Power switching circuit and communication module

Abstract

The utility model discloses a power supply switching circuit and a communication module, and relates to the technical field of wireless communication, and the circuit comprises a power supply switching control circuit and n voltage conversion circuits. Each output end of the power supply switching control circuit is connected with the enabling input end of each voltage conversion circuit, and is used for converting an external enabling signal output by the processor into a power supply control enabling signal corresponding to each voltage conversion circuit; the voltage conversion circuits are used for converting input external power supply into respective output voltage by utilizing respective low dropout linear voltage regulators when the received power supply control enable signals are working enable signals, and supplying power to connected power receiving equipment; according to the utility model, through the arrangement of the power supply switching control circuit, the processor can control the enabling input of each voltage conversion circuit by outputting corresponding enabling signals according to power supply requirements, so that the adaptive switching of at least two power supply voltages can be conveniently realized, and through simple circuit integration, the configuration cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of wireless communication technology, and in particular to a power switching circuit and a communication module. Background Technology

[0002] As we all know, wireless communication is inseparable from SIM (Subscriber Identification Module) cards. Whether it's mobile phone communication or the currently popular satellite communication, dedicated SIM cards are used. The ISO 7816 protocol (a basic international standard communication specification) stipulates that SIM cards can be divided into three types according to their power supply voltage: class-A 5V, class-B 3V, and class-C 1.8V. Currently, most commonly used SIM cards use class-B and class-C power supplies and can support both simultaneously.

[0003] Currently, most solutions for powering SIM cards employ platform chipsets or external integrated power supplies, but these have limited applications, lack flexibility in configuration, and are costly. External single-power supply solutions, on the other hand, only support one voltage mode, resulting in poor applicability. Therefore, how to easily achieve adaptive switching between multiple power supply voltages using simple circuit integration, thereby reducing configuration costs, is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this invention is to provide a power switching circuit and a communication module that can easily achieve adaptive switching of multiple power supply voltages by utilizing simple circuit integration, thereby reducing configuration costs.

[0005] To solve the above-mentioned technical problems, this utility model provides a power switching circuit, including: a power switching control circuit and n voltage conversion circuits; wherein, n is a positive integer greater than or equal to 2;

[0006] The input terminal of the power switching control circuit is connected to the enable output terminal of the processor; each output terminal of the power switching control circuit is connected to the enable input terminal of each voltage conversion circuit, and is used to convert the external enable signal output by the processor into a power control enable signal corresponding to each voltage conversion circuit; wherein, the power control enable signal includes a working enable signal and a sleep enable signal; when the external enable signals output by the processor are different, the power control enable signals corresponding to at least two voltage conversion circuits are different;

[0007] The voltage conversion circuit is used to convert the input external power supply into its respective output voltage to supply power to the connected powered device when the received power control enable signal is the working enable signal; wherein, the output voltages of at least two of the voltage conversion circuits are different.

[0008] On the other hand, the m input terminals of the power switching control circuit are connected one-to-one with the m enable output terminals of the processor; wherein, The power switching control circuit is used to convert the external enable signals output by the m enable output terminals into power control enable signals corresponding to each of the n voltage conversion circuits; wherein, the number of working enable signals among the n power control enable signals is less than or equal to m.

[0009] On the other hand, the working enable signal is a high-level signal, and the sleep enable signal is a low-level signal;

[0010] The power switching control circuit includes: a first resistor and m first controllable switches;

[0011] Wherein, the control terminal of each of the first controllable switches serves as one input terminal of the power switching control circuit and is connected to one enable output terminal corresponding to the processor. The first terminal of the first controllable switch is connected to the output terminal of the external power supply through the first resistor, and the second terminal of the first controllable switch is grounded.

[0012] The common terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes the first voltage conversion circuit and the second voltage conversion circuit, and when m=n / 2, the second voltage conversion circuit corresponding to each first controllable switch is different.

[0013] On the other hand, the working enable signal is a high-level signal, and the sleep enable signal is a low-level signal;

[0014] The power switching control circuit includes: m first resistors and m first controllable switches;

[0015] Wherein, the control terminal of each first controllable switch serves as an input terminal of the power switching control circuit and is connected to an enable output terminal corresponding to the processor; the first terminal of each first controllable switch is connected to the output terminal of the external power supply through its corresponding first resistor; and the second terminal of each first controllable switch is grounded.

[0016] The common terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes the first voltage conversion circuit and the second voltage conversion circuit, and when m=n / 2, the second voltage conversion circuit corresponding to each first controllable switch is different.

[0017] On the other hand, each of the voltage conversion circuits includes a low-dropout linear regulator and an isolation circuit;

[0018] The common terminal connecting the enable terminal of the low-dropout linear regulator and the enable input terminal of the isolation circuit serves as the enable input terminal of the voltage conversion circuit and is connected to the corresponding output terminal of the power switching control circuit. The low-dropout linear regulator is used to convert the input external power supply into the corresponding output voltage when the received power control enable signal is the working enable signal; and to go into sleep mode when the received power control enable signal is the sleep enable signal.

[0019] The input terminal of the isolation circuit is connected to the output terminal of the low-dropout linear regulator. When the received power control enable signal is the working enable signal, the circuit outputs the output voltage of the low-dropout linear regulator through the output terminal to supply power to the connected power-receiving device; when the received power control enable signal is the sleep enable signal, the circuit disconnects the input terminal from the output terminal.

[0020] On the other hand, the operation enable signal is a high-level signal, and the sleep enable signal is a low-level signal; each of the isolation circuits includes: a second controllable switch, a third controllable switch, and a second resistor;

[0021] Wherein, the control terminal of the second controllable switch serves as the enable input terminal of the isolation circuit and is connected to the enable terminal of the low-dropout linear regulator and the corresponding output terminal of the power switching control circuit, respectively; the common terminal of the first terminal of the second controllable switch and the first terminal of the second resistor is connected to the control terminal of the third controllable switch, the second terminal of the second controllable switch is grounded, the second terminal of the second resistor is connected to the output terminal of the external power supply, the second terminal of the third controllable switch serves as the input terminal of the isolation circuit and is connected to the output terminal of the corresponding low-dropout linear regulator, and the first terminal of the third controllable switch serves as the output terminal of the isolation circuit and is used to connect to the power supply terminal of the powered device.

[0022] On the other hand, each of the voltage conversion circuits also includes a third resistor;

[0023] The first end of the third resistor is connected to the enable terminal of the low-dropout linear regulator in the voltage conversion circuit and the enable input terminal of the isolation circuit, while the second end of the third resistor is grounded.

[0024] On the other hand, the power switching circuit also includes: a number of surface mount resistors reserved circuits;

[0025] The surface mount resistor reserved circuit is used to connect the two ends of the surface mount resistor reserved circuit when a corresponding surface mount resistor is set; and to disconnect the two ends of the surface mount resistor reserved circuit when no corresponding surface mount resistor is set. The surface mount resistor reserved circuit includes a first surface mount resistor reserved circuit disposed between the control terminal and the first terminal of at least one first controllable switch in the power switching control circuit, a second surface mount resistor reserved circuit disposed between the first terminal and the second terminal of each of the third controllable switches, and / or a third surface mount resistor reserved circuit disposed between the enable terminal and the preset sleep output terminal of the low dropout linear regulator of at least one of the voltage conversion circuits.

[0026] In addition, this utility model also provides a communication module, including: the power switching circuit as described above.

[0027] On the other hand, the communication module also includes a processor;

[0028] The processor's enable output is connected to the input of the power switching control circuit; the output of the power switching control circuit is connected to the power supply of the powered device for supplying power to the powered device; the powered device includes the processor and a SIM card; the external power supply input of the power switching control circuit is connected to the output of the onboard power supply for receiving external power from the onboard power supply.

[0029] This utility model provides a power switching circuit, comprising: a power switching control circuit and n voltage conversion circuits; wherein n is a positive integer greater than or equal to 2; the input terminal of the power switching control circuit is connected to the enable output terminal of the processor; each output terminal of the power switching control circuit is connected to the enable input terminal of each voltage conversion circuit, for converting the external enable signal output by the processor into a power control enable signal corresponding to each voltage conversion circuit; wherein the power control enable signal includes a working enable signal and a sleep enable signal; when the external enable signals output by the processor are different, the power control enable signals corresponding to at least two voltage conversion circuits are different; the voltage conversion circuits are used to convert the input external power supply into their respective output voltages using their respective low-dropout linear regulators when the received power control enable signal is a working enable signal, to power the connected powered devices; wherein the output voltages of at least two voltage conversion circuits are different.

[0030] As can be seen, this invention, through the setting of a power switching control circuit, enables the processor to control the enable input of each voltage conversion circuit according to power supply requirements by outputting corresponding enable signals, thereby switching the power supply voltage to the powered device. This conveniently achieves adaptive switching between at least two power supply voltages, and through simple circuit integration, it reduces configuration costs. Furthermore, this invention also provides a communication module that shares the same beneficial effects. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0032] Figure 1 A schematic diagram illustrating the power supply of a SIM card in a platform chipset solution for mobile communication in related technologies;

[0033] Figure 2 A schematic diagram illustrating the SIM card power supply for an external integrated power supply solution in satellite communication within related technologies;

[0034] Figure 3 A schematic diagram illustrating the SIM card power supply for a single-power-supply scheme in satellite communication within related technologies;

[0035] Figure 4 A structural block diagram of a power switching circuit provided in an embodiment of this utility model;

[0036] Figure 5 A schematic diagram of the framework of another power switching circuit provided in an embodiment of this utility model;

[0037] Figure 6 This is a circuit diagram of another power switching circuit provided in an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0039] In related technologies, there are generally three known SIM card power supply solutions. One is the platform chipset solution commonly used in mobile communication, such as... Figure 1 As shown, the CPU (Central Processing Unit) controls the PMU (Power Management Unit) via a control line to convert the output of the external power supply (EXT_PWR) into the required voltage for SIM card power supply (VSIM); the other two are the external integrated power supply solution and the single power supply solution commonly used in satellite communications, such as... Figure 2 As shown, the CPU (Central Processing Unit) controls the PMIC (Power Integrated Circuit chip) via the I2C (Inter-Integrated Circuit, a simple, bidirectional two-wire synchronous serial bus) bus to convert the output of the external power supply (EXT_PWR) into the required voltage for SIM card power supply (VSIM), thus realizing the aforementioned external integrated power supply solution; as shown... Figure 3 As shown, the output of the external power supply (EXT_PWR) is converted into a voltage for SIM card power supply (VSIM) using an LDO (low dropout linear regulator) to achieve the above single power supply solution.

[0040] However, platform-based chipset solutions have fixed configurations, limited applications, and lack flexibility in configuration; external integrated power supply solutions are similar to platform-based chipset solutions, controlling the load but at a higher cost; while external single power supply solutions can only support one voltage mode, resulting in poor adaptability. Therefore, this invention achieves adaptive switching between at least two power supply voltages through simple circuit integration, thereby improving configuration adaptability and flexibility and reducing configuration costs.

[0041] For details, please refer to Figure 4 , Figure 4 This is a structural block diagram of a power switching circuit provided in an embodiment of the present invention. The circuit may include: a power switching control circuit 10 and n voltage conversion circuits 20; wherein n is a positive integer greater than or equal to 2;

[0042] The input terminal of the power switching control circuit 10 is connected to the enable output terminal of the processor; each output terminal of the power switching control circuit 10 is connected to the enable input terminal of each voltage conversion circuit 20, and is used to convert the external enable signal output by the processor into the power control enable signal corresponding to each voltage conversion circuit 20; wherein, the power control enable signal includes a working enable signal and a sleep enable signal; when the external enable signals output by the processor are different, the power control enable signals corresponding to at least two voltage conversion circuits 20 are different;

[0043] The voltage conversion circuit 20 is used to convert the input external power supply into its own output voltage using its respective low-dropout linear regulator when the received power control enable signal is a working enable signal, so as to supply power to the connected power receiving device; wherein, the output voltages of at least two voltage conversion circuits 20 are different.

[0044] It is understood that the input terminal of the power switching control circuit 10 in this embodiment can be connected to the enable output terminal of the processor, and each output terminal of the power switching control circuit 10 is connected to the enable input terminal of each voltage conversion circuit 20, so that the power switching control circuit 10 can respond to the external enable signal (such as the one output by the enable output terminal of the processor) generated by the processor. Figure 6 The PWM_CS function converts the external enable signal into a power control enable signal corresponding to each voltage conversion circuit 20, thereby controlling the operation and sleep of each voltage conversion circuit 20 and switching the power supply voltage of different voltage conversion circuits 20. For example, when the output terminals of all voltage conversion circuits 20 are connected to the same powered device, at most only one voltage conversion circuit 20 can have a power control enable signal input at its enable input terminal as the operating enable signal at any given time; at the same time, more than one voltage conversion circuit 20 can also have a power control enable signal input at its enable input terminal as the operating enable signal, such as activating multiple voltage conversion circuits 20 to simultaneously power the same connected powered device, or to power different connected powered devices separately.

[0045] Accordingly, in this embodiment, the enable input terminal of each voltage conversion circuit 20 can be connected to a corresponding output terminal in the power switching control circuit 10, and the power input terminal of each voltage conversion circuit 20 can be connected to an external power supply (such as...). Figure 6 The output of EXT_VCC in the circuit is connected, and the output of each voltage conversion circuit 20 can be connected to a powered device (such as...). Figure 6 The power supply terminals of the SIM card and CPU (e.g.) Figure 6 The VSIM (Voltage-Signaling Module) connection allows each voltage conversion circuit 20 to control the start and stop of its respective voltage conversion device (such as an LDO or DC-DC converter) according to the power control enable signal input to its respective enable input terminal. When the voltage conversion device is working, it supplies power to the connected power receiving device. In other words, when the received power control enable signal is a working enable signal, the voltage conversion circuit 20 can convert the input external power supply into its own output voltage to supply power to the connected power receiving device; when the received power control enable signal is a sleep enable signal, it can stop supplying power to the connected power receiving device.

[0046] Correspondingly, the specific number of voltage conversion circuits 20 in this embodiment, i.e., the specific value of n, can be set by the designer according to the practical scenario and user needs. For example, n can be 2, that is, the output voltage of the two voltage conversion circuits 20 can be different. For example, the output voltage of one voltage conversion circuit 20 is 1.8V, and the output voltage of the other voltage conversion circuit 20 is 3V, so as to realize the switching between two power supply voltages. n can also be a positive integer greater than or equal to 3. For example, when n is 3, the output voltages of the three voltage conversion circuits 20 can be 1.8V, 3V and 5V respectively, so that the output voltages of each voltage conversion circuit 20 are different, and the switching between multiple power supply voltages can be realized.

[0047] It should be noted that the external enable signal received by the power switching control circuit 10 in this embodiment can be an enable signal output by the processor through the enable output terminal to control the start and stop (i.e., operation and sleep) of the voltage conversion circuit 20; that is, the processor can control the switching of the power supply voltage to the powered device by adjusting the output external enable signal (such as the operation enable signal or the sleep enable signal). In other words, under normal operation, when the external enable signals output by the processor are different, the power control enable signals corresponding to at least two voltage conversion circuits 20 will be different, thereby switching the operating voltage conversion circuit 20 and adjusting the power supply voltage to the powered device. For example, when at most one voltage conversion circuit 20 has a power control enable signal input at its enable input terminal that is an operation enable signal, under normal operation, when the external enable signals output by the processor are different, the power control enable signal corresponding to one voltage conversion circuit 20 will be different from the power control enable signals corresponding to other voltage conversion circuits 20, thereby switching the operating voltage conversion circuit 20.

[0048] Correspondingly, the circuit structure of the power switching control circuit 10 in this embodiment can be customized by the designer according to the usage scenario and user requirements. For example, the m input terminals of the power switching control circuit 10 can be connected one-to-one with the m enable output terminals of the processor; where, , The value indicates rounding up. The power switching control circuit 10 is used to convert the external enable signals output from m enable output terminals into power control enable signals corresponding to n voltage conversion circuits 20. The number of operating enable signals among the n power control enable signals is less than or equal to m. For example, when n is 2, the number of input terminals (m) of the power switching control circuit 10 can be 1, allowing the processor to control the switching of two power supply voltages using only one external enable signal. That is, one input terminal of the power switching control circuit 10 is connected to one enable output terminal of the processor, used to convert the external enable signal output from the enable output terminal into the operating enable signal of the first voltage conversion circuit 20 and the sleep enable signal of the second voltage conversion circuit 20, or to convert the external enable signal into the sleep enable signal of the first voltage conversion circuit 20 and the operating enable signal of the second voltage conversion circuit 20. When n is 3 or 4, the number of input terminals (m) of the power switching control circuit 10 can be 2, allowing the processor to control the switching of 3 or 4 power supply voltages using 2 external enable signals.

[0049] For example, when the working enable signal is a high-level signal and the sleep enable signal is a low-level signal, the power switching control circuit 10 may include: a first resistor and m first controllable switches; wherein, the control terminal of each first controllable switch serves as one input terminal of the power switching control circuit 10 and is connected to one enable output terminal corresponding to the processor, the first terminal of the first controllable switch is connected to the output terminal of the external power supply through the first resistor, and the second terminal of the first controllable switch is grounded; the common terminal of the first terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes a first voltage conversion circuit and a second voltage conversion circuit; when m=n / 2, the second voltage conversion circuits corresponding to each first controllable switch are different. In other words, the n voltage conversion circuits 20 can be divided into m first voltage conversion circuits and m or (m-1) second voltage conversion circuits; the first terminals of the m first controllable switches are connected one-to-one with the enable input terminals of the m first voltage conversion circuits; when m=n / 2, the control terminals of the m first controllable switches are connected to the enable input terminals of the m second voltage conversion circuits; when m≠n / 2, the control terminals of (m-1) first controllable switches are connected to the enable input terminals of (m-1) second voltage conversion circuits, and the control terminal of the remaining 1 first controllable switch can be connected to the enable input terminal of one of the second voltage conversion circuits; so that the external enable signal input to the control terminal of one first controllable switch is When a high-level signal (i.e., a working enable signal) is received, the first controllable switch can be turned on, causing the enable input terminal of the first voltage conversion circuit connected to it to receive a low-level signal (i.e., a sleep enable signal), while the enable input terminal of the second voltage conversion circuit connected to it receives a high-level signal. In other words, the first voltage conversion circuit connected to it is in sleep mode while the second voltage conversion circuit is working. When the external enable signal input to the control terminal of the first controllable switch is a low-level signal, the first controllable switch can be turned off, causing the enable input terminal of the first voltage conversion circuit connected to it to receive a high-level signal, while the enable input terminal of the second voltage conversion circuit receives a low-level signal. In other words, the first voltage conversion circuit connected to it is working while the second voltage conversion circuit is in sleep mode.

[0050] Correspondingly, the power switching control circuit 10 may also include: m first resistors and m first controllable switches; wherein, the control terminal of each first controllable switch serves as an input terminal of the power switching control circuit and is connected to an enable output terminal corresponding to the processor; the first terminal of each first controllable switch is connected to the output terminal of the external power supply through its corresponding first resistor; the second terminal of each first controllable switch is grounded; the common terminal connecting the first terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes a first voltage conversion circuit and a second voltage conversion circuit, and when m=n / 2, the second voltage conversion circuits corresponding to each first controllable switch are different. That is to say, by setting m first resistors, the situation where m first controllable switches share a single first resistor is avoided.

[0051] For example, when n is 2, the power switching control circuit 10 includes: a first controllable switch (such as...) Figure 6 Q4 in the middle) and the first resistor (such as Q4 ... Figure 6 R5 in the first controllable switch is used to connect to the enable output terminal of the processor. The first terminal of the first controllable switch is connected to the output terminal of the external power supply through the first resistor. The second terminal of the second controllable switch is grounded. The common terminal of the first terminal of the first controllable switch and the first resistor is connected to the enable input terminal of the first voltage conversion circuit 20 (i.e., the first voltage conversion circuit). The control terminal of the first controllable switch is connected to the enable input terminal of the second voltage conversion circuit 20 (i.e., the second voltage conversion circuit). In other words, when the external enable signal output by the processor is a high-level signal (i.e., a working enable signal), the first controllable switch can be turned on, causing the enable input terminal of the first voltage conversion circuit 20 to input a low-level signal (i.e., a sleep enable signal), while the enable input terminal of the second voltage conversion circuit 20 inputs a high-level signal, meaning the first voltage conversion circuit 20 is in sleep mode and the second voltage conversion circuit 20 is working; when the external enable signal output by the processor is a low-level signal, the first controllable switch can be turned off, causing the enable input terminal of the first voltage conversion circuit 20 to input a high-level signal, while the enable input terminal of the second voltage conversion circuit 20 inputs a low-level signal, meaning the first voltage conversion circuit 20 is working and the second voltage conversion circuit 20 is in sleep mode.

[0052] Correspondingly, the circuit structure with m first controllable switches described above is designed to enable the processor's m enable outputs to control the switching of the two voltage conversion circuits 20 by outputting two different levels of external enable signals (i.e., high and low level signals). To ensure that when n is a positive integer greater than or equal to 3, at most one voltage conversion circuit 20 has a power control enable signal input at its enable input at any given time, the processor's m enable outputs can also output medium-level signals. This allows one enable output to control both corresponding voltage conversion circuits 20 to sleep when it outputs a medium-level signal. Specifically, when one enable output outputs a medium-level signal, it controls the connected first controllable switch to turn on, causing the second voltage conversion circuit to sleep, and controlling the second voltage conversion circuit to sleep. Alternatively, the power switching control circuit 10 can also include m fourth controllable switches, such as grounding each second voltage conversion circuit's enable input through one fourth controllable switch, and controlling the m fourth controllable switches to... The control terminal can be connected one-to-one with the m second enable output terminals of the processor, so that the processor can control the conduction and de-conduction of m fourth controllable switches through the level signals (such as high and low level signals) output by the m second enable output terminals. When the two external enable signals output by the processor corresponding to a group of voltage conversion circuits 20 (i.e., the first voltage conversion circuit and the second voltage conversion circuit) are respectively a high level signal for controlling the conduction of the first controllable switch and a high level signal for controlling the conduction of the second controllable switch, this group of voltage conversion circuits 20 can all go into sleep mode. By setting the m fourth controllable switches, at most only one power control enable signal input to the enable input terminal of the voltage conversion circuit 20 can be the working enable signal at any given time.

[0053] In this embodiment, the circuit structure of each of the n voltage conversion circuits 20 can be customized by the designer according to the practical scenario and user requirements. For example, when the voltage conversion circuit 20 uses a low-dropout linear regulator (LDO) for voltage conversion, each voltage conversion circuit 20 includes a low-dropout linear regulator (e.g., Figure 6 The low-dropout linear regulator (LDO1 or LDO2) and isolation circuit; wherein, the enable terminal of the low-dropout linear regulator (e.g., LDO1 or LDO2) is used. Figure 6 The common terminal connected to the enable input terminal of the isolation circuit (EN1 or EN2) and the enable input terminal of the voltage conversion circuit 20 is used as the enable input terminal of the voltage conversion circuit 20 and connected to the corresponding output terminal of the power switching control circuit 10. The low dropout linear regulator is used to convert the input external power supply into the corresponding output voltage when the received power control enable signal is the working enable signal; and to go into sleep mode when the received power control enable signal is the sleep enable signal. The input terminal of the isolation circuit and the output terminal of the low dropout linear regulator (such as EN1 or EN2) are connected to the corresponding output terminal of the power switching control circuit 10. Figure 6The VOUT1 or VOUT2 connection is used to output the output voltage of the low-dropout linear regulator to power the connected device when the received power control enable signal is a working enable signal; and to disconnect the input and output terminals when the received power control enable signal is a sleep enable signal. In other words, this embodiment, through the isolation circuit in each voltage conversion circuit 20, enables the output terminal of the low-dropout linear regulator to disconnect from the power supply terminal of the device during sleep mode, effectively preventing voltage backflow and improving circuit quality. Furthermore, the low-dropout linear regulator and isolation circuit of each voltage conversion circuit 20 are controlled together by their respective input power control enable signals, further simplifying the control logic.

[0054] Correspondingly, this embodiment does not limit the specific device type to which the output terminal of each voltage conversion circuit 20 is connected to the powered device; that is, this embodiment does not limit the specific application scenario of the power switching circuit. For example, the power switching circuit provided in this embodiment can be applied to a SIM card powered scenario. For instance, the output terminal of each voltage conversion circuit 20 in this embodiment can be connected to the SIM card and the SIM card power supply terminal of the CPU (e.g., ...). Figure 6 VSIM in this context means that the powered device can include a SIM card and a CPU.

[0055] For example, when the work enable signal is high and the sleep enable signal is low, each isolation circuit may include: a second controllable switch (such as...) Figure 6 Q1 or Q2 in the middle), and the third controllable switch (such as Q1 or Q2 in the middle), Figure 6 Q6 or Q5 in the second resistor (e.g., Q6 or Q5 in the second resistor) and Q6 or Q5 in the third resistor (e.g., Q6 or Q5 in the second resistor) Figure 6 R2 or Q1 in the circuit); wherein, the control terminal of the second controllable switch serves as the enable input terminal of the isolation circuit and is respectively connected to the enable terminal of the low dropout linear regulator (e.g., R2 or Q1); where the control terminal of the second controllable switch serves as the enable input terminal of the isolation circuit and is respectively connected to the enable terminal of the low dropout linear regulator (e.g., R2 or Q1 in the circuit). Figure 6 The first terminal of the second controllable switch (EN1 or EN2) and the corresponding output terminal of the power switching control circuit 10 are connected; the common terminal of the first terminal of the second controllable switch and the first terminal of the second resistor are connected to the control terminal of the third controllable switch; the second terminal of the second controllable switch is grounded; the second terminal of the second resistor is connected to the output terminal of the external power supply; the second terminal of the third controllable switch serves as the input terminal of the isolation circuit and is connected to the output terminal of the corresponding low-dropout linear regulator; the first terminal of the third controllable switch serves as the output terminal of the isolation circuit and is used to connect to the power supply terminal of the powered equipment (such as...). Figure 6The connection between the SIM card and the CPU (VSIM) is as follows: When a high-level signal (i.e., a working enable signal) is input to the enable input of a voltage conversion circuit 20, the LDO in the circuit operates, the second controllable switch is turned on to control the third controllable switch to turn on, so that the output voltage of the LDO supplies power to the connected SIM card and processor; when a low-level signal (i.e., a sleep enable signal) is input to the enable input of a voltage conversion circuit 20, the LDO in the circuit goes into sleep mode, the second controllable switch is turned off to control the third controllable switch to turn off, so that the LDO output is disconnected from the SIM card power supply of the SIM card and the processor.

[0056] Furthermore, such as Figure 6 As shown, in this embodiment, each voltage conversion circuit 20 also includes a third resistor (R3 or R4); wherein, the first end of the third resistor is connected to the enable terminal of the low-dropout linear regulator and the enable input terminal of the isolation circuit in the voltage conversion circuit 20, and the second end of the third resistor is grounded. That is, through the third resistor in each voltage conversion circuit 20 (such as R3 or R4), Figure 6 The setting of the R4-100kΩ resistor enables resistance pull-down, improving the reliability of the switch.

[0057] Correspondingly, the specific switch types for the first, second, and third controllable switches can be set by the designer according to the usage scenario and user needs. For example, the first, second, and third controllable switches can use MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), transistors, or IGBTs (Insulated-Gate Bipolar Transistors). If all three switches use MOS transistors, such as... Figure 6 As shown, the first controllable switch (Q4) can be an NMOS transistor, the second controllable switches (Q1 and Q2) can be NMOS transistors, and the third controllable switches (Q5 and Q6) can be PMOS transistors. Specifically, the gate of the first controllable switch is connected to the processor's enable output, the drain of the first controllable switch is connected to the output of the external power supply (EXT_VCC) through the first resistor (R5), and the source of the first controllable switch is grounded. The gate of the second controllable switch (Q1 or Q2) serves as the enable input of the isolation circuit and is connected to the low-dropout line. The enable terminal of the voltage regulator (LDO1 or LDO2) is connected to the corresponding output terminal of the power switching control circuit 10; the common terminal of the drain of the second controllable switch and the first terminal of the second resistor (R2 or R1) is connected to the gate of the third controllable switch (Q6 or Q5), the source of the second controllable switch is grounded, the drain of the third controllable switch is connected to the output terminal of the corresponding low dropout linear regulator as the input terminal of the isolation circuit, and the source of the third controllable switch is used as the output terminal of the isolation circuit to connect to the SIM card power supply terminal of the SIM card and the processor.

[0058] Similarly, the specific resistance values ​​of the first, second, and third resistors mentioned above can be set by the designer, such as... Figure 6 As shown, in this embodiment, the first resistor, the second resistor, and the third resistor can all be 100kΩ resistors, or other resistor values ​​can be used. This embodiment does not impose any restrictions on this.

[0059] It is understood that, in order to further improve the configuration flexibility of the power switching circuit provided in this embodiment, the circuit provided in this embodiment may also include several surface mount resistor reserved circuits; wherein, the surface mount resistor reserved circuits are used to connect the connection at both ends of the surface mount resistor reserved circuit when the corresponding surface mount resistor is set; and to disconnect the connection at both ends of the surface mount resistor reserved circuit when the corresponding surface mount resistor is not set; so that users can adjust the circuit structure by selecting the corresponding surface mount resistors, such as to achieve single power supply, thereby reducing costs.

[0060] For example, the surface mount resistor reservation circuit may include a first surface mount resistor reservation circuit disposed between the control terminal and the first terminal of at least one first controllable switch in the power switching control circuit 10; for example, when n is 2, the power switching control circuit 10 may be provided with one first surface mount resistor reservation circuit; wherein, the control terminal of the first controllable switch is connected to the first terminal of the first controllable switch through the first surface mount resistor reservation circuit; wherein, the first surface mount resistor reservation circuit is used to set the corresponding surface mount resistor (e.g., ... Figure 6 When R6 (NC) is in the circuit, the connection between the control terminal and the first terminal of the first controllable switch is turned on; when no corresponding surface mount resistor is set, the connection between the control terminal and the first terminal of the first controllable switch is turned off.

[0061] Correspondingly, the surface mount resistor reserved circuit may also include a second surface mount resistor reserved circuit disposed between the first and second terminals of each third controllable switch; for example, each isolation circuit may also be provided with a second surface mount resistor reserved circuit; wherein, the first terminal of the third controllable switch is connected to the second terminal through the second surface mount resistor reserved circuit; the second surface mount resistor reserved circuit is used to set the corresponding surface mount resistor (e.g., Figure 6 When R8 NC or R9 NC is used, the connection between the first and second terminals of the third controllable switch is turned on; when no corresponding surface mount resistor is set, the connection between the first and second terminals of the third controllable switch is turned off.

[0062] Furthermore, the surface mount resistor reservation circuit may also include a third surface mount resistor reservation circuit disposed between the enable terminal and the preset sleep output terminal of the low dropout linear regulator in at least one voltage conversion circuit 20; that is, a third surface mount resistor reservation circuit may be disposed in at least one voltage conversion circuit 20; wherein, the first terminal of the third surface mount resistor reservation circuit is connected to the preset sleep output terminal, and the second terminal of the third surface mount resistor reservation circuit is connected to the enable terminal of the low dropout linear regulator in the voltage conversion circuit 20 and the enable input terminal of the isolation circuit, for setting the corresponding surface mount resistor (e.g., Figure 6 When R7 (NC) is turned on, the preset sleep output terminal is connected to the enable terminal of the low dropout linear regulator and the enable input terminal of the isolation circuit in the voltage conversion circuit 20, so as to turn off the output of the voltage conversion circuit 20.

[0063] like Figure 6 As shown, R6 NC, R7 NC, R8 NC, and R9 NC are reserved circuits for corresponding surface-mount resistors. They are not surface-mounted by default. When only one supply voltage needs to be supported, a single power supply can be achieved by selecting different combinations of surface-mount resistors, reducing costs. When higher power consumption is required, R7 NC can be selected. By controlling the preset sleep output terminal to output a sleep enable signal (SLEEP), the normally open power supply can be turned off, further reducing power consumption. For example, when setting R6 NC and R7 NC, the sleep enable signal (SLEEP) output through the preset sleep output terminal can control both LDOs to sleep. Figure 5 As shown, the power switching circuit provided in this embodiment can be applied to the OBU (On-Board Unit) of a vehicle, utilizing the onboard power supply unit in the OBU to convert the power supply from EXT_PWR (external power supply) to the required external power supply (e.g., ...). Figure 5 The PWR_CS in the circuit supplies power to the power switching circuit (power switching unit). When the corresponding surface mount resistor is set in the second surface mount resistor reserved circuit, the MCU (microcontroller) can output a sleep enable signal (SLEEP) to control the shutdown of the normally open power supply.

[0064] Correspondingly, such as Figure 6As shown, when no surface-mount resistors are set in the reserved circuits for each surface-mount resistor, the CPU (i.e., the processor) can default to not operating PWR_CS (external enable signal) at power-on, keeping it at a low level. Q4 is off, and EN1 of LDO1 is pulled high, causing LDO1 to output 1.8V. Simultaneously, Q1 controls Q6 to conduct, and the 1.8V output supplies power to the SIM card and the CPU. When the CPU recognizes a SIM card that is not 1.8V, it can pull PWR_CS high to switch the power supply (e.g., if the card switching interval is required to be >10ms). Q4 conducts, EN1 is pulled low, LDO1 is turned off, and Q1 controls Q5 to turn off. At this time, EN2 is pulled high, LDO2 outputs 3.0V, and Q2 controls Q5 to conduct, supplying 3.0V to the SIM card and the CPU. In other words, in this embodiment, the processor can identify the type of SIM card (e.g., 1.8V card or 3V card) and output the corresponding external enable signal through the enable output terminal according to the identified SIM type; such as Figure 6 As shown, the CPU's default power supply configuration is the commonly used 1.8V voltage. When a 1.8V SIM card is inserted, it will be automatically recognized as a 1.8V card. When a 3V SIM card is inserted, it will first recognize the 1.8V card. If the recognition fails, it will execute the card switching logic to switch to 3V voltage, and then it can normally recognize and power a 3V SIM card.

[0065] In this embodiment, when the power switching circuit supplies power to the SIM card, the processor can communicate with the SIM card, such as... Figure 6 As shown, the CPU (i.e., processor) can communicate with the SIM card via IO (input / output) lines, RST (reset) lines, and CLK (clock) lines.

[0066] In this embodiment, the power switching control circuit 10 enables the processor to control the enable input of each voltage conversion circuit 20 by outputting corresponding enable signals according to power supply requirements, thereby switching the power supply voltage to the powered device. This conveniently achieves adaptive switching of at least two power supply voltages, and reduces configuration costs through simple circuit integration.

[0067] Corresponding to the circuit embodiment above, this utility model embodiment also provides a communication module. The communication module described below and the power switching circuit described above can be referred to in correspondence.

[0068] A communication module includes a power switching circuit as provided in the above embodiments.

[0069] In some embodiments, the communication module provided in this embodiment may further include a processor;

[0070] The processor's enable output is connected to the input of the power switching control circuit; the output of the power switching control circuit is connected to the power supply of the powered device to supply power to the powered device; the powered device includes a processor and a SIM card; the external power supply input of the power switching control circuit is connected to the output of the onboard power supply to receive external power from the onboard power supply.

[0071] For example, such as Figure 5 As shown, the communication module provided in this embodiment can be applied to the OBU (On-Board Unit) of a vehicle, utilizing the onboard power supply unit in the OBU to convert the power supply from EXT_PWR (external power supply) to the required external power supply voltage (e.g., ...). Figure 5 The PWR_CS in the OBU supplies power to the power switching circuit (power switching unit) in the communication module. When the corresponding surface mount resistor is set in the second surface mount resistor reserved circuit, the MCU (microcontroller) in the OBU can output a sleep enable signal (SLEEP) to control the shutdown of the normally open power supply.

[0072] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the communication module disclosed in the embodiments, since it corresponds to the circuit disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the circuit section description.

[0073] The power switching circuit and communication module provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A power switching circuit, characterized in that, include: A power switching control circuit and n voltage conversion circuits; where n is a positive integer greater than or equal to 2; The input terminal of the power switching control circuit is connected to the enable output terminal of the processor; each output terminal of the power switching control circuit is connected to the enable input terminal of each voltage conversion circuit, and is used to convert the external enable signal output by the processor into a power control enable signal corresponding to each voltage conversion circuit; wherein, the power control enable signal includes a working enable signal and a sleep enable signal; when the external enable signals output by the processor are different, the power control enable signals corresponding to at least two voltage conversion circuits are different; The voltage conversion circuit is used to convert the input external power supply into its respective output voltage to supply power to the connected powered device when the received power control enable signal is the working enable signal; wherein, the output voltages of at least two of the voltage conversion circuits are different.

2. The power switching circuit according to claim 1, characterized in that, The power switching control circuit has m input terminals connected one-to-one with the processor's m enable output terminals; wherein, The power switching control circuit is used to convert the external enable signals output by the m enable output terminals into power control enable signals corresponding to each of the n voltage conversion circuits; wherein, the number of working enable signals among the n power control enable signals is less than or equal to m.

3. The power switching circuit according to claim 1, characterized in that, The working enable signal is a high-level signal, and the sleep enable signal is a low-level signal; The power switching control circuit includes: a first resistor and m first controllable switches; Wherein, the control terminal of each of the first controllable switches serves as one input terminal of the power switching control circuit and is connected to one enable output terminal corresponding to the processor. The first terminal of the first controllable switch is connected to the output terminal of the external power supply through the first resistor, and the second terminal of the first controllable switch is grounded. The common terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes the first voltage conversion circuit and the second voltage conversion circuit, and when m=n / 2, the second voltage conversion circuit corresponding to each first controllable switch is different.

4. The power switching circuit according to claim 1, characterized in that, The working enable signal is a high-level signal, and the sleep enable signal is a low-level signal; The power switching control circuit includes: m first resistors and m first controllable switches; Wherein, the control terminal of each first controllable switch serves as an input terminal of the power switching control circuit and is connected to an enable output terminal corresponding to the processor; the first terminal of each first controllable switch is connected to the output terminal of the external power supply through its corresponding first resistor; and the second terminal of each first controllable switch is grounded. The common terminal of each first controllable switch and the first resistor is connected to the enable input terminal of its corresponding first voltage conversion circuit; the control terminal of each first controllable switch is connected to the enable input terminal of its corresponding second voltage conversion circuit; the voltage conversion circuit includes the first voltage conversion circuit and the second voltage conversion circuit, and when m=n / 2, the second voltage conversion circuit corresponding to each first controllable switch is different.

5. The power switching circuit according to any one of claims 1 to 4, characterized in that, Each of the voltage conversion circuits includes a low-dropout linear regulator and an isolation circuit; The common terminal connecting the enable terminal of the low-dropout linear regulator and the enable input terminal of the isolation circuit serves as the enable input terminal of the voltage conversion circuit and is connected to the corresponding output terminal of the power switching control circuit. The low-dropout linear regulator is used to convert the input external power supply into the corresponding output voltage when the received power control enable signal is the working enable signal; and to go into sleep mode when the received power control enable signal is the sleep enable signal. The input terminal of the isolation circuit is connected to the output terminal of the low-dropout linear regulator. When the received power control enable signal is the working enable signal, the circuit outputs the output voltage of the low-dropout linear regulator through the output terminal to supply power to the connected power-receiving device; when the received power control enable signal is the sleep enable signal, the circuit disconnects the input terminal from the output terminal.

6. The power switching circuit according to claim 5, characterized in that, The working enable signal is a high-level signal, and the sleep enable signal is a low-level signal; each of the isolation circuits includes: a second controllable switch, a third controllable switch, and a second resistor; Wherein, the control terminal of the second controllable switch serves as the enable input terminal of the isolation circuit and is connected to the enable terminal of the low-dropout linear regulator and the corresponding output terminal of the power switching control circuit, respectively; the common terminal of the first terminal of the second controllable switch and the first terminal of the second resistor is connected to the control terminal of the third controllable switch, the second terminal of the second controllable switch is grounded, the second terminal of the second resistor is connected to the output terminal of the external power supply, the second terminal of the third controllable switch serves as the input terminal of the isolation circuit and is connected to the output terminal of the corresponding low-dropout linear regulator, and the first terminal of the third controllable switch serves as the output terminal of the isolation circuit and is used to connect to the power supply terminal of the powered device.

7. The power switching circuit according to claim 6, characterized in that, Each of the voltage conversion circuits also includes a third resistor; The first end of the third resistor is connected to the enable terminal of the low-dropout linear regulator in the voltage conversion circuit and the enable input terminal of the isolation circuit, while the second end of the third resistor is grounded.

8. The power switching circuit according to claim 6, characterized in that, Also includes: Several surface mount resistors are reserved in the circuit; The surface mount resistor reserved circuit is used to connect the two ends of the surface mount resistor reserved circuit when a corresponding surface mount resistor is set; and to disconnect the two ends of the surface mount resistor reserved circuit when no corresponding surface mount resistor is set. The surface mount resistor reserved circuit includes a first surface mount resistor reserved circuit disposed between the control terminal and the first terminal of at least one first controllable switch in the power switching control circuit, a second surface mount resistor reserved circuit disposed between the first terminal and the second terminal of each of the third controllable switches, and / or a third surface mount resistor reserved circuit disposed between the enable terminal and the preset sleep output terminal of the low dropout linear regulator of at least one of the voltage conversion circuits.

9. A communication module, characterized in that, include: The power switching circuit as described in any one of claims 1 to 8.

10. The communication module according to claim 9, characterized in that, Also includes: processor; The processor's enable output is connected to the input of the power switching control circuit; the output of the power switching control circuit is connected to the power supply of the powered device for supplying power to the powered device; the powered device includes the processor and a SIM card; the external power supply input of the power switching control circuit is connected to the output of the onboard power supply for receiving external power from the onboard power supply.

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