Output conversion circuit supporting input of multiple types of video streams to screen

Abstract

The utility model discloses an output conversion circuit supporting multiple types of video streams to be input to a screen. The output conversion circuit comprises a DP-to-MIPI CSI circuit, a protection circuit, a step-down circuit and two change-over switches. The input end of the DP-to-MIPI CSI circuit is set as a TYPE C plug, the TYPE C is connected to a TYPE C socket of a video supplier product, and the DP-to-MIPI CSI circuit converts a DP signal into an MIPI signal and outputs the MIPI signal; the protection circuit is connected to a VBUS pin of the TYPE C plug, the number of the step-down circuits is two, the two step-down circuits are both connected to the output end of the protection circuit, the two change-over switches are connected to a main control chip of the DP-to-MIPI CSI circuit, and the DP-to-MIPI CSI circuit sets a DP IN video signal and a camera video signal to be either output to a display device. According to the utility model, the requirements of inputting and playing various video sources can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to a video conversion circuit, specifically to a kind of output conversion circuit that supports multiple types of video stream input to screen. BACKGROUND

[0002] At present, general flat SOC does not support the function of DP IN, and the mode of audio and video input is mainly camera plus microphone, since the use scene of most user mobile phones is more and the popularization of mobile phone DP OUT technology, we use DP to MIPI CSI conversion chip (LT7911D) to convert DP signal into MIPICSI camera signal input supported by flat SoC chip, so as to realize the function of flat SoC supporting DP IN. Due to the high conversion capacity of LT7911D chip, it can ensure that the signal remains high quality during transmission, meet the needs of product in video input, so as to improve the compatibility and functionality of product. Since flat SOC has only one way of high-definition MIPI CSI, DP IN and camera video input need to be converted.

[0003] Therefore, it is necessary to provide an output conversion circuit to solve the above technical problems. UTILITY MODEL CONTENT

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the utility model is to provide an output conversion circuit that supports multiple types of video stream input to screen. The purpose of designing the output conversion circuit is to realize the input and play of multiple video sources.

[0005] To solve the above technical problems, the utility model realizes the following scheme: an output conversion circuit that supports multiple types of video stream input to screen, comprising:

[0006] DP to MIPI CSI circuit, the input end of the DP to MIPI CSI circuit is provided with TYPE C plug, the TYPE C is connected to the TYPE C receiving port of video supplier product, and the DP to MIPI CSI circuit converts DP signal into MIPI signal output;

[0007] Protection circuit, connected to the VBUS pin of TYPE C plug, the protection circuit has surge tube protection circuit and overvoltage protection circuit;

[0008] Buck circuit, provided with two ways, two buck circuits are connected to the output end of protection circuit, and the voltage after buck of two buck circuits is supplied to the main control chip in the DP to MIPI CSI circuit;

[0009] Two change-over switches connected to the master chip of the DP-to-MIPI CSI circuit, which set the DPIN video signal and the camera video signal to be output to the display device alternatively.

[0010] Further, the master chip of the DP-to-MIPI CSI circuit adopts a chip of model LT7911D.

[0011] Further, the surge tube protection circuit comprises a surge tube DU10, the negative electrode of which is grounded, and the positive electrode of which is connected to the VBUS pin of the TYPE C plug.

[0012] The overvoltage protection comprises a bidirectional breakdown diode D9211, the first end of which is connected to the VBUS pin of the TYPE C plug, and the second end of which is grounded; and an overvoltage chip U9012, the INO pin of which and the IN pin of which are connected to each other and to the VBUS pin of the TYPE C plug.

[0013] The branch of the VBUS pin of the TYPE C plug is further connected to a capacitor C90350 and a resistor R90507, the other end of the capacitor C90350 being grounded, the other end of the resistor R90507 being connected to the OVLO pin of the overvoltage chip U9012 and the first end of a resistor R90506 respectively, the second end of the resistor R90506 being grounded, and the resistor R90506 being connected in parallel to a capacitor C90349.

[0014] The OUT0 pin of the overvoltage chip U9012 and the OUT pin of the overvoltage chip U9012 are connected to each other and to the first end of a capacitor C90348 and a two-way voltage reduction circuit, the second end of the capacitor C90348 being grounded.

[0015] The GND pin of the overvoltage chip U9012 is grounded.

[0016] Further, the two-way voltage reduction circuit comprises a first voltage reduction circuit and a second voltage reduction circuit, which are identical in structure but different in output circuit.

[0017] The first voltage reduction circuit is connected with a voltage reduction chip U1521, the VIN pin of the voltage reduction chip U1521 is connected with the output end of the overvoltage protection circuit, the resistor R8421 and the capacitor C8332 respectively, the other end of the resistor R8421 is connected with the CK pin of the voltage reduction chip U1521, the first end of the resistor R127 and the first end of the resistor R9428, the other end of the capacitor C8332 is grounded, the capacitor C216 is connected with the capacitor C8332 in parallel, the second end of the resistor R127 is grounded, the second end of the resistor R9428 is connected with the LT-POW_H_GPIO3_B1 circuit, the LX pin of the voltage reduction chip U1521 is connected with the first end of the inductor L1103, the second end of the inductor L1103 is connected with the first end of the resistor R8426 and the first end of the capacitor C8333 respectively, the second end of the resistor R8426 is connected with the first end of the resistor R8427, the second end of the resistor R8427 is grounded, the PB pin of the voltage reduction chip U1521 is connected with the node between the resistor R8426 and the resistor R8427, the second end of the capacitor C8333 is grounded, and the capacitor C218 is connected with the capacitor C8333 in parallel.

[0018] The first voltage reduction circuit has FB3 output, FB4 output, FB5 output and FB6 output, and the FB3 output, the FB4 output, the FB5 output and the FB6 output are all connected with the output end of the inductor L1103.

[0019] The second voltage reduction circuit has FB1 output, FB2 output and VCC33 output, and the FB1 output, the FB2 output and the VCC33 output are all connected with the output end of the inductor L1104.

[0020] Further, the two conversion switches are both BCT642A type conversion switches.

[0021] Still further, one of the two conversion switches is turned on by default when the conversion switch is used to convert to the camera video signal.

[0022] Compared with the prior art, the output conversion circuit has the advantages that:

[0023] 1. The output conversion circuit can transmit the video output by the video supplier product and the camera video output by the video supplier product to the display screen through the same group of MIPI CSI interface.

[0024] 2. The output conversion circuit can be used as DP input and camera input, and can be flexibly converted without closing the system, thereby solving the defect that the tablet SOC has only one group of high-definition MIPI CSI input.

[0025] 3. In addition, by using the external power supply characteristics of the DP OUT device, the need for the device to supply power to the LT7911D model chip is avoided, thereby prolonging the use time of the device and reducing the overall power consumption. Provide a better experience for users to watch their own recorded videos and various short video platforms. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The output conversion circuit principle block diagram of the utility model.

[0027] Figure 2 The main control chip circuit diagram of the DP to MIPI CSI circuit of the utility model.

[0028] Figure 3 The A part of Figure 2 The A part of

[0029] Figure 4 The B part of Figure 2 The B part of

[0030] Figure 5 The C part of Figure 2 The C part of

[0031] Figure 6 The D part of Figure 2 The D part of

[0032] Figure 7 The TYPE C plug circuit diagram of the utility model.

[0033] Figure 8 The E part of Figure 7 The E part of

[0034] Figure 9 The F part of Figure 7 The F part of

[0035] Figures 10-11 After connection, the first voltage reduction circuit diagram is formed.

[0036] Figures 12-13 After connection, the second voltage reduction circuit diagram is formed.

[0037] Figure 14 The protection circuit diagram of the utility model.

[0038] Figure 15 The reset circuit diagram of the utility model.

[0039] Figures 16-17 The two conversion switch circuit diagrams of the utility model.

[0040] Figures 18-20 Both are anti-static protection circuits.

[0041] Figure 21 is connected to the detection point P11, the detection point P12 of Figure 26 the circuit.

[0042] Figure 22 is a level conversion chip circuit diagram.

[0043] Figures 23-24 is a filter circuit diagram.

[0044] Figure 25 is a crystal oscillator circuit diagram.

[0045] Figure 26 is a connector J4800 circuit diagram.

[0046] Figure 27 is a first rectifier filter circuit diagram connected to the connector J4800.

[0047] Figure 28 is a connector J9913 circuit diagram.

[0048] Figure 29 is a second rectifier filter circuit diagram connected to the connector J9913.

[0049] Figure 30 is an RK3568 chip circuit diagram. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, so that the advantages and characteristics of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined. Obviously, the described embodiments of the present application are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0051] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0052] The general tablet SOC does not support the function of DP IN, and the audio and video input mode is mainly a camera plus a microphone, and since most users' mobile phone use scenarios are more and the mobile phone DP OUT technology is popular, a DP to MIPI CSI conversion chip (LT7911D) is used to convert the DP signal into a MIPI CSI camera signal input supported by the tablet SoC chip, so that the tablet SoC supports the DP IN function. Due to the high conversion capability of the LT7911D chip, the signal can be kept high quality during transmission, meeting the product's demand in video input, thereby improving the product's compatibility and functionality. Since the tablet SOC has only one high-definition MIPI CSI, the DP IN and the camera video input need to be converted.

[0053] Embodiment 1: The specific structure of the utility model is as follows:

[0054] Please refer to the attached Figures 1-30 The utility model relates to an output conversion circuit supporting multiple types of video stream input to screen, which comprises a DP to MIPI CSI circuit, a protection circuit, a step-down circuit and two conversion switches.

[0055] The DP to MIPI CSI circuit, the input end of which is provided with a TYPE C plug, is connected to the TYPE C receiving port of the video supplier product, and the DP to MIPI CSI circuit converts the DP signal into a MIPI signal output; the main control chip of the DP to MIPI CSI circuit is an LT7911D chip.

[0056] Figure 14As shown, the protection circuit is connected to the VBUS pin of the TYPE C plug, and the protection circuit has a surge tube protection circuit and an overvoltage protection circuit. The surge tube protection circuit includes a surge tube DU10, the negative electrode of which is grounded, and the positive electrode of which is connected to the VBUS pin of the TYPE C plug; the overvoltage protection includes a bidirectional breakdown diode D9211, the first end of which is connected to the VBUS pin of the TYPE C plug, and the second end of which is grounded; the INO pin of the overvoltage chip U9012 and the IN pin of the overvoltage chip U9012 are connected to each other and connected to the VBUS pin of the TYPE C plug; the branch of the VBUS pin of the TYPE C plug is also connected with a capacitor C90350 and a resistor R90507, the other end of the capacitor C90350 is grounded, the other end of the resistor R90507 is connected to the OVLO pin of the overvoltage chip U9012 and the first end of the resistor R90506 respectively, the second end of the resistor R90506 is grounded, and the resistor R90506 is connected in parallel with a capacitor C90349; the OUT0 pin of the overvoltage chip U9012 and the OUT pin of the overvoltage chip U9012 are connected to each other and connected to the first end of a capacitor C90348 and two voltage reduction circuits, the second end of the capacitor C90348 is grounded; the GND pin of the overvoltage chip U9012 is grounded.

[0057] Figures 9-13 As shown, the voltage reduction circuit is provided with two paths, and the two voltage reduction circuits are connected to the output end of the protection circuit, and the voltage after being reduced by the two voltage reduction circuits is supplied to the master control chip in the DP to MIPI CSI circuit; the two voltage reduction circuits include a first voltage reduction circuit and a second voltage reduction circuit which have the same structure and different output circuits;

[0058] The first voltage reduction circuit is connected with a voltage reduction chip U1521, the VIN pin of the voltage reduction chip U1521 is connected with the output end of the overvoltage protection circuit, the resistor R8421 and the capacitor C8332 respectively, the other end of the resistor R8421 is connected with the CK pin of the voltage reduction chip U1521, the first end of the resistor R127 and the first end of the resistor R9428, the other end of the capacitor C8332 is grounded, the capacitor C216 is connected in parallel with the capacitor C8332, the second end of the resistor R127 is grounded, the second end of the resistor R9428 is connected with the LT-POW_H_GPIO3_B1 circuit, the LX pin of the voltage reduction chip U1521 is connected with the first end of the inductor L1103, the second end of the inductor L1103 is connected with the first end of the resistor R8426 and the first end of the capacitor C8333 respectively, the second end of the resistor R8426 is connected with the first end of the resistor R8427, the second end of the resistor R8427 is grounded, the PB pin of the voltage reduction chip U1521 is connected with a node between the resistor R8426 and the resistor R8427, the second end of the capacitor C8333 is grounded, and the capacitor C218 is connected in parallel with the capacitor C8333.

[0059] The first voltage reduction circuit has FB3 output, FB4 output, FB5 output and FB6 output, and the FB3 output, the FB4 output, the FB5 output and the FB6 output are all connected with the output end of the inductor L1103.

[0060] The second voltage reduction circuit has FB1 output, FB2 output and VCC33 output, and the FB1 output, the FB2 output and the VCC33 output are all connected with the output end of the inductor L1104.

[0061] As shown in the figure, Figures 16-17 Two conversion switches are connected with the master control chip of the DP conversion MIPI CSI circuit, and the DPIN video signal and the camera video signal are set to two selected outputs to the display device. One of the two conversion switches is used for converting the camera video signal, and the conversion switch is turned on by default when starting. The two conversion switches are both BCT642A type conversion switches.

[0062] The utility model supports the working principle of the output conversion circuit of the multiple type video stream input to the screen:

[0063] The utility model uses two BCT642A conversion switches, and designs the DPIN video signal and the camera video signal as two selected input modes. When the equipment starts, the hardware circuit will default to switch the camera signal input end, and ensure that the camera can be used for video recording when starting.

[0064] For DPIN audio and video input, the utility model utilizes the characteristics of the equipment supporting DP OUT function such as mobile phone or computer. When inserting, the system will detect and identify as OTG equipment, the TYPE C interface of mobile phone or computer enables external power supply function, provides 5V voltage to the TYPE C plug of the circuit. Before the voltage enters the voltage reduction chip, the utility model uses surge pipe DU10 and overvoltage protection IC U9012 to protect, to ensure that when the user misplug the charger to the TYPE C interface, will not damage the voltage reduction IC and LT7911D chip. The 5V voltage output by the equipment such as mobile phone provides 1.2V and 3.3V voltage power supply for LT7911D chip through voltage reduction IC (U1524 and U1522), and the chip starts to work. The CC pin of TYPE C plug and LT7911D complete protocol handshake, and the equipment such as mobile phone starts to output DP audio and video signal. LT7911D converts DP signal into MIPI CSI signal, and simultaneously pulls up the GPIO5 pin of LT7911D chip. The pin is connected to the IO port of RK3568, which is a default low level, when the IO port detects high level, BCT642A conversion switch will convert to DPIN video signal input end, thereby displaying the audio and video input signal of DPIN.

[0065] The conversion of simultaneously supporting the input of DP IN video signal and camera signal is realized: since the playing software used by the DP IN video signal and the camera signal is different, when connecting the mobile phone and the like to input the DP IN signal, the system allows conversion to the camera signal. The user can select different software to open according to the demand, and the system will automatically control the BCT642A conversion switch according to the software opened by the user, so as to ensure that the video input of the camera can be enabled while the DP IN input signal, and the seamless conversion of multiple input sources is realized. The circuit cooperates with the system to realize the input and playing of multiple video sources of the VR all-in-one machine, including local video playing, online video playing, mobile phone video playing through DP output, and camera video input. Moreover, by using the same set of MIPI CSI interface, the DP input and the camera input can be realized, and the system can be flexibly converted without being closed, thereby solving the disadvantage of the tablet SOC having only one set of high-definition MIPI CSI input. In addition, by using the external power supply characteristics of the DP OUT device, the need for the device to supply power for the LT7911D chip is avoided, thereby prolonging the use time of the device and reducing the overall power consumption. Better experience is provided for the user, and the user can watch the video recorded by himself and various short video platforms, which cannot be realized on the VR all-in-one machine end, and even the user can save the video website membership, because the membership of the VR end and the membership of the mobile phone end are not universal. The application makes the VR device more cost-effective.

[0066] In summary, the output conversion circuit can transmit the video output by the video supplier product and the camera video output by the video supplier product to the display screen through the same set of MIPI CSI interface. The output conversion circuit can be used as the DP input and the camera input, and can be flexibly converted without being closed, thereby solving the disadvantage of the tablet SOC having only one set of high-definition MIPI CSI input. In addition, by using the external power supply characteristics of the DP OUT device, the need for the device to supply power for the LT7911D chip is avoided, thereby prolonging the use time of the device and reducing the overall power consumption. Better experience is provided for the user, and the user can watch the video recorded by himself and various short video platforms.

[0067] The preferred embodiments of the utility model are described above, and the patent range of the utility model is not limited by this, and equivalent structures or equivalent process transformations are made by using the contents of the utility model specification and the drawings, or are directly or indirectly used in other related technical fields, and the same is included in the patent protection range of the utility model.

Claims

1. An output conversion circuit that supports input of multiple types of video streams to the screen, characterized in that, include: The DP to MIPI CSI circuit has a TYPE C connector as its input terminal. The TYPE C connector is connected to the TYPE C interface of the video supplier's product. The DP to MIPI CSI circuit converts the DP signal into a MIPI signal for output. The protection circuit, connected to the VBUS pin of the TYPE C connector, includes surge protection and overvoltage protection. The step-down circuit has two paths, both of which are connected to the output of the protection circuit. The voltage after stepping down by the two step-down circuits is supplied to the main control chip in the DP to MIPI CSI circuit. Two selector switches are connected to the main control chip of the DP to MIPI CSI circuit, which sets the DP IN video signal and the camera video signal to be output to the display device in a two-choice configuration.

2. The output conversion circuit supporting multiple types of video stream input to the screen according to claim 1, characterized in that, The main control chip used in the DP to MIPI CSI circuit is the LT7911D model.

3. The output conversion circuit supporting multiple types of video stream input to the screen according to claim 1, characterized in that, The surge protection circuit includes a surge tube DU10, the negative terminal of which is grounded and the positive terminal is connected to the VBUS pin of the TYPE C connector. The overvoltage protection includes a bidirectional breakdown diode D9211 and an overvoltage chip U9012. The first end of the bidirectional breakdown diode D9211 is connected to the VBUS pin of the TYPE C connector, and the second end is grounded. The INO pin and IN pin of the overvoltage chip U9012 are interconnected and connected to the VBUS pin of the TYPE C connector. A capacitor C90350 and a resistor R90507 are also connected to the VBUS pin branch of the TYPE C connector. The other end of the capacitor C90350 is grounded. The other end of the resistor R90507 is connected to the OVLO pin of the overvoltage chip U9012 and the first end of the resistor R90506. The second end of the resistor R90506 is grounded. A capacitor C90349 is connected in parallel with the resistor R90506. The OUT0 pin of the overvoltage chip U9012 and the OUT pin of the overvoltage chip U9012 are interconnected and connected to the first end of the capacitor C90348 and the two-way step-down circuit. The second end of the capacitor C90348 is grounded. The GND pin of the overvoltage chip U9012 is grounded.

4. The output conversion circuit supporting multiple types of video stream input to the screen according to claim 1, characterized in that, The two buck circuits include a first buck circuit and a second buck circuit with the same structure but different output circuits. The first step-down circuit includes a step-down chip U1521. The VIN pin of the step-down chip U1521 is connected to the output of the overvoltage protection circuit, resistor R8421, and capacitor C8332. The other end of resistor R8421 is connected to the CK pin of the step-down chip U1521, the first end of resistor R127, and the first end of resistor R9428. The other end of capacitor C8332 is grounded. Capacitor C216 is connected in parallel with capacitor C8332. The second end of resistor R127 is grounded. The second end of resistor R9428 is connected to LT-POW_H_G. The PIO3_B1 circuit: The LX pin of the step-down chip U1521 is connected to the first end of the inductor L1103. The second end of the inductor L1103 is connected to the first end of the resistor R8426 and the first end of the capacitor C8333. The second end of the resistor R8426 is connected to the first end of the resistor R8427. The second end of the resistor R8427 is grounded. The PB pin of the step-down chip U1521 is connected to the node between the resistor R8426 and the resistor R8427. The second end of the capacitor C8333 is grounded. The capacitor C8333 is connected in parallel with the capacitor C218. The first step-down circuit has FB3 output, FB4 output, FB5 output and FB6 output, and FB3 output, FB4 output, FB5 output and FB6 output are all connected to the output terminal of inductor L1103; The second step-down circuit has FB1 output, FB2 output and VCC33 output, all of which are connected to the output terminal of inductor L1104.

5. The output conversion circuit supporting multiple types of video stream input to the screen according to claim 1, characterized in that, Both changeover switches are BCT642A model changeover switches.

6. An output conversion circuit supporting multiple types of video stream input to the screen according to claim 1 or 5, characterized in that, Of the two switches, one of the switches used to switch to camera video signals is turned on by default when the device is powered on.

Images