CN215219002U

CN215219002U - Automatic identification circuit for OTG equipment mode

Info

Publication number: CN215219002U
Application number: CN202121201913.1U
Authority: CN
Inventors: 张小平; 吴述波; 蔡晓平
Original assignee: SHENZHEN ALONG ELECTRONICS CO LTD
Current assignee: SHENZHEN ALONG ELECTRONICS CO LTD
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2021-12-17
Anticipated expiration: 2031-05-27

Abstract

The utility model provides an OTG equipment mode automatic identification circuit, the utility model discloses link to each other with the Vbus power cord, the Vbus power cord is equipped with the first voltage end of keeping away from the OTG interface, is close to the second voltage end of OTG interface, its characterized in that: the automatic OTG equipment mode recognition circuit comprises an isolation unit arranged between a first voltage end and a second voltage end, a first voltage division unit arranged at the first voltage end, a second voltage division unit arranged at the second voltage end and a comparison unit, wherein a first input end of the comparison unit is connected with an output end of the first voltage division unit, a second input end of the comparison unit is connected with an output end of the second voltage division unit, and the comparison unit outputs corresponding recognition signals to an equipment main control according to the voltage signals of the first voltage division unit and the second voltage division unit. The utility model has the advantages that: the circuit is simple, the cost is low, and the plug and play function is realized.

Description

Automatic identification circuit for OTG equipment mode

Technical Field

The utility model relates to a communication technology especially relates to an OTG equipment mode automatic identification circuit.

Background

Many electronic products today support a USB OTG function (abbreviated as USB On-The-Go), and in order to implement data transmission between devices without Host, an OTG line or an OTG adapter is usually required to connect two devices, so as to allow The devices to operate as a Host or a peripheral, which has The following principle:

there are 5 lines in the USB OTG interface: comprises 2 lines for transmitting data (D +, D-), 1 power line (VBUS), 1 ground line (GND) and 1 ID line. The ID line is used to identify the different cable endpoints, as shown in fig. 1, the ID pin in the mini-a plug (i.e., a peripheral a) is grounded, and the ID pin in the mini-B plug (i.e., B peripheral) is floating. When the OTG device detects the grounded ID pin, the default is the device A (host), at the moment, the Vbus is powered by the device A, the device which detects the floating of the ID pin is considered as the device B (peripheral), and the peripheral takes power from the Vbus and is a power utilization device.

As can be seen from fig. 1, the implementation of the OTG function cannot leave the center, in which one ID pin is suspended, and the other ID pin is grounded, the OTG line (or OTG adapter) is used to set one of the devices a and B as a host and the other as a peripheral, so that the OTG line can normally operate. Therefore, an OTG adapter or an OTG cable needs to be additionally carried in the using process, which is inconvenient to use.

SUMMERY OF THE UTILITY MODEL

For solving the problem among the prior art, the utility model provides an OTG equipment mode automatic identification circuit.

The utility model discloses link to each other with the Vbus power cord, the Vbus power cord is equipped with the first voltage end of keeping away from the OTG interface, is close to the second voltage end of OTG interface, OTG equipment mode automatic identification circuit is including setting up isolation unit between first voltage end and the second voltage end still including setting up at the first partial pressure unit of first voltage end and setting up the second partial pressure unit at the second voltage end, still include the comparing element, the first input of comparing element links to each other with first partial pressure unit output, the second input of comparing element links to each other with the output of second partial pressure unit, the comparing element is according to the size of the voltage signal of first partial pressure unit and second partial pressure unit, exports corresponding identification signal and gives the equipment master control.

The utility model discloses make further improvement, the isolation unit includes diode D1 and D3 connected in parallel, diode D1 sets up with diode D3 opposite phase.

The utility model discloses make further improvement, still include diode D2, diode D3's negative pole links to each other with first voltage end, diode D2's positive pole links to each other with first voltage end, and the negative pole links to each other with first partial pressure unit and diode D3's negative pole respectively.

The utility model discloses make another kind of improvement, parallelly connected diode D1 and D3 replace with the resistance characteristic device, diode D2's positive pole links to each other with first voltage end, and the negative pole links to each other with first partial pressure unit.

The utility model discloses make further improvement, first partial pressure unit is including the resistance R3 and the R4 of establishing ties, resistance R3 and R4 establish ties the back, one end ground connection, another termination power supply, the first input termination resistance of comparing unit R3 and R4 between.

The utility model discloses make further improvement, the second partial pressure unit is including the resistance R1 and the R2 of establishing ties, resistance R1 and R2 establish ties the back, one end ground connection, another termination power, the second input termination resistance of comparison unit R1 and R2 between.

The utility model discloses make further improvement, the comparison unit includes the comparator.

Compared with the prior art, the beneficial effects of the utility model are that: the circuit is simple, the cost is low, the design of pure hardware does not need the debugging in the aspect of software, the lead-in is quicker, an OTG (on-the-go) line or an OTG adapter can be omitted, the plug and play is realized, the convenience and the rapidness are realized, and the use habit of the consumers is better fitted.

Drawings

FIG. 1 is a schematic view of the prior art structure of the present invention;

FIG. 2 is a schematic view of the present invention;

fig. 3 is a schematic circuit diagram according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 2, the novel circuit is arranged in the device on one side, so that an OTG line (or an OTG adapter) in the middle of the prior art is omitted, and the device is automatically recognized into a host or a peripheral mode in another mode, thereby realizing a normal OTG function.

As shown in fig. 3, as an embodiment of the present invention, the identification circuit of the present embodiment is disposed in an a-Device (a Device), but of course, the present embodiment may also be disposed in a B Device, so that the B Device also has an automatic identification function of a master Device and a slave Device.

The OTG Device mode automatic identification circuit comprises an isolation unit arranged between the first voltage end and the second voltage end, a first voltage division unit arranged at the first voltage end, a second voltage division unit arranged at the second voltage end and a comparator, wherein the reverse phase input end of the comparator is connected with the output end of the first voltage division unit, the in-phase input end of the comparator is connected with the output end of the second voltage division unit, and the comparator outputs corresponding identification signals to a Device main control according to the voltage signals of the first voltage division unit and the second voltage division unit.

The isolation unit in this example comprises diodes D1 and D3 connected in parallel, the diode D1 is arranged in reverse phase with the diode D3, and in order to achieve voltage stabilization at the isolation point C, the isolation unit in this example further comprises a diode D2, the cathode of the diode D3 is connected to the first voltage terminal, the anode of the diode D2 is connected to the first voltage terminal, and the cathodes of the diode D3 and the first voltage dividing unit are respectively connected to the cathodes.

The utility model discloses make another kind of improvement, parallelly connected diode D1 and D3 replace with the resistance characteristic device, diode D2's positive pole links to each other with first voltage end, and the negative pole links to each other with first partial pressure unit. As long as the difference in voltage between the first voltage terminal and the second voltage terminal can be achieved without affecting the power supply.

The first voltage division unit comprises resistors R3 and R4 which are connected in series, one end of the resistor R3 is connected with the ground, the other end of the resistor R4 is connected with the power supply, and the first input end of the comparison unit is connected between the resistors R3 and R4.

The second voltage division unit comprises resistors R1 and R2 which are connected in series, one end of the resistor R1 is connected with the ground after the resistor R2 is connected in series, the other end of the resistor R1 is connected with the power supply, and the second input end of the comparison unit is connected between the resistors R1 and R2.

The utility model discloses a theory of operation does:

Vbus-5V is 5V generated internally by device a when the master (ID pin low) supplies Vbus power to slave B through diode D1, about 4.8V, and is not output, 0V, when a is the slave (ID pin high).

When the device A has no external device, the signal of the positive phase input end of the comparator 1 is not larger than the signal of the reverse phase input end, the ID signal of the output end of the comparator is at a low level, the device A defaults to the state of the master device, meanwhile, Vbus-5V outputs 5V voltage, the voltage is subjected to voltage division by D1, R1 and R2, then D signal is sent to the non-phase input end of the comparator 1, meanwhile, the voltage is also subjected to voltage division by diodes D2, R3 and R4, then e signal is sent to the reverse phase input end of the comparator 1, the voltage of the non-phase end is compared with the voltage of the reverse phase end, the ID signal of the output end is at a low level, the device A is still identified as the state of the master device, the Vbus-5V voltage is continuously output by 5V, the device A is locked as the state of the master device, the device A provides the Vbus voltage for use of the slave device B, and the slave device B waits for access at any time.

When the access device B is a master device, that is, the Vbus voltage of the device B is 5V, the voltage at the point B is 5V, after the voltage passes through the diode D3, the voltage at the point c is 4.8V, the 2 voltages are divided by R1, R2, R3 and R4 respectively to obtain D and e voltage signals, it is easy to calculate, at this time, the D voltage signal at the inverting terminal of the comparator is greater than the e voltage signal at the inverting terminal, the ID signal at the comparing output terminal is high, and the device a enters the slave device mode.

Compared with the prior art, the utility model has the advantages of: the circuit is simple, the cost is low, the design of pure hardware does not need the debugging in the aspect of software, the lead-in is quicker, an OTG (on-the-go) line or an OTG adapter can be omitted, the plug and play is realized, the convenience and the rapidness are realized, and the use habit of the consumers is better fitted.

The above-mentioned embodiments are the preferred embodiments of the present invention, and the scope of the present invention is not limited to the above-mentioned embodiments, and the scope of the present invention includes and is not limited to the above-mentioned embodiments, and all equivalent changes made according to the present invention are within the protection scope of the present invention.

Claims

1. The utility model provides an OTG equipment mode automatic identification circuit, links to each other with the Vbus power cord, the Vbus power cord is equipped with the first voltage end of keeping away from the OTG interface, is close to the second voltage end of OTG interface, its characterized in that: the automatic OTG equipment mode recognition circuit comprises an isolation unit arranged between a first voltage end and a second voltage end, a first voltage division unit arranged at the first voltage end, a second voltage division unit arranged at the second voltage end and a comparison unit, wherein a first input end of the comparison unit is connected with an output end of the first voltage division unit, a second input end of the comparison unit is connected with an output end of the second voltage division unit, and the comparison unit outputs corresponding recognition signals to an equipment main control according to the voltage signals of the first voltage division unit and the second voltage division unit.

2. The OTG device mode auto-discrimination circuit of claim 1, wherein: the isolation unit comprises diodes D1 and D3 connected in parallel, and the diode D1 is arranged in reverse phase with the diode D3.

3. The OTG device mode auto-discrimination circuit of claim 2, wherein: the voltage divider further comprises a diode D2, wherein the cathode of the diode D3 is connected with the first voltage end, the anode of the diode D2 is connected with the first voltage end, and the cathodes of the diode D3526 are respectively connected with the first voltage dividing unit and the cathode of the diode D3.

4. The OTG device mode auto-discrimination circuit of claim 3, wherein: the parallel diodes D1 and D3 are replaced with resistive characteristic devices, and the diode D2 has an anode connected to the first voltage terminal and a cathode connected to the first voltage dividing unit.

5. The OTG device mode automatic identification circuit according to any of claims 1-4, wherein: the first voltage division unit comprises resistors R3 and R4 which are connected in series, one end of each resistor R3 and R4 is connected with the ground after the resistors R3 and R4 are connected in series, the other end of each resistor R3 and R4 are connected with a power supply, and the first input end of the comparison unit is connected between the resistors R3 and R4.

6. The OTG device mode automatic identification circuit according to any of claims 1-4, wherein: the second voltage division unit comprises resistors R1 and R2 which are connected in series, one end of each resistor R1 and R2 is grounded after the resistors R1 and R2 are connected in series, the other end of each resistor R1 and R2 are connected with a power supply, and the second input end of the comparison unit is connected between the resistors R1 and R2.

7. The OTG device mode automatic identification circuit according to any of claims 1-4, wherein: the comparison unit includes a comparator.