Threshold-adjustable low-voltage detection circuit, chip and integrated circuit

Abstract

The invention discloses a threshold-adjustable low-voltage detection circuit, a chip and an integrated circuit. The circuit comprises a signal control module, an inverted T-shaped resistance network digital-to-analog converter (DAC) module, a first inverting amplifier, a summing circuit and a comparator. When the signal control module receives a low-voltage detection instruction, a control signal is sent to the inverted T-shaped resistance network DAC module, the control signal is a signal matched with a target low-voltage detection gear corresponding to the low-voltage detection instruction, and the inverted T-shaped resistance network DAC module controls the low-voltage detection gear based on the output voltage of an external second voltage input end and the control signal. And the comparator outputs a voltage threshold corresponding to the target low voltage detection gear to the summing circuit, the summing circuit carries out addition operation on the voltage threshold and the output voltage of the first inverting amplifier to obtain a voltage after operation, and the comparator compares the voltage after operation with the output voltage of the voltage device to be detected based on the voltage after operation and outputs a voltage detection result. By applying the scheme provided by the invention, the detection cost can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a threshold adjustable low voltage detection circuit, a chip and an integrated circuit. Background Art

[0002] Integrated circuits are widely used in various consumer, industrial and automotive electronic devices. During the application of integrated circuits, the voltage of some devices may be too low, such as the power supply voltage. When the power supply voltage drops to a certain voltage value, the analog circuit where the power supply is located may not work properly or the memory may read incorrectly, affecting the internal logic state of the logic device and the logic state of the volatile memory.

[0003] At present, a low voltage detection circuit is used to detect whether the voltage is too low. The low voltage detection circuit is suitable for monitoring the power supply voltage or the external pin input voltage. When the comparison result between the monitored voltage and the threshold of the low voltage detection circuit meets the triggering condition, the low voltage detection circuit will generate an interrupt or reset signal to avoid the occurrence of faults.

[0004] However, the threshold value of the existing low voltage detection circuit is fixed and can only detect one voltage value. When the power supply voltage or the external pin input voltage changes, the low voltage detection circuit will not be able to successfully perform detection and can only be detected by a low voltage detection circuit with other threshold values. If the voltage values ​​required to be detected are different, multiple low voltage detection circuits are required to perform detection, resulting in high detection costs. Summary of the invention

[0005] The present invention provides a threshold adjustable low voltage detection circuit, chip and integrated circuit, which can reduce the detection cost. The specific technical solution is as follows.

[0006] In a first aspect, the present invention provides a threshold adjustable low voltage detection circuit, comprising: a signal control module, an inverted T-type resistor network digital-to-analog converter DAC module, a first inverting amplifier, an adding circuit and a comparator;

[0007] The inverting input terminal of the first inverting amplifier is connected to the external first voltage input terminal, and the output terminal of the first inverting amplifier is connected to the inverting input terminal of the adding circuit;

[0008] The voltage input terminal of the inverted T-type resistor network DAC module is connected to the external second voltage input terminal, the output terminal of the signal control module is connected to the signal input terminal of the inverted T-type resistor network DAC module, and the output terminal of the inverted T-type resistor network DAC module is connected to the non-inverting input terminal of the adding circuit, wherein the signal control module can control the inverted T-type resistor network DAC module to realize multiple low voltage detection gear switching, each low voltage detection gear corresponds to a different voltage threshold, and the voltage threshold difference between each two adjacent low voltage detection gears is the same, and the voltage threshold difference is a threshold adjustable voltage;

[0009] The output end of the adding circuit is connected to the first input end of the comparator, the second input end of the comparator is connected to the output end of the voltage device to be detected, and the output end of the comparator is connected to the external control device;

[0010] When the signal control module receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module, wherein the control signal is: a signal matching the target low voltage detection gear corresponding to the low voltage detection instruction;

[0011] The inverted T-type resistor network DAC module receives the control signal, and outputs a voltage threshold corresponding to the target low voltage detection gear to the adding circuit based on the output voltage of the external second voltage input terminal and the control signal;

[0012] The adding circuit performs an addition operation on the voltage threshold and the output voltage of the first inverting amplifier to obtain a calculated voltage;

[0013] The comparator compares the calculated voltage with the output voltage of the voltage device to be detected, and outputs a voltage detection result.

[0014] Optionally, the first inverting amplifier includes a first negative feedback resistor and a first inverting proportional operational amplifier;

[0015] The inverting input terminal of the first inverting proportional operational amplifier is connected to the external first voltage input terminal, the inverting input terminal of the first inverting proportional operational amplifier is also connected to the first negative feedback resistor, the first negative feedback resistor is connected to the output terminal of the first inverting proportional operational amplifier, the non-inverting input terminal of the first inverting proportional operational amplifier is grounded, and the output terminal of the first inverting proportional operational amplifier is connected to the inverting input terminal of the adding circuit.

[0016] Optionally, the inverted T-type resistor network DAC module includes n analog switches, the signal control module includes n output terminals, the signal control module stores the corresponding relationship between the voltage threshold and the low voltage detection gear, and the corresponding relationship between each analog switch matched with each low voltage detection gear and each control signal, wherein n is a positive integer, and the signal control module can control the inverted T-type resistor network DAC module to implement 2 n Low voltage detection gear switching;

[0017] When the signal control module receives a low voltage detection instruction, it searches for a target low voltage detection gear corresponding to the voltage value contained in the low voltage detection instruction, determines each control signal matching the target low voltage detection gear, and sends the determined control signals to each corresponding analog switch to control the shutdown of each analog switch, so that the inverted T-type resistor network DAC module outputs a voltage threshold corresponding to the target low voltage detection gear to the adding circuit based on the output voltage of the external second voltage input terminal.

[0018] Optionally, the n is five, and the inverted T-type resistor network DAC module further includes a second inverting amplifier, and six first resistors, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor with the same resistance value, and four seventh resistors, an eighth resistor, a ninth resistor and a tenth resistor with the same resistance value, wherein the resistance value of the first resistor is twice the resistance value of the seventh resistor;

[0019] The first resistor is connected to the seventh resistor, and a lead-out end on the circuit between the two is connected to the second resistor, the seventh resistor is connected to the eighth resistor, and a lead-out end on the circuit between the two is connected to the third resistor, the eighth resistor is connected to the ninth resistor, and a lead-out end on the circuit between the two is connected to the fourth resistor, the ninth resistor is connected to the tenth resistor, and a lead-out end on the circuit between the two is connected to the fifth resistor, and the tenth resistor is connected to the sixth resistor, and a lead-out end on the circuit between the two is connected to an external second voltage input terminal;

[0020] The second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are respectively connected to the five analog switches in a one-to-one correspondence;

[0021] The signal input end of each analog switch is connected to the five output ends of the signal control module one by one, the first end of each analog switch and the first resistor are connected to the non-inverting input end of the second inverting amplifier, the second end of each analog switch is connected to the inverting input end of the second inverting amplifier, and the output end of the second inverting amplifier is connected to the non-inverting input end of the adding circuit;

[0022] For each analog switch, when the control signal received by the analog switch is a disconnect signal, the analog switch switches to the first end; when the control signal received by the analog switch is a close signal, the analog switch switches to the second end.

[0023] Optionally, the second inverting amplifier includes a second negative feedback resistor and a second inverting proportional operational amplifier;

[0024] The first end of each analog switch and the first resistor are connected to the non-inverting input terminal of the second inverting proportional operational amplifier, the non-inverting input terminal of the second inverting proportional operational amplifier is grounded, the second end of each analog switch is connected to the inverting input terminal of the second inverting proportional operational amplifier, the inverting input terminal of the second inverting proportional operational amplifier is also connected to the second negative feedback resistor, the second negative feedback resistor is connected to the output terminal of the second inverting proportional operational amplifier, and the output terminal of the second inverting proportional operational amplifier is connected to the non-inverting input terminal of the adding circuit.

[0025] Optionally, the adding circuit includes a positive-phase terminal resistor, a negative-phase terminal resistor and a third inverting amplifier;

[0026] The output end of the inverted T-type resistor network DAC module is connected to the non-phase end resistor, and the non-phase end resistor is connected to the non-phase input end of the third inverting amplifier;

[0027] The output terminal of the first inverting amplifier is connected to the inverting terminal resistor, the inverting terminal resistor is connected to the inverting input terminal of the third inverting amplifier, and the output terminal of the third inverting amplifier is connected to the first input terminal of the comparator.

[0028] Optionally, the third inverting amplifier includes a third negative feedback resistor and a third inverting proportional operational amplifier;

[0029] The positive-phase terminal resistor is connected to the positive-phase input terminal of the third inverting proportional operational amplifier, the positive-phase input terminal of the third inverting proportional operational amplifier is grounded, the inverting terminal resistor is connected to the inverting terminal input of the third inverting proportional operational amplifier, the inverting input terminal of the third inverting proportional operational amplifier is also connected to the third negative feedback resistor, the third negative feedback resistor is connected to the output terminal of the third inverting proportional operational amplifier, and the output terminal of the third inverting proportional operational amplifier is connected to the first input terminal of the comparator, wherein the resistance values ​​of the positive-phase terminal resistor, the inverting terminal resistor and the third negative feedback resistor are the same.

[0030] Optionally, the comparator determines whether the output voltage of the voltage device to be detected is greater than the calculated voltage;

[0031] If yes, the output voltage detection result is that the voltage is normal;

[0032] If not, the output voltage detection result is low voltage.

[0033] In a second aspect, the present invention provides a chip, comprising: a substrate, on which is packaged the threshold adjustable low voltage detection circuit as described in any one of the first aspects.

[0034] In a third aspect, the present invention provides an integrated circuit, comprising: a voltage device to be detected and a threshold adjustable low voltage detection circuit as described in any one of the first aspects connected thereto.

[0035] It can be seen from the above content that a threshold adjustable low voltage detection circuit provided by an embodiment of the present invention includes: a signal control module, an inverted T-type resistor network digital-to-analog converter DAC module, a first inverting amplifier, an adding circuit and a comparator. The inverting input terminal of the first inverting amplifier is connected to the external first voltage input terminal, and the output terminal of the first inverting amplifier is connected to the inverting input terminal of the adding circuit; the voltage input terminal of the inverted T-type resistor network DAC module is connected to the external second voltage input terminal, the output terminal of the signal control module is connected to the signal input terminal of the inverted T-type resistor network DAC module, and the output terminal of the inverted T-type resistor network DAC module is connected to the positive input terminal of the adding circuit, wherein the signal control module can control the inverted T-type resistor network DAC module to realize multiple low voltage detection gear switching, and the voltage threshold corresponding to each low voltage detection gear is different, and the voltage threshold difference between each two adjacent low voltage detection gears is the same, and the voltage threshold difference is the threshold adjustable voltage; the output terminal of the adding circuit is connected to the first input terminal of the comparator The second input terminal of the comparator is connected to the output terminal of the voltage device to be detected, and the output terminal of the comparator is connected to the external control device; when the signal control module receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module, wherein the control signal is: a signal matching the target low voltage detection gear corresponding to the low voltage detection instruction, the inverted T-type resistor network DAC module receives the control signal, and based on the output voltage of the external second voltage input terminal and the control signal, outputs the voltage threshold corresponding to the target low voltage detection gear to the addition circuit, the addition circuit adds the voltage threshold and the output voltage of the first inverting amplifier to obtain the calculated voltage, and the comparator compares the calculated voltage and the output voltage of the voltage device to be detected, and outputs the voltage detection result. Thus, the inverted T-type resistor network DAC module is controlled by the signal control module to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier, the addition circuit and the comparator to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, the detection of different low voltages can be realized, which greatly reduces the detection cost.

[0036] The innovative features of the embodiments of the present invention include:

[0037] 1. The inverted T-type resistor network DAC module is controlled by the signal control module to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier, the adding circuit and the comparator to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, different low voltages can be detected, which greatly reduces the detection cost.

[0038] 2. Since the signal control module can control the inverted T-type resistor network DAC module to realize the switching of multiple low voltage detection gears, the voltage thresholds corresponding to each low voltage detection gear are different, and the voltage threshold difference between each two adjacent low voltage detection gears is the same. The voltage threshold difference is the threshold adjustable voltage. It can be seen that the threshold adjustable voltage is controlled by the signal control module. Therefore, the threshold adjustable voltage can be adjusted by the signal control module at any time, thereby changing the voltage threshold corresponding to each low voltage detection gear, and further realizing the detection of different low voltages.

[0039] 3. By setting the inverting input terminal of the first inverting proportional operational amplifier to be connected to the external first voltage input terminal, and the output terminal of the first inverting proportional operational amplifier to be connected to the inverting input terminal of the adding circuit, the output voltage of the external first voltage input terminal is inverted by the first inverting amplifier and enters the inverting input terminal of the adding circuit.

[0040] 4. By storing the correspondence between the voltage threshold and the low voltage detection gear, as well as the correspondence between each analog switch matching each low voltage detection gear and each control signal in the signal control module, when the signal control module receives a low voltage detection instruction, it can search for the target low voltage detection gear corresponding to the voltage value contained in the low voltage detection instruction, determine the control signals matching the target low voltage detection gear, and then control the inverted T-type resistor network DAC module to output the voltage threshold corresponding to the target low voltage detection gear to the addition circuit through the determined control signals.

[0041] 5. By setting the second end of each analog switch to be connected to the inverting input end of the second inverting proportional operational amplifier, and the output end of the second inverting proportional operational amplifier to be connected to the non-inverting input end of the adding circuit, the output voltage of the external second voltage input end passes through each analog switch and then is inverted by the second inverting amplifier before entering the non-inverting input end of the adding circuit.

[0042] 6. The signal control module can adjust the voltage threshold corresponding to each low voltage detection gear according to different situations through the resistor network inside the inverted T-type resistor network DAC module, thereby realizing the detection of different low voltages.

[0043] 7. By setting the inverted T-type resistor network DAC module to also include a second inverting amplifier, and six first resistors, second resistors, third resistors, fourth resistors, fifth resistors and sixth resistors with the same resistance value, and four seventh resistors, eighth resistors, ninth resistors and tenth resistors with the same resistance value, as well as the specific connection method between each resistor, each analog switch and the second inverting amplifier in the figure, the inverted T-type resistor network DAC module is controlled by the signal control module to realize the switching of low voltage detection gears, and further realize the detection of low voltages in different gears, which has the advantages of many adjustable gears and a large adjustable voltage range.

[0044] 8. The signal control module in the threshold adjustable low voltage detection circuit controls the inverted T-type resistor network DAC module to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier, the adding circuit and the comparator to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, the embodiment of the present invention provides a chip that can realize the detection of different low voltages, which greatly reduces the detection cost.

[0045] 9. The signal control module in the threshold adjustable low voltage detection circuit controls the inverted T-type resistor network DAC module to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier, the adding circuit and the comparator to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, the embodiment of the present invention provides an integrated circuit that can realize the detection of different low voltages of the voltage device to be detected inside the integrated circuit, which greatly reduces the detection cost.

[0046] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work.

[0048] Figure 1 A schematic diagram of a structure of a low voltage detection circuit with adjustable threshold provided by an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of a voltage detection process of a low voltage detection circuit with adjustable threshold provided in an embodiment of the present invention;

[0050] Figure 3A schematic diagram of the connection between an inverted T-type resistor network digital-to-analog converter DAC module, a first inverting amplifier and an adding circuit provided in an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of the structure of an inverted-T resistor network digital-to-analog converter DAC module provided in an embodiment of the present invention;

[0052] Figure 5 A schematic diagram of the structure of an adding circuit provided in an embodiment of the present invention.

[0053] See also Figure 1-Figure 5 , 1 signal control module, 11 output end, 2 inverted T-type resistor network DAC module, 21 analog switch, 210 signal input end, 211 first end, 212 second end, 22 second inverting amplifier, 221 second negative feedback resistor, 222 second inverting proportional operational amplifier, 231 first resistor, 232 second resistor, 233 third resistor, 234 fourth resistor, 235 fifth resistor, 236 sixth resistor, 237 seventh resistor, 238 eighth resistor, 239 ninth resistor, 230 tenth resistor, 3 first inverting amplifier, 31 first negative feedback resistor, 32 first inverting proportional operational amplifier, 4 adding circuit, 41 positive terminal resistor, 42 inverting terminal resistor, 43 third inverting amplifier, 431 third negative feedback resistor, 432 third inverting proportional operational amplifier, 5 comparator, 6 voltage device to be detected. DETAILED DESCRIPTION

[0054] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that the terms "including" and "having" and any variations thereof in the embodiments of the present invention and the accompanying drawings 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 limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0056] The embodiment of the present invention discloses a threshold adjustable low voltage detection circuit, chip and integrated circuit, which can reduce the detection cost. The embodiment of the present invention is described in detail below.

[0057] Embodiment 1

[0058] Figure 1 A schematic diagram of a low voltage detection circuit with adjustable threshold provided by an embodiment of the present invention. Figure 1 The embodiment of the present invention discloses a threshold adjustable low voltage detection circuit, which includes: a signal control module 1, an inverted T-type resistor network DAC (Digital to analog converter) module 2, a first inverting amplifier 3, an adding circuit 4 and a comparator 5. Specifically, the threshold adjustable low voltage detection circuit disclosed in the embodiment of the present invention can be applied to other integrated circuits, or packaged as a chip separately.

[0059] Among them, the inverted T-type resistor network DAC module 2 is a DAC module with an inverted T-type resistor network inside, and can realize multiple low voltage detection gear switching through the internal inverted T-type resistor network in cooperation with the control of the signal control module 1, that is, the signal control module 1 can control the inverted T-type resistor network DAC module 2 to realize multiple low voltage detection gear switching, and the voltage thresholds corresponding to each low voltage detection gear are different, and the voltage threshold difference between each adjacent low voltage detection gear is the same, and the voltage threshold difference is the threshold adjustable voltage, wherein the voltage value of the threshold adjustable voltage is adjustable, and the low voltage is a voltage whose voltage value is less than the preset voltage value. For example, the preset voltage value can be 5V.

[0060] See also Figure 1 The inverting input terminal of the first inverting amplifier 3 is connected to the external first voltage input terminal, and the output terminal of the first inverting amplifier 3 is connected to the inverting input terminal of the adding circuit 4.

[0061] The voltage input end of the inverted T-type resistor network DAC module 2 is connected to the external second voltage input end, the output end of the signal control module 1 is connected to the signal input end of the inverted T-type resistor network DAC module 2, and the output end of the inverted T-type resistor network DAC module 2 is connected to the non-inverting input end of the adding circuit 4.

[0062] The output end of the adding circuit 4 is connected to the first input end of the comparator 5 , the second input end of the comparator 5 is connected to the output end of the voltage device to be detected 6 , and the output end of the comparator 5 is connected to the external control device.

[0063] In specific operation, when the signal control module 1 receives a low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module 2, wherein the control signal is: a signal that matches the target low voltage detection gear corresponding to the low voltage detection instruction.

[0064] The inverted T-type resistor network DAC module 2 receives a control signal, and based on the output voltage of the external second voltage input terminal and the control signal, outputs a voltage threshold corresponding to the target low voltage detection gear to the adding circuit 4, and the adding circuit 4 adds the voltage threshold and the output voltage of the first inverting amplifier 3 to obtain the calculated voltage.

[0065] The comparator 5 compares the calculated voltage with the output voltage of the voltage device to be detected, and outputs a voltage detection result.

[0066] The comparator 5 compares the calculated voltage with the output voltage of the voltage device 6 to be detected, and the output voltage detection result can be:

[0067] The comparator 5 determines whether the output voltage of the voltage device 6 to be detected is greater than the calculated voltage;

[0068] If yes, the output voltage detection result is that the voltage is normal;

[0069] If not, the output voltage detection result is low voltage.

[0070] Specifically, Figure 2 The voltage detection flow diagram of the threshold adjustable low voltage detection circuit provided in the embodiment of the present invention is as follows during operation:

[0071] 1. The circuit is working, and the voltage is Vbatt.

[0072] The voltage Vbatt when the voltage device to be detected is working, that is, the output voltage of the voltage device to be detected 6 , and the output voltage of the voltage device to be detected is output to the comparator 5 .

[0073] 2. Determine the minimum voltage Vlow for the circuit to operate normally.

[0074] The staff must first determine the minimum voltage Vlow when the voltage device to be detected is working normally. The voltage device to be detected here is Figure 2 The circuit mentioned in .

[0075] 3. Set the threshold Vref according to Vlow.

[0076] Then the staff sets the threshold Vref according to Vlow, which is the voltage threshold corresponding to the target low voltage detection gear.

[0077] For example, the lowest voltage Vlow of the voltage device to be detected when it works normally is 3V, but it may not work well at 3.2V. Therefore, Vref can be set to 3.2V. Of course, Vref can also be set to 3V, according to actual needs.

[0078] 4. When the signal control module 1 receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module 2, wherein the control signal is a signal that matches the target low voltage detection gear corresponding to the low voltage detection instruction. (This step is Figure 2 (not shown)

[0079] After setting the threshold Vref, low voltage detection can be performed. The staff sends a low voltage detection instruction to the signal control module 1. When the signal control module 1 receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module 2, wherein the control signal is: a signal that matches the target low voltage detection gear corresponding to the low voltage detection instruction.

[0080] 5. The inverted T-type resistor network DAC module 2 receives the control signal, and based on the output voltage of the external second voltage input terminal and the control signal, outputs the voltage threshold corresponding to the target low voltage detection gear to the adding circuit 4. (This step is Figure 2 (not shown)

[0081] Since the signal control module 1 can control the inverted T-type resistor network DAC module 2 to realize multiple low voltage detection gear switching, the voltage thresholds corresponding to each low voltage detection gear are different. Therefore, after receiving the control signal, the inverted T-type resistor network DAC module 2 can output the voltage threshold corresponding to the target low voltage detection gear to the addition circuit 4 based on the output voltage of the external second voltage input terminal and the control signal.

[0082] 6. The adding circuit 4 adds the voltage threshold and the output voltage of the first inverting amplifier 3 to obtain the calculated voltage. (This step is Figure 2 (not shown)

[0083] Then, the adding circuit 4 adds the voltage threshold and the output voltage of the first inverting amplifier 3 to obtain a calculated voltage.

[0084] 7. Determine whether Vbatt is greater than Vref, if yes, output high level, if no, output low level. Finally, the comparator 5 compares the calculated voltage with the output voltage of the voltage device to be detected 6, and outputs the voltage detection result.

[0085] Specifically, the comparator 5 determines whether the output voltage of the voltage device 6 to be detected is greater than the voltage after calculation, that is, whether Vbatt is greater than Vref;

[0086] If so, the output voltage detection result is that the voltage is normal, that is, the output is high level;

[0087] If not, the output voltage detection result is that the voltage is too low, that is, the output is a low level.

[0088] In summary, a threshold adjustable low voltage detection circuit disclosed in an embodiment of the present invention includes: a signal control module 1, an inverted T-type resistor network digital-to-analog converter DAC module 2, a first inverting amplifier 3, an adding circuit 4 and a comparator 5. The inverting input terminal of the first inverting amplifier 3 is connected to the external first voltage input terminal, and the output terminal of the first inverting amplifier 3 is connected to the inverting input terminal of the adding circuit 4; the voltage input terminal of the inverted T-type resistor network DAC module 2 is connected to the external second voltage input terminal, the output terminal of the signal control module 1 is connected to the signal input terminal of the inverted T-type resistor network DAC module 2, and the output terminal of the inverted T-type resistor network DAC module 2 is connected to the positive input terminal of the adding circuit 4, wherein the signal control module can control the inverted T-type resistor network DAC module to realize multiple low voltage detection gear switching, and the voltage threshold corresponding to each low voltage detection gear is different, and the voltage threshold difference between each two adjacent low voltage detection gears is the same, and the voltage threshold difference is the threshold adjustable voltage; the output terminal of the adding circuit 4 is connected to the first input terminal of the comparator 5 The second input end of the comparator 5 is connected to the output end of the voltage device to be detected 6, and the output end of the comparator 5 is connected to the external control device; when the signal control module 1 receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module 2, wherein the control signal is: a signal matching the target low voltage detection gear corresponding to the low voltage detection instruction, the inverted T-type resistor network DAC module 2 receives the control signal, and based on the output voltage of the external second voltage input end and the control signal, outputs the voltage threshold corresponding to the target low voltage detection gear to the addition circuit 4, the addition circuit 4 adds the voltage threshold and the output voltage of the first inverting amplifier 3 to obtain the calculated voltage, and the comparator 5 compares the calculated voltage and the output voltage of the voltage device to be detected 6, and outputs the voltage detection result. Thus, the inverted T-type resistor network DAC module 2 is controlled by the signal control module 1 to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier 3, the addition circuit 4 and the comparator 5 to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, the detection of different low voltages can be realized, which greatly reduces the detection cost.

[0089] At the same time, since the signal control module can control the inverted T-type resistor network DAC module to realize the switching of multiple low voltage detection gears, the voltage thresholds corresponding to each low voltage detection gear are different, and the voltage threshold difference between each two adjacent low voltage detection gears is the same, and the voltage threshold difference is the threshold adjustable voltage. It can be seen that the threshold adjustable voltage is controlled by the signal control module. Therefore, the threshold adjustable voltage can be adjusted by the signal control module at any time, thereby changing the voltage threshold corresponding to each low voltage detection gear, and further realizing the detection of different low voltages.

[0090] Figure 3The connection diagram of the inverted T-type resistor network DAC module 2, the first inverting amplifier 3 and the adding circuit 4 provided in the embodiment of the present invention is shown in FIG. Figure 3 The first inverting amplifier 3 includes a first negative feedback resistor 31 and a first inverting proportional operational amplifier 32 .

[0091] The inverting input terminal of the first inverting proportional operational amplifier 32 is connected to the external first voltage input terminal, the inverting input terminal of the first inverting proportional operational amplifier 32 is also connected to the first negative feedback resistor 31, the first negative feedback resistor 31 is connected to the output terminal of the first inverting proportional operational amplifier 32, the non-inverting input terminal of the first inverting proportional operational amplifier 32 is grounded, and the output terminal of the first inverting proportional operational amplifier 32 is connected to the inverting input terminal of the adding circuit 4. Exemplarily, the output voltage of the external first voltage input terminal can be 1.8V.

[0092] Therefore, by setting the inverting input terminal of the first inverting proportional operational amplifier 32 to be connected to the external first voltage input terminal, and the output terminal of the first inverting proportional operational amplifier 32 to be connected to the inverting input terminal of the adding circuit 4, the output voltage of the external first voltage input terminal is inverted by the first inverting amplifier 3 and then enters the inverting input terminal of the adding circuit 4.

[0093] Figure 4 The schematic diagram of the structure of the inverted T-type resistor network digital-to-analog converter DAC module provided by the embodiment of the present invention is shown in FIG. Figure 4 The inverted T-type resistor network DAC module 2 includes n analog switches 21 , and the signal control module 1 includes n output terminals 11 .

[0094] The signal control module 1 stores the corresponding relationship between the voltage threshold and the low voltage detection gear, and the corresponding relationship between each analog switch matched by each low voltage detection gear and each control signal, wherein n is a positive integer, and the signal control module 1 can control the inverted T-type resistor network DAC module 2 to realize 2 n The control signal is used to control the shutdown of the analog switch.

[0095] When the signal control module 1 receives a low voltage detection instruction, it searches for the target low voltage detection gear corresponding to the voltage value contained in the low voltage detection instruction, determines the control signals matching the target low voltage detection gear, and sends the determined control signals to the corresponding analog switches 21 to control the shutdown of the analog switches 21, so that the inverted T-type resistor network DAC module 2 outputs the voltage threshold corresponding to the target low voltage detection gear based on the output voltage of the external second voltage input terminal to the adding circuit 4.

[0096] Therefore, by storing the correspondence between the voltage threshold and the low voltage detection gear, as well as the correspondence between each analog switch matching each low voltage detection gear and each control signal in the signal control module 1, when the signal control module 1 receives a low voltage detection instruction, it can search for the target low voltage detection gear corresponding to the voltage value contained in the low voltage detection instruction, determine the control signals matching the target low voltage detection gear, and then control the inverted T-type resistor network DAC module 2 to output the voltage threshold corresponding to the target low voltage detection gear to the addition circuit 4 through the determined control signals.

[0097] Continue to see Figure 4 The inverted T-type resistor network DAC module 2 has an inverted T-type resistor network inside. Specifically, n is five. The inverted T-type resistor network DAC module 2 also includes a second inverting amplifier 22, and six first resistors 231, second resistors 232, third resistors 233, fourth resistors 234, fifth resistors 235 and sixth resistors 236 with the same resistance value, and four seventh resistors 237, eighth resistors 238, ninth resistors 239 and tenth resistors 230 with the same resistance value, wherein the resistance value of the first resistor 231 is twice the resistance value of the seventh resistor 237.

[0098] The first resistor 231 is connected to the seventh resistor 237 and a lead-out end of the circuit between the two is connected to the second resistor 232, the seventh resistor 237 is connected to the eighth resistor 238 and a lead-out end of the circuit between the two is connected to the third resistor 233, the eighth resistor 238 is connected to the ninth resistor 239 and a lead-out end of the circuit between the two is connected to the fourth resistor 234, the ninth resistor 239 is connected to the tenth resistor 230 and a lead-out end of the circuit between the two is connected to the fifth resistor 235, and the tenth resistor 230 is connected to the sixth resistor 236 and a lead-out end of the circuit between the two is connected to the external second voltage input terminal.

[0099] The second resistor 232 , the third resistor 233 , the fourth resistor 234 , the fifth resistor 235 and the sixth resistor 236 are connected to the five analog switches 21 in a one-to-one correspondence.

[0100] The signal input end 210 of each analog switch 21 is connected to the five output ends 11 of the signal control module 1 in a one-to-one correspondence, the first end 211 of each analog switch 21 and the first resistor 231 are connected to the non-inverting input end of the second inverting amplifier 22, the second end 212 of each analog switch 21 is connected to the inverting input end of the second inverting amplifier 22, and the output end of the second inverting amplifier 22 is connected to the non-inverting input end of the adding circuit 4;

[0101] For each analog switch 21 , when the control signal received by the analog switch 21 is a disconnect signal, the analog switch is switched to the first end 211 , and when the control signal received by the analog switch 21 is a close signal, the analog switch is switched to the second end 212 .

[0102] Continue to see Figure 4 The second inverting amplifier 22 includes a second negative feedback resistor 221 and a second inverting proportional operational amplifier 222 .

[0103] The first end 211 of each analog switch 21 and the first resistor 231 are connected to the non-inverting input end of the second inverting proportional operational amplifier 222, the non-inverting input end of the second inverting proportional operational amplifier 222 is grounded, the second end 212 of each analog switch 21 is connected to the inverting input end of the second inverting proportional operational amplifier 222, the inverting input end of the second inverting proportional operational amplifier 222 is also connected to the second negative feedback resistor 221, the second negative feedback resistor 221 is connected to the output end of the second inverting proportional operational amplifier 222, and the output end of the second inverting proportional operational amplifier 222 is connected to the non-inverting input end of the adding circuit 4. The resistance value of the second negative feedback resistor 221 is the same as the resistance value of the seventh resistor 237.

[0104] Therefore, by setting the second end 212 of each analog switch 21 to be connected to the inverting input end of the second inverting proportional operational amplifier 222, and the output end of the second inverting proportional operational amplifier 222 to be connected to the non-inverting input end of the adding circuit 4, the output voltage of the external second voltage input end passes through each analog switch 21, and then is inverted by the second inverting amplifier 22 and enters the non-inverting input end of the adding circuit 4.

[0105] Continue to see Figure 4 Assuming that the resistance values ​​of the first resistor 231 and the second negative feedback resistor 221 are both R, the resistance value of the seventh resistor 237 is 2R, and the five analog switches 21 are Figure 4 The left side to the right side are S1-S5, and the control signal corresponding to S1 is d 0 , the control signal corresponding to S2 is d 1 , the control signal corresponding to S3 is d 2 , the control signal corresponding to S4 is d 3 , the control signal corresponding to S5 is d 4 .

[0106] Depend on Figure 4It can be obtained that the two 2R resistors in parallel of the S1 branch are equal to R, and the R obtained in parallel is connected in series with R to obtain 2R; by analogy, the resistance 2R of the S5 branch is equal to the overall resistance 2R on the left, and the total resistance after parallel connection is R, where the S1 branch is a circuit composed of the analog switch S1 and the second resistor 232 connected to it, and the S2 branch-S5 branch are similar and will not be repeated here.

[0107] Assuming the total current is I, according to Ohm's law, the current of the S5 branch is I / 2, the current of the S4 branch is I / 4, the current of the S3 branch is I / 8, the current of the S2 branch is I / 16, and the current of the S1 branch is I / 32. When di=1, it means that the control signal controls the i-th analog switch Si to be closed, that is, to be turned on, that is, to control the analog switch Si to switch to the second terminal 212, at this time, Ii flows into IΣ, when di is equal to 0, it means that the control signal controls the analog switch Si to be disconnected, that is, to control the analog switch Si to switch to the first terminal 211, at this time, Ii flows into the ground terminal, thus:

[0108]

[0109] In the formula, I ∑ is the total current, d 0 is the control signal corresponding to the analog switch S1, d 1 is the control signal corresponding to the analog switch S2, d 2 is the control signal corresponding to the analog switch S3, d 3 is the control signal corresponding to the analog switch S4, d 4 It is the control signal corresponding to the analog switch S5.

[0110] Then the output voltage v of the second inverting amplifier 22 is 2 for:

[0111]

[0112] Where V r is the voltage value inputted by the external second voltage input terminal, D is the voltage coefficient, and the range of D is 0 to 2 n -1, so:

[0113]

[0114] Because it passes through the second inverting amplifier 22, v 2 is negative.

[0115] Therefore, the signal control module 1 can adjust the voltage threshold corresponding to each low voltage detection gear according to different situations through the resistor network inside the inverted T-type resistor network DAC module, thereby realizing the detection of different low voltages.

[0116] And, by setting the inverted T-type resistor network DAC module, the module also includes a second inverting amplifier, and six first resistors, second resistors, third resistors, fourth resistors, fifth resistors and sixth resistors with the same resistance value, and four seventh resistors, eighth resistors, ninth resistors and tenth resistors with the same resistance value, and Figure 4 The specific connection mode between each resistor, each analog switch 21 and the second inverting amplifier 22 is realized by controlling the inverted T-type resistor network DAC module 2 through the signal control module 1. 5 The low voltage detection gear switch can further realize the detection of low voltage in 32 different gears, and has the advantages of many adjustable gears and a large adjustable voltage range.

[0117] Figure 5 A schematic diagram of the structure of the adding circuit provided in the embodiment of the present invention is shown in FIG. Figure 5 The adding circuit 4 includes a non-phase terminal resistor 41 , an inverting terminal resistor 42 and a third inverting amplifier 43 .

[0118] The output end of the inverted T-type resistor network DAC module 2 is connected to the non-phase terminal resistor 41 , and the non-phase terminal resistor 41 is connected to the non-phase input end of the third inverting amplifier 43 .

[0119] The output terminal of the first inverting amplifier 3 is connected to the inverting terminal resistor 42 , the inverting terminal resistor 42 is connected to the inverting input terminal of the third inverting amplifier 43 , and the output terminal of the third inverting amplifier 43 is connected to the first input terminal of the comparator 5 .

[0120] Among them, continue to see Figure 5 The third inverting amplifier 43 includes a third negative feedback resistor 431 and a third inverting proportional operational amplifier 432 .

[0121] The positive phase terminal resistor 41 is connected to the positive phase input terminal of the third inverting proportional operational amplifier 432, the positive phase input terminal of the third inverting proportional operational amplifier 432 is grounded, the inverting phase terminal resistor 42 is connected to the inverting phase input terminal of the third inverting proportional operational amplifier 432, the inverting phase input terminal of the third inverting proportional operational amplifier 432 is also connected to the third negative feedback resistor 431, the third negative feedback resistor 431 is connected to the output terminal of the third inverting proportional operational amplifier 432, the output terminal of the third inverting proportional operational amplifier 432 is connected to the first input terminal of the comparator 5, wherein the resistance values ​​of the positive phase terminal resistor 41, the inverting phase terminal resistor 42 and the third negative feedback resistor 431 are the same.

[0122] Continue to see Figure 5 , assuming that the positive phase terminal resistor 41 is R 2 , the inverting terminal resistor 42 is R 1 and the third negative feedback resistor 431 is R 3 .

[0123] The non-inverting input terminal of the third inverting proportional operational amplifier 432 is grounded. According to the virtual short characteristic, the potential of the inverting input terminal of the third inverting proportional operational amplifier 432 is also 0. Therefore, the currents of the two input branches are respectively:

[0124]

[0125] Since no current flows into the input terminal of the ideal third inverting proportional operational amplifier 432, I 1 ,I 2 After merging, all flows to R 3 According to Ohm's law, the output voltage v 3 That is, Vref is:

[0126]

[0127] When the configuration resistor is: R 3 =R 1 =R 2 When , the addition operation is realized:

[0128] v 3 =-(v 1 +v 2 )

[0129] Therefore, the addition operation is achieved by setting the adding circuit 4 to include a positive phase terminal resistor 41, a negative phase terminal resistor 42 and a third inverting amplifier 43, and the positive phase terminal resistor 41, the negative phase terminal resistor 42 and the third negative feedback resistor 431 have the same resistance value.

[0130] For ease of understanding, the voltage detection process of the threshold adjustable low voltage detection circuit provided by the embodiment of the present invention is introduced below through a specific embodiment:

[0131] Assume that the output voltage of the external second voltage input terminal is 3.2V and enters the inverted T-type resistor network DAC module 2 as the reference voltage of the inverted T-type resistor network inside the inverted T-type resistor network DAC module 2. The inverted T-type resistor network inside the inverted T-type resistor network DAC module 2 has five analog switches 21, which are controlled by a 5-bit control signal, which is 00000, 00001, 00010, 00011......11111. There are 32 control modes in total, corresponding to 32 low voltage detection gears. Because the reference voltage is 3.2V, the adjustment amplitude corresponding to each gear is 0.1V, that is, the threshold adjustable voltage, so the adjustable voltage output by the inverted T-type resistor network DAC module 2 is 0V~-3.1V.

[0132] The output voltage of the inverted-T resistor network DAC module 2 enters the non-inverting input terminal of the summing circuit 4, and the output voltage of 1.8V from the external first voltage input terminal is inverted by the first inverting amplifier 3 and then enters the inverting input terminal of the summing circuit 4.

[0133] The output voltage (0V to -3.1V) of the inverted-T resistor network DAC module 2 and the output voltage (-1.8V) of the first inverting amplifier 3 are added by the summing circuit 4, and the output voltage, that is, the voltage after operation, is 1.8V to 4.9V. This voltage is used as the reference voltage Vref, which is the threshold set above, and is compared with the output voltage Vbatt of the voltage device 6 to be detected in the comparator 5. If Vbatt < Vref, a low level is output; if Vbatt > Vref, a high level is output.

[0134] Thus, by changing the control signal to adjust the output voltage of the inverted-T resistor network DAC module 2, an adjustable voltage with a range of 1.8V to 4.9V, a range of 3.2V, and 32 steps, each step being 0.1V, is achieved, which is the threshold adjustable voltage of the entire system.

[0135] Embodiment Two

[0136] An embodiment of the present invention provides a chip, including: a substrate, on which a threshold adjustable low voltage detection circuit as provided in Embodiment One is encapsulated.

[0137] Thus, through the signal control module 1 in the threshold adjustable low voltage detection circuit, the inverted-T resistor network DAC module 2 is controlled to realize the switching of multiple low voltage detection gears, and then, in cooperation with the first inverting amplifier 3, the summing circuit 4 and the comparator 5, the final voltage detection result is obtained. Since the voltage thresholds corresponding to the respective low voltage detection gears are different and not fixed, an embodiment of the present invention provides a chip that can realize the detection of different low voltages, greatly reducing the detection cost.

[0138] This terminal embodiment and Figure 1 The system embodiment shown is an embodiment obtained based on the same inventive concept, and the relevant parts can be referred to each other. The above terminal embodiment corresponds to the system embodiment and has the same technical effect as the system embodiment. For specific descriptions, refer to the system embodiment.

[0139] Embodiment Three

[0140] An embodiment of the present invention provides an integrated circuit, including: a voltage device to be detected and a threshold adjustable low voltage detection circuit as provided in Embodiment One connected thereto.

[0141] Therefore, the signal control module 1 in the threshold adjustable low voltage detection circuit controls the inverted T-type resistor network DAC module 2 to realize the switching of multiple low voltage detection gears, so as to cooperate with the first inverting amplifier 3, the adding circuit 4 and the comparator 5 to obtain the final voltage detection result. Since the voltage thresholds corresponding to each low voltage detection gear are different and not fixed, the embodiment of the present invention provides an integrated circuit that can realize the detection of different low voltages of the voltage device to be detected inside the integrated circuit, which greatly reduces the detection cost.

[0142] The terminal embodiment and Figure 1 The system embodiments shown are embodiments based on the same inventive concept, and relevant parts can be referenced to each other. The above terminal embodiments correspond to the system embodiments and have the same technical effects as the system embodiments. For specific descriptions, refer to the system embodiments.

[0143] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0144] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from the embodiment. The modules in the above embodiment can be combined into one module, or can be further divided into multiple sub-modules.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A threshold adjustable low voltage detection circuit, characterized in that: include: A signal control module, an inverted T-type resistor network digital-to-analog converter DAC module, a first inverting amplifier, an adding circuit and a comparator; The inverting input terminal of the first inverting amplifier is connected to the external first voltage input terminal, and the output terminal of the first inverting amplifier is connected to the inverting input terminal of the adding circuit; The voltage input terminal of the inverted T-type resistor network DAC module is connected to the external second voltage input terminal, the output terminal of the signal control module is connected to the signal input terminal of the inverted T-type resistor network DAC module, and the output terminal of the inverted T-type resistor network DAC module is connected to the non-inverting input terminal of the adding circuit, wherein the signal control module can control the inverted T-type resistor network DAC module to realize multiple low voltage detection gear switching, each low voltage detection gear corresponds to a different voltage threshold, and the voltage threshold difference between each two adjacent low voltage detection gears is the same, and the voltage threshold difference is a threshold adjustable voltage; The output end of the adding circuit is connected to the first input end of the comparator, the second input end of the comparator is connected to the output end of the voltage device to be detected, and the output end of the comparator is connected to the external control device; When the signal control module receives the low voltage detection instruction, it sends a control signal to the inverted T-type resistor network DAC module, wherein the control signal is: a signal matching the target low voltage detection gear corresponding to the low voltage detection instruction; The inverted T-type resistor network DAC module receives the control signal, and outputs a voltage threshold corresponding to the target low voltage detection gear to the adding circuit based on the output voltage of the external second voltage input terminal and the control signal; The adding circuit performs an addition operation on the voltage threshold and the output voltage of the first inverting amplifier to obtain a calculated voltage; The comparator compares the calculated voltage with the output voltage of the voltage device to be detected, and outputs a voltage detection result.

2. The threshold adjustable low voltage detection circuit according to claim 1, characterized in that: The first inverting amplifier includes a first negative feedback resistor and a first inverting proportional operational amplifier; The inverting input terminal of the first inverting proportional operational amplifier is connected to the external first voltage input terminal, the inverting input terminal of the first inverting proportional operational amplifier is also connected to the first negative feedback resistor, the first negative feedback resistor is connected to the output terminal of the first inverting proportional operational amplifier, the non-inverting input terminal of the first inverting proportional operational amplifier is grounded, and the output terminal of the first inverting proportional operational amplifier is connected to the inverting input terminal of the adding circuit.

3. The threshold adjustable low voltage detection circuit according to claim 1, characterized in that: The inverted T-type resistor network DAC module includes n analog switches, the signal control module includes n output terminals, the signal control module stores the corresponding relationship between the voltage threshold and the low voltage detection gear, and the corresponding relationship between each analog switch matched with each low voltage detection gear and each control signal, wherein n is a positive integer, and the signal control module can control the inverted T-type resistor network DAC module to realize 2 n Low voltage detection gear switching; When the signal control module receives a low voltage detection instruction, it searches for a target low voltage detection gear corresponding to the voltage value contained in the low voltage detection instruction, determines each control signal matching the target low voltage detection gear, and sends the determined control signals to each corresponding analog switch to control the shutdown of each analog switch, so that the inverted T-type resistor network DAC module outputs a voltage threshold corresponding to the target low voltage detection gear to the adding circuit based on the output voltage of the external second voltage input terminal.

4. The threshold adjustable low voltage detection circuit as claimed in claim 3, characterized in that: The n is five, and the inverted T-type resistor network DAC module further includes a second inverting amplifier, and six first resistors, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor with the same resistance value, and four seventh resistors, an eighth resistor, a ninth resistor and a tenth resistor with the same resistance value, wherein the resistance value of the first resistor is twice the resistance value of the seventh resistor; The first resistor is connected to the seventh resistor, and a lead-out end on the circuit between the two is connected to the second resistor, the seventh resistor is connected to the eighth resistor, and a lead-out end on the circuit between the two is connected to the third resistor, the eighth resistor is connected to the ninth resistor, and a lead-out end on the circuit between the two is connected to the fourth resistor, the ninth resistor is connected to the tenth resistor, and a lead-out end on the circuit between the two is connected to the fifth resistor, and the tenth resistor is connected to the sixth resistor, and a lead-out end on the circuit between the two is connected to an external second voltage input terminal; The second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are respectively connected to the five analog switches in a one-to-one correspondence; The signal input end of each analog switch is connected to the five output ends of the signal control module one by one, the first end of each analog switch and the first resistor are connected to the non-inverting input end of the second inverting amplifier, the second end of each analog switch is connected to the inverting input end of the second inverting amplifier, and the output end of the second inverting amplifier is connected to the non-inverting input end of the adding circuit; For each analog switch, when the control signal received by the analog switch is a disconnect signal, the analog switch switches to the first end; when the control signal received by the analog switch is a close signal, the analog switch switches to the second end.

5. The threshold adjustable low voltage detection circuit as claimed in claim 4, characterized in that: The second inverting amplifier includes a second negative feedback resistor and a second inverting proportional operational amplifier; The first end of each analog switch and the first resistor are connected to the non-inverting input terminal of the second inverting proportional operational amplifier, the non-inverting input terminal of the second inverting proportional operational amplifier is grounded, the second end of each analog switch is connected to the inverting input terminal of the second inverting proportional operational amplifier, the inverting input terminal of the second inverting proportional operational amplifier is also connected to the second negative feedback resistor, the second negative feedback resistor is connected to the output terminal of the second inverting proportional operational amplifier, and the output terminal of the second inverting proportional operational amplifier is connected to the non-inverting input terminal of the adding circuit.

6. The threshold adjustable low voltage detection circuit as claimed in claim 1, characterized in that: The adding circuit includes a positive phase terminal resistor, a negative phase terminal resistor and a third inverting amplifier; The output end of the inverted T-type resistor network DAC module is connected to the non-phase end resistor, and the non-phase end resistor is connected to the non-phase input end of the third inverting amplifier; The output terminal of the first inverting amplifier is connected to the inverting terminal resistor, the inverting terminal resistor is connected to the inverting input terminal of the third inverting amplifier, and the output terminal of the third inverting amplifier is connected to the first input terminal of the comparator.

7. The threshold adjustable low voltage detection circuit as claimed in claim 6, characterized in that: The third inverting amplifier comprises a third negative feedback resistor and a third inverting proportional operational amplifier; The positive-phase terminal resistor is connected to the positive-phase input terminal of the third inverting proportional operational amplifier, the positive-phase input terminal of the third inverting proportional operational amplifier is grounded, the inverting terminal resistor is connected to the inverting terminal input of the third inverting proportional operational amplifier, the inverting input terminal of the third inverting proportional operational amplifier is also connected to the third negative feedback resistor, the third negative feedback resistor is connected to the output terminal of the third inverting proportional operational amplifier, and the output terminal of the third inverting proportional operational amplifier is connected to the first input terminal of the comparator, wherein the resistance values ​​of the positive-phase terminal resistor, the inverting terminal resistor and the third negative feedback resistor are the same.

8. The threshold adjustable low voltage detection circuit according to any one of claims 1 to 7, characterized in that: The comparator determines whether the output voltage of the voltage device to be detected is greater than the calculated voltage; If yes, the output voltage detection result is that the voltage is normal; If not, the output voltage detection result is low voltage.

9. A chip, characterized in that: include: A substrate on which the threshold adjustable low voltage detection circuit as claimed in any one of claims 1 to 8 is packaged.

10. An integrated circuit, characterized in that: include: A voltage device to be detected and a low voltage detection circuit with adjustable threshold as claimed in any one of claims 1 to 8 connected thereto.

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