherein the current receiving end is connected to a bus interface; the reference voltage circuit comprises a first reference voltage circuit and a second reference voltage circuit; the comparison circuit comprises a comparator; and the power supply circuit comprises a voltage regulation circuit and a reference voltage circuit.

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