Extension circuit, extension method and electronic device

Abstract

The application discloses an extension circuit, an extension method and an electronic device, relates to the technical field of electronic circuits, and is used for connecting with an input voltage and a signal detection circuit respectively and extending the range of the input voltage, wherein the signal detection circuit is used for detecting an electric signal related to a first resistor, the signal detection circuit comprises an amplifier and a detection resistor, and the extension circuit comprises a first current branch and a second current branch. The first current branch and the second current branch are both used for dividing the input voltage, so as to reduce the current or voltage input to the first input end and the second input end of the amplifier, and the maximum value of the input voltage at which the signal detection circuit can normally work is improved. In the above manner, the range of the input voltage at which the signal detection circuit can normally work can be extended.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to an extension circuit, an extension method, and an electronic device. Background Technology

[0002] Currently, various electrical signal detection circuits, such as current detection circuits and voltage detection circuits, are widely used in electronic products. Furthermore, electrical signal detection circuits typically include an amplifier to... Figure 1 The electrical signal detection circuit shown is an example.

[0003] like Figure 1 As shown, the output voltage of amplifier U1 controls the current I11 flowing through the seventeenth transistor MN1, ensuring that the voltages across the first resistor RSNS and the sensing resistor R1 are equal, i.e., I11*r1=rsns*Io1, where r1 is the resistance of the sensing resistor R1, rsns is the resistance of the first resistor Rsns, and Io1 is the current flowing through the first resistor Rsns. The eighteenth transistor MN2 then mirrors the current I11 from the seventeenth transistor MN1 to the output current Isns. Therefore, the current flowing through the first resistor Rsns can be determined by Io1=Isns*r1 / rsns.

[0004] However, for this type of electrical signal detection circuit, due to the presence of the amplifier and the limitation of the input signal voltage of amplifier U1, the input voltage VIN can only vary within a narrow range in order to maintain the normal operation of amplifier U1. Summary of the Invention

[0005] This application aims to provide an extension circuit, extension method, and electronic device that can extend the input voltage range in which an electrical signal detection circuit can operate normally.

[0006] To achieve the above objectives, in a first aspect, this application provides an extension circuit, which is connected to an input voltage and an electrical signal detection circuit respectively, and is used to extend the range of the input voltage. The electrical signal detection circuit is used to detect an electrical signal related to a first resistor, and includes an amplifier and a detection resistor. The extension circuit includes:

[0007] The first current branch and the second current branch;

[0008] The first end of the first current branch is connected to the input voltage through the detection resistor, the second end of the first current branch is connected to the first input terminal of the amplifier and the first current source respectively, the first end of the second current branch is connected to the input voltage through the first resistor, and the second end of the second current branch is connected to the second input terminal of the amplifier and the second current source.

[0009] Both the first current branch and the second current branch are used to divide the input capacitor to reduce the current or voltage input to the first and second input terminals of the amplifier, thereby increasing the maximum value of the input voltage at which the electrical signal detection circuit can operate normally.

[0010] In one alternative embodiment, the expansion circuit further includes a switching branch and a voltage detection branch;

[0011] The first end of the voltage detection branch is connected to the input voltage, the second end of the voltage detection branch is connected to the first end of the switch branch, the second end of the switch branch is connected to the third end of the first current branch, the third end of the switch branch is connected to the third end of the second current branch, the fourth end of the switch branch is connected to the second end of the first current branch, and the fifth end of the switch branch is connected to the second end of the second current branch.

[0012] The voltage detection branch is used to detect the magnitude of the input voltage, and outputs a first control signal when the input voltage is not greater than a first preset voltage, and outputs a second control signal when the input voltage is greater than the first preset voltage;

[0013] The switching branch is used to turn on the second and fourth terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the first current branch.

[0014] The switching branch is also used to turn on the third and fifth terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the second current branch.

[0015] The switch branch is also used to disconnect the connection between the second and fourth terminals of the switch branch in response to the second control signal, and to disconnect the connection between the third and fifth terminals of the switch branch.

[0016] In one alternative embodiment, the expansion circuit further includes a first voltage bias branch;

[0017] The first end of the first voltage bias branch is connected to the input voltage, the second end of the first voltage bias branch is connected to the sixth end of the switch branch, the third end of the first voltage bias branch is connected to the seventh end of the switch branch and the third current source respectively, and the voltage bias circuit also has at least one end connected to the first current branch and the second current branch respectively.

[0018] The first voltage bias branch is used to output at least one bias voltage based on the input voltage, so as to keep at least one transistor in the first current branch on and to keep at least one transistor in the second current branch on.

[0019] The switching branch is also used to turn on the sixth and seventh terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the first voltage bias branch.

[0020] The switch branch is also used to disconnect the connection between the sixth and seventh terminals of the switch branch in response to the second control signal.

[0021] In one alternative embodiment, the voltage detection branch includes a second voltage bias branch, a third current branch, and a trigger branch;

[0022] The first terminal of the second voltage bias branch and the first terminal of the third current branch are both connected to the input voltage. The second terminal of the second voltage bias branch is connected to the fourth current source. The second terminal of the third current branch is connected to the fifth current source and the first terminal of the trigger branch, respectively. The second terminal of the trigger branch is connected to the first terminal of the switch branch.

[0023] The second voltage bias branch is used to output at least one bias voltage to the third current branch based on the input voltage, so as to keep at least one transistor in the third current branch on and to adjust the pull-up current in the third current branch.

[0024] The third current branch is used to output a trigger current to the trigger branch based on the difference between the pull-up current and the pull-down current flowing into the fifth current source;

[0025] The trigger branch is used to output the first control signal when the trigger current is not greater than the first preset current, and to output the second control signal when the trigger current is greater than the first preset current.

[0026] In one alternative embodiment, the extension circuit further includes a current bias branch;

[0027] The first end of the current bias branch is connected to the first end of the main current source, the second end of the current bias branch is connected to the second end of the second voltage bias branch, the third end of the current bias branch is connected to the second end of the third current branch, the fourth end of the current bias branch is connected to the third end of the first voltage bias branch, the fifth end of the current bias branch is connected to the second end of the first current branch, and the sixth end of the current bias branch is connected to the second end of the second current branch.

[0028] The current bias branch is used to configure the input current of the first current source, the second current source, the third current source, the fourth current source, and the fifth current source based on the current output by the main current source.

[0029] In one alternative, the current flowing into the second terminal of the current bias branch is configured to be greater than the current flowing into the third terminal of the current bias branch.

[0030] In one alternative embodiment, the first current branch includes a first transistor and a second transistor;

[0031] The first terminal of the first transistor is connected to the first bias voltage, the second terminal of the first transistor is connected to the detection resistor, the third terminal of the first transistor is connected to the second terminal of the second transistor, the first terminal of the second transistor is connected to the second bias voltage, and the third terminal of the second transistor is connected to the first input terminal of the amplifier and the first current source, respectively.

[0032] Wherein, the second terminal of the first transistor is the first terminal of the first current branch, the third terminal of the second transistor is the second terminal of the first current branch, the third terminal of the first transistor is the third terminal of the first current branch, the first terminal of the first transistor is the fourth terminal of the first current branch, and the first terminal of the second transistor is the fifth terminal of the first current branch.

[0033] In one alternative embodiment, the second current branch includes a third transistor and a fourth transistor;

[0034] The first terminal of the third transistor is connected to the first bias voltage, the second terminal of the third transistor is connected to the first resistor, the third terminal of the third transistor is connected to the second terminal of the fourth transistor, the first terminal of the fourth transistor is connected to the second bias voltage, and the third terminal of the fourth transistor is connected to the second input terminal of the amplifier and the second current source, respectively.

[0035] Wherein, the second terminal of the third transistor is the first terminal of the second current branch, the third terminal of the fourth transistor is the second terminal of the second current branch, the third terminal of the third transistor is the third terminal of the second current branch, the first terminal of the third transistor is the fourth terminal of the second current branch, and the first terminal of the fourth transistor is the fifth terminal of the second current branch.

[0036] In one alternative embodiment, the switch branch includes a first switch and a second switch;

[0037] The first terminal of the first switch and the first terminal of the second switch are both connected to the voltage detection branch. The second terminal of the first switch is connected to the second terminal of the first current branch. The third terminal of the first switch is connected to the third terminal of the first current branch. The second terminal of the second switch is connected to the second terminal of the second current branch. The third terminal of the second switch is connected to the third terminal of the second current branch.

[0038] Wherein, the first end of the first switch is the first end of the switch branch, the third end of the first switch is the second end of the switch branch, the third end of the second switch is the third end of the switch branch, the second end of the first switch is the fourth end of the switch branch, and the second end of the second switch is the fifth end of the switch branch.

[0039] In an alternative embodiment, the switching branch further includes a third switch, and the first voltage bias branch includes a second resistor, a fifth transistor, and a sixth transistor;

[0040] The first end of the second resistor is connected to the input voltage, the second end of the second resistor is connected to the second end of the fifth transistor, the first end of the fifth transistor is connected to the third end of the fifth transistor, the second end of the sixth transistor, the third end of the third switch, the fourth end of the first current branch and the fourth end of the second current branch, respectively, and the first end of the sixth transistor is connected to the third end of the sixth transistor, the second end of the third switch, the third current source, the fifth end of the first current branch and the fifth end of the second current branch, respectively.

[0041] Wherein, the third terminal of the third switch is the sixth terminal of the switch branch, the second terminal of the third switch is the seventh terminal of the switch branch, the first terminal of the second resistor is the first terminal of the first voltage bias branch, the third terminal of the fifth transistor is the second terminal of the first voltage bias branch, the third terminal of the sixth transistor is the third terminal of the first voltage bias branch, the voltage at the first terminal of the fifth transistor is the first bias voltage, and the voltage at the first terminal of the sixth transistor is the second bias voltage.

[0042] In one alternative embodiment, the second voltage bias branch includes a third resistor, a seventh transistor, and an eighth transistor;

[0043] The first end of the third resistor is connected to the input voltage, the second end of the third resistor is connected to the second end of the seventh transistor, the first end of the seventh transistor is connected to the third end of the seventh transistor, the second end of the eighth transistor and the third end of the third current branch, and the first end of the eighth transistor is connected to the third end of the eighth transistor, the fourth current source and the fourth end of the third current branch.

[0044] Wherein, the first end of the third resistor is the first end of the second voltage bias branch, the third end of the eighth transistor is the second end of the second voltage bias branch, and the first end of the seventh transistor is the third end of the second voltage bias branch.

[0045] In one alternative embodiment, the third current branch includes a fourth resistor, a ninth transistor, and a tenth transistor;

[0046] The first end of the fourth resistor is connected to the input voltage, the second end of the fourth resistor is connected to the second end of the ninth transistor, the first end of the ninth transistor is connected to the third end of the second voltage bias branch, the third end of the ninth transistor is connected to the second end of the tenth transistor, the first end of the tenth transistor is connected to the second end of the second voltage bias branch, and the third end of the tenth transistor is connected to the first end of the fifth current source and the trigger branch, respectively.

[0047] Wherein, the first end of the fourth resistor is the first end of the third current branch, the third end of the tenth transistor is the second end of the third current branch, the first end of the ninth transistor is the third end of the third current branch, and the first end of the tenth transistor is the fourth end of the third current branch.

[0048] In one alternative approach, the triggering branch includes a Schmitt trigger;

[0049] The input terminal of the Schmitt trigger is connected to the second terminal of the third current branch, and the output terminal of the Schmitt trigger is connected to the first terminal of the switch branch.

[0050] Wherein, the input terminal of the Schmitt trigger is the first terminal of the trigger branch, and the output terminal of the Schmitt trigger is the second terminal of the trigger branch.

[0051] In one alternative embodiment, the current biasing circuit includes an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor;

[0052] The first terminal of the eleventh transistor is connected to the main current source, the third terminal of the eleventh transistor, the first terminal of the twelfth transistor, the first terminal of the thirteenth transistor, the first terminal of the fourteenth transistor, the first terminal of the fifteenth transistor, and the first terminal of the sixteenth transistor. The third terminal of the twelfth transistor is connected to the second terminal of the second voltage bias branch. The third terminal of the thirteenth transistor is connected to the second terminal of the third current branch. The third terminal of the fourteenth transistor is connected to the third terminal of the first voltage bias branch. The third terminal of the fifteenth transistor is connected to the second terminal of the first current branch. The third terminal of the sixteenth transistor is connected to the second terminal of the second current branch. The second terminals of the eleventh transistor, the twelfth transistor, the thirteenth transistor, the fourteenth transistor, the fifteenth transistor, and the sixteenth transistor are all grounded.

[0053] Specifically, the third terminal of the eleventh transistor is the first terminal of the current bias branch, the third terminal of the twelfth transistor is the second terminal of the current bias branch, the third terminal of the thirteenth transistor is the third terminal of the current bias branch, the third terminal of the fourteenth transistor is the fourth terminal of the current bias branch, the third terminal of the fifteenth transistor is the fifth terminal of the current bias branch, and the third terminal of the sixteenth transistor is the sixth terminal of the current bias branch.

[0054] In one alternative approach, the twelfth transistor is larger in size or area than the thirteenth transistor.

[0055] In an alternative embodiment, the electrical signal detection circuit further includes a seventeenth transistor and an eighteenth transistor;

[0056] The first terminal of the seventeenth transistor is connected to the output terminal of the amplifier and the first terminal of the eighteenth transistor. The second terminals of the seventeenth transistor and the eighteenth transistor are both grounded. The third terminal of the seventeenth transistor is connected to the second terminal of the detection resistor and the first terminal of the first current branch. The third terminal of the eighteenth transistor is the output terminal of the electrical signal detection circuit.

[0057] In one alternative embodiment, the electrical signal detection circuit is a current detection circuit;

[0058] The current signal output from the third terminal of the eighteenth transistor is directly proportional to the current flowing through the first resistor.

[0059] Secondly, this application provides an extension method applied to an extension circuit, the extension circuit being connected to an input voltage and an electrical signal detection circuit respectively, and being used to extend the range of the input voltage, wherein the electrical signal detection circuit is used to detect an electrical signal related to a first resistor, the electrical signal detection circuit including an amplifier and a detection resistor, the extension circuit including a first current branch and a second current branch, and the extension method including:

[0060] When the input voltage is greater than the first preset voltage, at least one transistor in the first current branch and the second current branch are controlled to be saturated and turned on to divide the input voltage, so as to increase the maximum value of the input voltage that the electrical signal detection circuit can operate normally.

[0061] When the input voltage is not greater than the first preset voltage, the second and third terminals of at least one transistor in the first current branch are short-circuited, and the second and third terminals of at least one transistor in the second current branch are also short-circuited, so as to reduce the minimum input voltage for the electrical signal detection circuit to work normally.

[0062] Thirdly, this application provides an electronic device, including an electrical signal detection circuit and an extension circuit as described above.

[0063] The beneficial effects of this application are as follows: The extension circuit provided in this application is used to connect to the input voltage and electrical signal detection circuits respectively, and is used to extend the range of the input voltage. The electrical signal detection circuit is used to detect the electrical signal related to the first resistor. The electrical signal detection circuit includes an amplifier and a detection resistor. The extension circuit includes a first current branch and a second current branch. The first end of the first current branch is connected to the input voltage through the detection resistor, and the second end of the first current branch is connected to the first input terminal of the amplifier and the first current source respectively. The first end of the second current branch is connected to the input voltage through the first resistor, and the second end of the second current branch is connected to the second input terminal of the amplifier and the second current source. Subsequently, both the first and second current branches are used to divide the input capacitor to reduce the current or voltage input to the first and second input terminals of the amplifier, thereby increasing the maximum value of the input voltage that the electrical signal detection circuit can operate normally, thus achieving the purpose of extending the range of the input voltage that the electrical signal detection circuit can operate normally. Attached Figure Description

[0064] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0065] Figure 1This is a schematic diagram of the circuit structure of an electrical signal detection circuit in related technologies;

[0066] Figure 2 The extended circuit provided in the embodiments of this application and Figure 1 A schematic diagram of the electrical signal detection circuit connection in the diagram;

[0067] Figure 3 A schematic diagram of the circuit structure of the extended circuit provided in the embodiments of this application;

[0068] Figure 4 A schematic diagram of the circuit structure of an extension circuit provided in another embodiment of this application;

[0069] Figure 5 A schematic diagram of the circuit structure of an extension circuit provided in another embodiment of this application;

[0070] Figure 6 A schematic diagram of the circuit structure of an extension circuit provided in another embodiment of this application;

[0071] Figure 7 A schematic diagram of the circuit structure of an extension circuit provided in another embodiment of this application;

[0072] Figure 8 A flowchart of the extended method provided in the embodiments of this application. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0074] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the circuit structure of an electrical signal detection circuit in related technologies. For example... Figure 1As shown, this electrical signal detection circuit is used to detect electrical signals related to the first resistor Rsns. For example, the electrical signals include the current flowing through the first resistor Rsns or the voltage across the first resistor Rsns. The electrical signal detection circuit includes an amplifier U1, a detection resistor R1, a seventeenth transistor MN1, and an eighteenth transistor MN2. The first terminals of both the detection resistor R1 and the first resistor Rsns are connected to the input voltage VIN. The second terminal of the detection resistor R1 is connected to the first input terminal of the amplifier U1 and the drain of the seventeenth transistor MN1. The second input terminal of the amplifier U1 is connected to the second terminal of the first resistor Rsns. The gates of both the seventeenth transistor MN1 and the eighteenth transistor MN2 are connected to the output terminal of the amplifier U1. The sources of both the seventeenth transistor MN1 and the eighteenth transistor MN2 are grounded. The current flowing into the drain of the eighteenth transistor MN2 is Isns, the current flowing into the drain of the seventeenth transistor MN1 is I11, and the current flowing through the first resistor Rsns is Io1. In this embodiment, amplifier U1 has a non-inverting input terminal and an inverting input terminal as an example. Furthermore, the gate of the seventeenth transistor MN1 is its first terminal, its source is its second terminal, and its drain is its third terminal; the gate of the eighteenth transistor MN2 is its first terminal, its source is its second terminal, and its drain is its third terminal. The drain of the eighteenth transistor MN2 is the output terminal of the electrical signal detection circuit.

[0075] Specifically, amplifier U1 is a voltage-input operational amplifier with an equivalent short circuit between its two input terminals. Amplifier U1 controls the current I11 flowing through the seventeenth transistor MN1 to achieve the same voltage across the first resistor Rsns and the detection resistor R1, i.e., I11*r1=rsns*Io1, where r1 is the resistance value of the detection resistor R1 and rsns is the resistance value of the first resistor Rsns. Subsequently, the eighteenth transistor MN2 mirrors the current I11 on the seventeenth transistor MN1 into the current Isns, and the current Isns is output from the drain of the eighteenth transistor MN2. Thus, after Isns is detected, the current flowing through the first resistor Rsns (i.e., Io1) can be determined by Io1=Isns*r1 / rsns, which realizes the current detection function. At this time, the electrical signal detection circuit corresponds to the current detection circuit, and the current signal output from the drain of the eighteenth transistor MN2 (i.e., the current Isns) is directly proportional to the current flowing through the first resistor Rsns (i.e., Io1). Of course, after determining Io1, the voltage across the first resistor Rsns can be determined by Io1*rsns, thus realizing the voltage detection function. At this time, the electrical signal detection circuit corresponds to the voltage detection circuit.

[0076] However, for this type of electrical signal detection circuit, due to the presence of the amplifier and the limitation of the voltage range of the input signal of amplifier U1, the input voltage VIN can only vary within a narrow range in order to maintain the normal operation of amplifier U1. Consequently, this type of electrical signal detection circuit cannot be applied in scenarios such as automotive applications that require support for high-voltage power input (such as 40V).

[0077] Based on this, this application provides an extension circuit that divides the input voltage by adding a first current branch and a second current branch, thereby reducing the current or voltage input to the first and second input terminals of amplifier U1, and thus increasing the maximum value of the input voltage that the electrical signal detection circuit can operate normally. This helps to apply the electrical signal detection circuit to scenarios such as automotive applications that require support for high-voltage power input.

[0078] For ease of understanding, the following embodiments all use an electrical signal detection circuit as an example. Figure 1 The circuit structure shown is an example. Of course, the extension circuit provided in this application embodiment can also be applied to other electrical signal detection circuits. As long as the electrical signal detection circuit is implemented using an amplifier, the range of its normally functioning input voltage can be extended by the extension circuit provided in this application embodiment.

[0079] Please refer to Figure 2 , Figure 2 The extended circuit provided in the embodiments of this application and Figure 1The diagram shows the structure of the electrical signal detection circuit. The specific structure of the electrical signal detection circuit can be found in the description of the above embodiments, and will not be repeated here.

[0080] The expansion circuit 100 includes a first current branch 10 and a second current branch 20. The first terminal of the first current branch 10 is connected to the input voltage VIN via a sensing resistor R1, and the second terminal of the first current branch 10 is connected to the first input terminal of amplifier U1 and the first current source IB1. The first terminal of the second current branch 20 is connected to the input voltage VIN via a first resistor Rsns, and the second terminal of the second current branch 20 is connected to the second input terminal of amplifier U1 and the second current source IB2.

[0081] Specifically, both the first current branch 10 and the second current branch 20 are used to divide the input voltage to reduce the current or voltage input to the first and second input terminals of amplifier U1, thereby increasing the maximum value of the input voltage that allows the electrical signal detection circuit to operate normally. Since amplifier U1 is a current-type amplifier (i.e., an amplifier whose input is current), the first current branch 10 and the second current branch 20 can be used to reduce the current input to the first and second input terminals of amplifier U1. Furthermore, the normal operation of the electrical signal detection circuit depends primarily on the normal operation of amplifier U1. Specifically, if the actual input current or voltage of amplifier U1 meets the amplifier's limitations on the input signal, amplifier U1 can operate normally; conversely, if the actual input current or voltage of amplifier U1 exceeds the amplifier's limitations on the input signal, amplifier U1 cannot operate normally. Therefore, by increasing the maximum value of the input voltage that allows the electrical signal detection circuit to operate normally, the range of input voltages that the electrical signal detection circuit can operate on is expanded.

[0082] It is understandable that in this embodiment, while the first current branch 10 and the second current branch 20 divide the input voltage VIN, they also convert the equal voltage relationship at the first terminals of the first current branch 10 and the second current branch 20 into an equal relationship between the current I2 flowing through the first current branch 10 and the current I3 flowing through the second current branch 20. Furthermore, the difference between current I2 and the current input to the first current source IB1 is input to the first input terminal of amplifier U1, and the difference between current I3 and the current input to the second current source IB2 is input to the second input terminal of amplifier U1. Therefore, in this case, the amplifier U1 used is a current-input operational amplifier, rather than a voltage-input operational amplifier. In summary, by converting the equal voltage relationship into an equal current relationship, decoupling between amplifier U1 and the input voltage VIN can be achieved, thereby enabling an expansion of the input voltage range.

[0083] In one embodiment, such as Figure 3 As shown, the first current branch 10 includes a first transistor Q1 and a second transistor MP1. The first terminal of the first transistor Q1 is connected to a first bias voltage VB1, the second terminal of the first transistor Q1 is connected to a detection resistor R1, the third terminal of the first transistor Q1 is connected to the second terminal of the second transistor MP1, the first terminal of the second transistor MP1 is connected to a second bias voltage VB2, and the third terminal of the second transistor MP1 is connected to both the first input terminal of the amplifier U1 and the first current source IB1. The second terminal of the first transistor Q1 is the first terminal of the first current branch 10, the third terminal of the second transistor MP1 is the second terminal of the first current branch 10, the third terminal of the first transistor Q1 is the third terminal of the first current branch 10, the first terminal of the first transistor Q1 is the fourth terminal of the first current branch 10, and the first terminal of the second transistor MP1 is the fifth terminal of the first current branch 10.

[0084] In this embodiment, the first transistor Q1 is a PNP transistor, and the second transistor MP1 is a PMOS transistor. The base of the PNP transistor is the first terminal of the first transistor Q1, the emitter of the PNP transistor is the second terminal of the first transistor Q1, and the collector of the PNP transistor is the third terminal of the first transistor Q1. The gate of the PMOS transistor is the first terminal of the second transistor MP1, the source of the PMOS transistor is the second terminal of the second transistor MP1, and the drain of the PMOS transistor is the third terminal of the second transistor MP1.

[0085] It should be noted that in this embodiment, the first current branch 10 includes a first transistor Q1 and a second transistor MP1 as an example. However, in other embodiments, the first current branch 10 may include only one transistor or more than two transistors, such as only the second transistor MP1. This can also achieve the purpose of voltage division and reduce the current or voltage input to the first and second input terminals of the amplifier U1.

[0086] Figure 3 The diagram also exemplarily illustrates one structure of the second current branch 20. For example... Figure 3 As shown, the second current branch 20 includes a third transistor Q2 and a fourth transistor MP2. The first terminal of the third transistor Q2 is connected to the first bias voltage VB1, the second terminal of the third transistor Q2 is connected to the first resistor Rsns, the third terminal of the third transistor Q2 is connected to the second terminal of the fourth transistor MP2, the first terminal of the fourth transistor MP2 is connected to the second bias voltage VB2, and the third terminal of the fourth transistor MP2 is connected to the second input terminal of the amplifier U1 and the second current source IB2, respectively.

[0087] In this circuit, the second terminal of the third transistor Q2 is the first terminal of the second current branch 20, the third terminal of the fourth transistor MP2 is the second terminal of the second current branch 20, the third terminal of the third transistor Q2 is the third terminal of the second current branch 20, the first terminal of the third transistor Q2 is the fourth terminal of the second current branch 20, and the first terminal of the fourth transistor MP2 is the fifth terminal of the second current branch 20.

[0088] In this embodiment, the third transistor Q2 is a PNP transistor and the fourth transistor MP2 is a PMOS transistor. The base of the PNP transistor is the first terminal of the third transistor Q2, the emitter is the second terminal of the third transistor Q2, and the collector is the third terminal of the third transistor Q2. The gate of the PMOS transistor is the first terminal of the fourth transistor MP2, the source is the second terminal of the fourth transistor MP2, and the drain is the third terminal of the fourth transistor MP2.

[0089] Similarly, in this embodiment, the second current branch 20 includes the third transistor Q2 and the fourth transistor MP2 as an example. In other embodiments, the second current branch 20 may include only one transistor or more than two transistors, such as only the fourth transistor MP2. This can also achieve the purpose of voltage division and reduce the current or voltage input to the first and second input terminals of the amplifier U1.

[0090] exist Figure 3 In the circuit structure shown, because the MOS process can withstand very high voltages, under appropriate bias conditions, the drain and source of the second transistor MP1 and the fourth transistor MP2 can carry the main portion of the high voltage across the first resistor Rsns. That is, the second transistor MP1 and the fourth transistor MP2 divide the input voltage VIN, keeping the voltage applied to the first and second input terminals of amplifier U2 within a lower voltage range to maintain the normal operation of amplifier U2.

[0091] Specifically, when both the first current branch 10 and the second current branch 20 include only one transistor, that is... Figure 3The circuit structure shown includes only the second transistor MP1 and the fourth transistor MP2. The second terminal of the second transistor MP1 is directly connected to the detection resistor R1, and the second terminal of the fourth transistor MP2 is directly connected to the first resistor Rsns. That is, the second and third terminals of the first transistor Q1 are short-circuited, and the second and third terminals of the third transistor Q2 are short-circuited. When this circuit is working, once a voltage difference appears between the source voltages of the second transistor MP1 and the fourth transistor MP2, that is, when the source-gate voltage VSG1 of the second transistor MP1 and the source-gate voltage VSG2 of the fourth transistor MP2 are different, the currents I2 and I3 flowing through the second transistor MP1 and the fourth transistor MP2 will also be different. The difference between the currents I2 and I3 in the first current branch 10 and the second current branch 20, and the currents provided by their respective first current sources IB1 and IB2, is input to amplifier U1 (in this embodiment, amplifier U1 is a current-input operational amplifier) ​​and amplified to output a voltage controlling the gate voltage of the seventeenth transistor MN1, thereby changing the current I11 flowing through the detection resistor R1 until currents I2 and I3 are equal. At this point, VSG1 = VSG2, meaning the source voltages of the second transistor MP1 and the fourth transistor MP2 are equal. Similar to... Figure 1 In the circuit, amplifier U1 controls the current I11 to ensure that the voltage across the first resistor Rsns and the detection resistor R1 are equal, i.e., I11*r1=rsns*Io1. Similarly, the eighteenth transistor MN2 mirrors the current I11 on the seventeenth transistor MN1 to obtain the drain current Isns of the eighteenth transistor. Therefore, after detecting the current Isns, the current flowing through the first resistor Rsns can be determined by Io1=Isns*r11 / rsns, thus achieving the current detection function. It should be noted that the currents flowing into the first current source IB1 and the second current source IB2, as well as currents I2 and I3, are sufficiently small compared to currents Io1 and Isns, and their influence can be ignored here. Furthermore, the second bias voltage VB2 is used to provide a suitable gate voltage so that the second transistor MP1 and the fourth transistor MP2 remain saturated and conducting when the extension circuit 100 and the electrical signal detection circuit are operating.

[0092] In this embodiment, although the process used to manufacture the second transistor MP1 and the fourth transistor MP2 can withstand high voltage, the matching degree of their source-gate voltage and drain-source current may be poor. This results in a fixed bias voltage between the source voltage of the second transistor MP1 and the source voltage of the fourth transistor MP2 when their output currents are equal. Therefore, to solve the bias voltage problem caused by poor MOSFET matching, a better matching of the voltages across the first resistor Rsns and the sensing resistor R1 can be achieved by connecting a bipolar transistor (e.g., a triode) in series with each of the second transistor MP1 and the fourth transistor MP2. The specific circuit is as follows... Figure 3 As shown, a first transistor Q1 is inserted between the sensing resistor R1 and the second transistor MP1, and a third transistor Q2 is inserted between the first resistor Rsns and the fourth transistor MP2, with the bases of the first transistor Q1 and the third transistor Q2 connected. Furthermore, when the voltages between the emitters and bases of the first transistor Q1 and the third transistor Q2 are equal (VEB1=VEB2), the collector currents flowing out of the first transistor Q1 and the third transistor Q2 are equal. Simultaneously, the second bias voltage VB2 is appropriately configured to saturate and conduct the second transistor MP1 and the fourth transistor MP2. In this way, the currents I2 and I3 flowing through the first current branch 10 and the second current branch 20 are no longer determined by the gate-source voltages of the second transistor MP1 and the fourth transistor MP2, but by the emitter voltages of the first transistor Q1 and the third transistor Q2. At this time, the second transistor MP1 and the fourth transistor MP2 are only used for voltage division of the input voltage. Similarly, Figure 3 The circuit shown can also achieve the method of making the two collector currents of the first transistor Q1 and the third transistor Q2 equal through the current input amplifier U1, thereby obtaining the current I11 when the voltages across the detection resistor R1 and the first resistor Rsns are equal (i.e., the emitter voltages of the first transistor Q1 and the third transistor Q2 are equal), and thus obtaining the current Isns representing the current Io1. Therefore, in this embodiment, by introducing the first transistor Q1 and the third transistor Q2, the error caused by the possible mismatch between the second transistor MP1 and the fourth transistor MP2 can be overcome, improving the accuracy of electrical signal detection.

[0093] In one embodiment, such as Figure 4As shown, the extension circuit 100 also includes a switching branch 30 and a voltage detection branch 40. The first terminal of the voltage detection branch 40 is connected to the input voltage VIN; the second terminal of the voltage detection branch 40 is connected to the first terminal of the switching branch 30; the second terminal of the switching branch 30 is connected to the third terminal of the first current branch 10; the third terminal of the switching branch 30 is connected to the third terminal of the second current branch 20; the fourth terminal of the switching branch 30 is connected to the second terminal of the first current branch 20; and the fifth terminal of the switching branch 30 is connected to the second terminal of the second current branch 20.

[0094] Specifically, the voltage detection branch 40 is used to detect the magnitude of the input voltage VIN, and outputs a first control signal when the input voltage VIN is not greater than a first preset voltage, and outputs a second control signal when the input voltage VIN is greater than the first preset voltage. The switching branch 30 is used to turn on its second and fourth terminals in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the first current branch 10. The switching branch 30 is also used to turn on its third and fifth terminals in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the second current branch 20. The switching branch 30 is also used to disconnect the connection between its second and fourth terminals in response to the second control signal, and disconnect the connection between its third and fifth terminals.

[0095] In this embodiment, by short-circuiting the second and third terminals of at least one transistor in the first current branch 10 and the second and third terminals of at least one transistor in the second current branch 20, the minimum input voltage for the electrical signal detection circuit to operate normally can be reduced, and the range of input voltage variation of the electrical signal detection circuit can also be expanded, so that the electrical signal detection circuit can be applied to more application scenarios.

[0096] Figure 4 The diagram also exemplarily illustrates one structure of the switch branch 30. For example... Figure 4 As shown, the switch branch 30 includes a first switch MN3 and a second switch MN4. The first terminal of the first switch MN3 and the first terminal of the second switch MN4 are both connected to the voltage detection branch 40. The second terminal of the first switch MN3 is connected to the second terminal of the first current branch 10, and the third terminal of the first switch MN3 is connected to the third terminal of the first current branch 10. The second terminal of the second switch MN4 is connected to the second terminal of the second current branch 20, and the third terminal of the second switch MN4 is connected to the third terminal of the second current branch 20.

[0097] Wherein, the first end of the first switch MN3 is the first end of the switch branch 30, the third end of the first switch MN3 is the second end of the switch branch 30, the third end of the second switch MN4 is the third end of the switch branch 30, the second end of the first switch MN3 is the fourth end of the switch branch 30, and the second end of the second switch MN4 is the fifth end of the switch branch 30.

[0098] In this embodiment, taking both the first switch MN3 and the second switch MN4 as NMOS transistors as an example, the gate of the NMOS transistor is the first terminal of the first switch MN3 (and the second switch MN4), the source of the NMOS transistor is the second terminal of the first switch MN3 (and the second switch MN4), and the drain of the NMOS transistor is the third terminal of the first switch MN3 (and the second switch MN4).

[0099] In addition, the first switch MN3 and the second switch MN4 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0100] Meanwhile, it is understood that, in this embodiment, taking the second transistor MP1 connected between the drain and source of the first switch MN3 and the fourth transistor MP2 connected between the source and drain of the second switch MN4 as an example, by setting the first switch MN3 and the second switch MN4, the second and third terminals of one switch (i.e., the second transistor MP1) in the first current branch 10 and the second and third terminals of one switch (i.e., the fourth switch MP2) in the second current branch 20 can be short-circuited. In other embodiments, if multiple switches are connected between the drain and source of the first switch MN3, or multiple switches are connected between the drain and source of the second switch MN4, the multiple switches can also be short-circuited to reduce the minimum input voltage required for the electrical signal detection circuit to operate normally.

[0101] Understandable, Figure 3The circuit structure shown can operate with a minimum input voltage VIN of VR1 + VEBQ1 + VTHMP1 + VSATIB1 ≈ 2V, where VR1 represents the voltage drop across the sense resistor R1; VEBQ1 represents the emitter-base voltage of the first transistor Q1 when it is turned on, approximately 0.7V; VTHMP1 represents the turn-on threshold voltage of the second transistor MP1, close to 1V; and VSATIB1 represents the minimum drain-source voltage difference required for the transistor implementing the first current source IB1 to maintain saturation conduction, approximately 0.3V. When the input voltage is less than 2V, because the drain-source voltage of the transistor implementing the first current source IB1 is lower than its saturation drain-source voltage VSATIB1, the transistor can no longer provide accurate bias current, causing... Figure 3 The circuit structure shown cannot function properly. Therefore, Figure 3 The circuit structure shown can operate with a minimum input voltage VIN of 2V. However, in automotive applications, a minimum input voltage of 1V is often required.

[0102] Therefore, in order to accommodate both high-voltage and low-voltage input applications, it is possible to... Figure 3 A switch branch 30 and a voltage detection branch 40 are added to the circuit structure to reduce the minimum input voltage required for the electrical signal detection circuit to operate normally.

[0103] Specifically, when the voltage detection branch 40 detects that the input voltage VIN is less than or equal to a first preset voltage threshold (in one embodiment, the first preset voltage threshold can be set to...), the voltage detection branch 40 detects that the input voltage VIN is less than or equal to a first preset voltage threshold. Figure 2 When the circuit structure shown is at its lowest acceptable operating voltage, the voltage detection branch 40 outputs a high level (corresponding to the first control signal) to turn on the first switch MN3 and the second switch MN4, and short-circuit the second transistor MP1 and the fourth transistor MP2, thereby providing voltage space for the normal operation of other circuit parts. Specifically, when the second transistor MP1 and the fourth transistor MP2 are short-circuited, Figure 4 The circuit shown can operate normally with a minimum input voltage VIN value reduced to VR1+VEBQ1+VSATIB1≈1V, which meets the minimum input voltage requirements for automotive applications. Conversely, it can be further configured that when the input voltage VIN is greater than a first preset voltage threshold, the voltage detection branch 40 outputs a low level (corresponding to the second control signal) to turn off the first switch MN3 and the second switch MN4, thereby connecting the second transistor MP1 and the fourth transistor MP2 to the circuit, and further dividing the input voltage VIN to adapt to high-voltage input.

[0104] In one embodiment, such as Figure 5As shown, the expansion circuit 100 also includes a first voltage bias branch 50. The first terminal of the first voltage bias branch 50 is connected to the input voltage VIN, the second terminal of the first voltage bias branch 50 is connected to the sixth terminal of the switching branch 30, the third terminal of the first voltage bias branch 50 is connected to the seventh terminal of the switching branch 30 and the third current source IB3, and the voltage bias circuit 50 also has at least one terminal connected to the first current branch 10 and the second current branch 20, respectively.

[0105] Specifically, the first voltage bias branch 50 is used to output at least one bias voltage based on the input voltage VIN, so as to keep at least one transistor in the first current branch 10 on and at least one transistor in the second current branch 20 on. For example, the first voltage bias branch 50 is used to output a first bias voltage VB1 and a second bias voltage VB2, so as to keep the first transistor Q1, the second transistor MP1, the third transistor Q2 and the fourth transistor MP2 on.

[0106] The switching branch 30 is also configured to turn on its sixth and seventh terminals in response to a first control signal, thereby short-circuiting the second and third terminals of at least one transistor in the first voltage bias branch 50. The switching branch 30 is also configured to disconnect the connection between its sixth and seventh terminals in response to a second control signal.

[0107] Figure 5 The diagram also exemplarily illustrates a structure of the switching branch 30 and the first voltage bias branch 50. For example... Figure 5 As shown, the switching branch 30 also includes a third switch MN5, and the first voltage bias branch 50 includes a second resistor R2, a fifth transistor Q3, and a sixth transistor MP3.

[0108] In this configuration, the first terminal of the second resistor R2 is connected to the input voltage VIN, the second terminal of the second resistor R2 is connected to the second terminal of the fifth transistor Q3, the first terminal of the fifth transistor Q3 is connected to the third terminal of the fifth transistor Q3, the second terminal of the sixth transistor MP3, the third terminal of the third switch MN5, the fourth terminal of the first current branch 10, and the fourth terminal of the second current branch 20, respectively. The first terminal of the sixth transistor MP3 is connected to the third terminal of the sixth transistor MP3, the second terminal of the third switch MN5, the third current source IB3, the fifth terminal of the first current branch 10, and the fifth terminal of the second current branch 20, respectively.

[0109] Among them, the third terminal of the third switch MN5 is the sixth terminal of the switch branch 30, the second terminal of the third switch MN5 is the seventh terminal of the switch branch 30, the first terminal of the second resistor R2 is the first terminal of the first voltage bias branch 50, the third terminal of the fifth transistor Q3 is the second terminal of the first voltage bias branch 50, the third terminal of the sixth transistor MP3 is the third terminal of the first voltage bias branch 50, the voltage at the first terminal of the fifth transistor Q3 is the first bias voltage VB1, and the voltage at the first terminal of the sixth transistor MP3 is the second bias voltage VB2.

[0110] In this embodiment, the third switch MN5 is an NMOS transistor, the fifth transistor Q3 is a PNP transistor, and the sixth transistor MP3 is a PMOS transistor. Specifically, the gate of the NMOS transistor is the first terminal of the third switch MN5, the source of the NMOS transistor is the second terminal of the third switch MN5, and the drain of the NMOS transistor is the third terminal of the third switch MN5; the base of the PNP transistor is the first terminal of the fifth transistor Q3, the emitter of the PNP transistor is the second terminal of the fifth transistor Q3, and the collector of the PNP transistor is the third terminal of the fifth transistor Q3; the gate of the PMOS transistor is the first terminal of the sixth transistor MP3, the source of the PMOS transistor is the second terminal of the sixth transistor MP3, and the drain of the PMOS transistor is the third terminal of the sixth transistor MP3.

[0111] In addition, the third switch MN5 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0112] In addition, the third switch MN5 can be used to short-circuit a switch (the sixth transistor MP3 in this embodiment) or to short-circuit multiple switches. The specific implementation process is similar to that of the first switch MN3 and the second switch MN4, and will not be described in detail here.

[0113] In this embodiment, the structure of the first voltage bias branch 50 is similar to that of the first current branch 10 and the second current branch 20. This choice maximizes the similarity of voltage distribution among the branches, ensuring that appropriate first bias voltage VB1 and second bias voltage VB2 are continuously provided to the first current branch 10 and the second current branch 20 when the input voltage VIN changes. Specifically, the fifth transistor Q3 is connected as a diode, and its base is connected to the bases of the first transistor Q1 and the third transistor Q2, thereby providing a first bias voltage VB1 to the first transistor Q1 and the third transistor Q2 to maintain their conduction. Similarly, the gate and drain of the sixth transistor MP3 are shorted, and the gate of the sixth transistor MP3 is connected to the gates of the second transistor MP1 and the fourth transistor MP2, thereby providing a second bias voltage VB2 to the second transistor MP1 and the fourth transistor MP2 to maintain their saturation conduction. Simultaneously, when the input voltage VIN is less than or equal to the first preset voltage threshold, the third switch MN5 is also turned on under the control of the first control signal, short-circuiting the sixth transistor MP3. This ensures that the first voltage bias branch 50 can continue to provide a suitable bias voltage to the first current branch 10 and the second current branch 20 when the input voltage is low (e.g., 1V). The value of the second resistor R2 depends on the range of the detected current I11. Appropriate selection of the second resistor R2 ensures that the voltage bias branch 50 can provide a suitable bias voltage to the first current branch 10 and the second current branch 20 within a wider detection range of the electrical signal. In one embodiment, the second resistor R2 can be equal to the resistance value of the detection circuit R1.

[0114] In one embodiment, the voltage detection branch 40 includes a second voltage bias branch 41, a third current branch 42, and a trigger branch 43. The first terminals of both the second voltage bias branch 41 and the third current branch 42 are connected to the input voltage VIN. The second terminal of the second voltage bias branch 41 is connected to a fourth current source IB4. The second terminal of the third current branch 42 is connected to a fifth current source IB5 and the first terminal of the trigger branch 43, respectively. The second terminal of the trigger branch 43 is connected to the first terminal of the switch branch 30.

[0115] Specifically, the second voltage bias branch 41 is used to output at least one bias voltage to the third current branch 42 based on the input voltage VIN, so as to keep at least one transistor in the third current branch 42 on and to regulate the pull-up current I4 in the third current branch 42. The third current branch 42 is used to output a trigger current to the trigger branch 43 based on the difference between the pull-up current I4 and the pull-down current flowing into the fifth current source IB4 (denoted as pull-down current Ib4). The trigger branch 43 is used to output a first control signal when the trigger current is not greater than a first preset current, and to output a second control signal when the trigger current is greater than the first preset current.

[0116] In this embodiment, when the input voltage VIN is less than or equal to the first preset voltage threshold, the pull-up current I4 decreases due to the decrease in input voltage VIN, making the difference between the pull-up current I4 and the pull-down current Ib4 less than or equal to the first preset current, thereby causing the trigger branch 43 to output the first control signal; when the input voltage VIN is greater than the first preset voltage threshold, the pull-up current I4 increases as the input voltage VIN increases, making the difference between the pull-up current I4 and the current Ib4 greater than the first preset current, thereby causing the trigger branch 43 to output the second control signal.

[0117] Figure 6 The diagram also exemplarily illustrates one structure of the second voltage bias branch 41. For example... Figure 6 As shown, the second voltage bias branch 41 includes a third resistor R3, a seventh transistor Q4, and an eighth transistor MP4. The first terminal of the third resistor R3 is connected to the input voltage VIN, and the second terminal of the third resistor R3 is connected to the second terminal of the seventh transistor Q4. The first terminal of the seventh transistor Q4 is connected to the third terminal of the seventh transistor Q4, the second terminal of the eighth transistor MP4, and the third terminal of the third current branch 42. The first terminal of the eighth transistor MP4 is connected to the third terminal of the eighth transistor MP4, the fourth current source IB4, and the fourth terminal of the third current branch 42.

[0118] Among them, the first end of the third resistor R3 is the first end of the second voltage bias branch 41, the third end of the eighth transistor MP4 is the second end of the second voltage bias branch 41, and the first end of the seventh transistor Q4 is the third end of the second voltage bias branch 41.

[0119] In this embodiment, the seventh transistor Q4 is a PNP transistor, and the eighth transistor MP4 is a PMOS transistor. The base of the PNP transistor is the first terminal of the seventh transistor Q4, the emitter is the second terminal of the seventh transistor Q4, and the collector is the third terminal of the seventh transistor Q4. The gate of the PMOS transistor is the first terminal of the eighth transistor MP4, the source is the second terminal of the eighth transistor MP4, and the drain is the third terminal of the eighth transistor MP4.

[0120] Figure 6 The diagram also exemplarily illustrates one structure of the third current branch 42. For example... Figure 6 As shown, the third current branch 42 includes a fourth resistor R4, a ninth transistor Q5, and a tenth transistor MP5. The first terminal of the fourth resistor R4 is connected to the input voltage VIN, the second terminal of the fourth resistor R4 is connected to the second terminal of the ninth transistor Q5, the first terminal of the ninth transistor Q5 is connected to the third terminal of the second voltage bias branch 41, the third terminal of the ninth transistor Q5 is connected to the second terminal of the tenth transistor MP5, the first terminal of the tenth transistor MP5 is connected to the second terminal of the second voltage bias branch 41, and the third terminal of the tenth transistor MP5 is connected to both the fifth current source IB5 and the first terminal of the trigger branch 43.

[0121] Among them, the first end of the fourth resistor R4 is the first end of the third current branch 42, the third end of the tenth transistor MP5 is the second end of the third current branch 42, the first end of the ninth transistor Q5 is the third end of the third current branch 42, and the first end of the tenth transistor MP5 is the fourth end of the third current branch 42.

[0122] In this embodiment, the ninth transistor Q5 is a PNP transistor, and the tenth transistor MP5 is a PMOS transistor. The base of the PNP transistor is the first terminal of the ninth transistor Q5, the emitter is the second terminal of the ninth transistor Q5, and the collector is the third terminal of the ninth transistor Q5. The gate of the PMOS transistor is the first terminal of the tenth transistor MP5, the source is the second terminal of the tenth transistor MP5, and the drain is the third terminal of the tenth transistor MP5.

[0123] Figure 6 The diagram also exemplarily illustrates one structure for trigger branch 43. For example... Figure 6 As shown, the trigger branch 43 includes a Schmitt trigger U2.

[0124] The input terminal of Schmitt trigger U2 is connected to the second terminal of the third current branch 42, and the output terminal of Schmitt trigger U2 is connected to the first terminal of the switch branch 30. The input terminal of Schmitt trigger U2 is the first terminal of the trigger branch 43, and the output terminal of Schmitt trigger U2 is the second terminal of the trigger branch 43.

[0125] In this embodiment, the structure of the combination of the second voltage bias branch 41 and the third current branch 42 is similar to the structure of the combination of the first voltage bias branch 50 and the second current branch 2. Therefore, the second voltage bias branch 41 can also provide a suitable voltage bias for the ninth transistor Q5 and the tenth transistor MP5 in the third current branch 42, so that the ninth transistor Q5 and the tenth transistor MP5 remain on. Simultaneously, the second voltage bias branch 41 can also determine the magnitude (i.e., pull-up capability) of the pull-up current I4 in the third current branch 42. Furthermore, in one embodiment, the values ​​of the third resistor R3 and the fourth resistor R4 can be equal to those of the sensing resistor R1.

[0126] In one embodiment, such as Figure 7 As shown, the extension circuit 100 also includes a current bias branch 60. The first terminal of the current bias branch 60 is connected to the first terminal of the main current source IB0; the second terminal of the current bias branch 60 is connected to the second terminal of the second voltage bias branch 41; the third terminal of the current bias branch 60 is connected to the second terminal of the third current branch 42; the fourth terminal of the current bias branch 60 is connected to the third terminal of the first voltage bias branch 50; the fifth terminal of the current bias branch 60 is connected to the second terminal of the first current branch 10; and the sixth terminal of the current bias branch 60 is connected to the second terminal of the second current branch 20.

[0127] Specifically, the current bias branch 60 is used to configure the input current of the first current source IB1, the second current source IB2, the third current source IB3, the fourth current source IB4 and the fifth current source IB5 based on the current output of the main current source IB0.

[0128] Figure 7 The diagram also exemplarily illustrates one structure of the current bias branch 60. For example... Figure 7 As shown, the current bias branch 60 includes the eleventh transistor MN6, the twelfth transistor MN7, the thirteenth transistor MN8, the fourteenth transistor MN9, the fifteenth transistor MN10, and the sixteenth transistor MN11.

[0129] Among them, the first terminal of the eleventh transistor MN6 is connected to the main current source IB0, the third terminal of the eleventh transistor MN6, the first terminal of the twelfth transistor MN7, the first terminal of the thirteenth transistor MN8, the first terminal of the fourteenth transistor MN9, the first terminal of the fifteenth transistor MN10, and the first terminal of the sixteenth transistor MN11. The third terminal of the twelfth transistor MN7 is connected to the second terminal of the second voltage bias branch 41. The third terminal of the thirteenth transistor MN8 is connected to the second terminal of the third current branch 42. The third terminal of the fourteenth transistor MN9 is connected to the third terminal of the first voltage bias branch 50. The third terminal of the fifteenth transistor MN10 is connected to the second terminal of the first current branch 10. The third terminal of the sixteenth transistor MN11 is connected to the second terminal of the second current branch 20. The second terminals of the eleventh transistor MN6, the twelfth transistor MN7, the thirteenth transistor MN8, the fourteenth transistor MN9, the fifteenth transistor MN10, and the sixteenth transistor MN11 are all grounded to GND.

[0130] Among them, the third terminal of the eleventh transistor MN6 is the first terminal of the current bias branch 60, the third terminal of the twelfth transistor MN7 is the second terminal of the current bias branch 60, the third terminal of the thirteenth transistor MN8 is the third terminal of the current bias branch 60, the third terminal of the fourteenth transistor MN9 is the fourth terminal of the current bias branch 60, the third terminal of the fifteenth transistor MN10 is the fifth terminal of the current bias branch 60, and the third terminal of the sixteenth transistor MN11 is the sixth terminal of the current bias branch 60.

[0131] In this embodiment, the drain and gate of the eleventh transistor MN6 are connected, and the gate of the eleventh transistor MN6 is connected to the input main current source IB0. The current of the main current source IB0 is mirrored proportionally to the second voltage bias branch 41, the third current branch 42, the first voltage bias branch 50, the first current branch 10, and the second current branch 20, respectively, to provide appropriate current bias for each bias branch (e.g., the first voltage bias branch) or current branch (e.g., the first current branch). In one embodiment, the eleventh transistor MN6, the twelfth transistor MN7, the fourteenth transistor MN9, the fifteenth transistor MN10, and the sixteenth transistor MN11 can be selected with the same size and area to maintain uniform current bias, while the size or area of ​​the thirteenth transistor MN8 needs to be smaller than that of the twelfth transistor MN7 so that the bias current (i.e., the pull-down current I5) provided by the thirteenth transistor MN8 is less than that provided by the twelfth transistor MN7. For example, in some embodiments, the size or area of ​​the thirteenth transistor MN8 can be selected to be half that of the twelfth transistor MN7.

[0132] Subsequently, since the size or area of ​​the twelfth transistor MN7 is larger than that of the thirteenth transistor MN8, the current flowing into the second terminal of the current bias branch 60 is greater than the current flowing into the third terminal of the current bias branch 60. When the input voltage VIN is greater than the first preset voltage threshold, the seventh transistor Q4, the ninth transistor Q5, the eighth transistor MP4, the tenth transistor MP5, the twelfth transistor MN7, and the thirteenth transistor MN8 can all remain saturated and turned on. The current input to the twelfth transistor MN7 is mirrored to the third current branch 42 through the seventh transistor Q4 and the ninth transistor Q5, becoming the pull-up current I4 of the third current branch 42. At this point, because the size or area of ​​the twelfth transistor MN7 is larger than that of the thirteenth transistor MN8, the pull-up current I4 mirrored from the current in the second voltage bias branch 41 to the third current branch is greater than the pull-down current I5 provided by the thirteenth transistor MN8. This causes the voltage at the input of the Schmitt trigger U2 to be pulled high, and the output of the Schmitt trigger U2 to output a low level. The first switch MN3, the second switch MN4, and the third switch MN5 remain open, and the second transistor MP1, the fourth transistor MP2, and the sixth transistor MP3 continue to divide the input voltage VIN. When the input voltage VIN is less than the first preset voltage threshold, neither the twelfth transistor MN7 nor the thirteenth transistor MN8 has sufficient drain-source voltage difference to maintain saturation conduction, and the current flowing through the second voltage bias branch 41 and the third current branch 42 decreases. However, since the size or area of ​​the twelfth transistor MN7 is larger than that of the thirteenth transistor MN8, the current reduction in the second voltage bias branch 41 is greater, thereby reducing the pull-up current I4 mirrored to the third current branch 42. The voltage at the input of Schmitt trigger U2 is pulled down by the pull-down current I5 provided by the thirteenth transistor MN8, so that Schmitt trigger U2 outputs a high level, which in turn turns on the first switch MN3, the second switch MN4 and the third switch MN5, so that the second transistor MP1, the fourth transistor MP2 and the sixth transistor MP3 are short-circuited, thereby reducing the minimum input voltage for the electrical signal detection circuit to work normally.

[0133] Meanwhile, since the series structure of the third current branch 42 is the same as that of the first current branch 10, when the input voltage VIN gradually decreases, the time point when the input voltage of the third current branch 42 is insufficient coincides with the time point when the input voltage of the first current branch 10 is too low. This allows the second transistor MP1, the fourth transistor MP2, and the sixth transistor MP3 to be short-circuited when the input voltage VIN drops to less than or equal to the first preset voltage threshold, thus achieving a smooth switch from a high-voltage circuit structure to a low-voltage circuit structure. Conversely, when the input voltage VIN rises, the smooth switch from a low-voltage circuit structure to a high-voltage circuit structure can be achieved when the input voltage VIN increases to greater than the first preset voltage threshold. This involves disconnecting the first switch MN3, the second switch MN4, and the third switch MN5 to connect the second transistor MP1, the fourth transistor MP2, and the sixth transistor MP3.

[0134] Please refer to Figure 8 , Figure 8 This is a flowchart illustrating an extension method provided in an embodiment of this application. The extension method is applied to an extension circuit, which is connected to both an input voltage detection circuit and an electrical signal detection circuit, and is used to extend the range of the input voltage. The electrical signal detection circuit detects an electrical signal related to a first resistor and includes an amplifier and a detection resistor. The extension circuit includes a first current branch and a second current branch. In some embodiments, the electrical signal detection circuit can be... Figure 1 The circuit structure shown is implemented as described above. In one embodiment, the electrical signal detection circuit is a current detection circuit, used to detect the current flowing through the first resistor Rsns. Furthermore, the extension circuit here can be implemented as follows: Figures 2-7 The circuit structure shown is implemented in detail in the above embodiments, and will not be repeated here.

[0135] like Figure 8 As shown, the extension method includes the following steps:

[0136] Step 801: When the input voltage is greater than the first preset voltage, control at least one transistor in the first current branch and the second current branch to be saturated and turned on to divide the input voltage.

[0137] Step 802: When the input voltage is not greater than the first preset voltage, short-circuit the second and third terminals of at least one transistor in the first current branch, and short-circuit the second and third terminals of at least one transistor in the second current branch.

[0138] The first preset voltage can be set according to the actual application, and this application embodiment does not impose specific limitations on it. For example, in one embodiment, the first preset voltage can be the lowest input voltage at which the electrical signal detection circuit can currently operate normally, that is, the first preset voltage can correspond to the first preset voltage threshold in the above embodiment.

[0139] In this embodiment, when the input voltage is greater than the first preset voltage, at least one transistor in each of the first and second current branches is controlled to be saturated and turned on. That is, at least one transistor in the first current branch is controlled to be saturated and turned on, and at least one transistor in the second current branch is controlled to be saturated and turned on, so as to achieve the purpose of voltage division, thereby increasing the maximum value of the input voltage for which the electrical signal detection circuit can work normally. When the input voltage is not greater than the first preset voltage, the second and third terminals of at least one transistor in the first current branch and the second and third terminals of at least one transistor in the second current branch need to be short-circuited to reduce the conduction voltage of the first and second current branches, thereby reducing the minimum value of the input voltage for which the electrical signal detection circuit can work normally.

[0140] It should be understood that the specific control of the extension circuit and the beneficial effects produced in the method embodiment can be referred to the corresponding description in the above-described extension circuit embodiment, and will not be repeated here for the sake of brevity.

[0141] This application also provides an electronic device, which includes an electrical signal detection circuit and an extension circuit as described in any embodiment of this application.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An extension circuit, characterized in that, The expansion circuit is used to connect to the input voltage and electrical signal detection circuits respectively, and to expand the range of the input voltage. The electrical signal detection circuit is used to detect an electrical signal related to the first resistor, and includes an amplifier and a detection resistor. The expansion circuit includes: A first current branch and a second current branch, wherein the first current branch includes at least one transistor; The first end of the first current branch is connected to the input voltage through the detection resistor, the second end of the first current branch is connected to the first input terminal of the amplifier and the first current source respectively, the first end of the second current branch is connected to the input voltage through the first resistor, and the second end of the second current branch is connected to the second input terminal of the amplifier and the second current source. Both the first current branch and the second current branch are used to divide the input voltage to reduce the current or voltage input to the first and second input terminals of the amplifier, thereby increasing the maximum value of the input voltage at which the electrical signal detection circuit can operate normally.

2. The extended circuit according to claim 1, characterized in that, The expansion circuit also includes a switching branch and a voltage detection branch; The first end of the voltage detection branch is connected to the input voltage, the second end of the voltage detection branch is connected to the first end of the switch branch, the second end of the switch branch is connected to the third end of the first current branch, the third end of the switch branch is connected to the third end of the second current branch, the fourth end of the switch branch is connected to the second end of the first current branch, and the fifth end of the switch branch is connected to the second end of the second current branch. The voltage detection branch is used to detect the magnitude of the input voltage, and outputs a first control signal when the input voltage is not greater than a first preset voltage, and outputs a second control signal when the input voltage is greater than the first preset voltage; The switching branch is used to turn on the second and fourth terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the first current branch. The switching branch is also used to turn on the third and fifth terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the second current branch. The switch branch is also used to disconnect the connection between the second and fourth terminals of the switch branch in response to the second control signal, and to disconnect the connection between the third and fifth terminals of the switch branch.

3. The extended circuit according to claim 2, characterized in that, The extended circuit also includes a first voltage bias branch; The first end of the first voltage bias branch is connected to the input voltage, the second end of the first voltage bias branch is connected to the sixth end of the switch branch, the third end of the first voltage bias branch is connected to the seventh end of the switch branch and the third current source respectively, and the voltage bias circuit also has at least one end connected to the first current branch and the second current branch respectively. The first voltage bias branch is used to output at least one bias voltage based on the input voltage, so as to keep at least one transistor in the first current branch on and to keep at least one transistor in the second current branch on. The switching branch is also used to turn on the sixth and seventh terminals of the switching branch in response to the first control signal, so as to short-circuit the second and third terminals of at least one transistor in the first voltage bias branch. The switch branch is also used to disconnect the connection between the sixth and seventh terminals of the switch branch in response to the second control signal.

4. The extended circuit according to claim 3, characterized in that, The voltage detection branch includes a second voltage bias branch, a third current branch, and a trigger branch; The first terminal of the second voltage bias branch and the first terminal of the third current branch are both connected to the input voltage. The second terminal of the second voltage bias branch is connected to the fourth current source. The second terminal of the third current branch is connected to the fifth current source and the first terminal of the trigger branch, respectively. The second terminal of the trigger branch is connected to the first terminal of the switch branch. The second voltage bias branch is used to output at least one bias voltage to the third current branch based on the input voltage, so as to keep at least one transistor in the third current branch on and to adjust the pull-up current in the third current branch. The third current branch is used to output a trigger current to the trigger branch based on the difference between the pull-up current and the pull-down current flowing into the fifth current source; The trigger branch is used to output the first control signal when the trigger current is not greater than the first preset current, and to output the second control signal when the trigger current is greater than the first preset current.

5. The extended circuit according to claim 4, characterized in that, The extended circuit also includes a current biasing branch; The first end of the current bias branch is connected to the first end of the main current source, the second end of the current bias branch is connected to the second end of the second voltage bias branch, the third end of the current bias branch is connected to the second end of the third current branch, the fourth end of the current bias branch is connected to the third end of the first voltage bias branch, the fifth end of the current bias branch is connected to the second end of the first current branch, and the sixth end of the current bias branch is connected to the second end of the second current branch. The current bias branch is used to configure the input current of the first current source, the second current source, the third current source, the fourth current source, and the fifth current source based on the current output by the main current source.

6. The extended circuit according to claim 5, characterized in that, The current flowing into the second terminal of the current bias branch is configured to be greater than the current flowing into the third terminal of the current bias branch.

7. The extended circuit according to claim 1, characterized in that, The first current branch includes a first transistor and a second transistor; The first terminal of the first transistor is connected to the first bias voltage, the second terminal of the first transistor is connected to the detection resistor, the third terminal of the first transistor is connected to the second terminal of the second transistor, the first terminal of the second transistor is connected to the second bias voltage, and the third terminal of the second transistor is connected to the first input terminal of the amplifier and the first current source, respectively. Wherein, the second terminal of the first transistor is the first terminal of the first current branch, the third terminal of the second transistor is the second terminal of the first current branch, the third terminal of the first transistor is the third terminal of the first current branch, the first terminal of the first transistor is the fourth terminal of the first current branch, and the first terminal of the second transistor is the fifth terminal of the first current branch.

8. The extended circuit according to claim 1, characterized in that, The second current branch includes a third transistor and a fourth transistor; The first terminal of the third transistor is connected to the first bias voltage, the second terminal of the third transistor is connected to the first resistor, the third terminal of the third transistor is connected to the second terminal of the fourth transistor, the first terminal of the fourth transistor is connected to the second bias voltage, and the third terminal of the fourth transistor is connected to the second input terminal of the amplifier and the second current source, respectively. Wherein, the second terminal of the third transistor is the first terminal of the second current branch, the third terminal of the fourth transistor is the second terminal of the second current branch, the third terminal of the third transistor is the third terminal of the second current branch, the first terminal of the third transistor is the fourth terminal of the second current branch, and the first terminal of the fourth transistor is the fifth terminal of the second current branch.

9. The extended circuit according to claim 2, characterized in that, The switch branch includes a first switch and a second switch; The first terminal of the first switch and the first terminal of the second switch are both connected to the voltage detection branch. The second terminal of the first switch is connected to the second terminal of the first current branch. The third terminal of the first switch is connected to the third terminal of the first current branch. The second terminal of the second switch is connected to the second terminal of the second current branch. The third terminal of the second switch is connected to the third terminal of the second current branch. Wherein, the first end of the first switch is the first end of the switch branch, the third end of the first switch is the second end of the switch branch, the third end of the second switch is the third end of the switch branch, the second end of the first switch is the fourth end of the switch branch, and the second end of the second switch is the fifth end of the switch branch.

10. The extended circuit according to claim 3, characterized in that, The switching branch also includes a third switch, and the first voltage biasing branch includes a second resistor, a fifth transistor, and a sixth transistor. The first end of the second resistor is connected to the input voltage, the second end of the second resistor is connected to the second end of the fifth transistor, the first end of the fifth transistor is connected to the third end of the fifth transistor, the second end of the sixth transistor, the third end of the third switch, the fourth end of the first current branch and the fourth end of the second current branch, respectively, and the first end of the sixth transistor is connected to the third end of the sixth transistor, the second end of the third switch, the third current source, the fifth end of the first current branch and the fifth end of the second current branch, respectively. Wherein, the third terminal of the third switch is the sixth terminal of the switch branch, the second terminal of the third switch is the seventh terminal of the switch branch, the first terminal of the second resistor is the first terminal of the first voltage bias branch, the third terminal of the fifth transistor is the second terminal of the first voltage bias branch, the third terminal of the sixth transistor is the third terminal of the first voltage bias branch, the voltage at the first terminal of the fifth transistor is the first bias voltage, and the voltage at the first terminal of the sixth transistor is the second bias voltage.

11. The extended circuit according to claim 4, characterized in that, The second voltage bias branch includes a third resistor, a seventh transistor, and an eighth transistor; The first end of the third resistor is connected to the input voltage, the second end of the third resistor is connected to the second end of the seventh transistor, the first end of the seventh transistor is connected to the third end of the seventh transistor, the second end of the eighth transistor and the third end of the third current branch, and the first end of the eighth transistor is connected to the third end of the eighth transistor, the fourth current source and the fourth end of the third current branch. Wherein, the first end of the third resistor is the first end of the second voltage bias branch, the third end of the eighth transistor is the second end of the second voltage bias branch, and the first end of the seventh transistor is the third end of the second voltage bias branch.

12. The extended circuit according to claim 4, characterized in that, The third current branch includes a fourth resistor, a ninth transistor, and a tenth transistor; The first end of the fourth resistor is connected to the input voltage, the second end of the fourth resistor is connected to the second end of the ninth transistor, the first end of the ninth transistor is connected to the third end of the second voltage bias branch, the third end of the ninth transistor is connected to the second end of the tenth transistor, the first end of the tenth transistor is connected to the second end of the second voltage bias branch, and the third end of the tenth transistor is connected to the first end of the fifth current source and the trigger branch, respectively. Wherein, the first end of the fourth resistor is the first end of the third current branch, the third end of the tenth transistor is the second end of the third current branch, the first end of the ninth transistor is the third end of the third current branch, and the first end of the tenth transistor is the fourth end of the third current branch.

13. The extended circuit according to claim 4, characterized in that, The triggering branch includes a Schmitt trigger; The input terminal of the Schmitt trigger is connected to the second terminal of the third current branch, and the output terminal of the Schmitt trigger is connected to the first terminal of the switch branch. Wherein, the input terminal of the Schmitt trigger is the first terminal of the trigger branch, and the output terminal of the Schmitt trigger is the second terminal of the trigger branch.

14. The extended circuit according to claim 5, characterized in that, The current bias circuit includes an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor; The first terminal of the eleventh transistor is connected to the main current source, the third terminal of the eleventh transistor, the first terminal of the twelfth transistor, the first terminal of the thirteenth transistor, the first terminal of the fourteenth transistor, the first terminal of the fifteenth transistor, and the first terminal of the sixteenth transistor. The third terminal of the twelfth transistor is connected to the second terminal of the second voltage bias branch. The third terminal of the thirteenth transistor is connected to the second terminal of the third current branch. The third terminal of the fourteenth transistor is connected to the third terminal of the first voltage bias branch. The third terminal of the fifteenth transistor is connected to the second terminal of the first current branch. The third terminal of the sixteenth transistor is connected to the second terminal of the second current branch. The second terminals of the eleventh transistor, the twelfth transistor, the thirteenth transistor, the fourteenth transistor, the fifteenth transistor, and the sixteenth transistor are all grounded. Specifically, the third terminal of the eleventh transistor is the first terminal of the current bias branch, the third terminal of the twelfth transistor is the second terminal of the current bias branch, the third terminal of the thirteenth transistor is the third terminal of the current bias branch, the third terminal of the fourteenth transistor is the fourth terminal of the current bias branch, the third terminal of the fifteenth transistor is the fifth terminal of the current bias branch, and the third terminal of the sixteenth transistor is the sixth terminal of the current bias branch.

15. The extended circuit according to claim 14, characterized in that, The twelfth transistor is larger in size or area than the thirteenth transistor.

16. The extended circuit according to claim 1, characterized in that, The electrical signal detection circuit also includes the seventeenth transistor and the eighteenth transistor; The first terminal of the seventeenth transistor is connected to the output terminal of the amplifier and the first terminal of the eighteenth transistor. The second terminals of the seventeenth transistor and the eighteenth transistor are both grounded. The third terminal of the seventeenth transistor is connected to the second terminal of the detection resistor and the first terminal of the first current branch. The third terminal of the eighteenth transistor is the output terminal of the electrical signal detection circuit.

17. The extended circuit according to claim 16, characterized in that, The electrical signal detection circuit is a current detection circuit; The current signal output from the third terminal of the eighteenth transistor is directly proportional to the current flowing through the first resistor.

18. An extension method, characterized in that, An extension circuit is applied to extend the range of the input voltage. The extension circuit is connected to both an input voltage detection circuit and an electrical signal detection circuit, and extends the range of the input voltage. The electrical signal detection circuit detects an electrical signal related to a first resistor and includes an amplifier and a detection resistor. The extension circuit includes a first current branch and a second current branch. The extension method includes: When the input voltage is greater than the first preset voltage, at least one transistor in the first current branch and the second current branch are controlled to be saturated and turned on to divide the input voltage, thereby increasing the maximum value of the input voltage that the electrical signal detection circuit can operate normally. When the input voltage is not greater than the first preset voltage, the second and third terminals of at least one transistor in the first current branch are short-circuited, and the second and third terminals of at least one transistor in the second current branch are also short-circuited, so as to reduce the minimum input voltage for the electrical signal detection circuit to work normally.

19. An electronic device, characterized in that, It includes an electrical signal detection circuit and an extension circuit as described in any one of claims 1-17.

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