CN111682869B - Anti-backflow current load switch and electronic equipment - Google Patents
Anti-backflow current load switch and electronic equipment Download PDFInfo
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- CN111682869B CN111682869B CN202010636539.1A CN202010636539A CN111682869B CN 111682869 B CN111682869 B CN 111682869B CN 202010636539 A CN202010636539 A CN 202010636539A CN 111682869 B CN111682869 B CN 111682869B
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
Abstract
The invention provides a load switch capable of preventing reverse current and electronic equipment, comprising a P-type power tube, a control selection circuit and a control switch circuit, wherein the control selection circuit is connected with the P-type power tube; when the load voltage is larger than the sum of the power supply voltage and the first set voltage, the substrate of the P-type power tube is controlled to be electrically connected with the load end, and the grid electrode of the P-type power tube is controlled to be electrically connected with the substrate of the P-type power tube; and when the load voltage is smaller than the sum of the power supply voltage and the second set voltage, the substrate of the control P-type power tube is electrically connected with the power supply voltage end, and the grid electrode of the control P-type power tube is electrically connected with the grounding end. When the load voltage is overlarge, the substrate of the control P-type power tube is electrically connected with the load end, and the grid electrode of the control P-type power tube is electrically connected with the substrate of the P-type power tube, so that the P-type power tube is controlled to be closed, a path from the load end to the power voltage end is free of current, the purpose of preventing reverse current is achieved, the reverse current preventing function of a load switch can be prevented from being triggered and closed frequently, and the load switch performance is improved.
Description
Technical Field
The invention relates to the technical field of load switches, in particular to a load switch capable of preventing reverse current and electronic equipment.
Background
The load switch is a common electronic device in an electronic system, and is mainly used for connecting a power supply and a load to realize connection and isolation between the power supply and the load. The load switch can be integrated with the control circuit or can be a separate device. The field effect transistor is a common load switch, however, in practical application, a phenomenon that the output is higher than the input may occur when the existing field effect transistor is used as the load switch, for example, the output end has interference or the output end is touched at high voltage, so that charge may be reversely poured from the output end to the input end, resulting in an increase of the potential of the input end and causing disturbance of system operation. The design of the load switch to prevent the reverse current is one of the important points of research nowadays.
Disclosure of Invention
In view of the above, the invention provides a load switch and electronic equipment for preventing reverse current, which effectively solve the technical problems existing in the prior art, prevent the load switch from generating reverse current, and improve the performance of the load switch.
In order to achieve the above purpose, the technical scheme provided by the invention is as follows:
a reverse current resistant load switch comprising: the power supply comprises a P-type power tube, a control selection circuit and a control switch circuit;
the source electrode of the P-type power tube is electrically connected with a power supply voltage end, the drain electrode of the P-type power tube is electrically connected with a load end, the substrate of the P-type power tube is electrically connected with the control selection circuit, and the grid electrode of the P-type power tube is electrically connected with the control switch circuit;
the control selection circuit is used for comparing the power supply voltage of the power supply voltage end with the load voltage of the load end and controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end or the load end; the control switch circuit is used for controlling the grid electrode of the P-type power tube to be electrically connected with the substrate or the grounding end of the P-type power tube according to the comparison result of the power supply voltage and the load voltage;
when the load voltage is larger than the sum of the power supply voltage and a first set voltage, controlling the substrate of the P-type power tube to be electrically connected with the load end, and controlling the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube; and controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end and controlling the grid electrode of the P-type power tube to be electrically connected with the grounding end until the load voltage is smaller than the sum of the power supply voltage and the second set voltage, wherein the first set voltage is larger than the second set voltage.
Optionally, the control selection circuit includes: a comparison module and a selection switch module;
the first input end of the comparison module is connected with the power supply voltage, the second input end of the comparison module is connected with the load voltage, and the output end of the comparison module is electrically connected with the control end of the selection switch module; the comparison module is used for comparing the power supply voltage with the load voltage, and outputting a first level control signal when the load voltage is larger than the sum of the power supply voltage and a first set voltage; outputting a second level control signal until the load voltage is smaller than the sum of the power supply voltage and a second set voltage, wherein the levels of the first level control signal and the second level control signal are inverted;
the first input end of the selection switch module is electrically connected with the power supply voltage end, the second input end of the selection switch module is electrically connected with the load end, and the output end of the selection switch module is electrically connected with the substrate of the P-type power tube; the selection switch module is used for responding to the first level control signal to control the substrate of the P-type power tube to be electrically connected with the load end, and responding to the second level control signal to control the substrate of the P-type power tube to be electrically connected with the power supply voltage end.
Optionally, the comparing module includes a comparator;
the first input end of the comparator is connected with the power supply voltage, the second input end of the comparator is connected with the load voltage, and the output end of the comparator is electrically connected with the control end of the selection switch module.
Optionally, the selection switch module includes: a first transistor and a second transistor, the first transistor and the second transistor having opposite conduction types;
the first end of the first transistor is electrically connected with the power supply voltage end, the second end of the first transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the first transistor is electrically connected with the output end of the comparison module;
the first end of the second transistor is electrically connected with the load end, the second end of the second transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the second transistor is electrically connected with the output end of the comparison module.
Optionally, the selection switch module includes: a third transistor, a fourth transistor and a first inverter, wherein the conduction types of the third transistor and the fourth transistor are the same;
the first end of the third transistor is electrically connected with the power supply voltage end, the second end of the third transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the third transistor is electrically connected with the output end of the comparison module; the first end of the fourth transistor is electrically connected with the load end, the second end of the fourth transistor is electrically connected with the substrate of the P-type power tube, the grid electrode of the fourth transistor is electrically connected with the output end of the first inverter, and the input end of the first inverter is electrically connected with the output end of the comparison module;
or, the first end of the third transistor is electrically connected with the power supply voltage end, the second end of the third transistor is electrically connected with the substrate of the P-type power tube, the grid electrode of the third transistor is electrically connected with the output end of the first inverter, and the input end of the first inverter is electrically connected with the output end of the comparison module; the first end of the fourth transistor is electrically connected with the load end, the second end of the fourth transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the fourth transistor is electrically connected with the output end of the comparison module.
Optionally, the control switch circuit includes: a logic gate module and a second inverter;
the first input end of the logic gate module is connected with an enabling signal, the second input end of the logic gate module is electrically connected with the output end of the comparison module, and the output end of the logic gate module is electrically connected with the input end of the second inverter; the logic gate module is used for responding to the first level control signal and outputting a turn-off signal and responding to the second level control signal and outputting a turn-on signal;
the output end of the second inverter is electrically connected with the grid electrode of the P-type power tube, and the power end of the second inverter is electrically connected with the substrate of the P-type power tube; the second inverter is used for responding to the turn-off signal to control the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube, and responding to the turn-on signal to control the grid electrode of the P-type power tube to be electrically connected with the grounding end of the second inverter.
Optionally, the control switch circuit further includes: a buffer and a third inverter;
the input end of the buffer is connected with the enabling signal, the output end of the buffer is electrically connected with the input end of the third inverter, and the output end of the third inverter is electrically connected with the first input end of the logic gate module.
Optionally, when the first level control signal is a high level signal and the enable signal is a high level signal, the logic gate module includes: a fourth inverter and an and gate;
the first input end of the AND gate is connected with the enabling signal; the input end of the fourth inverter is electrically connected with the output end of the comparison module, and the output end of the fourth inverter is electrically connected with the second input end of the AND gate;
correspondingly, the invention also provides electronic equipment, which comprises the load switch for preventing the backflow of the current.
Compared with the prior art, the technical scheme provided by the invention has at least the following advantages:
the invention provides a load switch for preventing reverse current and an electronic device, comprising: the power supply comprises a P-type power tube, a control selection circuit and a control switch circuit; when the load voltage is larger than the sum of the power supply voltage and a first set voltage, controlling the substrate of the P-type power tube to be electrically connected with the load end, and controlling the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube; and controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end and controlling the grid electrode of the P-type power tube to be electrically connected with the grounding end until the load voltage is smaller than the sum of the power supply voltage and the second set voltage. When the load voltage is overlarge, the substrate of the control P-type power tube is electrically connected with the load end, and the grid electrode of the control P-type power tube is electrically connected with the substrate of the P-type power tube, so that the control P-type power tube is closed, a path from the load end to the power voltage end is free of current, the purpose of preventing current from flowing backwards is achieved, and the load switch performance is improved.
The first set voltage and the second set voltage provided by the invention are equivalent to hysteresis voltage, namely, when the load voltage is larger than the sum of the power voltage and the first set voltage, the anti-backflow function of the load switch is triggered, and the anti-backflow function of the load switch is closed until the load voltage is smaller than the sum of the power voltage and the second set voltage, so that the anti-backflow function of the load switch is prevented from being frequently triggered and closed, and the practicability of the load switch is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a load switch for preventing reverse current according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention;
fig. 9 is a schematic voltage diagram of the corresponding end of fig. 8.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As described in the background, a load switch is a common electronic device in an electronic system, and is mainly used for connecting a power supply and a load, so as to realize connection and isolation between the power supply and the load. The load switch can be integrated with the control circuit or can be a separate device. The field effect transistor is a common load switch, however, in practical application, a phenomenon that the output is higher than the input may occur when the existing field effect transistor is used as the load switch, for example, the output end has interference or the output end is touched at high voltage, so that charge may be reversely poured from the output end to the input end, resulting in an increase of the potential of the input end and causing disturbance of system operation. The design of the load switch to prevent the reverse current is one of the important points of research nowadays.
Based on the above, the embodiment of the invention provides a load switch capable of preventing reverse current and electronic equipment, which effectively solve the technical problems existing in the prior art, prevent the load switch from generating the reverse current, and improve the performance of the load switch.
In order to achieve the above objective, the technical solutions provided by the embodiments of the present invention are described in detail below, with reference to fig. 1 to 9.
Referring to fig. 1, a schematic structural diagram of a load switch for preventing reverse current according to the embodiment of the present invention is shown, where the load switch includes: the P-type power tube P0, the control selection circuit 100, and the control switch circuit 200, D1 and D2 are parasitic diodes.
The source electrode of the P-type power tube P0 is electrically connected to the power supply voltage terminal IN, the drain electrode of the P-type power tube P0 is electrically connected to the load terminal OUT, the substrate bulk of the P-type power tube P0 is electrically connected to the control selection circuit 100, and the gate electrode of the P-type power tube P0 is electrically connected to the control switch circuit 200.
The control selection circuit 100 is configured to compare a power voltage Vin of the power voltage terminal IN with a load voltage Vout of the load terminal OUT, and control a substrate bulk of the P-type power transistor P0 to be electrically connected with the power voltage terminal IN or electrically connected with the load terminal OUT; and the control switch circuit 200 is configured to control the gate of the P-type power tube P0 to be electrically connected to the substrate bulk or the ground GND of the P-type power tube P0 according to the comparison result of the power supply voltage Vin and the load voltage Vout.
When the load voltage Vout is greater than the sum of the power voltage Vin and a first set voltage, controlling the substrate bulk of the P-type power tube P0 to be electrically connected with the load terminal OUT, and controlling the gate of the P-type power tube P0 to be electrically connected with the substrate bulk of the P-type power tube P0; and controlling the substrate bulk of the P-type power tube P0 to be electrically connected with the power voltage end IN until the load voltage Vout is smaller than the sum of the power voltage Vin and a second set voltage, controlling the grid of the P-type power tube P0 to be electrically connected with the grounding end GND, wherein the first set voltage and the second voltage are both larger than 0, and the first set voltage is larger than the second set voltage.
It can be appreciated that in the technical solution provided by the embodiment of the present invention, when the load voltage is greater than the sum of the power supply voltage and the first set voltage, the substrate of the P-type power tube is controlled to be electrically connected to the load terminal, and the gate of the P-type power tube is controlled to be electrically connected to the substrate of the P-type power tube; controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end and controlling the grid electrode of the P-type power tube to be electrically connected with the grounding end until the load voltage is smaller than the sum of the power supply voltage and the second set voltage; and then, the substrate of the control P-type power tube is electrically connected with the power supply voltage end, the grid electrode of the control P-type power tube is electrically connected with the grounding end, and the substrate of the control P-type power tube is electrically connected with the load end and the grid electrode of the control P-type power tube is electrically connected with the substrate of the P-type power tube until the load voltage is judged to be larger than the sum of the power supply voltage and the first set voltage again. When the load voltage is overlarge, the substrate of the control P-type power tube is electrically connected with the load end, and the grid electrode of the control P-type power tube is electrically connected with the substrate of the P-type power tube, so that the control P-type power tube is closed, a path from the load end to the power voltage end is free of current, the purpose of preventing current from flowing backwards is achieved, and the load switch performance is improved.
The first set voltage and the second set voltage provided by the embodiment of the invention are equivalent to hysteresis voltage, namely, when the load voltage is larger than the sum of the power voltage and the first set voltage, the anti-backflow function of the load switch is triggered, and the anti-backflow function of the load switch is closed until the load voltage is smaller than the sum of the power voltage and the second set voltage, so that the anti-backflow function of the load switch is prevented from being frequently triggered and closed, and the practicability of the load switch is improved.
Referring to fig. 2, a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention is shown, where the control selection circuit 100 provided in the embodiment of the present invention includes: a comparison module 110 and a selection switch module 120.
A first input end of the comparison module 110 is connected to the power voltage Vin, a second input end of the comparison module 110 is connected to the load voltage Vout, and an output end of the comparison module 110 is electrically connected to a control end of the selection switch module 120; the comparison module 110 is configured to compare the power supply voltage Vin with the load voltage Vout, and output a first level control signal when the load voltage Vout is greater than a sum of the power supply voltage Vin and a first set voltage; and outputting a second level control signal until the load voltage Vout is smaller than the sum of the power voltage Vin and a second set voltage, wherein the levels of the first level control signal and the second level control signal are inverted, and then the comparison module 110 keeps outputting the second level control signal until the comparison module 110 judges that the load voltage Vout is larger than the sum of the power voltage Vin and the first set voltage again, and outputs the first level control signal.
The first input end of the selection switch module 120 is electrically connected with the power supply voltage end IN, the second input end of the selection switch module 120 is electrically connected with the load end OUT, and the output end of the selection switch module 120 is electrically connected with the substrate bulk of the P-type power tube P0; the selection switch module 120 is configured to control the substrate bulk of the P-type power tube P0 to be electrically connected to the load terminal OUT IN response to the first level control signal, and control the substrate bulk of the P-type power tube P0 to be electrically connected to the power supply voltage terminal IN response to the second level control signal.
The specific circuit structures of the comparison module and the selection switch module provided by the embodiment of the invention are described below with reference to the accompanying drawings. Referring to fig. 3, a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention is shown, and the comparing module 110 according to an embodiment of the present invention includes a comparator CMP.
A first input terminal of the comparator CMP is connected to the power voltage Vin, a second input terminal of the comparator CMP is connected to the load voltage Vout, and an output terminal of the comparator CMP is electrically connected to a control terminal of the selection switch module 120.
As shown in fig. 3, the selection switch module 120 provided in the embodiment of the present invention may include: the first transistor M1 and the second transistor M2 are opposite in conduction type, namely when the first transistor M1 is an N-type transistor, the second transistor M2 is a P-type transistor; or when the first transistor M1 is a P-type transistor, the second transistor M2 is an N-type transistor.
The first end of the first transistor M1 is electrically connected to the power voltage end IN, the second end of the first transistor M1 is electrically connected to the substrate bulk of the P-type power transistor P0, and the gate of the first transistor M1 is electrically connected to the output end of the comparison module 110.
The first end of the second transistor M2 is electrically connected to the load end OUT, the second end of the second transistor M2 is electrically connected to the substrate bulk of the P-type power transistor P0, and the gate of the second transistor M2 is electrically connected to the output end of the comparison module 110.
It can be understood that the first transistor and the second transistor provided in the embodiment of the invention have opposite conduction types, so that the gate of the first transistor and the gate of the second transistor are electrically connected to the output end of the comparison module, and the purpose of controlling the second transistor to be turned off when the comparison module controls the first transistor to be turned on and controlling the first transistor to be turned off when the comparison module controls the second transistor to be turned on can be achieved. When the comparison module outputs a first level control signal, the second transistor is controlled to be turned on and the first transistor is controlled to be turned off, so that the substrate of the P-type power tube is controlled to be electrically connected with the load end; when the comparison module outputs a second level control signal, the first transistor is controlled to be turned on and the second transistor is controlled to be turned off, so that the substrate of the P-type power tube is controlled to be electrically connected with the power supply voltage end.
In an embodiment of the present invention, the on types of the transistors included in the switch module provided in the embodiment of the present invention may also be the same. Referring to fig. 4, a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention is shown, where the selection switch module 120 according to an embodiment of the present invention includes: the third transistor M3, the fourth transistor M4 and the first inverter INV1, the conduction types of the third transistor M3 and the fourth transistor M4 are the same, that is, the third transistor M3 and the fourth transistor M4 may be both N-type transistors, or the third transistor M3 and the fourth transistor M4 may be both P-type transistors.
A first end of the third transistor M3 is electrically connected to the power voltage end IN, a second end of the third transistor M3 is electrically connected to the substrate bulk of the P-type power transistor, and a gate of the third transistor M3 is electrically connected to the output end of the comparison module 110; the first end of the fourth transistor M4 is electrically connected to the load end OUT, the second end of the fourth transistor M4 is electrically connected to the substrate bulk of the P-type power transistor P0, the gate of the fourth transistor M4 is electrically connected to the output end of the first inverter INV1, and the input end of the first inverter INV1 is electrically connected to the output end of the comparison module 110.
It can be understood that the third transistor and the fourth transistor provided in the embodiment of the present invention have the same conduction type, so that a first inverter is electrically connected between the gate of the fourth transistor and the output terminal of the comparison module, so as to ensure the purpose of controlling the fourth transistor to be turned off when the comparison module controls the third transistor to be turned on, and controlling the third transistor to be turned off when the fourth transistor is controlled to be turned on.
It should be noted that, the first inverter provided in the embodiment of the present invention may be further electrically connected between the gate of the third transistor and the output terminal of the comparison module, and the gate of the fourth transistor is directly electrically connected to the output terminal of the comparison module, where the first inverter is determined according to specific levels of the first level control signal and the second level control signal, and specific conduction types of the third transistor and the fourth transistor. The third transistor and the fourth transistor provided by the embodiment of the invention have the same conduction type, the first end of the third transistor is electrically connected with the power supply voltage end, the second end of the third transistor is electrically connected with the substrate of the P-type power transistor, the grid electrode of the third transistor is electrically connected with the output end of the first inverter, and the input end of the first inverter is electrically connected with the output end of the comparison module; the first end of the fourth transistor is electrically connected with the load end, the second end of the fourth transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the fourth transistor is electrically connected with the output end of the comparison module.
Referring to fig. 5, a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention is shown, where the control switch circuit 200 according to an embodiment of the present invention includes: a logic gate module 210 and a second inverter 220.
The signal accessed by the first input end of the logic gate module 210 is an enable signal EN, the second input end of the logic gate module 210 is electrically connected with the output end of the comparison module 110, and the output end of the logic gate module 210 is electrically connected with the input end of the second inverter INV 2; the logic gate module 210 is configured to output an off signal in response to the first level control signal and to output an on signal in response to the second level control signal.
The output end of the second inverter INV2 is electrically connected with the grid electrode of the P-type power tube P0, and the power end of the second inverter INV2 is electrically connected with the substrate bulk of the P-type power tube P0; the second inverter INV2 is configured to control, in response to the turn-off signal, the gate of the P-type power transistor P0 to be electrically connected to the bulk of the substrate of the P-type power transistor P0, and to control, in response to the turn-on signal, the gate of the P-type power transistor P0 to be electrically connected to the ground GND of the second inverter INV 2.
It can be understood that, in the control switch circuit provided by the embodiment of the invention, when the comparison module outputs the first level control signal, the logic gate module outputs the turn-off signal according to the first level control signal and the enable signal, and the turn-off signal can control the power end of the second inverter to be electrically connected with the grid electrode of the P-type power tube, so that the grid electrode of the P-type power tube is electrically connected with the substrate bulk of the P-type power tube, and the purpose of controlling the turn-off of the P-type power tube is achieved; and when the comparison module outputs the second level control signal, the logic gate module outputs an opening signal according to the second level control signal and the enabling signal, and the opening signal can control the grounding end of the second inverter to be electrically connected with the grid electrode of the P-type power tube, so that the purpose of controlling the conduction of the P-type power tube is achieved.
Furthermore, in order to achieve the purpose of controlling the P-type power tube to be opened slowly, the control switch circuit provided by the embodiment of the invention can further comprise a buffer and other components. Referring to fig. 6, a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention is shown, where the control switch circuit 200 according to an embodiment of the present invention further includes: buffer and third inverter INV3.
The input end of the Buffer is connected to the enable signal EN, the output end of the Buffer is electrically connected to the input end of the third inverter INV3, the output end of the third inverter INV3 is electrically connected to the first input end of the logic gate module 210, and the output signal of the third inverter INV3 is used as the input signal of the first input end of the logic gate module 210.
It can be understood that the enable signal provided by the embodiment of the invention is transmitted to the first input end of the logic gate module after passing through the buffer and the third inverter, so that the output of the control switch circuit can be slowly changed from high level to low level, and the P-type power tube is slowly turned on, so that the performance of the load switch is improved.
Referring to fig. 7, which is a schematic structural diagram of a load switch for preventing reverse current according to an embodiment of the present invention, when the first level control signal is a high level signal and the enable signal EN is a high level signal, the logic gate module 210 includes: a fourth inverter INV4 And an And gate nd;
the first input end of the AND gate And is connected with the enable signal EN; an input end of the fourth inverter INV4 is electrically connected to an output end of the comparison module 110, and an output end of the fourth inverter INV4 is electrically connected to a second input end of the And gate nd.
It can be understood that when the first level control signal provided by the embodiment of the invention is a high level signal and the enabling signal is a high level signal, the first level control signal is a low level signal after being inverted by the fourth inverter, and the high level signals of the low level signal and the enabling signal are input to the and gate, so that the and gate outputs a low level turn-off signal, and the turn-off signal can control the substrate of the P-type power tube connected with the power end of the second inverter to be electrically connected with the grid electrode of the P-type power tube, thereby achieving the purpose of controlling the turn-off of the P-type power tube; and when the second level control signal is a low level signal and the enabling signal is a high level signal, the signal input into the AND gate is two high level signals, so that the AND gate outputs a high level starting signal, and the starting signal can control the grounding end of the second inverter to be electrically connected with the grid electrode of the P-type power tube, thereby achieving the purpose of controlling the opening of the P-type power tube.
A specific load switch operation procedure according to an embodiment of the present invention is described below with reference to fig. 8 and 9. Fig. 8 is a schematic structural diagram of another load switch for preventing reverse current according to an embodiment of the present invention, and fig. 9 is a schematic voltage diagram of a corresponding port of fig. 8; in fig. 8, the load switch includes the comparator CMP, the Buffer, the first inverter INV1 to the fourth inverter INV4, the And gate nd, the P-type third transistor M3, the P-type fourth transistor M4, the enable signal is a high level signal, and the first level control signal is a high level signal provided in the above embodiment; and the first inverter INV1 is electrically connected to the fourth transistor M4, the power supply terminal of the Buffer, the power supply terminal of the third inverter INV3, the power supply terminal of the fourth inverter INV4, and the power supply terminal of the And gate nd are all electrically connected to the power supply voltage terminal IN, and the power supply terminal of the comparator CMP, the power supply terminal of the first inverter INV1, and the power supply terminal of the second inverter INV2 are all electrically connected to the substrate bulk of the P-type power transistor P0.
When the load voltage Vout suddenly appears a pulse voltage higher than the power voltage and the load voltage Vout is greater than the sum of the power voltage Vin and the first set voltage Vt1 (i.e., at the node S1 in fig. 9), the comparator CMP outputs a high-level first level control signal, which can control the third transistor M3 to be turned off, and the first level control signal is inverted by the first inverter INV1 to control the fourth transistor M4 to be turned on, so that the substrate bulk of the P-type power transistor P0 is electrically connected to the load terminal OUT. Meanwhile, the AND Gate And outputs a low-level turn-off signal, the turn-off signal controls the substrate bulk of the P-type power tube P0 electrically connected with the power end of the third inverter INV3 to be electrically connected with the grid electrode of the P-type power tube P0, so that the grid voltage Gate of the P-type power tube P0 is quickly pulled up to the voltage at the substrate bulk, the P-type power tube P0 is turned off, no current exists from the load end OUT to the power voltage end IN, and the purpose of preventing backflow of current is achieved.
The load voltage Vout continues to rise, the voltage of the substrate bulk and the Gate voltage of the P-type power tube P0 follow the load voltage Vout, and the P-type power tube P0 is kept off; the load voltage Vout starts to drop until the load voltage Vout is smaller than the sum of the power voltage Vin and the second set voltage Vt2 (i.e. at the node S2 IN fig. 9), the comparator CMP outputs a low-level second level control signal, which can control the third transistor M3 to be turned on, and the second level control signal is inverted by the first inverter INV1 and then controls the fourth transistor M4 to be turned off, so that the substrate bulk of the P-type power transistor P0 is electrically connected to the power voltage terminal IN. Meanwhile, the And Gate And outputs a high-level start signal, the start signal controls the ground end GND of the third inverter INV3 to be electrically connected with the Gate of the P-type power tube P0, so that the Gate voltage Gate of the P-type power tube P0 starts to decrease, the P-type power tube P0 starts to be slowly turned on, and the path from the power voltage end IN to the load end OUT normally transmits current.
And then, maintaining the state that the substrate bulk of the P-type power tube P0 is electrically connected with the power supply voltage end IN and the grid electrode of the P-type power tube P0 is electrically connected with the grounding end GND until the load voltage Vout is greater than the sum of the power supply voltage Vin and the first set voltage Vt1, and recycling the working process.
Correspondingly, the embodiment of the invention also provides electronic equipment, which comprises the load switch for preventing reverse current.
The embodiment of the invention provides a load switch capable of preventing reverse current and electronic equipment, comprising: the power supply comprises a P-type power tube, a control selection circuit and a control switch circuit; when the load voltage is larger than the sum of the power supply voltage and a first set voltage, controlling the substrate of the P-type power tube to be electrically connected with the load end, and controlling the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube; and controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end and controlling the grid electrode of the P-type power tube to be electrically connected with the grounding end until the load voltage is smaller than the sum of the power supply voltage and the second set voltage. When the load voltage is overlarge, the substrate of the control P-type power tube is electrically connected with the load end, and the grid electrode of the control P-type power tube is electrically connected with the substrate of the P-type power tube, so that the control P-type power tube is closed, a path from the load end to the power voltage end is free of current, the purpose of preventing current from flowing backwards is achieved, and the load switch performance is improved.
The first set voltage and the second set voltage provided by the embodiment of the invention are equivalent to hysteresis voltage, namely, when the load voltage is larger than the sum of the power voltage and the first set voltage, the anti-backflow function of the load switch is triggered, and the anti-backflow function of the load switch is closed until the load voltage is smaller than the sum of the power voltage and the second set voltage, so that the anti-backflow function of the load switch is prevented from being frequently triggered and closed, and the practicability of the load switch is improved.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. A reverse current resistant load switch comprising: the power supply comprises a P-type power tube, a control selection circuit and a control switch circuit;
the source electrode of the P-type power tube is electrically connected with a power supply voltage end, the drain electrode of the P-type power tube is electrically connected with a load end, the substrate of the P-type power tube is electrically connected with the control selection circuit, and the grid electrode of the P-type power tube is electrically connected with the control switch circuit;
the control selection circuit is used for comparing the power supply voltage of the power supply voltage end with the load voltage of the load end and controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end or the load end; the control switch circuit is used for controlling the grid electrode of the P-type power tube to be electrically connected with the substrate or the grounding end of the P-type power tube according to the comparison result of the power supply voltage and the load voltage;
when the load voltage is larger than the sum of the power supply voltage and a first set voltage, controlling the substrate of the P-type power tube to be electrically connected with the load end, and controlling the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube; controlling the substrate of the P-type power tube to be electrically connected with the power supply voltage end and controlling the grid electrode of the P-type power tube to be electrically connected with the grounding end until the load voltage is smaller than the sum of the power supply voltage and the second set voltage, wherein the first set voltage is larger than the second set voltage;
the control selection circuit includes: a comparison module and a selection switch module;
the first input end of the comparison module is connected with the power supply voltage, the second input end of the comparison module is connected with the load voltage, and the output end of the comparison module is electrically connected with the control end of the selection switch module;
the first input end of the selection switch module is electrically connected with the power supply voltage end, the second input end of the selection switch module is electrically connected with the load end, and the output end of the selection switch module is electrically connected with the substrate of the P-type power tube;
the control switch circuit includes: a logic gate module and a second inverter;
the first input end of the logic gate module is connected with an enabling signal, the second input end of the logic gate module is electrically connected with the output end of the comparison module, and the output end of the logic gate module is electrically connected with the input end of the second inverter;
the output end of the second inverter is electrically connected with the grid electrode of the P-type power tube, and the power end of the second inverter is electrically connected with the substrate of the P-type power tube.
2. The reverse current preventing load switch according to claim 1, wherein,
the comparison module is used for comparing the power supply voltage with the load voltage, and outputting a first level control signal when the load voltage is larger than the sum of the power supply voltage and a first set voltage; outputting a second level control signal until the load voltage is smaller than the sum of the power supply voltage and a second set voltage, wherein the levels of the first level control signal and the second level control signal are inverted; the selection switch module is used for responding to the first level control signal to control the substrate of the P-type power tube to be electrically connected with the load end, and responding to the second level control signal to control the substrate of the P-type power tube to be electrically connected with the power supply voltage end.
3. The anti-reverse current load switch of claim 2, wherein the comparison module comprises a comparator;
the first input end of the comparator is connected with the power supply voltage, the second input end of the comparator is connected with the load voltage, and the output end of the comparator is electrically connected with the control end of the selection switch module.
4. The reverse current preventing load switch of claim 2, wherein the selection switch module comprises: a first transistor and a second transistor, the first transistor and the second transistor having opposite conduction types;
the first end of the first transistor is electrically connected with the power supply voltage end, the second end of the first transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the first transistor is electrically connected with the output end of the comparison module;
the first end of the second transistor is electrically connected with the load end, the second end of the second transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the second transistor is electrically connected with the output end of the comparison module.
5. The reverse current preventing load switch of claim 2, wherein the selection switch module comprises: a third transistor, a fourth transistor and a first inverter, wherein the conduction types of the third transistor and the fourth transistor are the same;
the first end of the third transistor is electrically connected with the power supply voltage end, the second end of the third transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the third transistor is electrically connected with the output end of the comparison module; the first end of the fourth transistor is electrically connected with the load end, the second end of the fourth transistor is electrically connected with the substrate of the P-type power tube, the grid electrode of the fourth transistor is electrically connected with the output end of the first inverter, and the input end of the first inverter is electrically connected with the output end of the comparison module;
or, the first end of the third transistor is electrically connected with the power supply voltage end, the second end of the third transistor is electrically connected with the substrate of the P-type power tube, the grid electrode of the third transistor is electrically connected with the output end of the first inverter, and the input end of the first inverter is electrically connected with the output end of the comparison module; the first end of the fourth transistor is electrically connected with the load end, the second end of the fourth transistor is electrically connected with the substrate of the P-type power tube, and the grid electrode of the fourth transistor is electrically connected with the output end of the comparison module.
6. The anti-reverse current load switch of claim 2, wherein the logic gate module is configured to output an off signal in response to the first level control signal and to output an on signal in response to the second level control signal; the second inverter is used for responding to the turn-off signal to control the grid electrode of the P-type power tube to be electrically connected with the substrate of the P-type power tube, and responding to the turn-on signal to control the grid electrode of the P-type power tube to be electrically connected with the grounding end of the second inverter.
7. The reverse current resistant load switch of claim 6 wherein said control switch circuit further comprises: a buffer and a third inverter;
the input end of the buffer is connected with the enabling signal, the output end of the buffer is electrically connected with the input end of the third inverter, and the output end of the third inverter is electrically connected with the first input end of the logic gate module.
8. The reverse current protection load switch according to claim 6, wherein when the first level control signal is a high level signal and the enable signal is a high level signal, the logic gate module comprises: a fourth inverter and an and gate;
the first input end of the AND gate is connected with the enabling signal; the input end of the fourth inverter is electrically connected with the output end of the comparison module, and the output end of the fourth inverter is electrically connected with the second input end of the AND gate.
9. An electronic device comprising a reverse current preventing load switch according to any one of claims 1-8.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5142171A (en) * | 1988-04-05 | 1992-08-25 | Hitachi, Ltd. | Integrated circuit for high side driving of an inductive load |
| JP2003347913A (en) * | 2002-05-27 | 2003-12-05 | Rohm Co Ltd | Power supply circuit and mobile electronic apparatus having the same |
| JP2009301209A (en) * | 2008-06-11 | 2009-12-24 | Mitsumi Electric Co Ltd | Power control semiconductor integrated circuit |
| CN101997526A (en) * | 2010-09-21 | 2011-03-30 | 上海山景集成电路技术有限公司 | Power tube circuit structure capable of preventing current from flowing backwards |
| JP2011065634A (en) * | 2009-09-15 | 2011-03-31 | Seiko Instruments Inc | Voltage regulator |
| JP2013055813A (en) * | 2011-09-05 | 2013-03-21 | Rohm Co Ltd | Backflow prevention circuit, step-down dc/dc converter using the same, control circuit for the same, charging circuit, and electronic apparatus |
| CN105915056A (en) * | 2016-05-30 | 2016-08-31 | 武汉新芯集成电路制造有限公司 | Boost circuit preventing reverse current |
| CN209283083U (en) * | 2019-01-22 | 2019-08-20 | 西安拓尔微电子有限责任公司 | A kind of quantifiable anti-charge is counter to fill load switching circuit |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1482640B1 (en) * | 2003-05-30 | 2006-11-15 | Texas Instruments Incorporated | Power switching circuit with controlled reverse leakage |
| JP4463635B2 (en) * | 2004-07-20 | 2010-05-19 | 株式会社リコー | Switching regulator, power supply circuit using switching regulator, and rechargeable battery charging circuit using switching regulator |
| JP4597044B2 (en) * | 2005-12-09 | 2010-12-15 | 株式会社リコー | Backflow prevention circuit |
| JP5338387B2 (en) * | 2009-03-05 | 2013-11-13 | ミツミ電機株式会社 | Power supply switching device |
| JP5969221B2 (en) * | 2012-02-29 | 2016-08-17 | エスアイアイ・セミコンダクタ株式会社 | Voltage regulator |
-
2020
- 2020-07-03 CN CN202010636539.1A patent/CN111682869B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5142171A (en) * | 1988-04-05 | 1992-08-25 | Hitachi, Ltd. | Integrated circuit for high side driving of an inductive load |
| JP2003347913A (en) * | 2002-05-27 | 2003-12-05 | Rohm Co Ltd | Power supply circuit and mobile electronic apparatus having the same |
| JP2009301209A (en) * | 2008-06-11 | 2009-12-24 | Mitsumi Electric Co Ltd | Power control semiconductor integrated circuit |
| JP2011065634A (en) * | 2009-09-15 | 2011-03-31 | Seiko Instruments Inc | Voltage regulator |
| CN101997526A (en) * | 2010-09-21 | 2011-03-30 | 上海山景集成电路技术有限公司 | Power tube circuit structure capable of preventing current from flowing backwards |
| JP2013055813A (en) * | 2011-09-05 | 2013-03-21 | Rohm Co Ltd | Backflow prevention circuit, step-down dc/dc converter using the same, control circuit for the same, charging circuit, and electronic apparatus |
| CN105915056A (en) * | 2016-05-30 | 2016-08-31 | 武汉新芯集成电路制造有限公司 | Boost circuit preventing reverse current |
| CN209283083U (en) * | 2019-01-22 | 2019-08-20 | 西安拓尔微电子有限责任公司 | A kind of quantifiable anti-charge is counter to fill load switching circuit |
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