CN217360779U - OTG detection circuitry and electronic equipment - Google Patents

Abstract

The utility model discloses an OTG detection circuitry and electronic equipment, wherein, OTG detection circuitry includes: the USB interface is used for connecting OTG equipment; the input end of the current-limiting protection circuit is used for being connected with a power supply, the output end of the current-limiting protection circuit is connected with the USB interface, and the current-limiting protection circuit is used for limiting the current of the connected power supply and then outputting the current to the USB interface; the OTG equipment access detection circuit comprises an OTG equipment access detection circuit, wherein a first detection end and a second detection end of the OTG equipment access detection circuit are respectively connected with an input end and an output end of a current-limiting protection circuit, and the OTG equipment access detection circuit is used for outputting corresponding OTG equipment access detection signals according to voltages of the input end and the output end of the current-limiting protection circuit. The utility model discloses technical scheme has solved the unable problem as the OTG interface of USB interface that does not take the detection foot.

Description

OTG detection circuitry and electronic equipment

Technical Field

The utility model relates to an electronic equipment technical field, in particular to OTG detection circuitry and electronic equipment.

Background

With the popularization of PAD (tablet computer), mobile phone, digital camera, printer and other consumer products, the high-speed data transmission technology between these devices and computer or between devices is getting more and more attention, and the launch of OTG technology can realize data transmission between devices without host. For example: the digital camera can be directly connected with a printer and prints photos, thereby expanding the application range of the USB technology. At present, the OTG interface scheme is mostly mini USB interface and Type-C interface, and the USB interface does not possess the detection foot, consequently uses the electronic equipment of USB interface as the OTG interface less, makes user's selection become few.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a OTG detection circuitry and electronic equipment aims at solving and does not take the USB interface of detecting the foot can't regard as the problem of OTG interface.

In order to achieve the above object, the utility model provides an OTG detection circuit, include:

the USB interface is used for connecting OTG equipment;

the input end of the current-limiting protection circuit is used for accessing a power supply, the output end of the current-limiting protection circuit is connected with the USB interface, and the current-limiting protection circuit is used for outputting the current-limited power supply to the USB interface after the current-limited power supply is accessed;

the OTG equipment access detection circuit comprises an OTG equipment access detection circuit, wherein a first detection end and a second detection end of the OTG equipment access detection circuit are respectively connected with an input end and an output end of the current-limiting protection circuit, and the OTG equipment access detection circuit is used for outputting corresponding OTG equipment access detection signals according to voltages of the input end and the output end of the current-limiting protection circuit.

Optionally, the OTG detection circuit further comprises:

the voltage conversion circuit is connected with the output end of the OTG equipment access detection circuit and is used for converting the OTG equipment access detection signal with a first voltage value into the OTG equipment access detection signal with a second voltage value and outputting the OTG equipment access detection signal; wherein the first voltage value is greater than the second voltage value.

Optionally, the current-limiting protection circuit includes a current-limiting protection chip and a first capacitor, an input end of the current-limiting protection chip, a first end of the first capacitor are respectively connected to the first detection end of the OTG device access detection circuit and the first direct current power supply, an output end of the current-limiting protection chip are respectively connected to the second detection end of the OTG device access detection circuit and the USB interface, and a third end of the current-limiting protection chip and a second end of the first capacitor are both grounded.

Optionally, the OTG device access detection circuit includes a voltage comparator, a first resistor and a second resistor, a first input end of the voltage comparator is interconnected with a first end of the first resistor, a second end of the first resistor is connected with an input end of the current-limiting protection circuit, a second input end of the voltage comparator is interconnected with a first end of the second resistor, a second end of the second resistor is connected with an output end of the current-limiting protection circuit, a power input end of the voltage comparator is connected with a first direct-current power supply, an output end of the voltage comparator is connected with an input end of the voltage conversion circuit, and a ground end of the voltage comparator is grounded.

Optionally, the voltage conversion circuit includes a first NMOS transistor, a second NMOS transistor, a third resistor, and a fourth resistor, a gate of the first NMOS transistor is connected to an output terminal of the OTG device access detection circuit, a source of the first NMOS transistor and a source of the second NMOS transistor are both grounded, a drain of the first NMOS transistor and a gate of the second NMOS transistor are interconnected with a first end of the third resistor, a second end of the third resistor is connected to the second dc power supply, a drain of the second NMOS transistor and a first end of the fourth resistor are connected to an output terminal of the voltage conversion circuit, and a second end of the fourth resistor is connected to the second dc power supply.

Optionally, the OTG detection circuit further comprises:

the output end of the short circuit is connected with the input end of the voltage conversion circuit, and the short circuit is used for outputting a corresponding short circuit signal when triggered by a user;

the voltage conversion circuit is further configured to receive the short-circuit signal, convert the short-circuit signal of the third voltage value into the OTG device access detection signal of the fourth voltage value, and output the OTG device access detection signal.

The utility model also provides an electronic equipment, electronic equipment includes as above OTG detection circuitry.

Optionally, the electronic device further comprises:

the controller is connected with the output end of the OTG detection circuit;

and the controller is used for controlling the electronic equipment to work according to the OTG equipment access detection signal when receiving the OTG equipment access detection signal.

Optionally, the electronic device further comprises:

the trigger circuit is connected with the output end of the current-limiting protection circuit and is used for receiving the voltage signal output by the current-limiting protection circuit and outputting a corresponding trigger signal according to the voltage signal;

the controller is further configured to control the electronic device to communicate with the OTG device according to the trigger signal when receiving the trigger signal.

Optionally, the electronic device further comprises:

the output end of the power supply circuit is respectively connected with the current-limiting protection circuit and the OTG equipment access detection circuit, and the power supply circuit is used for providing working voltage for the OTG equipment access detection circuit; the power supply circuit is also used for supplying power to the USB interface through the current-limiting protection circuit.

The embodiment of the utility model provides a connect OTG equipment through the USB interface, current-limiting protection circuit input inserts power supply to export to the USB interface after carrying out the current-limiting to power supply; the first detection end and the second detection end of the OTG equipment access detection circuit are respectively connected with the input end and the output end of the current-limiting protection circuit, and corresponding OTG equipment access detection signals are output according to the voltages of the input end and the output end of the current-limiting protection circuit. The utility model discloses technical scheme has solved the unable problem as the OTG interface of USB interface that does not take the detection foot.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic diagram of a functional module of an embodiment of the OTG detection circuit of the present invention;

fig. 2 is a schematic diagram of a functional module of another embodiment of the OTG detection circuit of the present invention;

fig. 3 is a schematic circuit diagram of an embodiment of a current-limiting protection circuit in the OTG detection circuit of the present invention;

fig. 4 is a schematic circuit structure diagram of an embodiment of an OTG device access detection circuit in the OTG detection circuit of the present invention;

fig. 5 is a schematic circuit structure diagram of an embodiment of a voltage conversion circuit in the OTG detection circuit of the present invention;

fig. 6 is a schematic circuit diagram of an embodiment of a short circuit in the OTG detection circuit of the present invention;

fig. 7 is a schematic diagram of functional modules of an embodiment of the electronic device of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	USB interface	120	Power supply circuit
20	Current-limiting protection circuit	R1～R4	First to fourth resistors
				30	OTG equipment access detection circuit	V1～V2	First DC power supply to second DC power supply
40	Voltage conversion circuit	Q1～Q2	First NMOS transistor to second NMOS transistor
				50	Short circuit	U1	Current-limiting protection chip
60	Trigger circuit	U2	Voltage comparator
				100	OTG detection circuit	C1	First capacitor
110	Controller	J1	Jumping cap

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, if directional indications (such as upper, lower, left, right, front and rear … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides an OTG detection circuitry 100 and electronic equipment.

Referring to fig. 1, in an embodiment of the present invention, the OTG detection circuit 100 includes:

the USB interface 10, the USB interface 10 is used for connecting OTG equipment;

the input end of the current-limiting protection circuit 20 is used for accessing a power supply, the output end of the current-limiting protection circuit 20 is connected with the USB interface 10, and the current-limiting protection circuit 20 is used for outputting the current-limited power supply to the USB interface 10;

the OTG device access detection circuit 30 includes a first detection end and a second detection end, where the first detection end and the second detection end of the OTG device access detection circuit 30 are respectively connected to the input end and the output end of the current limiting protection circuit 20, and the OTG device access detection circuit 30 is configured to output a corresponding OTG device access detection signal according to voltages of the input end and the output end of the current limiting protection circuit 20.

In this embodiment, the OTG detection circuit 100 is connected to the OTG device through the USB interface 10, the input end of the current-limiting protection circuit 20 is connected to the power supply, and the current-limited power supply is output to the USB interface 10 through the output end, so that a voltage difference exists between the input end and the output end of the current-limiting protection circuit 20; the input end and the output end of the current-limiting protection circuit 20 are connected with the first detection end and the second detection end of the OTG equipment access detection circuit 30; under the condition that an OTG device is connected to the OTG detection circuit 100 through the USB interface 10 or no OTG device is connected to the OTG detection circuit 100 through the USB interface 10, voltages acquired by a first detection end and a second detection end of the OTG device access detection circuit 30 are different, for example, under the condition that no OTG device is connected to the OTG detection circuit 100 through the USB interface 10, the voltage of the first detection end of the OTG device access detection circuit 30 is greater than the voltage of the second detection end, and the OTG device access detection circuit 30 outputs a first OTG device access detection signal to the voltage conversion circuit 40; and under the condition that there is the OTG device to be connected with the OTG detection circuit 100 through the USB interface 10, the voltage that the second detection end of the OTG device access detection circuit 30 collected becomes large, and meanwhile, due to the reverse blocking effect of the current-limiting protection circuit 20, the voltage that the first detection end of the OTG device access detection circuit 30 collected does not change, so that the voltage that the first detection end of the OTG device access detection circuit 30 is smaller than the voltage of the second detection end, and then the OTG device access detection circuit 30 can output the corresponding second OTG device access detection signal to the voltage conversion circuit 40.

Under the condition that no OTG device is connected with OTG detection circuit 100 through USB interface 10, if other non-OTG devices are connected to USB interface 10, power supply can supply power to the non-OTG devices through USB interface 10, and after the power supply is limited by current-limiting protection circuit 20, it can prevent large current from entering the non-OTG devices through USB interface 10 to cause damage to internal components of the non-OTG devices.

It can be understood that, after the OTG device is connected to the electronic device through the USB interface 10, the OTG device may read data of the electronic device or transmit data to the electronic device through the USB interface 10, and the OTG device may be a PAD (tablet computer), a mobile phone, a digital camera, a printer, or the like. When no OTG device is connected to the electronic device through the USB interface 10, the voltage at the output end of the current-limiting protection circuit 20 will not change, and the voltage at the input end of the current-limiting protection circuit 20 will have a certain loss after passing through the current-limiting protection circuit 20 to the output end of the current-limiting protection circuit 20 in a normal state, and then the voltage at the input end of the current-limiting protection circuit 20 will be slightly higher than the voltage at the output end of the current-limiting protection circuit 20, that is, the voltage at the first detection end is higher than the voltage at the second detection end, and then the OTG device access detection circuit 30 outputs a first OTG device access detection signal; when the OTG device is connected to the electronic device through the USB interface 10, the OTG device supplies power to pull up the voltage at the output end of the current-limiting protection circuit 20, and the current-limiting protection circuit 20 can prevent the high voltage at the output end of the current-limiting protection circuit 20 from flowing into the input end of the current-limiting protection circuit 20, at this time, the voltage at the output end of the current-limiting protection circuit 20 is higher than the voltage at the input end of the current-limiting protection circuit 20, that is, the voltage at the first detection end is lower than the voltage at the second detection end, and then the OTG device access detection circuit 30 outputs a second OTG device access detection signal; the current-limiting protection circuit 20 and the OTG device access detection circuit 30 can determine whether an OTG device is accessed even if the USB interface 10 has no detection pin.

The embodiment of the utility model provides a connect OTG equipment through USB interface 10, current-limiting protection circuit 20 input inserts power supply, and export to USB interface 10 after carrying out the current-limiting to power supply; the first detection end and the second detection end of the OTG device access detection circuit 30 are respectively connected to the input end and the output end of the current-limiting protection circuit 20, and output corresponding OTG device access detection signals according to voltages of the input end and the output end of the current-limiting protection circuit 20. The utility model discloses technical scheme has solved the unable problem as the OTG interface of USB interface 10 that does not take the detection foot.

Referring to fig. 2, in an embodiment, the OTG detection circuit 100 further includes:

the voltage conversion circuit 40, the voltage conversion circuit 40 is connected to the output end of the OTG device access detection circuit 30, and the voltage conversion circuit 40 is configured to convert the OTG device access detection signal with the first voltage value into the OTG device access detection signal with the second voltage value and output the OTG device access detection signal; wherein the first voltage value is greater than the second voltage value.

In this embodiment, after receiving the first OTG device access detection signal with the first voltage value, the voltage conversion circuit 40 converts and outputs the corresponding first OTG device access detection signal with the second voltage value to the controller 110 in the electronic device, and after receiving the second OTG device access detection signal with the first voltage value, the voltage conversion circuit 40 converts and outputs the corresponding second OTG device access detection signal with the second voltage value to the controller 110 in the electronic device, because the controller 110 may be damaged due to an excessive voltage, the voltage conversion circuit 40 converts the determination signal with a large voltage into a smaller electrical signal with a small voltage, that is, the conversion signal is output to the controller 110 in the electronic device. The present embodiment converts the determination signal into a converted signal with an appropriate voltage and outputs the converted signal through the voltage conversion circuit 40.

Referring to fig. 3, in an embodiment, the current-limiting protection circuit 20 includes a current-limiting protection chip U1 and a first capacitor C1, an input end of the current-limiting protection chip U1 and a first end of the first capacitor C1 are respectively connected to a first detection end of the OTG device access detection circuit 30 and a first dc power supply V1, an output end of the current-limiting protection chip U1 is respectively connected to a second detection end of the OTG device access detection circuit 30 and the USB interface 10, and a third end of the current-limiting protection chip U1 and a second end of the first capacitor C1 are both grounded.

In this embodiment, the first capacitor C1 plays a role of filtering, when no OTG device is connected, the voltage at the input end of the current-limiting protection chip U1 is 4.85V, and the voltage has a certain voltage loss output after passing through the current-limiting protection chip U1, so the voltage at the input end of the current-limiting protection chip U1 is slightly higher than the voltage at the output end of the current-limiting protection chip U1; when an OTG device is connected, the voltage of the output end of the current-limiting protection chip U1 is pulled to 5V, and because the selected current-limiting protection chip U1 has a reverse cut-off function, the voltage of the output end of the current-limiting protection chip U1 is higher than the voltage of the input end of the current-limiting protection chip U1; the current-limiting protection chip U1 can also limit the current, and prevent the non-OTG device from being damaged by excessive current when the non-OTG device is connected to the USB interface 10. In this embodiment, the current-limiting protection chip U1 enables the input terminal and the output terminal of the current-limiting protection circuit 20 to output different voltages when the OTG device is not connected and when the OTG device is connected.

Referring to fig. 4, in an embodiment, the OTG device access detection circuit 30 includes a voltage comparator U2, a first resistor R1 and a second resistor R2, a first input terminal of the voltage comparator U2 is interconnected with a first terminal of the first resistor R1, a second terminal of the first resistor R1 is connected with an input terminal of the current limiting protection circuit 20, a second input terminal of the voltage comparator U2 is interconnected with a first terminal of the second resistor R2, a second terminal of the second resistor R2 is connected with an output terminal of the current limiting protection circuit 20, a power supply input terminal of the voltage comparator U2 is connected with a first dc power supply V1, an output terminal of the voltage comparator U2 is connected with an input terminal of the voltage conversion circuit 40, and a ground terminal of the voltage comparator U2 is grounded.

In this embodiment, the first resistor R1 and the second resistor R2 function as current limiting resistors, so as to prevent the voltage comparator U2 from being damaged by excessive current; a first input end and a second input end of the voltage comparator U2 respectively receive voltage signals from an input end of the current-limiting protection circuit 20 and an output end of the current-limiting protection circuit 20, when no OTG device is connected, a voltage received by the first input end of the voltage comparator U2 is greater than a voltage received by the second input end of the voltage comparator U2, the voltage comparator U2 outputs an electrical signal at a low level, that is, when an OTG device is connected, a detection signal is sent to the voltage conversion circuit 40, when an OTG device is connected, a voltage received by the first input end of the voltage comparator U2 is less than a voltage received by the second input end of the voltage comparator U2, and the voltage comparator U2 outputs an electrical signal at a high level, that is, a detection signal is sent to the voltage conversion circuit 40 by the second OTG device.

In this embodiment, the voltage comparator U2 compares the voltage signals at the input end and the output end of the current limiting protection circuit 20 in the OTG detection circuit 100, and outputs the corresponding OTG device access detection signal to the voltage conversion circuit 40.

Referring to fig. 5, in an embodiment, the voltage conversion circuit 40 includes a first NMOS transistor Q1, a second NMOS transistor Q2, a third resistor R3, and a fourth resistor R4, a gate of the first NMOS transistor Q1 is connected to an output terminal of the OTG device access detection circuit 30, a source of the first NMOS transistor Q1 and a source of the second NMOS transistor Q2 are both grounded, a drain of the first NMOS transistor Q1 and a gate of the second NMOS transistor Q2 are interconnected to a first end of the third resistor R3, a second end of the third resistor R3 is connected to a second dc power source V2, a drain of the second NMOS transistor Q2 and a first end of the fourth resistor R4 are connected to an output terminal of the voltage conversion circuit 40, and a second end of the fourth resistor R4 is connected to a second dc power source V2.

In this embodiment, the third resistor R3 and the fourth resistor R4 function as pull-up resistors, and are configured to pull up the gate of the second NMOS transistor Q2 when the first NMOS transistor Q1 is not turned on, and pull up the voltage at the drain of the second NMOS transistor Q2 when the second NMOS transistor Q2 is not turned on; when the gate of the first NMOS transistor Q1 receives the low-level electrical signal output by the OTG device access detection circuit 30, that is, the first OTG device access detection signal, the first NMOS transistor Q1 is not turned on, the gate voltage of the second NMOS transistor Q2 is pulled high, the second NMOS transistor Q2 is turned on, and the low-level OTG device access detection signal is output to the controller 110; when the gate of the first NMOS transistor Q1 receives the high-level electrical signal output by the OTG device access detection circuit 30, that is, the second OTG device access detection signal, the first NMOS transistor Q1 is turned on, the gate of the second NMOS transistor Q2 is grounded, the second NMOS transistor Q2 is turned off, the voltage of the drain of the second NMOS transistor Q2 is pulled high, and the high-level OTG device access detection signal is output to the controller 110; because the voltage output by the second dc power supply V2 is 1.8V, the voltage conversion circuit 40 can convert the OTG device access detection signal of the high voltage output by the OTG device access detection circuit 30 to the voltage conversion circuit 40 into an OTG device access detection signal of 1.8V, and output the OTG device access detection signal to the controller 110, so as to prevent the controller 110 from being damaged due to an excessively large voltage.

Referring to fig. 2 and 6, in an embodiment, the OTG detection circuit 100 further includes:

the output end of the short circuit 50 is connected with the input end of the voltage conversion circuit 40, and the short circuit 50 is used for outputting a corresponding short circuit signal when triggered by a user;

the voltage conversion circuit 40 is further configured to receive the short-circuit signal, convert the short-circuit signal of the third voltage value into the OTG device access detection signal of the fourth voltage value, and output the OTG device access detection signal.

The short circuit 50 comprises a jump cap J1, a first end of the jump cap J1 is connected with the input end of the voltage conversion circuit 40, and a second end of the jump cap J1 is grounded.

In this embodiment, a user can enable the short circuit 50 to output a short-circuit signal to the voltage conversion circuit 40 by triggering the short circuit 50, so that the voltage conversion circuit 40 outputs an OTG device access detection signal; the short circuit 50 may adopt a jump cap J1, and a user manually triggers the jump cap J1 to short the circuit to the ground, so that the electrical signal output to the voltage conversion circuit 40 is an electrical signal with a low level, and the voltage conversion circuit 40 only outputs an OTG device access detection signal with a low level, at this time, the OTG detection circuit 100 cannot detect whether an OTG device is accessed, and the OTG detection circuit 100 keeps a host mode to connect a slave device.

The utility model also provides an electronic equipment.

Referring to fig. 7, in one embodiment, the electronic device includes the OTG detection circuit 100 as described above. The specific structure of the OTG detection circuit 100 refers to the above embodiments, and since the electronic device adopts all technical solutions of all the above embodiments, at least all the beneficial effects brought by the technical solutions of the above embodiments are achieved, and no further description is given here.

Referring to fig. 7, in an embodiment, the electronic device further includes:

a controller 110, wherein the controller 110 is connected with an output end of the OTG detection circuit 100;

the controller 110 is configured to control the electronic device to operate according to the access detection signal of the OTG device when receiving the access detection signal of the OTG device.

In this embodiment, when the controller 110 receives a low-level electrical signal output by the voltage conversion circuit 40 in the OTG detection circuit 100, that is, when the first OTG device accesses the detection signal, the electronic device is switched to the host mode, and if the electronic device is already in the host mode, the electronic device continues to be maintained; when the controller 110 receives the high-level electrical signal output by the voltage conversion circuit 40 in the OTG detection circuit 100, that is, the second OTG device accesses the detection signal, the electronic device is switched to the device mode, and if the electronic device is already in the device mode, the electronic device continues to be maintained.

In this embodiment, the controller 110 receives the access detection signal of the OTG device to control the electronic device to change the operating mode.

Referring to fig. 7, in an embodiment, the electronic device further includes:

the trigger circuit 60, the trigger circuit 60 is connected to the output end of the current-limiting protection circuit 20, and the trigger circuit 60 is configured to receive the voltage signal output by the current-limiting protection circuit 20 and output a corresponding trigger signal according to the voltage signal;

the controller 110 is further configured to control the electronic device to communicate with the OTG device according to the trigger signal when receiving the trigger signal.

In this embodiment, when receiving the voltage signal output by the current-limiting protection circuit 20, the trigger circuit 60 outputs a high-level electrical signal, i.e., a first trigger signal, to the controller 110; when the current limiting protection circuit 20 does not receive the voltage signal output by the current limiting protection circuit 20, the trigger circuit 60 outputs a low-level electrical signal, i.e., a second trigger signal, to the controller 110; the controller 110 in the electronic device is connected to the output terminal of the trigger circuit 60; when the controller 110 receives the high-level electrical signal output by the trigger circuit 60, that is, the first trigger signal, the electronic device may communicate with the OTG device; when the controller 110 receives the low-level electrical signal output by the trigger circuit 60, that is, the second trigger signal, the electronic device stops communicating with the OTG device.

In the present embodiment, the trigger circuit 60 outputs corresponding trigger signals to the controller 110 when the current-limiting protection circuit 20 has a voltage output and does not have a voltage output, so that the controller 110 controls the electronic device to communicate with the OTG device.

Referring to fig. 7, in an embodiment, the electronic device further includes:

the output end of the power supply circuit 120 is connected to the current-limiting protection circuit 20 and the OTG device access detection circuit 30, respectively, and the power supply circuit 120 supplies power to the USB interface 10 through the current-limiting protection circuit 20, so as to supply power to the non-OTG device when the non-OTG device is accessed to the USB interface 10; the power supply circuit 120 is further configured to provide a working voltage to the OTG device access detection circuit 30.

In this embodiment, the power supply circuit 120 may be implemented by a DC-DC voltage reduction circuit, an output end of the power supply circuit 120 is configured to output a first DC power supply V1 and a second DC power supply V2, a voltage of the first DC power supply V1 is 4.85V, a voltage of the second DC power supply V2 is 1.8V, and the power supply circuit 120 provides suitable working voltages for the OTG device access detection circuit 30 and the voltage conversion circuit 40, so as to ensure a normal working state of the whole circuit; the power supply circuit 120 can also provide a suitable operating voltage to the non-OTG device through the current limiting protection chip U1 in the current limiting protection circuit 20.

The above is only the optional embodiment of the present invention, and not therefore the limit to the patent scope of the present invention, all the technical ideas of the present invention are utilized, the equivalent structure transformation made by the contents of the specification and the drawings, or the direct/indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims (10)

1. An OTG detection circuit, comprising:

the USB interface is used for connecting OTG equipment;

the input end of the current-limiting protection circuit is used for being connected with a power supply, the output end of the current-limiting protection circuit is connected with the USB interface, and the current-limiting protection circuit is used for outputting the current-limiting power supply to the USB interface after the current-limiting power supply is limited;

the OTG equipment access detection circuit comprises an OTG equipment access detection circuit, wherein a first detection end and a second detection end of the OTG equipment access detection circuit are respectively connected with an input end and an output end of the current-limiting protection circuit, and the OTG equipment access detection circuit is used for outputting corresponding OTG equipment access detection signals according to voltages of the input end and the output end of the current-limiting protection circuit.

2. The OTG detection circuit of claim 1, wherein the OTG detection circuit further comprises:

the voltage conversion circuit is connected with the output end of the OTG equipment access detection circuit and is used for converting the OTG equipment access detection signal with a first voltage value into the OTG equipment access detection signal with a second voltage value and outputting the OTG equipment access detection signal; wherein the first voltage value is greater than the second voltage value.

3. The OTG detection circuit of claim 1, wherein the current-limiting protection circuit comprises a current-limiting protection chip and a first capacitor, the input terminal of the current-limiting protection chip and the first terminal of the first capacitor are respectively connected to the first detection terminal of the OTG device access detection circuit and the first DC power supply, the output terminal of the current-limiting protection chip is respectively connected to the second detection terminal of the OTG device access detection circuit and the USB interface, and the third terminal of the current-limiting protection chip and the second terminal of the first capacitor are both grounded.

4. The OTG detection circuit of claim 2, wherein the OTG device access detection circuit comprises a voltage comparator, a first resistor and a second resistor, a first input terminal of the voltage comparator is interconnected with a first terminal of the first resistor, a second terminal of the first resistor is connected with an input terminal of the current limiting protection circuit, a second input terminal of the voltage comparator is interconnected with a first terminal of the second resistor, a second terminal of the second resistor is connected with an output terminal of the current limiting protection circuit, a power input terminal of the voltage comparator is connected with a first direct current power supply, an output terminal of the voltage comparator is connected with an input terminal of the voltage conversion circuit, and a ground terminal of the voltage comparator is grounded.

5. The OTG detection circuit of claim 2, wherein the voltage conversion circuit comprises a first NMOS transistor, a second NMOS transistor, a third resistor, and a fourth resistor, a gate of the first NMOS transistor is connected to the output terminal of the OTG device access detection circuit, a source of the first NMOS transistor and a source of the second NMOS transistor are both grounded, a drain of the first NMOS transistor and a gate of the second NMOS transistor are interconnected to a first end of the third resistor, a second end of the third resistor is connected to a second dc power supply, a drain of the second NMOS transistor and a first end of the fourth resistor are connected to the output terminal of the voltage conversion circuit, and a second end of the fourth resistor is connected to the second dc power supply.

6. The OTG detection circuit of claim 2, wherein the OTG detection circuit further comprises:

the output end of the short circuit is connected with the input end of the voltage conversion circuit, and the short circuit is used for outputting a corresponding short circuit signal when triggered by a user;

the voltage conversion circuit is further configured to receive the short-circuit signal, convert the short-circuit signal of the third voltage value into the OTG device access detection signal of the fourth voltage value, and output the OTG device access detection signal.

7. An electronic device, characterized in that the electronic device comprises an OTG detection circuit according to any of claims 1-6.

8. The electronic device of claim 7, wherein the electronic device further comprises:

the controller is connected with the output end of the OTG detection circuit;

and the controller is used for controlling the electronic equipment to work according to the OTG equipment access detection signal when receiving the OTG equipment access detection signal.

9. The electronic device of claim 8, wherein the electronic device further comprises:

the trigger circuit is connected with the output end of the current-limiting protection circuit and is used for receiving a voltage signal output by the current-limiting protection circuit and outputting a corresponding trigger signal according to the voltage signal;

the controller is further configured to control the electronic device to communicate with the OTG device according to the trigger signal when receiving the trigger signal.

10. The electronic device of claim 7, wherein the electronic device further comprises:

the output end of the power supply circuit is respectively connected with the current-limiting protection circuit and the OTG equipment access detection circuit, and the power supply circuit is used for providing working voltage for the OTG equipment access detection circuit; the power supply circuit is also used for supplying power to the USB interface through the current-limiting protection circuit.

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