Control system for variable polarity switching transistors

Abstract

This invention provides a control system for a variable-pole switch, which includes a gate, a first variable drain-source port, a second variable drain-source port, and a BULK body terminal. The gate is connected to an external gate circuit, the first variable drain-source port is connected to an external first circuit, the second variable drain-source port is connected to an external second circuit, and the BULK body terminal is connected to an external body circuit. The external gate circuit generates a gate voltage; the external body circuit generates a body voltage at the BULK body terminal; and the variable-pole switch is used to turn on and off based on the gate voltage and / or the body voltage at the BULK body terminal. In this system, the variable-pole switch can turn on or off based on the gate voltage and / or the body voltage, eliminating the need for a series-connected diode or switch to prevent reverse polarity, thus avoiding increased loop voltage drop, saving component space, and reducing circuit cost.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a control system for a variable-pole switching transistor. Background Technology

[0002] Conventional switching transistors typically use ground (GND) or the power supply voltage (VCC) as a fixed reference point. However, when a floating control voltage is required in a circuit, a reverse-biased diode is usually connected in series with the switching transistor to prevent reverse polarity, or an additional reverse-biased switching transistor is added. This approach increases the loop voltage difference, increases the component footprint, and raises the circuit cost. Summary of the Invention

[0003] The purpose of this invention is to provide a control system for a variable polarity switch to avoid increasing the voltage difference in the loop, while saving the area occupied by components and reducing circuit costs.

[0004] This invention provides a control system for a variable-pole switch, the variable-pole switch comprising: a gate, a first variable drain-source port, a second variable drain-source port, and a BULK body terminal; the gate is connected to an external gate circuit, the first variable drain-source port is connected to an external first circuit, the second variable drain-source port is connected to an external second circuit, and the BULK body terminal is connected to an external body circuit; the external gate circuit is used to generate a gate voltage for the gate; the external body circuit is used to generate a body voltage for the BULK body terminal; the variable-pole switch is used to turn on and off according to the gate voltage of the gate and / or the body voltage of the BULK body terminal.

[0005] Furthermore, if the variable-pole switch is an NMOS, the body voltage is controlled to decrease, and there is no conduction between the BULK body terminal and the first variable drain-source port, and between the BULK body terminal and the second variable drain-source port. Then, the gate voltage is controlled to increase. When the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage, the variable-pole switch is turned on; when the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, the variable-pole switch is turned off.

[0006] If the variable-polarity switch is a PMOS, the body voltage is controlled to increase, and the connection between the BULK body terminal and the first variable drain-source port, as well as between the BULK body terminal and the second variable drain-source port, is not made. Then, the gate voltage is controlled to decrease. When the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, the variable-polarity switch is turned on; when the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, the variable-polarity switch is turned off.

[0007] Furthermore, the external body circuit includes: a first switching transistor, a first sub-circuit, a second switching transistor, and a second sub-circuit; the BULK body terminal is connected to the first sub-circuit through the first switching transistor and to the second sub-circuit through the second switching transistor; the variable polarity switch is used to determine the drain or source of the variable polarity switch by controlling the on / off state of the first switching transistor and the second switching transistor.

[0008] Furthermore, the BULK body terminal is connected to the first variable drain-source port via the first switching transistor; the BULK body terminal is connected to the second variable drain-source port via the second switching transistor; the variable-pole switching transistor is used to determine that the first variable drain-source port is the source and the second variable drain-source port is the drain if the second switching transistor is turned off and the first switching transistor is turned on; and to determine that the second variable drain-source port is the source and the first variable drain-source port is the drain if the first switching transistor is turned off and the second switching transistor is turned on.

[0009] Furthermore, if the variable-pole switch, the first switching switch, and the second switching switch are all NMOS transistors, the first variable drain-source port is connected to the drain of the first switching switch, the source of the first switching switch is connected to the BULK body terminal, and the gate of the first switching switch is connected to the second variable drain-source port; the second variable drain-source port is connected to the drain of the second switching switch, the source of the second switching switch is connected to the BULK body terminal, and the gate of the second switching switch is connected to the first variable drain-source port;

[0010] The variable-pole switch is further configured to: when the first variable drain-source port is at a high potential and the second variable drain-source port is at a low potential, turn on the second switching switch to connect the second variable drain-source port to the BULK body terminal, thus determining that the second variable drain-source port is the source and the first variable drain-source port is the drain; when the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage, turn on the variable-pole switch; when the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, turn off the variable-pole switch.

[0011] If the variable-pole switch, the first switching switch, and the second switching switch are all PMOS transistors, the first variable drain-source port is connected to the drain of the first switching switch, the source of the first switching switch is connected to the BULK body terminal, and the gate of the first switching switch is connected to the second variable drain-source port; the second variable drain-source port is connected to the drain of the second switching switch, the source of the second switching switch is connected to the BULK body terminal, and the gate of the second switching switch is connected to the first variable drain-source port.

[0012] The variable-pole switch is further configured to: when the first variable drain-source port is at a high potential and the second variable drain-source port is at a low potential, turn on the first switching switch to connect the first variable drain-source port to the BULK body terminal, thus determining that the first variable drain-source port is the source and the second variable drain-source port is the drain; when the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, turn on the variable-pole switch; when the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, turn off the variable-pole switch.

[0013] Furthermore, the system also includes:

[0014] The first switching transistor has its first terminal connected to the gate of the variable polarity switching transistor;

[0015] A first capacitor has its first terminal connected to the second terminal of the first switching transistor, and its second terminal connected to either the first variable drain-source port or the second variable drain-source port. When the first switching transistor is turned on, if the variable-polarity switching transistor is an NMOS, it is turned on when the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage; if the variable-polarity switching transistor is a PMOS, it is turned on when the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage.

[0016] The second switching transistor has its first end connected to the gate of the variable polarity switching transistor and its second end connected to the BULK body terminal; when the second switching transistor is turned on, the variable polarity switching transistor is turned off.

[0017] Furthermore, both the first switching transistor and the second switching transistor are diodes; the anodes of both the first and second switching transistors are connected to the BULK body terminal; the cathode of the first switching transistor is connected to the first variable drain-source port; and the cathode of the second switching transistor is connected to the second variable drain-source port.

[0018] Furthermore, the first switching transistor includes: a first MOSFET and a second MOSFET connected in a transistor-to-transistor configuration, wherein the gates of the first MOSFET and the second MOSFET are connected; the third terminal of the first MOSFET is connected to the first capacitor; and the third terminal of the second MOSFET is connected to the gate of the variable-pole switching transistor.

[0019] The second switching transistor includes a third MOS transistor and a fourth MOS transistor connected in a transistor pair configuration, with the gates of the third MOS transistor and the fourth MOS transistor connected together; the third terminal of the third MOS transistor is connected to the gate of the variable-pole switching transistor; and the third terminal of the fourth MOS transistor is connected to the BULK body terminal.

[0020] Furthermore, the system also includes at least one discharge module; the discharge module is connected between the gate and source of the first MOS transistor; the discharge module is a discharge resistor, a switching transistor discharge circuit, or multiple cascaded discharge switching transistors; the at least one discharge module includes multiple discharge modules to accelerate turn-off.

[0021] Furthermore, the system also includes:

[0022] A voltage limiting protection module is used to limit the voltage at the location to be limited based on a preset reference voltage; the voltage limiting protection module includes:

[0023] The third switch has its gate connected to the corresponding driving module and its source grounded.

[0024] The fourth switching transistor has its drain connected to the drain of the third switching transistor and its source connected to the location to be restricted.

[0025] The reference point voltage module is connected to the gate of the fourth switch and is used to provide the reference voltage.

[0026] Furthermore, the reference point voltage module includes:

[0027] The first resistor has its first end grounded and its second end connected to the gate of the fourth switch.

[0028] The second resistor has its first end connected to the gate of the fourth switch and its second end connected to the reference voltage.

[0029] Alternatively, the reference point voltage module includes:

[0030] The first Zener diode has its cathode connected to the reference voltage and its anode connected to the gate of the fourth switch.

[0031] A current source, the current input terminal of which is connected to the gate of the fourth switching transistor, and the current output terminal of which is grounded;

[0032] Alternatively, the reference point voltage module includes:

[0033] At least one first diode is connected in series, with the anode of the first first diode connected to the reference voltage and the cathode of the last first diode connected to the gate of the fourth switch.

[0034] The third resistor has its first end connected to the gate of the fourth switch and its second end grounded.

[0035] Furthermore, the system also includes:

[0036] The third switching transistor has its first end connected to the gate of the variable polarity switching transistor and its second end connected to the second variable drain-source port of the variable polarity switching transistor.

[0037] The fifth switching transistor has its gate connected to the gate of the variable-polarity switching transistor; the source of the fifth switching transistor is connected to an external circuit.

[0038] The fourth switching transistor has its first end connected to the gate of the fifth switching transistor and its second end connected to the drain of the fifth switching transistor.

[0039] If both the variable-pole switch and the fifth switch are PMOS, when the voltage at the first variable drain-source port of the variable-pole switch is higher than the voltage at the second variable drain-source port, the first and fourth switching switches are turned on, and the second and third switching switches are turned off. Then, the first variable drain-source port of the variable-pole switch becomes the source, and the variable-pole switch generates a mirror current according to the gate voltage of the fifth switch.

[0040] When the voltage at the first variable drain-source port of the variable polarity switch is lower than the voltage at the second variable drain-source port, the second and third switching switches are turned on, and the first and fourth switching switches are turned off. Then, the second variable drain-source port of the variable polarity switch becomes the source, and the variable polarity switch is in the off state.

[0041] The present invention provides a control system for a variable-pole switch, wherein the variable-pole switch includes: a gate, a first variable drain-source port, a second variable drain-source port, and a BULK body terminal; the gate is connected to an external gate circuit, the first variable drain-source port is connected to an external first circuit, the second variable drain-source port is connected to an external second circuit, and the BULK body terminal is connected to an external body circuit; the external gate circuit is used to generate a gate voltage; the external body circuit is used to generate a body voltage at the BULK body terminal; the variable-pole switch is used to turn on and off according to the gate voltage and / or the body voltage at the BULK body terminal. In this system, the variable-pole switch can turn on or off according to the gate voltage and / or the body voltage, eliminating the need for a series diode or switch to prevent reverse polarity, thus avoiding increased loop voltage drop, saving component space, and reducing circuit cost. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 A schematic diagram of a control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0044] Figure 2(a) is a schematic diagram of a variable pole switching transistor provided in an embodiment of the present invention;

[0045] Figure 2(b) is a schematic diagram of another variable pole switching transistor provided in an embodiment of the present invention;

[0046] Figure 3(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0047] Figure 3(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0048] Figure 4(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0049] Figure 4(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0050] Figure 4(c) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0051] Figure 4(d) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0052] Figure 4(e) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0053] Figure 5(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0054] Figure 5(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0055] Figure 6 A schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0056] Figure 7 A schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0057] Figure 8(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0058] Figure 8(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0059] Figure 8(c) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0060] Figure 9(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0061] Figure 9(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0062] Figure 9(c) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0063] Figure 10(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0064] Figure 10(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0065] Figure 11(a) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0066] Figure 11(b) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0067] Figure 11(c) is a schematic diagram of another control system for a variable pole switching transistor provided in an embodiment of the present invention;

[0068] Figure 12(a) is a schematic diagram of the application of a current mirror provided in an embodiment of the present invention;

[0069] Figure 12(b) is a schematic diagram of the application of a current mirror provided in an embodiment of the present invention. Detailed Implementation

[0070] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] In related technologies, when a floating voltage needs to be controlled in a circuit, a reverse-biased diode is usually connected in series with the switching transistor to prevent reverse polarity, or a reverse-biased switching transistor is added. This approach leads to an increase in the loop voltage difference, an increase in the component area occupied, and an increase in circuit cost. Therefore, this invention provides a control system for a variable-polarity switching transistor, which can be applied to control scenarios involving variable-polarity switching transistors.

[0072] To facilitate understanding of this embodiment, a control system for a variable pole switching transistor disclosed in this embodiment of the invention will first be introduced, such as... Figure 1 As shown, the variable-pole switch includes: a gate, a first variable drain-source port, a second variable drain-source port, and a BULK body terminal. The gate is connected to an external gate circuit, the first variable drain-source port is connected to an external first circuit, the second variable drain-source port is connected to an external second circuit, and the BULK body terminal is connected to an external body circuit. Both the first and second variable drain-source ports can be either sources or drains, and their configurations in the actual circuit are variable. Furthermore, the first and second variable drain-source ports are different; that is, if the first variable drain-source port is a source, then the second variable drain-source port is a drain, and vice versa. The BULK body terminal can be understood as the unique electrical connection point exhibited externally from the internal semiconductor substrate of the variable-pole switch. The aforementioned external first circuit, external second circuit, and external body circuit can all be selected according to actual needs, and are not limited here.

[0073] The external gate circuit generates the gate voltage of the gate; the external body circuit generates the body voltage of the BULK body terminal; the variable-pole switch is used to turn on and off according to the gate voltage of the gate and / or the body voltage of the BULK body terminal. In practical applications, the gate voltage of the variable-pole switch can be determined according to the external gate circuit; the body voltage of the BULK body terminal of the variable-pole switch can be determined according to the external body circuit; the variable-pole switch can turn on and off according to the magnitude of the gate voltage and / or the body voltage.

[0074] The variable-polarity switch can be a PMOS or an NMOS transistor, for example, as shown in Figure 2(a) and Figure 2(b). The variable-polarity switch in Figure 2(a) is implemented using a PMOS transistor, with its two ends (excluding the gate) being the first and second variable drain-source ports, respectively. Additionally, the PMOS transistor has a BULK body terminal. The variable-polarity switch in Figure 2(b) is implemented using an NMOS transistor, with its two ends (excluding the gate) being the first and second variable drain-source ports, respectively. Additionally, the NMOS transistor has a BULK body terminal.

[0075] The control system of the aforementioned variable-pole switch allows the variable-pole switch to be turned on or off according to the gate voltage and / or the body voltage. It eliminates the need for a diode or switch in series to prevent reverse polarity, thus avoiding an increase in the loop voltage difference. It also saves on component space and reduces circuit cost.

[0076] Furthermore, if the variable-pole switch is an NMOS, the body voltage is controlled to decrease, and there is no conduction between the BULK body terminal and the first variable drain-source port, and between the BULK body terminal and the second variable drain-source port. Then, the gate voltage is controlled to increase. When the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage, the variable-pole switch is turned on; when the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, the variable-pole switch is turned off.

[0077] In practical implementation, when the variable-polarity switch is an NMOS, the voltage at the BULK body terminal can be reduced by adjusting the external body circuit, and the BULK body terminal is not connected to either the first or second variable drain-source port. Then, the gate voltage can be increased by adjusting the external gate circuit. When the gate voltage is higher than the body voltage, and the difference between the two is greater than or equal to a preset gate threshold voltage, the variable-polarity switch will automatically turn on. The preset gate threshold voltage can be set according to actual needs. When the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, the variable-polarity switch will automatically turn off.

[0078] If the variable-polarity switch is a PMOS, the body voltage is controlled to increase, and the connection between the BULK body terminal and the first variable drain-source port, as well as between the BULK body terminal and the second variable drain-source port, is not made. Then, the gate voltage is controlled to decrease. When the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, the variable-polarity switch is turned on; when the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, the variable-polarity switch is turned off.

[0079] In practical implementation, when the variable-polarity switch is a PMOS, the voltage at the BULK body terminal can be increased by adjusting the external body circuit, and the BULK body terminal is not connected to either the first or second variable drain-source port. Then, the gate voltage can be decreased by adjusting the external gate circuit. When the gate voltage is less than the body voltage, and the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, the variable-polarity switch will automatically turn on. When the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, the variable-polarity switch will automatically turn off.

[0080] Furthermore, the external body circuit includes: a first switching transistor S2, a first sub-circuit, a second switching transistor S3, and a second sub-circuit; the BULK body terminal is connected to the first sub-circuit through the first switching transistor S2 and to the second sub-circuit through the second switching transistor S3; the variable polarity switch S1 is used to determine the drain or source of the variable polarity switch S1 by controlling the on / off state of the first switching transistor S2 and the second switching transistor S3.

[0081] The first and second sub-circuits mentioned above can be designed according to actual needs. In actual implementation, the first switching transistor S2 can be controlled to be turned on or off by its corresponding switching control circuit, and the second switching transistor S3 can be controlled to be turned on or off by its corresponding switching control circuit. The variable-pole switching transistor S1 can determine the first variable drain-source port of the variable-pole switching transistor S1 as the drain and the second variable drain-source port as the source, or the first variable drain-source port as the source and the second variable drain-source port as the drain, based on the on / off states of the first switching transistor S2 and the second switching transistor S3.

[0082] As shown in Figure 3(a), another schematic diagram of the control system of the variable pole switching transistor is provided. When the variable pole switching transistor S1 is a PMOS, the first variable drain-source port, the second variable drain-source port, and the first switching transistor S2 and the second switching transistor S3 led out from the BULK body can all be connected to the corresponding external circuits according to actual needs.

[0083] Figure 3(b) shows a schematic diagram of another control system for a variable polarity switch. When the variable polarity switch S1 is an NMOS, the first variable drain-source port, the second variable drain-source port, and the first switching switch S2 and the second switching switch S3 led out from the BULK body can all be connected to the corresponding external circuits according to actual needs.

[0084] Furthermore, the BULK body terminal is connected to the first variable drain-source port via the first switching transistor S2; the BULK body terminal is connected to the second variable drain-source port via the second switching transistor S3; the variable-pole switching transistor S1 is used to determine that the first variable drain-source port is the source and the second variable drain-source port is the drain if the second switching transistor S3 is turned off and the first switching transistor S2 is turned on; and if the first switching transistor S2 is turned off and the second switching transistor S3 is turned on, determine that the second variable drain-source port is the source and the first variable drain-source port is the drain.

[0085] Figure 4(a) shows a schematic diagram of another control system for a variable-pole switch. In one embodiment, taking the first variable-pole switch S1 as a PMOS, the first variable drain-source port can be directly connected to the first switching switch S2, and the second variable drain-source port can be directly connected to the second switching switch S3. When the first switching switch S2 is turned on, the first variable drain-source port is automatically defined as the source, and the second variable drain-source port is defined as the drain. Figure 4(b) shows a schematic diagram of another control system for a variable-pole switch. When the second switching switch S3 is turned on, the second variable drain-source port is automatically defined as the source, and the first variable drain-source port is defined as the drain.

[0086] Figure 4(c) shows a schematic diagram of another control system for a variable-pole switch. In one embodiment, taking the first variable-pole switch S1 as an NMOS, the first variable drain-source port can be directly connected to the first switching switch S2, and the second variable drain-source port can be directly connected to the second switching switch S3. When the first switching switch S2 is turned on, the first variable drain-source port is automatically defined as the source, and the second variable drain-source port is defined as the drain. Figure 4(d) shows a schematic diagram of another control system for a variable-pole switch. When the second switching switch S3 is turned on, the second variable drain-source port is automatically defined as the source, and the first variable drain-source port is defined as the drain.

[0087] The first switching transistor S2 and the second switching transistor S3 mentioned above can also be implemented using MOS transistors, as shown in Figure 4(e), which is a schematic diagram of another variable-polarity switching transistor control system. In one embodiment, both the first switching transistor S2 and the second switching transistor S3 are implemented using NMOS transistors. The sources of both NMOS transistors are connected to the BULK body terminal. The drain of the first switching transistor S2 is connected to the first variable drain-source port, and the drain of the second switching transistor S3 is connected to the second variable drain-source port. The gate of each MOS transistor is connected to its corresponding switching control circuit. As can be seen from the above, in practical applications, the first switching transistor S2 and the second switching transistor S3 can be turned on as needed, and the turned-on end is automatically defined as the source.

[0088] Furthermore, as shown in Figure 5(a), another schematic diagram of the control system for a variable-pole switch is provided. If the variable-pole switch S1, the first switching switch S2, and the second switching switch S3 are all NMOS transistors, the first variable drain-source port is connected to the drain of the first switching switch S2, the source of the first switching switch S2 is connected to the BULK body terminal, and the gate of the first switching switch S2 is connected to the second variable drain-source port; the second variable drain-source port is connected to the drain of the second switching switch S3, the source of the second switching switch S3 is connected to the BULK body terminal, and the gate of the second switching switch S3 is connected to the first variable drain-source port.

[0089] The variable-pole switch S1 is further configured to, when the first variable drain-source port is at a high potential and the second variable drain-source port is at a low potential, turn on the second switching switch S3, making the second variable drain-source port connected to the BULK body terminal, thus determining the second variable drain-source port as the source and the first variable drain-source port as the drain; that is, the second variable drain-source port connected to the BULK body terminal can be automatically defined as the source; when the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage, the variable-pole switch S1 is turned on; when the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, the variable-pole switch S1 is turned off.

[0090] Figure 5(b) shows a schematic diagram of another control system for a variable-pole switch. If the variable-pole switch S1, the first switching switch S2, and the second switching switch S3 are all PMOS transistors, the first variable drain-source port is connected to the drain of the first switching switch S2, the source of the first switching switch S2 is connected to the BULK body terminal, and the gate of the first switching switch S2 is connected to the second variable drain-source port; the second variable drain-source port is connected to the drain of the second switching switch S3, the source of the second switching switch S3 is connected to the BULK body terminal, and the gate of the second switching switch S3 is connected to the first variable drain-source port.

[0091] The variable-pole switch S1 is further configured to turn on the first switching switch S2 when the first variable drain-source port is at a high potential and the second variable drain-source port is at a low potential, thereby connecting the first variable drain-source port to the BULK body terminal and determining that the first variable drain-source port is the source and the second variable drain-source port is the drain; that is, the first variable drain-source port connected to the BULK body terminal can be automatically defined as the source; when the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, the variable-pole switch S1 is turned on; when the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, the variable-pole switch S1 is turned off.

[0092] Furthermore, such as Figure 6 The diagram shows another control system for a variable-pole switch, the system further comprising:

[0093] The first switch S4 has its first terminal connected to the gate of the variable pole switch S1; the first switch S4 can be implemented by selecting one or more suitable switches according to actual needs.

[0094] A first capacitor C1 has its first end connected to the second end of the first switching transistor S4, and its second end connected to either the first variable drain-source port or the second variable drain-source port. The capacitance value of the first capacitor C1 can be set according to actual needs. When the first switching transistor S4 is turned on, if the variable-polarity switching transistor S1 is an NMOS, it is turned on when the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage. If the variable-polarity switching transistor S1 is a PMOS, it is turned on when the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage.

[0095] The second switch S5 has its first end connected to the gate of the variable polarity switch S1 and its second end connected to the BULK body terminal; when the second switch S5 is turned on, the variable polarity switch S1 is turned off; the second switch S5 can be implemented by selecting one or more suitable switches according to actual needs.

[0096] Furthermore, such as Figure 7 The schematic diagram shown illustrates another control system for a variable-pole switch. To further simplify the circuit structure and reduce control logic, both the first switching transistor S2 and the second switching transistor S3 can be implemented using diodes, such as... Figure 7 The diodes D2 and D3 are connected to the BULK body terminal; the anodes of the first switching transistor S2 and the second switching transistor S3 are both connected to the first variable drain-source port; the cathode of the first switching transistor S2 is connected to the first variable drain-source port; the cathode of the second switching transistor S3 is connected to the second variable drain-source port. That is, the anodes of diodes D2 and D3 are both connected to the BULK body terminal, the cathode of diode D2 is connected to the first variable drain-source port, and the cathode of diode D3 is connected to the second variable drain-source port.

[0097] Furthermore, as shown in Figure 8(a), another schematic diagram of a control system for a variable-pole switch is provided, wherein the first switch S4 includes:

[0098] A first MOSFET S4B and a second MOSFET S4A are connected in a pair configuration, with the gate of the first MOSFET S4B and the gate of the second MOSFET S4A connected together; the third terminal of the first MOSFET S4B is connected to the first capacitor C1; and the third terminal of the second MOSFET S4A is connected to the gate of the variable polarity switch S1.

[0099] The second switching transistor S5 includes:

[0100] A third MOSFET S5B and a fourth MOSFET S5A are connected in a pair configuration, with the gate of the third MOSFET S5B and the gate of the fourth MOSFET S5A connected together; the third terminal of the third MOSFET S5B is connected to the gate of the variable polarity switch S1; and the third terminal of the fourth MOSFET S5A is connected to the BULK body terminal.

[0101] Figure 8(b) shows a schematic diagram of another control system for a variable polarity switch. In Figure 8(b), the first switch S4 includes a first MOS transistor S4B and a second MOS transistor S4A connected in a transistor pair. The second switch S5 includes a third MOS transistor S5B and a fourth MOS transistor S5A connected in a transistor pair. The variable polarity switch S1, the first switching switch S2 and the second switching switch S3 are all implemented using NMOS transistors.

[0102] Figure 8(c) shows a schematic diagram of another control system for a variable polarity switch. In this figure, the first switch S4 includes a first MOS transistor S4B and a second MOS transistor S4A connected in a pair. The second switch S5 includes a third MOS transistor S5B and a fourth MOS transistor S5A connected in a pair. The variable polarity switch S1 is an NMOS transistor. The first switching switch S2 includes a fifth MOS transistor S2B and a sixth MOS transistor S2A connected in a pair. The second switching switch S3 includes a seventh MOS transistor S3B and an eighth MOS transistor S3A connected in a pair.

[0103] Furthermore, the system also includes at least one discharge module; the discharge module is connected between the gate and source of the first MOS transistor S4B; the discharge module is a discharge resistor, a switching transistor discharge circuit, or multiple cascaded discharge switching transistors; the at least one discharge module includes multiple discharge modules to accelerate turn-off.

[0104] Figure 9(a) shows a schematic diagram of another control system for a variable-pole switching transistor. If the discharge module uses a discharge resistor, this discharge resistor may include resistor R1. Resistor R1 is connected between the gate and source of the first MOSFET S4B, and also between the gate and source of the second MOSFET S4A. When the first MOSFET S4B and the second MOSFET S4A are turned off, at the moment of turn-off, there may still be charge in the parasitic capacitance of the first MOSFET S4B and the second MOSFET S4A, which may prevent them from being turned off immediately. Resistor R1 can provide a discharge path for the charge of the parasitic capacitance of the gate, ensuring that the first MOSFET S4B and the second MOSFET S4A can be turned off quickly and reliably.

[0105] Figure 9(b) shows a schematic diagram of another control system for a variable-pole switching transistor. If the discharge module uses a switching transistor discharge circuit, the switching transistor discharge circuit may include a MOS transistor S60 and a resistor R2. The MOS transistor S60 may be a PMOS transistor or the like. The drain of the MOS transistor S60 is connected to the gate of the first MOS transistor S4B and the gate of the second MOS transistor S4A, respectively. The source of the MOS transistor S60 is connected to the source of the first MOS transistor S4B and the source of the second MOS transistor S4A, respectively. The resistor R2 is connected between the gate and the source of the MOS transistor S60.

[0106] If the discharge module uses multiple cascaded discharge switching transistors, the number of stages of the discharge switching transistors can be set according to actual needs. For example, as shown in Figure 9(c), another schematic diagram of the control system of a variable pole switching transistor can be used. The discharge switching transistors can include MOSFET S600 and MOSFET S700. MOSFET S600 and MOSFET S700 can be PMOS transistors, etc. The drain of MOSFET S600 is connected to the gate of the first MOSFET S4B and the gate of the second MOSFET S4A, respectively. The source of MOSFET S600 is connected to the source of the first MOSFET S4B and the source of the second MOSFET S4A, respectively. The drain of MOSFET S700 is connected to the gate of MOSFET S600. The source of MOSFET S700 is connected to the source of the first MOSFET S4B and the source of the second MOSFET S4A, respectively. The gate of MOSFET S700 can be connected to the corresponding switching control circuit.

[0107] Furthermore, as shown in Figure 10(a), another schematic diagram of a control system for a variable-pole switch includes:

[0108] A voltage limiting protection module is used to limit the voltage at the location to be limited based on a preset reference voltage. This reference voltage can be a voltage at a specified location selected from the control system of the variable-pole switch. This specified location can be selected according to actual needs and is not limited here. The location to be limited can be determined according to actual needs; for example, it can be the gate of the first MOSFET S4B, the second MOSFET S4A, etc. The voltage limiting protection module includes:

[0109] The gate of the third switch S9 is connected to the driving module corresponding to the third switch S9, and its source is grounded.

[0110] The fourth switch S8 has its drain connected to the drain of the third switch S9 and its source connected to the location to be restricted.

[0111] The reference point voltage module is connected to the gate of the fourth switch S8 and is used to provide the reference voltage. That is, in this embodiment, when the fourth switch S8 is turned on, the reference point voltage module can directly provide a reference voltage to the location point to be restricted through the fourth switch S8, thereby restricting the voltage of the location point to be restricted.

[0112] For example, in Figure 10(a), when overvoltage protection is applied to the first MOSFET S4B and the second MOSFET S4A, the fourth switch S8 is turned on when the limiting position (i.e., the gate of the first MOSFET S4B and the second MOSFET S4A) is in a high position. After the third switch S9 is turned on, the source port of the fourth switch S8 is pulled low. When the voltage drops to the gate voltage of the fourth switch S8 + the gate-on voltage of S8, the fourth switch S8 is turned off, so that the voltage at the limiting position is equal to the gate voltage of S8 + the gate-on voltage of S8, thereby protecting the gate of the first MOSFET S4B and the second MOSFET S4A or other circuits that need protection.

[0113] Figure 10(b) shows another schematic diagram of the control system of a variable pole switching transistor. In order to improve the reliability of limiting the voltage at the limiting position point, a voltage limiting protection module can be added on the basis of Figure 10(a) according to actual needs. As shown in Figure 10(b), there are switching transistors S10 and S11. The gate of switching transistor S10 is connected to the reference point voltage module, the drain of switching transistor S10 is connected to the drain of switching transistor S11, the gate of switching transistor S11 is connected to the corresponding drive module, and the source of switching transistor S11 is grounded. The source of switching transistor S10 is connected to the source of the first MOSFET S4B and the second MOSFET S4A through resistor R20. The source of switching transistor S10 can also be connected to the gate of MOSFET S6A. The source of MOSFET S6A is connected to the source of the first MOSFET S4B, and the drain of MOSFET S6A is connected to the gate of the first MOSFET S4B.

[0114] Furthermore, as shown in Figure 11(a), another schematic diagram of a control system for a variable-pole switch includes:

[0115] The first resistor R3 has its first end grounded and its second end connected to the gate of the fourth switch S8.

[0116] The second resistor R4 has its first end connected to the gate of the fourth switch S8 and its second end connected to the reference voltage. The resistance values ​​of the first resistor R3 and the first resistor R4 can be set according to actual needs. That is, in this embodiment, the reference voltage can be divided by the first resistor R3 and the first resistor R4. When the fourth switch S8 is turned on, the voltage at the location to be limited can be limited according to the voltage division result.

[0117] Alternatively, as shown in Figure 11(b), another schematic diagram of a control system for a variable-pole switch is provided, wherein the reference point voltage module includes:

[0118] The first Zener diode ZD1 has its cathode connected to the reference voltage and its anode connected to the gate of the fourth switch S8.

[0119] The current source has its current input terminal connected to the gate of the fourth switch S8, and its current output terminal grounded. That is, in this embodiment, when the first Zener diode ZD1 is reverse-broken and conducts, and the fourth switch S8 is turned on, the voltage at the location to be limited can be limited by the first Zener diode ZD1.

[0120] Alternatively, as shown in Figure 11(c), another schematic diagram of a control system for a variable-pole switch includes the reference point voltage module comprising:

[0121] At least one first diode D1 is connected in series, with the anode of the first first diode D1 connected to the reference voltage and the cathode of the last first diode D1 connected to the gate of the fourth switch S8; the number of first diodes D1 can be set according to actual needs and is not limited here;

[0122] The third resistor R30 has its first end connected to the gate of the fourth switch S8, and its second end grounded. The resistance value of the third resistor R30 can be set according to actual needs; that is, in this embodiment, the voltage at the location to be limited can be limited by at least one first diode D1 connected in series.

[0123] Furthermore, the system also includes:

[0124] The third switching transistor S6 has its first end connected to the gate of the variable polarity switching transistor S1, and its second end connected to the second variable drain-source port of the variable polarity switching transistor S1.

[0125] The fifth switch S12 has its gate connected to the gate of the variable-pole switch S1; the source of the fifth switch S12 is connected to an external circuit.

[0126] The fourth switching transistor S50 has its first end connected to the gate of the fifth switching transistor S12 and its second end connected to the drain of the fifth switching transistor S12.

[0127] If both the variable-pole switch S1 and the fifth switch S12 are PMOS, when the voltage at the first variable drain-source port of the variable-pole switch S1 is higher than the voltage at the second variable drain-source port, the first switching switch S2 and the fourth switching switch S50 are turned on, and the second switching switch S3 and the third switching switch S6 are turned off. Then, the first variable drain-source port of the variable-pole switch S1 becomes the source, and the variable-pole switch S1 generates a mirror current according to the gate voltage of the fifth switch S12.

[0128] When the voltage at the first variable drain-source port of the variable polarity switch S1 is lower than the voltage at the second variable drain-source port, the second switching switch S3 and the third switching switch S6 are turned on, and the first switching switch S2 and the fourth switching switch S50 are turned off. Then, the second variable drain-source port of the variable polarity switch S1 becomes the source, and the variable polarity switch S1 is in the off state.

[0129] Figure 12(a) shows a schematic diagram of the application of a current mirror. When the current mirror is P-type, when the upper potential of the variable-pole switch S1 is higher than the lower potential (i.e., the voltage of the first variable drain-source port is higher than the voltage of the second variable drain-source port), the first switching switch S2 and the fourth switching switch S50 are closed, and the second switching switch S3 and the third switching switch S6 are opened, so that the first variable drain-source port of the variable-pole switch S1 is SOURCE, and the variable-pole switch S1 enters the current mirror with reference to the GATE potential of the fifth switch S12. Figure 12(b) shows another schematic diagram of the application of a current mirror. When the lower voltage of the variable-pole switch S1 is higher than the upper voltage (i.e., the voltage of the first variable drain-source port is lower than the voltage of the second variable drain-source port), the second switching switch S3 and the third switching switch S6 are closed, and the first switching switch S2 and the fourth switching switch S50 are opened, so the second variable drain-source port of the variable-pole switch S1 is SOURCE, and the variable-pole switch S1 is in the off state. When the current mirror is N-type MOS, the reverse control is the same. Applying this variable-pole switch to a current mirror can result in a lower driving voltage drop and a larger driving current.

[0130] In the control system of the variable pole switching transistor described above, the variable pole switching transistor can be turned on or off according to the gate voltage and / or the body voltage. There is no need for a diode or switching transistor connected in series to prevent reverse polarity, which can avoid the increase of the loop voltage difference. At the same time, it saves the component area, improves the control efficiency, and reduces the circuit cost.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control system for a variable-pole switching transistor, characterized in that, The variable-pole switch includes: a gate, a first variable drain-source port, a second variable drain-source port, and a BULK body terminal; the gate is connected to an external gate circuit, the first variable drain-source port is connected to an external first circuit, the second variable drain-source port is connected to an external second circuit, and the BULK body terminal is connected to an external body circuit. The external gate circuit is used to generate the gate voltage of the gate; The external body circuit is used to generate the body voltage at the BULK body terminal; The variable-pole switch is used to turn on and off according to the gate voltage of the gate and / or the body voltage of the BULK body terminal. The system also includes: The first switching transistor has its first terminal connected to the gate of the variable polarity switching transistor; A first capacitor has its first terminal connected to the second terminal of the first switching transistor, and its second terminal connected to either the first variable drain-source port or the second variable drain-source port. When the first switching transistor is turned on, if the variable-polarity switching transistor is an NMOS, it is turned on when the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage; if the variable-polarity switching transistor is a PMOS, it is turned on when the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage. The second switching transistor has its first end connected to the gate of the variable polarity switching transistor and its second end connected to the BULK body terminal; when the second switching transistor is turned on, the variable polarity switching transistor is turned off.

2. The system according to claim 1, characterized in that, If the variable-pole switch is an NMOS, the body voltage is controlled to decrease, and there is no conduction between the BULK body terminal and the first variable drain-source port, and between the BULK body terminal and the second variable drain-source port. Then, the gate voltage is controlled to increase. When the difference between the gate voltage and the body voltage is greater than or equal to a preset gate threshold voltage, the variable-pole switch is turned on; when the difference between the gate voltage and the body voltage is less than the preset gate threshold voltage, the variable-pole switch is turned off. If the variable-polarity switch is a PMOS, the body voltage is controlled to increase, and the connection between the BULK body terminal and the first variable drain-source port, as well as between the BULK body terminal and the second variable drain-source port, is not made. Then, the gate voltage is controlled to decrease. When the difference between the body voltage and the gate voltage is greater than or equal to the preset gate threshold voltage, the variable-polarity switch is turned on; when the difference between the body voltage and the gate voltage is less than the preset gate threshold voltage, the variable-polarity switch is turned off.

3. The system according to claim 1, characterized in that, The external main circuit includes: a first switching transistor, a first sub-circuit, a second switching transistor, and a second sub-circuit; The BULK body is connected to the first sub-circuit via the first switching transistor and to the second sub-circuit via the second switching transistor. The variable-pole switch is used to determine the drain or source of the variable-pole switch by controlling the on / off state of the first switching switch and the second switching switch.

4. The system according to claim 3, characterized in that, The BULK body terminal is connected to the first variable drain-source port through the first switching transistor. The BULK body terminal is connected to the second variable drain-source port via the second switching transistor; The variable-pole switch is used to determine that if the second switching switch is turned off and the first switching switch is turned on, the first variable drain-source port is the source and the second variable drain-source port is the drain; if the first switching switch is turned off and the second switching switch is turned on, the second variable drain-source port is the source and the first variable drain-source port is the drain.

5. The system according to claim 3, characterized in that, Both the first switching transistor and the second switching transistor are diodes; the anodes of both the first and second switching transistors are connected to the BULK body terminal; the cathode of the first switching transistor is connected to the first variable drain-source port; and the cathode of the second switching transistor is connected to the second variable drain-source port.

6. The system according to claim 1, characterized in that, The first switching transistor includes: A first MOSFET and a second MOSFET are connected in a transistor-to-transistor configuration, with the gates of the first MOSFET and the second MOSFET connected together; the third terminal of the first MOSFET is connected to the first capacitor; and the third terminal of the second MOSFET is connected to the gate of the variable-pole switch. The second switching transistor includes: A third MOS transistor and a fourth MOS transistor are connected in a pair configuration, with the gates of the third MOS transistor and the fourth MOS transistor connected together; the third terminal of the third MOS transistor is connected to the gate of the variable polarity switch; and the third terminal of the fourth MOS transistor is connected to the BULK body terminal.

7. The system according to claim 6, characterized in that, The system further includes at least one discharge module; the discharge module is connected between the gate and source of the first MOS transistor; The discharge module is: a discharge resistor, a switching transistor discharge circuit, or multiple cascaded discharge switching transistors; The at least one level of the discharge module includes multiple levels of discharge modules to accelerate shutdown.

8. The system according to claim 6, characterized in that, The system also includes: A voltage limiting protection module is used to limit the voltage at the location to be limited based on a preset reference voltage; the voltage limiting protection module includes: The third switch has its gate connected to the corresponding driving module and its source grounded. The fourth switching transistor has its drain connected to the drain of the third switching transistor and its source connected to the location to be restricted. The reference point voltage module is connected to the gate of the fourth switch and is used to provide the reference voltage.

9. The system according to claim 8, characterized in that, The reference point voltage module includes: The first resistor has its first end grounded and its second end connected to the gate of the fourth switch. The second resistor has its first end connected to the gate of the fourth switch and its second end connected to the reference voltage. Alternatively, the reference point voltage module includes: The first Zener diode has its cathode connected to the reference voltage and its anode connected to the gate of the fourth switch. A current source, the current input terminal of which is connected to the gate of the fourth switching transistor, and the current output terminal of which is grounded; Alternatively, the reference point voltage module includes: At least one first diode is connected in series, with the anode of the first first diode connected to the reference voltage and the cathode of the last first diode connected to the gate of the fourth switch. The third resistor has its first end connected to the gate of the fourth switch and its second end grounded.

10. The system according to claim 3, characterized in that, The system also includes: The third switching transistor has its first end connected to the gate of the variable polarity switching transistor and its second end connected to the second variable drain-source port of the variable polarity switching transistor. The fifth switching transistor has its gate connected to the gate of the variable-polarity switching transistor; the source of the fifth switching transistor is connected to an external circuit. The fourth switching transistor has its first end connected to the gate of the fifth switching transistor and its second end connected to the drain of the fifth switching transistor. If both the variable-pole switch and the fifth switch are PMOS, when the voltage at the first variable drain-source port of the variable-pole switch is higher than the voltage at the second variable drain-source port, the first and fourth switching switches are turned on, and the second and third switching switches are turned off. Then, the first variable drain-source port of the variable-pole switch becomes the source, and the variable-pole switch generates a mirror current according to the gate voltage of the fifth switch. When the voltage at the first variable drain-source port of the variable polarity switch is lower than the voltage at the second variable drain-source port, the second and third switching switches are turned on, and the first and fourth switching switches are turned off. Then, the second variable drain-source port of the variable polarity switch becomes the source, and the variable polarity switch is in the off state.

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