Intelligent electronic switch, chip, chip product and automobile

Abstract

The invention provides an intelligent electronic switch, a chip, a chip product and an automobile, the intelligent electronic switch comprises a power switch, a control circuit and a current sampling circuit, and the control circuit outputs a corresponding control signal when obtaining a first indication signal. The first indication signal is used for indicating the magnitude of the current flowing through the power switch, the larger the current flowing through the power switch is, the smaller the sampling proportion is, and the smaller the current flowing through the power switch is, the larger the sampling proportion is; the sampling proportion is equal to the ratio of the output to the input of the current sampling circuit. In the scheme, the control circuit adjusts the sampling proportion of the current sampling circuit according to the received first indication signal, the power consumption and the sampling precision of the current sampling circuit are both considered, and the product competitiveness is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to an intelligent electronic switch, a chip, a chip product and a car. Background Art

[0002] With the development of automobile intelligence, the functions of automobiles are becoming more and more complex, and the realization of these functions requires different loads and different actuators. Among them, the intelligent electronic switch is an electronic component that controls the on and off of the load circuit. It integrates multiple protection functions and diagnostic functions to improve the reliability of the intelligent electronic switch.

[0003] In the prior art, the intelligent electronic switch includes a current sampling circuit connected to a control circuit, and the current sampling circuit can sample the current flowing through the power switch (the output current of the intelligent electronic switch) based on an internal preset sampling ratio to obtain a target sampling signal. The target sampling signal is used to characterize the magnitude of the current flowing through the power switch, so as to serve as a basis for protecting and / or diagnosing the power switch.

[0004] In practical applications, the sampling accuracy and power consumption of the current sampling circuit are usually consistent and related to the output current of the power switch. If the output current of the power switch is larger, the power consumption of the current sampling circuit is higher and the sampling accuracy is higher. If the output current is smaller, the power consumption of the current sampling circuit is smaller but the sampling accuracy is lower. Therefore, how to balance the power consumption and sampling accuracy of the current sampling circuit is an important factor to consider when designing the current sampling circuit. Summary of the invention

[0005] The present application provides an intelligent electronic switch, a chip, a chip product and a car, which are used to take into account both power consumption and sampling accuracy during the design process of a current sampling circuit.

[0006] In a first aspect, the present application provides an intelligent electronic switch, including a power supply terminal, a power ground terminal, a load output terminal, a power switch, a control circuit, and a current sampling circuit;

[0007] The power supply end and the power ground end are used to be connected to a battery, the power switch is used to be connected in series with a load, a first end thereof is connected to the power supply end or the power ground end, a second end thereof is connected to the load output end, a control end thereof is connected to the control circuit, the control circuit is used to control the power switch to be turned on or off, and the current sampling circuit is connected to the power switch and the control circuit;

[0008] The control circuit outputs a corresponding control signal when acquiring the first indication signal, the control signal is used to indicate the sampling ratio of the current sampling circuit, the current sampling circuit collects the current flowing through the power switch based on the sampling ratio and outputs the target sampling signal, the first indication signal is used to indicate the magnitude of the current flowing through the power switch, the larger the current flowing through the power switch, the smaller the sampling ratio, the smaller the current flowing through the power switch, the larger the sampling ratio, the sampling ratio is equal to the ratio of the output to the input of the current sampling circuit.

[0009] Optionally, the first indication signal includes a drain-source voltage value of the power switch; when the power switch operates in a linear resistance region, the drain-source voltage value is used to characterize a current flowing through the power switch, and the larger the drain-source voltage value, the larger the current flowing through the power switch, and the smaller the drain-source voltage value, the smaller the current flowing through the power switch;

[0010] The intelligent electronic switch also includes a voltage sampling circuit, which is connected to the source, drain and control circuit of the power switch; the voltage sampling circuit is used to obtain the drain-source voltage value of the power switch and output the first indication signal when the power switch operates in the linear resistance area, and the control circuit outputs the control signal according to the threshold interval of the drain-source voltage value in the first indication signal; wherein, for two adjacent threshold intervals, the lower limit value of the larger threshold interval is greater than or equal to the upper limit value of the smaller threshold interval, and the larger the threshold interval of the drain-source voltage value is, the smaller the sampling ratio indicated by the control signal is.

[0011] Optionally, the threshold interval includes at least a first threshold interval and a second threshold interval;

[0012] The control circuit outputs a first control signal when the drain-source voltage value is within a first threshold interval, so that the current sampling circuit samples the current flowing through the power switch at a first sampling ratio; the control circuit outputs a second control signal when the drain-source voltage value is within a second threshold interval, so that the current sampling circuit samples the current flowing through the power switch at a second sampling ratio;

[0013] When the upper limit of the first threshold interval is less than or equal to the lower limit of the second threshold interval, the first sampling ratio is greater than the second sampling ratio.

[0014] Optionally, the intelligent electronic switch further comprises an indication terminal, and the indication terminal is connected to the control circuit;

[0015] The control circuit receives the first indication signal through the indication end. The first indication signal is determined based on the weight information of the load. The weight information of the load is used to characterize the current flowing through the power switch. The heavier the load, the greater the current flowing through the power switch. The lighter the load, the smaller the current flowing through the power switch.

[0016] Optionally, the current sampling circuit includes a current sensing unit, an operational amplifier unit and a switch tube;

[0017] The current sensing unit, whose control end is connected to the control circuit, whose first end is connected to the first end of the power switch, whose second end is connected to the switch tube and the connection point is the first connection point, whose first input end of the operational amplifier unit is connected to the first connection point, whose second end is connected to the load output end, whose output end is connected to the control end of the switch tube, and whose second end of the switch tube is used to output the target sampling current;

[0018] The operational amplifier unit outputs a third signal when the voltages at the first connection point and the load output terminal are equal. At this time, the switch tube is turned on, and the current sensing unit outputs the sensed target sampling current through the switch tube.

[0019] As an example, the current sensing unit includes n sensing transistors and (n-1) branch switches, where n is an integer greater than or equal to 2;

[0020] n sensing transistors, whose control ends are all connected to the control end of the power switch, whose first ends are all connected to the first end of the power switch, whose second ends are sequentially connected through (n-1) branch switches, and the first sensing transistor is connected to the first connection point, and the nth sensing transistor is connected to the first connection point through the (n-1)th branch switch;

[0021] When the control signal indicates that the first (x-1) branch switches are turned on and the last (Nx) branch switches are turned off, the current sensing unit senses the current flowing through the power switch through the first x sensing transistors and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the first x sensing transistors. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the first x sensing transistors and the power switch, and x is an integer greater than or equal to 1 and less than or equal to n.

[0022] As another example, the current sensing unit includes n sensing transistors and n branch switches, where n is an integer greater than or equal to 2;

[0023] n sensing transistors, each of which has a control end connected to the control end of the power switch, a first end connected to the first end of the power switch, and a second end connected to the first connection point via n branch switches;

[0024] When the control signal indicates that m of the n branch switches are turned on and the remaining (nm) branch switches are turned off, the current sensing unit senses the current flowing through the power switch through the m sensing branches where the m branch switches are located and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the m sensing branches and the power switch, and m is an integer greater than or equal to 1 and less than or equal to n.

[0025] As another example, the current sensing unit includes n sensing transistors and n branch switches, where n is an integer greater than or equal to 2;

[0026] n sensing transistors, whose control ends are connected to the control circuit via n branch switches, whose first ends are connected to the first end of the power switch, and whose second ends are connected to the first connection point;

[0027] When the control circuit controls the power switch to turn on, if the control signal indicates that m of the n branch switches are turned on and the remaining (nm) branch switches are turned off, then the m sensing transistors controlled by the m branch switches are turned on and the (nm) sensing transistors controlled by the remaining (nm) branch switches are turned off. At this time, the current sensing unit senses the current flowing through the power switch through the m sensing branches and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the m sensing branches and the power switch, and m is an integer greater than or equal to 1 and less than or equal to n.

[0028] Optionally, the intelligent electronic switch also includes an abnormality protection unit, a first end of the abnormality protection unit is connected to the first connection point, and a second end of the abnormality protection unit is connected to the load output end, and the abnormality protection unit is used to protect the current sensing unit when the branch where the power switch is located is abnormal.

[0029] Optionally, the current sampling circuit includes a gain adjustable unit;

[0030] The branch where the power switch is located is also used to connect a sampling resistor in series, the current flowing through the sampling resistor is equal to the current flowing through the power switch, the two input ends of the gain adjustable unit are correspondingly connected to the two ends of the sampling resistor, the gain control end of the gain adjustable unit is connected to the control circuit, and the output end of the gain adjustable unit is used to output a target sampling voltage;

[0031] The control circuit adjusts the gain of the gain adjustable unit to a target sampling ratio through a control signal. The gain adjustable unit receives the voltage difference across the sampling resistor through its two input terminals, amplifies the voltage difference across the sampling resistor based on the target sampling ratio, and outputs a target sampling voltage. The target sampling voltage is equal to the product of the voltage difference across the sampling resistor and the target sampling ratio.

[0032] Exemplarily, the gain adjustable unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an operational amplifier unit and a reference power supply, wherein the resistance values ​​of the first resistor and the second resistor are equal and fixed, and the resistance values ​​of the third resistor and the fourth resistor are equal and adjustable;

[0033] The operational amplifier unit, wherein the first input terminal thereof is connected to the first terminal of the sampling resistor through the first resistor, the second input terminal thereof is connected to the second terminal of the sampling resistor through the second resistor, the first input terminal thereof is further connected to the output terminal thereof through the third resistor, the second input terminal thereof is further connected to the power ground terminal through the fourth resistor and the reference power supply, the output terminal thereof is used to output the target sampling voltage, and the reference power supply is used to provide a common-mode power supply for the operational amplifier unit;

[0034] The sampling ratio of the gain adjustable unit is equal to the ratio of the third resistor to the first resistor. The control circuit adjusts the resistance values ​​of the third resistor and the fourth resistor through a control signal to adjust the ratio of the third resistor to the first resistor, so that the gain of the operational amplifier unit is equal to the target sampling ratio. The operational amplifier unit amplifies the voltage difference across the sampling resistor by the target sampling ratio and then outputs a target sampling voltage.

[0035] Optionally, the intelligent electronic switch further comprises a sampling end, and the sampling end is connected to the current sampling circuit;

[0036] The current sampling circuit is used to output a target sampling signal through the sampling end, and the target sampling signal is used to represent the current flowing through the power switch.

[0037] Optionally, the intelligent electronic switch further comprises a feedback end, and the feedback end is connected to the control circuit;

[0038] The control circuit is further configured to output a first indication signal through the feedback terminal, wherein the first indication signal is configured to indicate a sampling ratio indicated by the control signal.

[0039] In a second aspect, an embodiment of the present application further provides an integrated circuit chip, comprising the intelligent electronic switch as described in the first aspect, wherein the power supply end is a power supply pin, the power ground end is a power ground pin, and the load output end is a load output pin.

[0040] In a third aspect, an embodiment of the present application provides a chip product, comprising the intelligent electronic switch as described in the first aspect, wherein components of the intelligent electronic switch other than a power switch and some components of a current sampling circuit are located on a first integrated circuit chip, and the power switch and some components of the current sampling circuit are located on a second integrated circuit chip;

[0041] Among them, the power supply end is a power supply pin, the power ground end is a power ground pin, the load output end is a load output pin, the power supply pin and the power ground pin are located on a first integrated circuit chip, and the load output pin is located on a second integrated circuit chip.

[0042] In a fourth aspect, an embodiment of the present application provides an automobile, comprising the intelligent electronic switch as described in the first aspect, or the integrated circuit chip as described in the second aspect, or the chip product as described in the third aspect;

[0043] It also includes a battery, a load, and a microcontroller, wherein the positive electrode of the battery is connected to the power supply terminal, the negative electrode of the battery is connected to the power ground terminal, one end of the load is connected to the load output terminal, and the other end of the load is connected to the power ground terminal or the power supply terminal, the intelligent electronic switch is connected to the microcontroller, and the microcontroller is used to control the intelligent electronic switch.

[0044] The present application provides an intelligent electronic switch, a chip, a chip product, and a car. In the intelligent electronic switch, the control circuit outputs a corresponding control signal when obtaining a first indication signal, so that the current sampling circuit collects the current flowing through the power switch based on the sampling ratio indicated by the control signal and outputs a target sampling signal. The first indication signal is used to indicate the magnitude of the current flowing through the power switch. If the current flowing through the power switch is larger, the sampling ratio is smaller; if the current flowing through the power switch is smaller, the sampling ratio is larger. The sampling ratio is equal to the ratio of the output to the input of the current sampling circuit, that is, the current sampling circuit collects the output current of the power switch at a relatively small sampling ratio when the current flowing through the power switch may be larger, and collects the output current of the power switch at a relatively large sampling ratio when the current flowing through the power switch may be smaller. This not only reduces the degree of influence of the circuit error of the current sampling circuit on the smaller output current, but also reduces the power consumption wasted by the current sampling circuit caused by the larger output current, thereby achieving the purpose of taking into account both the power consumption and sampling accuracy of the current sampling circuit, and improving the product competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0046] Figure 1 It is a circuit module schematic diagram of the intelligent electronic switch and its peripheral components provided in the first embodiment of the present application;

[0047] Figure 2A This is a circuit module schematic diagram of an intelligent electronic switch and its peripheral components provided in the second embodiment of the present application;

[0048] Figure 2B is another structural schematic diagram of the intelligent electronic switch and its peripheral components provided in the second embodiment of the present application;

[0049] Figure 3 This is a schematic diagram of a circuit module of an intelligent electronic switch provided in the third embodiment of the present application;

[0050] FIG. 4A to FIG. 4C yes Figure 3 Schematic diagrams of several possible circuit structures of the intelligent electronic switch shown;

[0051] Figure 5 This is a schematic diagram of a circuit module of an intelligent electronic switch provided in the fourth embodiment of the present application;

[0052] Figure 6 yes Figure 5 A possible circuit structure diagram of an intelligent electronic switch is shown.

[0053] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0055] The terms "including" and "having" and any variations thereof appearing in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or modules is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0056] In addition, the terms "first", "second" and "third" are used to distinguish different objects, rather than to describe a specific order. The electrical connection of the present application includes direct electrical connection and indirect electrical connection. Indirect electrical connection means that other electronic components, pins, etc. may exist between the two electrically connected components. The XX end mentioned in the present application may be an actual terminal, or it may not be an actual terminal, for example, it is only one end of a component or one end of a wire. The "and / or" mentioned in the present application includes three situations. For example, A and / or B includes three situations: A, B, A and B.

[0057] With the acceleration of the transformation of the automotive intelligent industry, more and more electronic switches are installed in cars. In practical applications, intelligent electronic switches are used to drive and switch the loads in the car, and to protect and diagnose the loads because of their high reliability, flexibility, low power consumption, small size and light weight. Therefore, intelligent electronic switches have gradually become the trend of switch development.

[0058] The intelligent electronic switch, for example, includes a current sampling circuit, which is used to collect the current flowing through the power switch and output a target sampling signal, which can be a target sampling current or a target sampling voltage, which is an important indicator of the working state of the power switch and serves as a reference factor for protecting or controlling the intelligent electronic switch. Exemplarily, the intelligent electronic switch can implement a current protection function (e.g., overcurrent shutdown, current limiting, etc.) based on the target sampling signal, and can also output it to a host computer (e.g., a microcontroller), so that the microcontroller controls the intelligent electronic switch according to the received target sampling signal.

[0059] According to the contents recorded in the background technology, in the intelligent electronic switch, the sampling accuracy and power consumption of the current sampling circuit are usually consistent and related to the output current of the power switch. This is because, in the existing current sampling circuit, the sampling ratio (ratio of the sampling current to the output current of the power switch) and the circuit error are fixed. At this time, if the output current of the power switch is larger, the sampling current is larger, the power consumption of the current sampling circuit is higher, and the influence of the circuit error on the sampling current is smaller, so that the sampling accuracy is higher. If the output current is smaller, the power consumption of the current sampling circuit is smaller, but the influence of the circuit error on the sampling current is greater, so that the sampling accuracy is lower.

[0060] In view of the above technical problems, an embodiment of the present application provides an intelligent electronic switch, which includes a power switch, a control circuit and a current sampling circuit. The current sampling circuit is connected to the control circuit, so that the control circuit outputs a corresponding control signal when obtaining a first indication signal, so that the current sampling circuit collects the current flowing through the power switch based on the sampling ratio indicated by the control signal and outputs a target sampling signal, wherein the first indication signal is used to indicate the magnitude of the current flowing through the power switch. If the current flowing through the power switch is larger, the sampling ratio is smaller, and if the current flowing through the power switch is smaller, the sampling ratio is larger. The sampling ratio is equal to the ratio of the output to the input of the current sampling circuit, that is, when it is determined that the current flowing through the power switch may be larger, the current sampling circuit is controlled to collect the output current of the power switch at a relatively small sampling ratio, and when it is determined that the current flowing through the power switch may be smaller, the current sampling circuit is controlled to collect the output current of the power switch at a relatively large sampling ratio, which not only reduces the influence of the circuit error of the current sampling circuit on the smaller output current, but also reduces the power consumption of the current sampling circuit wasted when the output current is larger, thereby achieving the purpose of taking into account both the power consumption and sampling accuracy of the current sampling circuit.

[0061] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0062] Figure 1 1 is a schematic diagram of a circuit module of an intelligent electronic switch and its peripheral components provided in the first embodiment of the present application. Figure 1 As shown, the intelligent electronic switch 20 includes a power supply terminal VBAT, a power ground terminal GND, a load output terminal OUT, a power switch Q0 , a control circuit 21 and a current sampling circuit 23 .

[0063] The power supply terminal VBAT and the power ground terminal GND are used to connect to the battery 10, that is, the power supply terminal VBAT is used to connect to the positive electrode of the battery 10, and the power ground terminal GND is used to connect to the negative electrode of the battery 10. The power switch Q0 is used to be connected in series with the load 30, a first end of which is connected to the power supply terminal VBAT or the power ground terminal GND, a second end of which is connected to the load output terminal OUT, and a control end (i.e., the gate g) is connected to the control circuit 21, and the control circuit 21 is used to control the power switch Q0 to turn on or off, and the current sampling circuit 23 is connected to the power switch Q0 and the control circuit 21.

[0064] It can be understood that when the power switch Q0 and the control circuit 21 are integrated on the same chip, the first end of the power switch Q0 is connected to the power supply terminal VBAT or the power ground terminal GND, and when the power switch Q0 and the control circuit 21 are located on different chips, the first end of the power switch Q0 can be directly connected to the positive electrode or the negative electrode of the battery 10.

[0065] For example, refer to Figure 1As shown, the first end of the power switch Q0 is connected to the power supply terminal VBAT. At this time, the power switch Q0 is connected as a high-side switch (high-side switch), which is actually a switch connected between the positive electrode of the battery 10 and the load 30. At this time, if the power switch Q0 is implemented by an N-type switch tube, the control circuit 21 may include a signal processing unit, a boost unit and a drive unit. The signal processing unit and the boost unit are respectively connected to the drive unit. The signal processing unit can control the working state of the drive unit according to the received Input signal, and the boost unit can be a device such as a charge pump, one end of which is connected to the power supply terminal VBAT and the other end is connected to the drive unit, which can increase the output voltage of the drive unit. In this way, when the switch control signal (Input signal) received by the control circuit 21 is an on signal, that is, when the signal processing unit receives the on signal, it can control the power switch Q0 to turn on through the drive unit. It is understandable that when the power switch Q0 is implemented by a P-type switch tube, the control circuit 21 may not include a boost unit, but if the same driving current is to be provided, the P-type switch tube has a larger area and higher cost than the N-type switch tube.

[0066] In other embodiments, the first end of the power switch Q0 can be directly connected to the power ground terminal GND or the negative electrode of the battery 10, that is, the power switch Q0 is actually connected between the negative electrode of the battery 10 and the load 30. At this time, the power switch Q0 is connected as a low-side switch (low-side switch), which will not be elaborated here.

[0067] Optionally, in this embodiment, the power switch Q0 may be an N-type metal-oxide-semiconductor field-effect transistor (N Metal-Oxide-Semiconductor Field-Effect Transistor, NMOS FET, referred to as NMOS tube), a PMOS tube, a junction field effect transistor (Junction Field Effect Transistor, referred to as JFET) or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, referred to as IGBT), etc., and the power switch Q0 is illustrated as an NMOS tube as an example. In another possible design of this embodiment, the power switch Q0 may also be implemented as a silicon device, or implemented using other semiconductor materials, such as silicon carbide (SiC), gallium arsenide (GaAs) or gallium nitride (GaN), etc., and the embodiment of the present application does not limit the form of expression of the power switch Q1.

[0068] In view of the problem that the sampling accuracy and power consumption of the existing current sampling circuit cannot be balanced, the inventors found that the target sampling signal output by the current sampling circuit 23 is not only related to the output current of the power switch Q0, but also related to the sampling ratio of the current sampling circuit 23. For example, when the output current of the power switch Q0 is fixed, the larger the sampling ratio, the higher the sampling accuracy, the larger the obtained sampling current, and the greater the power consumption of the current sampling circuit 23 at this time, while the smaller the sampling ratio, the lower the sampling accuracy, the smaller the obtained sampling current, and the smaller the power consumption of the current sampling circuit 23 at this time. Based on this principle, the embodiment of the present application provides a solution, that is, the sampling ratio of the current sampling circuit 23 is set in combination with the current flowing through the power switch Q0, and the target sampling signal can be obtained by sampling the output current of the power switch Q0 based on the sampling ratio, and the target sampling signal can balance the power consumption and sampling accuracy of the current sampling circuit 23.

[0069] In the embodiments of the present application, refer to Figure 1 As shown, the control circuit 21 outputs the corresponding control signal Con(k) when acquiring the first indication signal Dir. The control signal Con(k) is used to indicate the sampling ratio k of the current sampling circuit 23. The current sampling circuit 23 collects the current flowing through the power switch Q0 based on the sampling ratio k and outputs the target sampling signal. The first indication signal Dir is used to indicate the magnitude of the current flowing through the power switch Q0. When the current flowing through the power switch Q0 is larger, the sampling ratio k is smaller, and when the current flowing through the power switch Q0 is smaller, the sampling ratio k is larger. The sampling ratio k is equal to the ratio of the output to the input of the current sampling circuit.

[0070] Optionally, the control circuit 21, as the control core of the intelligent electronic switch 20, can communicate not only with other circuits or components in the intelligent electronic switch 20, but also with external devices. For example, the control circuit 21 can obtain the first indication signal Dir from the internal circuit or the external device to determine the magnitude of the current (output current) flowing through the power switch Q0 when the power switch Q0 works in the linear resistance region, and then determine a suitable sampling ratio based on the relationship between the output current preset in the control circuit 21 and the sampling ratio k, and output it to the current sampling circuit 23 through a control signal, so that the current sampling circuit 23 performs current sampling according to the sampling ratio.

[0071] For example, assuming that when the first indication signal Dir indicates that the current flowing through the power switch is 20A, the sampling ratio indicated by the control signal is k1, for example, k1=1 / 10000, and if the first indication signal Dir indicates that the current flowing through the power switch is 2A, the corresponding sampling ratio is k2, for example, k2=1 / 1000, etc. That is, the larger the current flowing through the power switch, the smaller the sampling ratio.

[0072] In practical applications, the target sampling signal output by the current sampling circuit 23 can be used for protection and diagnosis inside the intelligent electronic switch, and can also be output to an external device to reflect the working state of the intelligent electronic switch 20 .

[0073] Optionally, the intelligent electronic switch 20 includes a current protection circuit, and the target sampling signal output by the current sampling circuit 23 can be obtained by the current protection circuit to perform current protection on the power switch Q0. For example, when the target sampling current exceeds the overcurrent protection threshold, the control circuit 21 can control the power switch Q0 to be turned off to protect the power switch Q0 from being damaged by overcurrent; for another example, when the target sampling current is greater than the current limiting protection threshold, the control circuit 21 can control the signal output to the control end of the power switch Q0 through the current limiting protection circuit to reduce the current flowing through the power switch Q0, thereby protecting the power switch Q0 from being damaged by overcurrent or overtemperature.

[0074] Optionally, the current sampling circuit 23 can also output the target sampling signal to an external microcontroller (not shown), so that the microcontroller can judge the working state of the power switch Q0 according to the target sampling signal, and then reasonably control the power switch Q0. For example, when the target sampling current exceeds the overcurrent protection threshold, the microcontroller believes that the current flowing through the power switch Q0 is too large and may burn the power switch Q0. At this time, the switch control signal (Input signal) of the power switch Q0 can be set low to trigger the control circuit 21 to turn off the power switch Q0, thereby protecting the power switch Q0 from being damaged by overcurrent.

[0075] Optionally, in an embodiment of the present application, a fuse may be connected in series between the battery 10 and the power supply terminal VBAT to prevent a fault caused by excessive current in the line. Other components may be provided between the power ground terminal GND and the negative electrode of the battery 10, for example, a reverse connection prevention diode and a current limiting resistor connected in parallel to improve the stability of the intelligent electronic switch.

[0076] In an embodiment of the present application, the control circuit outputs a corresponding control signal when acquiring the first indication signal, so that the current sampling circuit collects the current flowing through the power switch based on the sampling ratio indicated by the control signal and outputs a target sampling signal, wherein the first indication signal is used to indicate the magnitude of the current flowing through the power switch. If the current flowing through the power switch is larger, the sampling ratio is smaller, and if the current flowing through the power switch is smaller, the sampling ratio is larger. The sampling ratio is equal to the ratio of the output to the input of the current sampling circuit, that is, when it is determined that the current flowing through the power switch may be larger, the current sampling circuit is controlled to collect the output current of the power switch at a relatively small sampling ratio, and when it is determined that the current flowing through the power switch may be smaller, the current sampling circuit is controlled to collect the output current of the power switch at a relatively large sampling ratio, which not only reduces the influence of the circuit error of the current sampling circuit on the smaller output current, but also reduces the power consumption wasted by the current sampling circuit caused by the larger output current, thereby achieving the purpose of taking into account both the power consumption and sampling accuracy of the current sampling circuit.

[0077] The above embodiment provides a general introduction to the intelligent electronic switch 20. Figure 1 On the basis of the illustrated embodiment, the acquisition method of the first indication signal Dir, the specific implementation of the current sampling circuit 23 and the like are respectively described in principle through different embodiments.

[0078] In a possible design of the present application, when the output current of the power switch Q0 is not collected, how to know the output current of the power switch Q0 is critical. To solve this problem, the inventor found that when the power switch Q0 works in the linear resistance region, the internal resistance of the power switch Q0 remains basically unchanged, that is, the output current of the power switch Q0 (the current flowing through the power switch Q0) Iout is substantially proportional to the drain-source voltage value Vds of the power switch Q0, and thus, the current Iout flowing through the power switch Q0 can be determined by detecting the drain-source voltage value Vds of the power switch Q0. That is, in the embodiment of the present application, the first indication signal Dir received by the control circuit 21 includes the drain-source voltage value of the power switch Q0; when the power switch Q0 works in the linear resistance region, the drain-source voltage value Vds is used to characterize the current Iout flowing through the power switch Q0; and, the larger the drain-source voltage value Vds, the larger the current Iout flowing through the power switch Q0, and the smaller the drain-source voltage value Vds, the smaller the current Iout flowing through the power switch Q0.

[0079] Accordingly, Figure 2A Schematic diagram of a circuit module of an intelligent electronic switch and its peripheral components provided in the second embodiment of the present application. Figure 2AAs shown, the intelligent electronic switch 20 further includes a voltage sampling circuit 22, which is connected to the source s, the drain d of the power switch Q0 and the control circuit 21. The voltage sampling circuit 22 is used to obtain the drain-source voltage value Vds of the power switch Q0 when the power switch Q0 works in the linear resistance region and output the first indication signal Dir. Correspondingly, the control circuit 21 outputs a control signal according to the threshold interval of the drain-source voltage value Vds in the first indication signal Dir.

[0080] Among them, for two adjacent threshold intervals, the lower limit value of the larger threshold interval is greater than or equal to the upper limit value of the smaller threshold interval, and the larger the threshold interval where the drain-source voltage value Vds is located, the smaller the sampling ratio indicated by the control signal.

[0081] For example, refer to Figure 2A As shown, the voltage sampling circuit 22 can be implemented by an operation processor, and its two input terminals are connected to the drain d and source s of the power switch Q0, and its output terminal is connected to the control circuit 21. In this way, the operation processor obtains the drain voltage value Vd and the source voltage value Vs of the power switch Q0 through the two input terminals, respectively, and performs a subtraction operation on the two, so as to output the drain-source voltage value Vds of the power switch Q0. The drain-source voltage value Vds is equal to the product of the current flowing through the power switch Q0 and the internal resistance of the power switch Q0. Since the internal resistance of the power switch Q0 is basically unchanged when it works in the linear resistance region, the drain-source voltage value Vds of the power switch Q0 can represent the current Iout flowing through the power switch Q0.

[0082] Optionally, the relationship between the threshold interval and the sampling ratio can be preset in the control circuit 21, that is, the drain-source voltage value Vds can be divided into at least two threshold intervals by at least one threshold, and a sampling ratio is set for each threshold interval, and as the threshold interval increases, the sampling ratio becomes smaller, so that the target sampling signal output by the current sampling circuit 23 is maintained within an appropriate range, thereby taking into account the power consumption and sampling accuracy of the current sampling circuit 23.

[0083] In this embodiment, the size of the threshold interval can be defined by the upper limit value and the lower limit value of the threshold interval. For example, for any two adjacent threshold intervals, if the lower limit value of the first threshold interval is greater than or equal to the upper limit value of the second threshold interval, then the first threshold interval is considered to be greater than the second threshold interval. Correspondingly, the sampling ratio corresponding to the first threshold interval is smaller, and the sampling ratio corresponding to the second threshold interval is larger.

[0084] Exemplarily, in the control circuit 21, the threshold interval includes at least a first threshold interval and a second threshold interval; at this time, as an example, the control circuit 21 outputs a first control signal when the drain-source voltage value Vds is within the first threshold interval, so that the current sampling circuit 23 collects the current flowing through the power switch Q0 at a first sampling ratio k1; as another example, the control circuit 21 outputs a second control signal when the drain-source voltage value Vds is in the second threshold interval, so that the current sampling circuit 23 collects the current flowing through the power switch Q0 at a second sampling ratio k2; wherein, when the upper limit value of the first threshold interval is less than or equal to the lower limit value of the second threshold interval, the first sampling ratio k1 is greater than the second sampling ratio k2.

[0085] For example, for the drain-source voltage value Vds, assuming that the first threshold interval is Vds∈(10,20] mV and the second threshold interval is Vds∈(20,30] mV, the first sampling ratio k1=1 / 100 corresponding to Vds∈(20,30] is greater than the second sampling ratio k2=1 / 1000 corresponding to Vds∈(20,30].

[0086] In the embodiment of the present application, the first indication signal includes the drain-source voltage value of the power switch, and the intelligent electronic switch obtains the drain-source voltage value of the power switch when it works in the linear resistance region through the voltage sampling circuit and outputs the first indication signal, so that the control circuit outputs the control signal according to the threshold interval where the drain-source voltage value is located. That is, in this solution, the intelligent electronic switch collects the drain-source voltage value of the power switch through the voltage sampling circuit to characterize the current flowing through the power switch, with high accuracy, which provides a basis for the control circuit to determine a suitable sampling ratio.

[0087] Optionally, in another possible design of the present application, Figure 2B FIG. 2 is another structural diagram of the intelligent electronic switch and its peripheral components provided in the second embodiment of the present application. Figure 2B As shown, in this embodiment, the intelligent electronic switch 20 further includes an indication terminal IND, and the indication terminal IND is connected to the control circuit 21. The control circuit 21 receives a first indication signal Dir through the indication terminal IND, and the first indication signal Dir is determined according to the weight information of the load 30. The weight information of the load 30 is used to characterize the current flowing through the power switch Q0. The heavier the load 30, the greater the current flowing through the power switch Q0, and the lighter the load 30, the smaller the current flowing through the power switch Q0.

[0088] It is understandable that the indication terminal IND can be a new terminal of the intelligent electronic switch 20, or can reuse the original terminal of the intelligent electronic switch 20, such as an input terminal, a diagnosis enable terminal, a function selection terminal, a diagnosis release terminal, etc. The embodiment of the present application does not limit the specific implementation of the indication terminal IND.

[0089] In this embodiment, the current sampling scheme of the existing current sampling circuit 23 has the problem that power consumption and sampling accuracy cannot be taken into account at the same time. The intelligent electronic switch 20 provided in the embodiment of the present application may include an indication terminal IND. Figure 2B As shown, the indication terminal IND can be used to connect the internal control circuit 21 and an external device (such as a microcontroller 40).

[0090] For a certain application scenario, the weight of the load 30 connected to the intelligent electronic switch 20 usually does not change too much, so when the power switch Q0 of the intelligent electronic switch 20 is in the on state, the current Iout flowing through the power switch Q0 will be within a predictable range. Generally, the heavier the load 30, the greater the current Iout flowing through the power switch Q0, and the lighter the load 30, the smaller the current Iout flowing through the power switch Q0. Therefore, after the microcontroller 40 stores the weight information of the load, the microcontroller 40 can calculate the current flowing through the power switch Q0 based on the weight information of the load 30, and then output the first indication signal Dir, that is, the heavier the load 30, the greater the current flowing through the power switch Q0 indicated by the first indication signal Dir, and the lighter the load 30, the smaller the current flowing through the power switch Q0 indicated by the first indication signal Dir. For example, when the load is 1000Ω, the current flowing through the power switch Q0 is 20A, and the corresponding sampling ratio is 1 / 1000, and when the load is 100Ω, the current flowing through the power switch Q0 is 2A, and the corresponding sampling ratio is 1 / 100, etc. It can be understood that the embodiment of the present application is not limited thereto, and it can be determined according to actual needs.

[0091] Correspondingly, after the intelligent electronic switch 20 is powered on, the microcontroller 40 can send the first indication signal Dir to the intelligent electronic switch 20 through the indication terminal IND, and thus, the control circuit 21 of the intelligent electronic switch 20 can output a control signal based on receiving the first indication signal Dir, so that the current sampling circuit 23 collects the current flowing through the power switch Q0 based on the sampling ratio indicated by the control signal.

[0092] In an embodiment of the present application, an external device, such as a microcontroller, can determine a first indication signal based on the weight information of the load connected to the intelligent electronic switch, and transmit it to the control circuit of the intelligent electronic switch based on the indication terminal to indicate the current flowing through the power switch, which lays the foundation for the control circuit to determine a suitable sampling ratio, so that the target sampling signal output by the current sampling circuit is maintained within a suitable range, taking into account the power consumption and sampling accuracy requirements of the current sampling circuit, thereby improving the product competitiveness of the intelligent electronic switch.

[0093] Based on the above embodiments, Figure 3Schematic diagram of a circuit module of an intelligent electronic switch provided in the third embodiment of the present application. Figure 3 As shown, in this embodiment, the current sampling circuit 23 includes a current sensing unit 231, an operational amplifier unit 232 and a switch tube P0.

[0094] Continue to refer to Figure 3 As shown, the current sensing unit 231 has a control end connected to the control circuit 21, a first end connected to the first end of the power switch Q0, a second end connected to the switch tube P0 and the connection point is the first connection point A1, a first input end of the operational amplifier unit 232 is connected to the first connection point A1, a second end connected to the load output end OUT, an output end connected to the control end of the switch tube P0, and a second end of the switch tube P0 is used to output the target sampling current.

[0095] In an embodiment of the present application, the operational amplifier unit 232 outputs a third signal when the voltages at the first connection point A1 and the load output terminal OUT are equal. At this time, the switch tube P0 is turned on, and the current sensing unit 231 outputs the sensed target sampling current through the switch tube P0.

[0096] Exemplarily, the current sensing unit 231 may include two or more sensing transistors, and the control end of each sensing transistor may be directly or indirectly connected to the control end of the power switch Q0 and are all connected to the control circuit 21, so that when the power switch Q0 is turned on, at least one sensing transistor of the current sensing unit 231 is in an on state, and the current sensing unit 231 senses the current flowing through the power switch Q0 and outputs a target sampling current, which increases the voltage of the first connection point A1. Accordingly, when the voltage of the first connection point A1 is equal to the voltage of the load output terminal OUT, the operational amplifier unit 232 outputs a third signal to trigger the switch tube P0 to turn on, so that the current sensing unit 231 can output the sensed target sampling current through the switch tube P0.

[0097] Optional, see Figure 3 As shown, the intelligent electronic switch 20 further includes a sampling terminal CS, which is connected to the second end of the switch tube P0. In this way, when the switch tube P0 is turned on, the current sensing unit 231 outputs the target sampling current to the sampling terminal CS through the switch tube P0.

[0098] It is understandable that the control circuit 21 can output a branch control signal according to the current sensing branch in the current sensing unit 231 to control the number of sensing transistors in the on state, thereby controlling the target sampling current output by the current sensing unit 231 .

[0099] In practical applications, the current sensing unit 231 can be implemented by various circuit module structures, which are explained below through specific embodiments.

[0100] Optional, FIG. 4A to FIG. 4C yes Figure 3 The following are some possible circuit structure diagrams of intelligent electronic switches. FIG. 4A to FIG. 4C As shown, the control circuit 21 may include a control unit 211 and a driving unit 212 , and the current sensing unit 231 includes at least two sensing transistors and at least one branch switch.

[0101] The control unit 211 is connected to the voltage sampling circuit 22 and the driving unit 212, and is also connected to the control end of the branch switch in the current sensing unit 231. On the one hand, the control unit 211 can control the switch state of the power switch Q0 and the sensing transistor via the driving unit 212 according to the received switch control signal. On the other hand, the control unit 211 can also determine the threshold interval of the drain-source voltage value Vds according to the drain-source voltage value Vds obtained from the voltage sampling circuit 22, output a branch control signal for at least one branch switch, and then control the switch state of at least one branch switch respectively. Correspondingly, the branch control signal can be a multi-bit coded signal, and the number of bits of the coded signal is the same as the number of branch switches.

[0102] As an example, Figure 4A As shown, the current sensing unit 231 includes n sensing transistors M1 to Mn and (n-1) branch switches K1 to K(n-1), where n is an integer greater than or equal to 2. Among them, the control ends of the n sensing transistors M1 to Mn are all connected to the control end of the power switch Q0, the first ends are all connected to the first end of the power switch Q0, and the second ends are sequentially connected through (n-1) branch switches, and the first sensing transistor is connected to the first connection point A1, and the nth sensing transistor is connected to the first connection point A1 through the (n-1)th branch switch.

[0103] In this example, (n-1) branch switches K1 to K(n-1) are interconnected between adjacent current sensing branches. Therefore, for any branch switch, when the branch switch is turned on and the branch switches connected before the branch switch are all turned on, the current sensing branch controlled by the branch switch is turned on, so that the current sensing unit 231 has a sensing current output.

[0104] Optionally, when the control signal indicates that the first (x-1) branch switches are turned on and the last (Nx) branch switches are turned off, the current sensing unit 231 senses the current flowing through the power switch Q0 through the first x sensing transistors and outputs a target sampling current, which is equal to the sum of the currents flowing through the first x sensing transistors. At this time, the target sampling ratio of the current sampling circuit 23 is equal to the sum of the mirror ratios of the first x sensing transistors and the power switch Q0, and x is an integer greater than or equal to 1 and less than or equal to n.

[0105] For example, when the (n-1) branch switches are all in the off state, the current sensing unit 231 senses the current flowing through the power switch Q0 through the first sensing transistor M1, and the target sampling current is equal to the current flowing through the sensing transistor M1. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the mirror ratio k1 of the sensing transistor M1 and the power switch Q0, and the mirror ratio k1 is equal to the ratio of the effective area of ​​the sensing transistor to the effective area of ​​the power switch Q0.

[0106] For another example, when the first two branch switches (K1 and K2) are in the on state and the last (n-3) branch switches (K3 to K(n-1)) are all turned off, the current sensing unit 231 senses the current flowing through the power switch Q0 through the first three sensing transistors M1 to M3, and the target sampling current is equal to the sum of the currents flowing through the first three sensing transistors M1 to M3. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the sum of the mirror ratio k1 of the sensing transistor M1 and the power switch Q0, the mirror ratio k2 of the sensing transistor M2 and the power switch Q0, and the mirror ratio k3 of the sensing transistor M3 and the power switch Q0.

[0107] It can be understood that in this example, the mirror ratios of the current sensing branches can be the same or different, for example, 1 / 100, 1 / 1000, 1 / 10000, etc., which can be determined according to actual needs and will not be elaborated here.

[0108] As another example, Figure 4B As shown, in this example, the current sensing unit 231 includes n sensing transistors M1 to Mn and n branch switches K0 to K(n-1), where n is an integer greater than or equal to 2. Among them, the control ends of the n sensing transistors M1 to Mn are all connected to the control end of the power switch Q0, the first ends are connected to the first end of the power switch Q0, and the second ends are correspondingly connected to the first connection point A1 through the n branch switches to form n sensing branches.

[0109] In this example, n branch switches K0 to K(n-1) are correspondingly connected to the sensing branches where n sensing transistors M1 to Mn are located, that is, each branch switch is used to control the conduction or shutdown of the sensing branch where it is located. In this way, for any branch switch, when the branch switch is turned on, the current sensing branch where the branch switch is located is turned on, and accordingly, the current sensing unit 231 has a sensing current output.

[0110] Optionally, when the control signal indicates that m of the n branch switches are turned on and the remaining (nm) branch switches are turned off, the current sensing unit 231 senses the current flowing through the power switch Q0 through the m sensing branches where the m branch switches are located and outputs a target sampling current, where the target sampling current is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit 23 is equal to the sum of the mirror ratios of the m sensing branches and the power switch Q0, where m is an integer greater than or equal to 1 and less than or equal to n.

[0111] In this example, the control circuit 21 can control the switch states of n branch switches correspondingly through a control signal (i.e., an n-bit coded signal) to control different current sensing branches to be turned on or control different numbers of current sensing branches to be turned on. For example, when the second branch switch K1 is in the on state, but the other (n-1) branch switches are all in the off state, the current sensing unit 231 senses the current flowing through the power switch Q0 through the second sensing transistor M2, and the target sampling current is equal to the current flowing through the sensing transistor M2. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the mirror ratio k2 of the sensing transistor M2 and the power switch Q0.

[0112] For another example, when the first branch switch and the third branch switch (K0 and K2) are in the on state and the other branch switches are all off, the current sensing unit 231 senses the current flowing through the power switch Q0 through the first sensing transistor M1 and the third sensing transistor M2, and the target sampling current is equal to the sum of the current flowing through the first sensing transistor M1 and the current flowing through the third sensing transistor M2. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the sum of the mirror ratio k1 of the sensing transistor M1 and the power switch Q0 and the mirror ratio k3 of the sensing transistor M3 and the power switch Q0.

[0113] As another example, Figure 4CAs shown, in this example, the current sensing unit 231 includes n sensing transistors M1 to Mn and n branch switches K0 to K(n-1), where n is an integer greater than or equal to 2. Among them, the control ends of the n sensing transistors M1 to Mn are correspondingly connected to the control circuit 21 through the n branch switches K0 to K(n-1), the first ends thereof are connected to the first end of the power switch Q0, and the second ends thereof are connected to the first connection point A1.

[0114] In this example, n branch switches K0 to K(n-1) are correspondingly connected to the control ends of n sensing transistors M1 to Mn, that is, when the control circuit 21 outputs a drive signal to control the power switch Q0 to turn on, for any branch switch, if the branch switch is turned on, the control circuit 21 can also control the sensing transistor corresponding to the branch switch to turn on through the drive signal, so that the corresponding current sensing branch is turned on, and accordingly, the current sensing unit 231 has a sensing current output.

[0115] Optionally, when the control circuit 21 controls the power switch Q0 to turn on and conduct, if the control signal indicates that m of the n branch switches are turned on and conducted and the remaining (nm) branch switches are turned off and cut off, then the m sensing transistors controlled by the m branch switches are turned on and conducted and the (nm) sensing transistors controlled by the remaining (nm) branch switches are turned off and cut off. At this time, the current sensing unit 231 senses the current flowing through the power switch Q0 through the m sensing branches and outputs a target sampling current, which is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit 23 is equal to the sum of the mirror ratios of the m sensing branches and the power switch Q0, and m is an integer greater than or equal to 1 and less than or equal to n.

[0116] In this example, the control circuit 21 can control the switch states of the n branch switches correspondingly through the control signal (i.e., the n-bit coded signal) to control different sensing transistors to be turned on or control different numbers of sensing transistors to be turned on. For example, when the second branch switch K1 is in the on state, but the other (n-1) branch switches are all in the off state, the second sensing transistor M2 is turned on, and accordingly, the current sensing unit 231 senses the current flowing through the power switch Q0 through the second sensing transistor M2, and the target sampling current is equal to the current flowing through the sensing transistor M2. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the mirror ratio k2 of the sensing transistor M2 and the power switch Q0.

[0117] For another example, when the first branch switch and the third branch switch (K0 and K2) are in the on state and the other branch switches are all off, the first sensing transistor M1 and the third sensing transistor M3 are turned on, and the current sensing unit 231 senses the current flowing through the power switch Q0 through the first sensing transistor M1 and the third sensing transistor M2. The target sampling current is equal to the sum of the current flowing through the first sensing transistor M1 and the current flowing through the third sensing transistor M2. At this time, the target sampling ratio k0 of the current sampling circuit 23 is equal to the sum of the mirror ratio k1 of the sensing transistor M1 and the power switch Q0 and the mirror ratio k3 of the sensing transistor M3 and the power switch Q0.

[0118] Understandably, Figure 4B and Figure 4C In the example shown, the mirror ratio of each current sensing branch is usually different, for example, 1 / 100, 1 / 1000, 2 / 1000, 1 / 10000, etc., which can be determined according to actual needs and will not be described in detail here.

[0119] Optionally, the intelligent electronic switch 20 provided in this embodiment also includes an abnormal protection unit, a first end of the abnormal protection unit is connected to the first connection point A1, and a second end of the abnormal protection unit is connected to the load output terminal OUT, and the abnormal protection unit is used to protect the current sensing unit 231 when the branch where the power switch Q0 is located is abnormal.

[0120] In practical applications, the current capability of the sensing transistor included in the current sensing unit 231 is usually much smaller than the current capability of the power switch Q0. Therefore, in order to protect the sensing transistor in the current sensing unit 231, an abnormal protection unit may be connected between the load output terminal OUT and the first connection point A1. FIG. 4A to FIG. 4C In the illustrated embodiment, the abnormal protection unit is exemplified by a diode D0. When a load is short-circuited, the diode D0 can prevent a large current at the load output terminal OUT from flowing back to the current sensing unit 231, thereby protecting the sensing transistor in the current sensing unit 231 from being damaged.

[0121] In an embodiment of the present application, a current sensing unit is provided in the intelligent electronic switch, and the current sensing unit includes at least two sensing transistors and at least one branch switch, so that the control circuit can control the output current of the current sensing unit by controlling the switching state of the branch switch, thereby changing the sampling ratio of the current sampling circuit, so that the intelligent electronic switch meets both the power requirements and the sampling accuracy requirements when performing current sampling, thereby improving the product competitiveness.

[0122] In another possible design, Figure 5 Schematic diagram of a circuit module of an intelligent electronic switch provided in the fourth embodiment of the present application. Figure 5 As shown, in this embodiment, the current sampling circuit 23 includes a gain adjustable unit 23A.

[0123] Continue to refer to Figure 5 As shown, in this embodiment, the branch where the power switch Q0 is located is also used to connect the sampling resistor Rsen in series, and the current flowing through the sampling resistor Rsen is equal to the current flowing through the power switch Q0. The two input ends of the gain adjustable unit 23A are correspondingly connected to the two ends of the sampling resistor Rsen, the gain control end of the gain adjustable unit 23A is connected to the control circuit 21, and the output end of the gain adjustable unit 23A is used to output the target sampling voltage.

[0124] Optionally, the control circuit 21 adjusts the gain of the gain adjustable unit 23A to a target sampling ratio through a control signal. The gain adjustable unit 23A receives the voltage difference across the sampling resistor Rsen through its two input terminals, and amplifies the voltage difference across the sampling resistor Rsen based on the target sampling ratio to output a target sampling voltage. The target sampling voltage is equal to the product of the voltage difference across the sampling resistor Rsen and the target sampling ratio.

[0125] In practical applications, the sampling resistor Rsen is connected in series to the branch where the power switch Q0 is located. According to the power consumption formula, the power consumption on the sampling resistor Rsen is positively correlated with the current flowing through the sampling resistor Rsen and the resistance value of the sampling resistor Rsen. The larger the resistance value of the sampling resistor Rsen or the larger the current flowing through the sampling resistor Rsen, the higher the power consumption on the sampling resistor Rsen. Therefore, in order to reduce the power consumption on the sampling resistor Rsen, the resistance value of the sampling resistor Rsen is generally small, but this will result in a lower voltage drop across the sampling resistor Rsen, and there may be problems such as failure to sample or very low sampling accuracy. Therefore, in practical applications, the voltage drop across the sampling resistor Rsen generally needs to be amplified before output.

[0126] Optionally, if the voltage drop across the sampling resistor Rsen is amplified according to a fixed multiple, then, when the fixed multiple is small, if the drain-source voltage value Vds of the power switch Q0 is also small, the current flowing through the power switch Q0 is also small. At this time, even if the voltage drop across the sampling resistor Rsen is amplified by a fixed multiple, the sampling voltage output by the current acquisition circuit may still be small and cannot meet the accuracy requirement; similarly, when the fixed multiple is large, if the drain-source voltage value Vds of the power switch Q0 is also large, the current flowing through the power switch Q0 is also large. At this time, after the voltage drop across the sampling resistor Rsen is amplified by a fixed multiple, the sampling voltage output by the current acquisition circuit may be very large, resulting in a large overall power consumption of the current sampling circuit 23. Therefore, in response to this problem, in an embodiment of the present application, the current sampling circuit 23 may include a gain adjustable unit 23A, so that the control circuit 21 can adjust the gain of the gain adjustable unit 23A based on the drain-source voltage value of the power switch Q0, so that the target sampling ratio of the gain adjustable unit 23A can be compatible with the power consumption and sampling accuracy requirements. In this way, after the gain adjustable unit 23A obtains the voltage difference between the two ends of the sampling resistor Rsen through its two input ends, it can amplify the voltage difference based on the target sampling ratio and then output the target sampling voltage.

[0127] Optionally, in this embodiment, when the drain-source voltage value is larger, the target sampling ratio indicated by the control signal is smaller, and when the drain-source voltage value Vds is smaller, the target sampling ratio indicated by the control signal is larger. This ensures that the target sampling voltage output by the gain adjustable unit 23A is within a suitable voltage sampling range, thereby enabling the current sampling circuit 23 to achieve compatible power consumption and sampling accuracy requirements.

[0128] As an example, Figure 6 yes Figure 5 A possible circuit structure diagram of an intelligent electronic switch is shown in FIG. Figure 6 As shown, in this embodiment, the gain adjustable unit 23A includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, an operational amplifier unit 23A1 and a reference power supply I1, wherein the resistance values ​​of the first resistor R1 and the second resistor R2 are equal and fixed, and the resistance values ​​of the third resistor R3 and the fourth resistor R4 are equal and adjustable.

[0129] Optionally, the operational amplifier unit 23A1 has a first input terminal connected to the first end of the sampling resistor Rsen through a first resistor R1, a second input terminal connected to the second end of the sampling resistor Rsen through a second resistor R2, and a first input terminal connected to its output terminal through a third resistor R3, and a second input terminal connected to the power ground terminal GND through a fourth resistor R4 and a reference power supply I1, and an output terminal is used to output a target sampling voltage, and the reference power supply I1 is used to provide a common-mode power supply for the operational amplifier unit 23A1.

[0130] In this embodiment, the sampling ratio of the gain adjustable unit 23A is equal to the ratio of the third resistor R3 to the first resistor R1. The control circuit 21 adjusts the resistance values ​​of the third resistor R3 and the fourth resistor R4 through a control signal to adjust the ratio of the third resistor R3 to the first resistor R1, so that the gain of the operational amplifier unit 23A1 is equal to the target sampling ratio. The operational amplifier unit 23A1 amplifies the voltage difference across the sampling resistor Rsen by the target sampling ratio and outputs the target sampling voltage.

[0131] Exemplarily, the first input terminal and the second input terminal of the operational amplifier unit 23A1 are symmetrically arranged, so that the sampling ratio of the gain adjustable unit 23A is equal to the ratio of the third resistor R3 to the first resistor R1, and is equal to the ratio of the fourth resistor R4 to the second resistor R2. Since the resistance values ​​of the first resistor R1 and the second resistor R2 are the same and fixed, and the resistance values ​​of the third resistor R3 and the fourth resistor R4 are the same and adjustable, the control circuit 21 can output a control signal according to the threshold interval of the drain-source voltage value, thereby synchronously adjusting the resistance values ​​of the third resistor R3 and the fourth resistor R4, and then adjusting the gain of the gain adjustable unit 23A.

[0132] In this embodiment, when the threshold interval of the drain-source voltage value is large, the control circuit 21 can output a control signal to reduce the resistance of the third resistor R3 and the fourth resistor R4, thereby reducing the target sampling ratio of the current sampling circuit 23; and when the threshold interval of the drain-source voltage value is small, the control circuit can output a control signal to increase the resistance of the third resistor R3 and the fourth resistor R4, thereby increasing the target sampling ratio of the current sampling circuit 23.

[0133] In this embodiment, the gain adjustable unit is realized by cooperating with the computing unit and the resistor, which not only makes the current sampling circuit compatible with the power consumption and sampling accuracy requirements, but also has a simple implementation scheme and is easy to implement, thereby improving the competitiveness of the product.

[0134] Optionally, based on the above embodiments, the intelligent electronic switch 20 further includes a sampling terminal CS.

[0135] For example, refer to the above Figures 3 to 6 As shown, the sampling terminal CS is connected to the current sampling circuit 23. The current sampling circuit 23 is used to output a target sampling signal through the sampling terminal CS. The target sampling signal is used to represent the current flowing through the power switch Q0.

[0136] Optional, in Figures 3 to 4CIn the illustrated embodiment, the current sampling circuit 23 outputs a target sampling current. At this time, the sampling terminal CS can also be used to connect a detection resistor Rcs, and the detection resistor Rcs is grounded. In this way, the microcontroller connected to the sampling terminal CS can obtain a sampling voltage corresponding to the target sampling current by collecting the voltage of the sampling terminal CS. The microcontroller can determine the current flowing through the power switch Q0 according to the target sampling ratio of the current sampling circuit 23 and the detection resistor Rcs, and then control the power switch Q0.

[0137] exist Figure 5 and Figure 6 In the illustrated embodiment, the current sampling circuit 23 outputs a target sampling voltage. At this time, the sampling terminal CS can also be used to connect the filter capacitor C1 and the filter capacitor C1 is grounded. In this way, the filter capacitor C1 can filter the target sampling voltage, so that the microcontroller connected to the sampling terminal CS can obtain the target sampling voltage by collecting the voltage of the sampling terminal CS. The microcontroller can determine the current flowing through the power switch Q0 according to the target sampling ratio of the current sampling circuit 23.

[0138] In this embodiment, the intelligent electronic switch 20 outputs a target sampling signal through the feedback terminal, so that the microcontroller can calculate the current flowing through the power switch Q0 according to the acquired target sampling signal, so as to reasonably control the current.

[0139] In a possible design of the present application, after the intelligent electronic switch 20 obtains the target sampling signal, it can infer the target sampling ratio of the current sampling circuit 23 based on the load size, and then calculate the current flowing through the power switch Q0.

[0140] In another possible design of the present application, the intelligent electronic switch 20 further includes a feedback terminal (not shown), which is connected to the control circuit 21, so that the control circuit 21 is also used to output a second indication signal through the feedback terminal, and the second indication signal is used to indicate the sampling ratio indicated by the control signal.

[0141] In this embodiment, after the intelligent electronic switch outputs the target sampling signal through the sampling end, it can also output the second indication signal through the feedback end, so that the microcontroller can calculate the current flowing through the power switch based on the received second indication signal and the target sampling signal, thereby improving the accuracy of the microcontroller in calculating the output current.

[0142] It can be understood that other parts not described in detail in the above embodiments can refer to the contents recorded in other embodiments and will not be repeated here.

[0143] Optionally, based on the above embodiments, the present application embodiment further provides an integrated circuit chip, the integrated circuit chip comprising the above Figures 1 to 6The intelligent electronic switch 20 provided in each embodiment, that is, the intelligent electronic switch 20 described above, can be fabricated on the same semiconductor substrate, wherein the power supply terminal VBAT is a power supply pin, the power ground terminal GND is a power ground pin, and the load output terminal OUT is a load output pin.

[0144] Optionally, other embodiments of the present application further provide a chip product, which may include the intelligent electronic switch 20 provided in the above embodiments, wherein the components of the intelligent electronic switch 20 except for the power switch Q0 and some components of the current sampling circuit 23 are located on a first integrated circuit chip, and the power switch Q0 and some components of the current sampling circuit 23 are located on a second integrated circuit chip, that is, the first integrated circuit chip is made on one semiconductor substrate, and the second integrated circuit chip is made on another semiconductor substrate.

[0145] Among them, the power supply terminal VBAT is a power supply pin, the power ground terminal GND is a power ground pin, the load output terminal OUT is a load output pin, the power supply pin and the power ground pin are located on the first integrated circuit chip, and the load output pin is located on the second integrated circuit chip. It can be understood that the first integrated circuit chip and the second integrated circuit chip can also add other pins, omit related pins, or merge related pins as needed. Here, the first integrated circuit chip and the second integrated circuit chip are packaged into one product.

[0146] In addition, in other embodiments of the present application, a car is also provided, which may be an electric car, such as an electric passenger car or an electric commercial vehicle, or a hybrid car, a fuel car, or a car. The car may include the above Figures 1 to 6 The intelligent electronic switch 20 shown or the above-mentioned integrated circuit chip or the above-mentioned chip product, in addition, the car may also include a battery 10, a load 30 and a microcontroller 40. The positive electrode of the battery 10 is connected to the power supply terminal VBAT, the negative electrode of the battery 10 is connected to the power ground terminal GND, one end of the load 30 is connected to the load output terminal OUT, the other end of the load 30 is connected to the power ground terminal GND or the power supply terminal VBAT, the intelligent electronic switch 20 is connected to the microcontroller 40, and the microcontroller 40 is used to control the intelligent electronic switch 20.

[0147] The battery 10 is generally a storage battery, which provides voltages such as 12V, 24V, 48V, 72V, etc., and can also be other types of batteries. The load 30 includes at least one of a resistive load, an inductive load, and a capacitive load. The resistive load is, for example, a seat adjustment device, an auxiliary heating device, a window heating device, a light emitting diode (LED), a rear lighting, or other resistive loads. The inductive load is, for example, a pump, an actuator, a motor, an anti-lock braking system (ABS), an electronic braking system (EBS), a fan, or other systems including inductive loads for one or more wiper systems. The capacitive load is, for example, a lighting element, such as a xenon arc lamp.

[0148] It is understandable that the intelligent electronic switch, integrated circuit chip, chip product, etc. of this embodiment is not limited to use in automotive electronics, but can also be used in industrial automation, aerospace and other fields, which will not be elaborated here.

[0149] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0150] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. An intelligent electronic switch, characterized in that: It includes a power supply terminal, a power ground terminal, a load output terminal, a power switch, a control circuit and a current sampling circuit; The power supply end and the power ground end are used to be connected to a battery, the power switch is used to be connected in series with a load, a first end thereof is connected to the power supply end or the power ground end, a second end thereof is connected to the load output end, a control end thereof is connected to the control circuit, the control circuit is used to control the power switch to be turned on or off, and the current sampling circuit is connected to the power switch and the control circuit; The control circuit outputs a corresponding control signal when acquiring the first indication signal, the control signal is used to indicate the sampling ratio of the current sampling circuit, the current sampling circuit collects the current flowing through the power switch based on the sampling ratio and outputs the target sampling signal, the first indication signal is used to indicate the magnitude of the current flowing through the power switch, the larger the current flowing through the power switch, the smaller the sampling ratio, the smaller the current flowing through the power switch, the larger the sampling ratio, the sampling ratio is equal to the ratio of the output to the input of the current sampling circuit.

2. The intelligent electronic switch according to claim 1, characterized in that: The first indication signal includes a drain-source voltage value of the power switch; when the power switch operates in a linear resistance region, the drain-source voltage value is used to characterize a current flowing through the power switch, and the larger the drain-source voltage value, the larger the current flowing through the power switch, and the smaller the drain-source voltage value, the smaller the current flowing through the power switch; The intelligent electronic switch also includes a voltage sampling circuit, which is connected to the source, drain and control circuit of the power switch; the voltage sampling circuit is used to obtain the drain-source voltage value of the power switch and output the first indication signal when the power switch operates in the linear resistance area, and the control circuit outputs the control signal according to the threshold interval of the drain-source voltage value in the first indication signal; wherein, for two adjacent threshold intervals, the lower limit value of the larger threshold interval is greater than or equal to the upper limit value of the smaller threshold interval, and the larger the threshold interval of the drain-source voltage value is, the smaller the sampling ratio indicated by the control signal is.

3. The intelligent electronic switch according to claim 2, characterized in that: The threshold interval includes at least a first threshold interval and a second threshold interval; The control circuit outputs a first control signal when the drain-source voltage value is within a first threshold interval, so that the current sampling circuit samples the current flowing through the power switch at a first sampling ratio; the control circuit outputs a second control signal when the drain-source voltage value is within a second threshold interval, so that the current sampling circuit samples the current flowing through the power switch at a second sampling ratio; When the upper limit of the first threshold interval is less than or equal to the lower limit of the second threshold interval, the first sampling ratio is greater than the second sampling ratio.

4. The intelligent electronic switch according to claim 1, characterized in that: It also includes an indication terminal, wherein the indication terminal is connected to the control circuit; The control circuit receives the first indication signal through the indication end. The first indication signal is determined based on the weight information of the load. The weight information of the load is used to characterize the current flowing through the power switch. The heavier the load, the greater the current flowing through the power switch. The lighter the load, the smaller the current flowing through the power switch.

5. The intelligent electronic switch according to any one of claims 1 to 4, characterized in that: The current sampling circuit includes a current sensing unit, an operational amplifier unit and a switch tube; The current sensing unit, whose control end is connected to the control circuit, whose first end is connected to the first end of the power switch, whose second end is connected to the switch tube and the connection point is the first connection point, whose first input end of the operational amplifier unit is connected to the first connection point, whose second end is connected to the load output end, whose output end is connected to the control end of the switch tube, and whose second end of the switch tube is used to output the target sampling current; The operational amplifier unit outputs a third signal when the voltages at the first connection point and the load output terminal are equal. At this time, the switch tube is turned on, and the current sensing unit outputs the sensed target sampling current through the switch tube.

6. The intelligent electronic switch according to claim 5, characterized in that: The current sensing unit includes n sensing transistors and (n-1) branch switches, where n is an integer greater than or equal to 2; n sensing transistors, whose control ends are all connected to the control end of the power switch, whose first ends are all connected to the first end of the power switch, whose second ends are sequentially connected through (n-1) branch switches, and the first sensing transistor is connected to the first connection point, and the nth sensing transistor is connected to the first connection point through the (n-1)th branch switch; When the control signal indicates that the first (x-1) branch switches are turned on and the last (Nx) branch switches are turned off, the current sensing unit senses the current flowing through the power switch through the first x sensing transistors and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the first x sensing transistors. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the first x sensing transistors and the power switch, and x is an integer greater than or equal to 1 and less than or equal to n.

7. The intelligent electronic switch according to claim 5, characterized in that: The current sensing unit includes n sensing transistors and n branch switches, where n is an integer greater than or equal to 2; n sensing transistors, each of which has a control end connected to the control end of the power switch, a first end connected to the first end of the power switch, and a second end connected to the first connection point via n branch switches; When the control signal indicates that m of the n branch switches are turned on and the remaining (nm) branch switches are turned off, the current sensing unit senses the current flowing through the power switch through the m sensing branches where the m branch switches are located and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the m sensing branches and the power switch, and m is an integer greater than or equal to 1 and less than or equal to n.

8. The intelligent electronic switch according to claim 5, characterized in that: The current sensing unit includes n sensing transistors and n branch switches, where n is an integer greater than or equal to 2; n sensing transistors, whose control ends are connected to the control circuit via n branch switches, whose first ends are connected to the first end of the power switch, and whose second ends are connected to the first connection point; When the control circuit controls the power switch to turn on, if the control signal indicates that m of the n branch switches are turned on and the remaining (nm) branch switches are turned off, then the m sensing transistors controlled by the m branch switches are turned on and the (nm) sensing transistors controlled by the remaining (nm) branch switches are turned off. At this time, the current sensing unit senses the current flowing through the power switch through the m sensing branches and outputs a target sampling current, and the target sampling current is equal to the sum of the currents flowing through the m sensing branches. At this time, the target sampling ratio of the current sampling circuit is equal to the sum of the mirror ratios of the m sensing branches and the power switch, and m is an integer greater than or equal to 1 and less than or equal to n.

9. The intelligent electronic switch according to claim 5, characterized in that: It also includes an abnormal protection unit, a first end of which is connected to the first connection point, and a second end of which is connected to the load output end. The abnormal protection unit is used to protect the current sensing unit when the branch where the power switch is located is abnormal.

10. The intelligent electronic switch according to any one of claims 1 to 4, characterized in that: The current sampling circuit includes a gain adjustable unit; The branch where the power switch is located is also used to connect a sampling resistor in series, the current flowing through the sampling resistor is equal to the current flowing through the power switch, the two input ends of the gain adjustable unit are correspondingly connected to the two ends of the sampling resistor, the gain control end of the gain adjustable unit is connected to the control circuit, and the output end of the gain adjustable unit is used to output a target sampling voltage; The control circuit adjusts the gain of the gain adjustable unit to a target sampling ratio through a control signal. The gain adjustable unit receives the voltage difference across the sampling resistor through its two input terminals, amplifies the voltage difference across the sampling resistor based on the target sampling ratio, and outputs a target sampling voltage. The target sampling voltage is equal to the product of the voltage difference across the sampling resistor and the target sampling ratio.

11. The intelligent electronic switch according to claim 10, characterized in that: The gain adjustable unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an operational amplifier unit and a reference power supply, wherein the resistance values ​​of the first resistor and the second resistor are equal and fixed, and the resistance values ​​of the third resistor and the fourth resistor are equal and adjustable; The operational amplifier unit, wherein the first input terminal thereof is connected to the first terminal of the sampling resistor through the first resistor, the second input terminal thereof is connected to the second terminal of the sampling resistor through the second resistor, the first input terminal thereof is further connected to the output terminal thereof through the third resistor, the second input terminal thereof is further connected to the power ground terminal through the fourth resistor and the reference power supply, the output terminal thereof is used to output the target sampling voltage, and the reference power supply is used to provide a common-mode power supply for the operational amplifier unit; The sampling ratio of the gain adjustable unit is equal to the ratio of the third resistor to the first resistor. The control circuit adjusts the resistance values ​​of the third resistor and the fourth resistor through a control signal to adjust the ratio of the third resistor to the first resistor, so that the gain of the operational amplifier unit is equal to the target sampling ratio. The operational amplifier unit amplifies the voltage difference across the sampling resistor by the target sampling ratio and then outputs a target sampling voltage.

12. The intelligent electronic switch according to any one of claims 1 to 4, characterized in that: It also includes a sampling terminal, which is connected to the current sampling circuit; The current sampling circuit is used to output a target sampling signal through the sampling end, and the target sampling signal is used to represent the current flowing through the power switch.

13. The intelligent electronic switch according to claim 12, characterized in that: It also includes a feedback terminal, wherein the feedback terminal is connected to the control circuit; The control circuit is further configured to output a second indication signal through the feedback terminal, wherein the second indication signal is configured to indicate a sampling ratio indicated by the control signal.

14. An integrated circuit chip, characterized in that: The intelligent electronic switch comprises the intelligent electronic switch according to any one of claims 1 to 13, wherein the power supply end is a power supply pin, the power ground end is a power ground pin, and the load output end is a load output pin.

15. A chip product, characterized in that: The intelligent electronic switch according to any one of claims 1 to 13, wherein the components of the intelligent electronic switch except for the power switch and some components of the current sampling circuit are located on a first integrated circuit chip, and the power switch and some components of the current sampling circuit are located on a second integrated circuit chip; Among them, the power supply end is a power supply pin, the power ground end is a power ground pin, the load output end is a load output pin, the power supply pin and the power ground pin are located on a first integrated circuit chip, and the load output pin is located on a second integrated circuit chip.

16. A car, characterized in that: Comprising the intelligent electronic switch according to any one of claims 1 to 13, or the integrated circuit chip according to claim 14, or the chip product according to claim 15; It also includes a battery, a load, and a microcontroller, wherein the positive electrode of the battery is connected to the power supply terminal, the negative electrode of the battery is connected to the power ground terminal, one end of the load is connected to the load output terminal, and the other end of the load is connected to the power ground terminal or the power supply terminal, the intelligent electronic switch is connected to the microcontroller, and the microcontroller is used to control the intelligent electronic switch.

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