Automobile cabin MIPI-DSI to AHD dual-path homologous output circuit
By designing a dual-channel co-source output circuit for MIPI-DSI to AHD conversion, and utilizing Longxun LT9211, Kedian TP2912, and Saint-Gobain SGM9117 chips, the defect of direct DSI to AHD conversion in automotive cockpit systems was solved, enabling multi-screen display without external devices, reducing costs and improving hardware resource utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HENAN TIANMAI TECH CO LTD
- Filing Date
- 2025-07-24
- Publication Date
- 2026-06-05
AI Technical Summary
Existing automotive cockpit systems lack the function of direct DSI to AHD conversion and support for dual-channel output from the same source, which leads to the need for external equipment, increasing costs, and cannot directly meet the needs of multi-screen display.
Using integrated chips such as Longxun LT9211, Kedian TP2912, and Saint-Gobain SGM9117, a MIPI-DSI to AHD dual-channel co-source output circuit was designed. Through a MIPI-DSI signal output module, a MIPI-DSI input to converter BT1120 output circuit, a BT1120 input to converter AHD output circuit, and an AHD buffer output circuit, a single AHD signal is converted into two independent outputs, ensuring the consistency of the displayed content.
It achieves AHD conversion without relying on the internal resources of the SOC, directly converting MIPI-DSI signals to AHD, adapting to the interface requirements of in-vehicle TVs and advertising machines, improving hardware resource utilization, reducing costs, and meeting the needs of multi-screen displays.
Smart Images
Figure CN224329509U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of conversion circuit technology, specifically relating to a dual-channel co-source output circuit for MIPI-DSI to AHD conversion in an automotive cockpit. Background Technology
[0002] In modern automotive cockpit systems, the demand for in-vehicle TVs is increasing daily. The AHD interface, with its low cost, high reliability, and low latency, holds a significant position in this field, especially suitable for mid-to-low-end vehicles and multi-screen expansion scenarios. However, current cockpit solutions almost exclusively use MIPI-CSI to AHD interfaces directly from the SoC, requiring video conversion. Commonly, this is a MIPI-CSI to AHD conversion solution, with few offering direct DSI to AHD conversion supporting dual-channel output. Furthermore, due to varying internal resources across different platform solutions, limitations exist, making it impossible to directly support two screens with AHD output. In such cases, achieving dual-screen support often necessitates external devices, resulting in additional costs. Utility Model Content
[0003] To address the shortcomings and problems of current cockpit solutions that lack DSI-to-AHD direct conversion and support for dual-channel output from the same source, this utility model provides an automotive cockpit MIPI-DSI-to-AHD dual-channel output circuit from the same source.
[0004] A dual-channel co-source output circuit for MIPI-DSI to AHD conversion in an automotive cockpit includes a MIPI-DSI signal output module for providing a signal source;
[0005] The MIPI-DSI input to output converter BT1120 circuit is connected to the MIPI-DSI signal output module and is used to convert the MIPI-DSI input signal into a BT1120 parallel signal output.
[0006] The BT1120 input-to-AHD output circuit is connected to the MIPI-DSI input-to-BT1120 output circuit and is used to convert the BT1120 input signal into an AHD signal output.
[0007] The AHD buffer output circuit is connected to the BT1120 input-to-AHD output conversion circuit to increase the AHD signal output drive capability, enabling the AHD signal to be converted into two AHD outputs.
[0008] The aforementioned automotive cockpit MIPI-DSI to AHD dual-channel same-source output circuit uses the Longxun LT9211 integrated chip as its MIPI-DSI input conversion BT1120 output circuit.
[0009] The aforementioned automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit uses the BT1120 input to AHD output conversion circuit with the Kedian TP2912 integrated chip.
[0010] The aforementioned automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit uses the SGM9117 buffer chip from Saint-Gobain as its AHD buffer output circuit.
[0011] The aforementioned automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit, in the AHD buffer output circuit, the input external AHD signal is connected in parallel to the input pin after passing through a voltage divider network composed of resistors R333 and R753. After being processed by the chip, it is output as two independent AHD signals after passing through impedance matching resistors R755 and R756 respectively.
[0012] Compared with the prior art, the beneficial effects of this utility model are:
[0013] This invention utilizes the Longxun LT9211 integrated chip, the Kedian TP2912 integrated chip, and the Saint-Gobain SGM9117 buffer chip to achieve the conversion of MIPI-DSI signals to AHD. It converts a single AHD signal into two independent outputs, with both signals originating from the same source, ensuring consistent display content and meeting the needs of multi-screen displays in vehicles. This circuit does not rely on the internal resources of the SOC and can directly convert the SOC's MIPI-DSI signal to AHD, adapting to the interface requirements of in-vehicle TVs, advertising machines, and other devices. It eliminates the need to modify existing wiring structures or replace high-cost SOC solutions for AHD interface adaptation; the conversion can be achieved using existing MIPI-DSI output SOCs, improving hardware resource utilization, filling functional gaps at the SOC hardware level, and solving the problem of SOCs lacking direct AHD output. Attached Figure Description
[0014] Figure 1 This is a functional block diagram of the MIPI-DSI to AHD dual-channel same-source output circuit implementation scheme of this utility model.
[0015] Figure 2 This is the circuit diagram of the MIPI-DSI to BT1120 converter of this utility model.
[0016] Figure 3 This is the circuit diagram of the BT1120 to AHD converter of this utility model.
[0017] Figure 4 This is the circuit diagram of the dual AHD co-source output circuit of this utility model. Detailed Implementation
[0018] To address the current lack of DSI-to-AHD direct conversion circuits that support dual-channel output from the same source, this invention provides a dual-channel output circuit for automotive cockpit MIPI-DSI to AHD conversion. The invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments.
[0019] Example: This example provides a dual-channel co-source output circuit for automotive cockpit MIPI-DSI to AHD conversion, such as... Figure 1 As shown, it includes a MIPI-DSI signal output module 1, which provides a signal source for the backend; a MIPI-DSI input converter BT1120 output circuit 2 connected to the MIPI-DSI signal output module 1, which converts the MIPI-DSI input signal into a BT1120 parallel signal output; a BT1120 input converter AHD output circuit 3 connected to the MIPI-DSI input converter BT1120 output circuit 2, which converts the BT1120 input signal into an AHD signal output; and an AHD buffer output circuit 4 connected to the BT1120 input converter AHD output circuit 3, which increases the AHD signal output driving capability and converts the AHD signal into two AHD outputs.
[0020] In this embodiment, the MIPI-DSI input converter BT1120 output circuit is a Longxun LT9211 integrated chip, such as... Figure 2 As shown, the MT9211 receives signals through its MIPI DSI input pins, converting the input signals into BT1120 parallel signal outputs. Specifically, the MIPI_DSI2_CLK_N / P and MIPI_DSI2_D0_N / P ~ D3_N / P inputs from the front-end MIPI source are input to the MT9211C. Serial video / command data is received through the MIPI DSI data channels of MIPI_DSI2_D0_N / P ~ D3_N / P, and synchronous data transmission is performed through the MIPI DSI clock channel of MIPI_DSI2_CLK_N / P. After processing, the converted parallel video data is output to the back-end BT1120 input-to-AHD output circuit through the multi-parallel pins TD0~TD23.
[0021] The BT1120 input-to-AHD output circuit uses the Kedian TP2912 integrated chip, such as... Figure 3As shown, the chip receives signal data from the BT1120 through its internal parallel interface, processes it, and converts it into an AHD signal. Specifically, the digital video signal is input to the TP2912 via the left-side pins, connecting the image sensor / video source's VD0~VD7 (pins 30~23), CD0~CD7 (pins 19~12), and PIXCLK (pin 22). FVLD1 / LVLD1 (pins 16 / 31) mark the valid frames and line ranges, ensuring that the chip only processes "real video data." The TP2912 internally encodes the digital video into AHD format and outputs differential current signals from IOUTP (pin 8) and IOUTN (pin 9). R754, C460, and R771 form an external RC network, where R754 and C460 act as filters and impedance matchers, converting the current signal to voltage while filtering out high-frequency noise. R771 further matches the 75Ω impedance requirement for AHD transmission, ultimately outputting the AHD_OUTP signal.
[0022] The AHD buffer output circuit uses the SGM9117 buffer chip from Saint-Gobain, such as... Figure 4 As shown, the external AHD signal (positive phase) input is connected in parallel to the IN1 (pin 2) and IN2 (pin 1) inputs of U15 after passing through a voltage divider network composed of a 75Ω resistor R333 and a 1MΩ resistor R753, utilizing multi-channel enhanced drive. The positive power supply VCC (pin 4) is connected to vap_2v3 for power supply, and GND (pin 5) is grounded. C656 is a power supply filter capacitor, which stabilizes the power supply and filters out noise. Pins OUT1 / OUT2 / OUT3 (pins 8 / 7 / 6) serve as signal input terminals, with OUT1 (pin 8) and OUT2 (pin 7) used for branch outputs. OUT1 (pin 8) is connected through... After R755, one AHD signal, AHD1_OUTP, is output. OUT2 (pin 7) outputs two AHD signals, AHD2_OUTP, after passing through R756. R755 and R756 serve as matching impedances, with an output impedance of 75 ohms. The AHD signal input from AHD_OUTP is buffered and amplified by the SGM9117 buffer chip, and then duplicated into two independent outputs, AHD1_OUTP and AHD2_OUTP. At the same time, a 75Ω resistor is used to match the transmission impedance to ensure signal integrity, thus realizing the function of MIPI-DSI to dual-channel AHD output.
[0023] The above description is only a preferred embodiment of the present utility model and does not limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A dual-channel co-source output circuit for automotive cockpit MIPI-DSI to AHD conversion, characterized in that: Includes a MIPI-DSI signal output module for providing a signal source; The MIPI-DSI input to output converter BT1120 circuit is connected to the MIPI-DSI signal output module and is used to convert the MIPI-DSI input signal into a BT1120 parallel signal output. The BT1120 input-to-AHD output circuit is connected to the MIPI-DSI input-to-BT1120 output circuit and is used to convert the BT1120 input signal into an AHD signal output. The AHD buffer output circuit is connected to the BT1120 input-to-AHD output conversion circuit to increase the AHD signal output drive capability, enabling the AHD signal to be converted into two AHD outputs.
2. The automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit according to claim 1, characterized in that: The MIPI-DSI input converter BT1120 output circuit is a Longxun LT9211 integrated chip.
3. The automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit according to claim 1, characterized in that: The BT1120 input-to-AHD output circuit is a Kedian TP2912 integrated chip.
4. The automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit according to claim 1, characterized in that: The AHD buffer output circuit uses the SGM9117 buffer chip from Saint-Gobain.
5. The automotive cockpit MIPI-DSI to AHD dual-channel co-source output circuit according to claim 4, characterized in that: In the AHD buffer output circuit, the input external AHD signal is connected in parallel to the input pin after passing through a voltage divider network composed of resistors R333 and R753. After being processed by the chip, it is output as two independent AHD signals after passing through impedance matching resistors R755 and R756 respectively.