A multi-protocol interface adaptive switching touch screen driving integrated circuit

Abstract

The application discloses a kind of multi-protocol interface adaptive switching touch screen driving integrated circuits, including protocol detection module, protocol switching controller, I2C interface circuit, USB interface circuit, touch signal processing module and power management module.Protocol detection module is automatically identified input signal protocol type by voltage comparator and frequency detection unit, protocol switching controller completes interface switching within 100ns, supports the seamless switching of I2C (100kHz-1MHz) and USB (1.5MHz-12MHz) protocol.Touch signal processing module uses 12-bit ADC and digital filter to realize high-precision touch coordinate calculation.The integrated circuit uses 7mm×7mm QFN package, single-chip solution multi-protocol compatibility problem, can reduce system complexity by more than 30%.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit design technology, specifically relating to a touch screen driver integrated circuit with adaptive switching of multiple protocol interfaces. Background Technology

[0002] With the widespread adoption of touchscreen technology, touchscreen driver ICs need to be compatible with multiple host interface protocols, such as I²C and USB. Existing technologies typically employ two approaches: one is to design multiple independent ICs to support different protocols, leading to high system complexity and increased costs; the other is to select the protocol via pin configuration within a single IC, requiring manual intervention and lacking dynamic switching capabilities. Especially in industrial control applications, devices may require frequent switching of communication protocols, and existing technologies struggle to meet real-time requirements. Therefore, there is an urgent need for a touchscreen driver integrated circuit capable of automatically identifying and rapidly switching communication protocols. Summary of the Invention

[0003] 1. Technical Problem Solved by this Implementation Scheme: This scheme addresses the issue of touchscreen driver ICs failing to automatically adapt to different communication protocols, achieving adaptive switching between multiple protocol interfaces. Technical Solution Adopted in this Implementation Scheme: A touchscreen driver integrated circuit with adaptive switching of multiple protocol interfaces, comprising a protocol detection module, a protocol switching controller, an I²C interface circuit, a USB interface circuit, a touch signal processing module, and a power management module. The input terminal of the protocol detection module is connected to an external interface bus, and its output terminal is connected to the protocol switching controller. The output terminals of the protocol switching controller are respectively connected to the I²C interface circuit and the USB interface circuit. The output terminals of both the I²C interface circuit and the USB interface circuit are connected to the touch signal processing module. The power management module supplies power to each functional module. Beneficial Effects of this Implementation Scheme: A single chip enables automatic identification and switching of I²C and USB protocols, reducing system complexity. Working Principle of this Implementation Scheme: Data transmission is dynamically selected based on real-time detection of interface signal characteristics.

[0004] 2. Technical problem solved under optimal implementation: Improving the accuracy and response speed of protocol identification. Technical solution adopted under optimal implementation: The protocol detection module includes a voltage comparator, a frequency detection unit, and a protocol feature recognition unit. The input of the voltage comparator is connected to an external interface bus, and its output is connected to the frequency detection unit. The output of the frequency detection unit is connected to the protocol feature recognition unit. Beneficial effect achieved under optimal implementation: Protocol identification accuracy reaches over 99.9%. Working principle: Multi-level signal feature analysis ensures accurate protocol judgment.

[0005] 3. Technical problem solved under preferred implementation: Optimizing the electrical parameter matching of protocol detection. Technical solution adopted under preferred implementation: The reference voltage of the voltage comparator is set to 1.8V ± 5%, and the operating frequency range of the frequency detection unit is 100kHz–12MHz. Beneficial effect produced under preferred implementation: Compatibility with the electrical characteristics of mainstream I²C and USB devices. Working principle: Filtering invalid signals through a preset threshold.

[0006] 4. Technical problem solved under the preferred implementation: Achieving fast and seamless protocol switching. Technical solution adopted under the preferred implementation: The protocol switching controller includes a state machine and a switching array. The input of the state machine is connected to the protocol detection module, and the output is connected to the switching array. The outputs of the switching array are connected to the I²C interface circuit and the USB interface circuit, respectively. Beneficial effect produced under the preferred implementation: No data loss during the switching process. Working principle: Hardware state machine controls physical switch array.

[0007] 5. Technical problem solved under preferred implementation: Ensuring reliability of high-speed switching. Technical solution adopted under preferred implementation: Switching time of the switching array is less than 100ns, and on-resistance is less than 5Ω. Beneficial effect produced under preferred implementation: Supporting real-time switching in USB full-speed mode. Working principle: Low-impedance switching matrix reduces signal attenuation.

[0008] 6. Technical problem solved in the preferred implementation: Ensuring I²C interface compatibility. Technical solution adopted in the preferred implementation: The I²C interface circuit includes a level converter and an I²C protocol engine. The input of the level converter is connected to a switching array, and the output is connected to the I²C protocol engine. The output of the I²C protocol engine is connected to the touch signal processing module. Beneficial effect produced in the preferred implementation: Supports automatic 1.8V / 3.3V level adaptation. Working principle: The level converter dynamically adjusts according to the bus voltage.

[0009] 7. Technical problem solved under preferred implementation: Achieving high-speed USB communication. Technical solution adopted under preferred implementation: The USB interface circuit includes a USBPHY and a USB protocol stack. The input of the USBPHY is connected to a switching array, and the output is connected to the USB protocol stack. The output of the USB protocol stack is connected to a touch signal processing module. Beneficial effect produced under preferred implementation: Support for 12Mbps full-speed transmission. Working principle adopted: Decoupled design of physical layer and protocol layer.

[0010] 8. Technical problem solved under preferred implementation: Improving touch signal processing accuracy. Technical solution adopted under preferred implementation: The touch signal processing module includes an ADC, a digital filter, and a coordinate calculation unit. The input of the ADC is connected to an I²C interface circuit and a USB interface circuit, and the output is connected to the digital filter. The output of the digital filter is connected to the coordinate calculation unit. Beneficial effect produced under preferred implementation: The coordinate reporting rate can reach 200Hz. Working principle: A 12-bit ADC combined with a digital filtering algorithm.

[0011] 9. Technical problem solved under preferred implementation conditions: Optimizing power management efficiency. Technical solution adopted under preferred implementation conditions: The power management module includes an LDO and a DC-DC converter; the LDO output voltage is 1.8V±2%, and the DC-DC output voltage is 3.3V±2%. Beneficial effect produced under preferred implementation conditions: Overall power consumption is less than 50mW. Working principle employed: Multi-voltage domain zoned power supply.

[0012] 10. Technical problem solved under preferred implementation: Achieving a compact package design. Technical solution adopted under preferred implementation: The integrated circuit uses a QFN-48 package with dimensions of 7mm × 7mm × 0.9mm. Beneficial effect produced under preferred implementation: 40% reduction in board area. Operating principle: High-density pin layout and thermal pad design. Attached Figure Description

[0013] Figure 1 This is a block diagram of the overall structure of the present invention;

[0014] Figure 2 This is a schematic diagram of the protocol detection module circuit;

[0015] Figure 3 This is a schematic diagram of the protocol switching controller circuit;

[0016] Figure 4 This is a schematic diagram of the I²C interface circuit;

[0017] Figure 5 This is a schematic diagram of a USB interface circuit.

[0018] Figure 6 This is a circuit diagram of the touch signal processing module;

[0019] Figure 7 This is a circuit diagram of the power management module.

[0020] 1. Protocol detection module; 2. Protocol switching controller; 3. I²C interface circuit; 4. USB interface circuit; 5. Touch signal processing module; 6. Power management module; 11. Voltage comparator; 12. Frequency detection unit; 13. Protocol feature recognition unit; 21. State machine; 22. Switch array; 31. Level converter; 32. I²C protocol engine; 41. USBPHY; 42. USB protocol stack; 51. ADC; 52. Digital filter; 53. Coordinate calculation unit; 61. LDO; 62. DC-DC converter. Detailed Implementation

[0021] Combined with appendix Figure 1-7 This section describes in detail the specific implementation methods of this technology.

[0022] Example 1 (Basic Implementation)

[0023] This embodiment provides a basic implementation scheme for adaptive switching of multi-protocol interfaces:

[0024] A multi-protocol interface adaptive switching touch screen driver integrated circuit includes a protocol detection module 1, a protocol switching controller 2, an I²C interface circuit 3, a USB interface circuit 4, a touch signal processing module 5, and a power management module 6. The input terminal of the protocol detection module 1 is connected to an external interface bus, and the output terminal is connected to the protocol switching controller 2. The output terminals of the protocol switching controller 2 are respectively connected to the I²C interface circuit 3 and the USB interface circuit 4. The output terminals of both the I²C interface circuit 3 and the USB interface circuit 4 are connected to the touch signal processing module 5. The power management module 6 supplies power to each functional module.

[0025] 1. Protocol Detection: Voltage comparator 11 monitors the interface bus voltage in real time. When a valid level of 1.8V–3.3V is detected, frequency detection unit 12 is activated to analyze the signal frequency characteristics. Signals between 100kHz and 1MHz are identified as I²C protocol, and signals between 1.5MHz and 12MHz are identified as USB protocol.

[0026] 2. Protocol Switching: After receiving the protocol identification result, state machine 21 controls the switching array 22 to conduct the corresponding path within 20ns. When the I²C path is conducted, level converter 31 automatically matches the bus voltage, and I²C protocol engine 32 processes communication data; when the USB path is conducted, USBPHY 41 completes signal conditioning, and USB protocol stack 42 parses data packets.

[0027] 3. Touch processing: ADC51 acquires touch signals at 12-bit resolution, digital filter 52 uses FIR structure to filter out noise, and coordinate calculation unit 53 outputs touch coordinates every 5ms.

[0028] 4. Power Management: The LDO61 provides a core voltage of 1.8V, and the DC-DC62 provides a 3.3V interface power supply. The total operating current is 15mA@3.3V.

[0029] Example 2 (Industrial-grade implementation)

[0030] This embodiment is optimized for industrial environments:

[0031] 1. Enhanced Protocol Detection: The protocol feature recognition unit 13 adds a CRC check function, maintaining a 99.99% recognition accuracy within a temperature range of -40℃ to 85℃. The voltage comparator 11 adopts a hysteresis design, with an anti-interference capability of ±200mV.

[0032] 2. Fast switching mechanism: The switching array 22 uses GaN devices, reducing the switching time to 50ns. The state machine 21 adds an error recovery mechanism, which can automatically retry 3 times when communication is interrupted.

[0033] 3. High-precision touch processing: The ADC51 is upgraded to 14-bit, the coordinate calculation unit 53 supports simultaneous 10-point touch recognition, and the report rate is increased to 500Hz. The digital filter 52 adopts an adaptive algorithm, which can dynamically adjust parameters according to the noise environment.

[0034] 4. Enhanced power management: The DC-DC62 features overcurrent protection, with an instantaneous current withstand capability of up to 2A. The LDO61 employs a dual-redundant design and supports hot-swappable power supply switching.

[0035] Example 3 (Implementation Method for In-Vehicle Application)

[0036] This embodiment meets the AEC-Q100 certification requirements:

[0037] 1. Protocol Expansion: An SPI protocol identification function is added to the protocol detection module 1, supporting a 20MHz clock frequency. The switch array 22 is expanded to 3 outputs, and a new SPI interface circuit is added.

[0038] 2. Environmental adaptability: The entire chip operates over a temperature range of -40℃ to 125℃, and all MOSFET devices utilize SOI technology. Power management module 6 integrates a watchdog timer for automatic reset in abnormal conditions.

[0039] 3. Anti-interference design: The USBPHY41 incorporates a common-mode choke, providing ESD protection up to 8kV. The I²C interface circuit 3 adopts a differential transmission structure, improving EMI immunity by 20dB.

[0040] 4. Reliability Verification: Passed 1000 thermal shock cycles (-40℃ ←→ 125℃), with a communication bit error rate of <1e-9. No performance degradation after 1000 hours of continuous operation.

[0041] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A touchscreen driver integrated circuit with adaptive switching of multiple protocol interfaces, characterized in that: The system includes a protocol detection module (1), a protocol switching controller (2), an I²C interface circuit (3), a USB interface circuit (4), a touch signal processing module (5), and a power management module (6). The input of the protocol detection module (1) is connected to an external interface bus, and the output is connected to the protocol switching controller (2). The output of the protocol switching controller (2) is connected to the I²C interface circuit (3) and the USB interface circuit (4), respectively. The outputs of the I²C interface circuit (3) and the USB interface circuit (4) are both connected to the touch signal processing module (5). The power management module (6) supplies power to each functional module.

2. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The protocol detection module (1) includes a voltage comparator (11), a frequency detection unit (12), and a protocol feature recognition unit (13). The input of the voltage comparator (11) is connected to an external interface bus, and the output is connected to the frequency detection unit (12). The output of the frequency detection unit (12) is connected to the protocol feature recognition unit (13).

3. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 2, characterized in that: The reference voltage of the voltage comparator (11) is set to 1.8V ± 5%, and the operating frequency range of the frequency detection unit (12) is 100kHz to 12MHz.

4. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The protocol switching controller (2) includes a state machine (21) and a switching array (22). The input of the state machine (21) is connected to the protocol detection module (1), and the output is connected to the switching array (22). The output of the switching array (22) is connected to the I²C interface circuit (3) and the USB interface circuit (4) respectively.

5. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 4, characterized in that: The switching time of the switching array (22) is less than 100 ns and the on-resistance is less than 5 Ω.

6. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The I²C interface circuit (3) includes a level converter (31) and an I²C protocol engine (32). The input of the level converter (31) is connected to the switching array (22), and the output is connected to the I²C protocol engine (32). The output of the I²C protocol engine (32) is connected to the touch signal processing module (5).

7. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The USB interface circuit (4) includes a USBPHY (41) and a USB protocol stack (42). The input end of the USBPHY (41) is connected to the switching array (22), and the output end is connected to the USB protocol stack (42). The output end of the USB protocol stack (42) is connected to the touch signal processing module (5).

8. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The touch signal processing module (5) includes an ADC (51), a digital filter (52), and a coordinate calculation unit (53). The input terminal of the ADC (51) is connected to the I²C interface circuit (3) and the USB interface circuit (4), and the output terminal is connected to the digital filter (52). The output terminal of the digital filter (52) is connected to the coordinate calculation unit (53).

9. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The power management module (6) includes an LDO (61) and a DC-DC (62), with the LDO (61) having an output voltage of 1.8V ± 2% and the DC-DC (62) having an output voltage of 3.3V ± 2%.

10. The touchscreen driver integrated circuit with multi-protocol interface adaptive switching according to claim 1, characterized in that: The integrated circuit is packaged in a QFN-48 package and measures 7mm × 7mm × 0.9mm.

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