Display screen PCBA circuit and LED display screen

Abstract

The invention provides a display screen PCBA circuit and an LED display screen. The display screen PCBA circuit comprises an input interface, a signal protection circuit, a plurality of integrated circuits, a voltage stabilizing circuit, a booster circuit, an anti-surge circuit, a filter circuit and a GAMMA circuit. The input end of the signal protection circuit is connected with the input interface, and the signal protection circuit is used for protecting a signal line output by the input interface from being influenced by electrostatic discharge and electrical overstress; the voltage stabilizing circuit is used for stabilizing the voltage input by the input interface; the booster circuit is used for boosting the stabilized voltage to a specific voltage level required by the liquid crystal display screen; the input end of the anti-surge circuit is connected with the output end of the booster circuit, and the anti-surge circuit is used for preventing voltage surge from damaging the circuit; and the input ends of the integrated circuits are respectively connected with the output ends of the signal protection circuit and the anti-surge circuit, so that the stable work of the liquid crystal display is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of display screens, and in particular relates to a display screen PCBA circuit and an LED display screen. Background Art

[0002] As a daily means of transportation, the development of in-vehicle electronic products has a history of more than 120 years. With the popularization of automobiles, in-vehicle visual products such as MP4 players, in-vehicle DVDs and navigation systems have gradually become the focus of public attention. One of the core components of these products is the in-vehicle LCD display, whose working stability is crucial to the user experience. In order to meet market demand, the size of LCD displays has been upgraded from 3-6 inches to 7-17 inches.

[0003] However, with the increase in size and enhancement of functions, relying solely on the voltage (AVDD, AVEE, VGH, VGL) required to drive the LCD screen can no longer guarantee the stability of the LCD screen IC after long-term operation. This may lead to increased power consumption and problems such as flickering and black screen. In order to ensure the stable operation of the LCD display, a DC-DC module on the PCBA (printed circuit board assembly) is designed to provide the various voltage signals required for LCD driving. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a display screen PCBA circuit and an LED display screen, which are used to solve the technical problems in the prior art.

[0005] On the one hand, the invention provides the following technical solution, a display PCBA circuit, including:

[0006] Input interface, signal protection circuit, multiple integrated circuits, voltage stabilization circuit, boost circuit, surge protection circuit, filter circuit and GAMMA circuit;

[0007] The input end of the signal protection circuit is connected to the input interface, and the signal protection circuit is used to protect the signal line output by the input interface from electrostatic discharge and electrical overstress;

[0008] The input end of the voltage stabilizing circuit is connected to the input interface, and the voltage stabilizing circuit is used to stabilize the voltage input by the input interface;

[0009] The input end of the boost circuit is connected to the output end of the voltage stabilizing circuit, and the boost circuit is used to increase the stabilized voltage to a specific voltage level required by the liquid crystal display;

[0010] The input end of the surge protection circuit is connected to the output end of the boost circuit, and the surge protection circuit is used to prevent voltage surges from causing damage to the circuit;

[0011] The input ends of the multiple integrated circuits are respectively connected to the signal protection circuit and the output ends of the surge protection circuit, and the multiple integrated circuits are connected in sequence. The filter circuit and the GAMMA circuit are connected between two adjacent integrated circuits. The multiple integrated circuits are responsible for coordinating and managing all circuits. The filter circuit is used to remove noise from the signal input by the input interface, and the GAMMA circuit is used to adjust the amplitude or shape of the signal.

[0012] Compared with the prior art, the beneficial effects of the present application are: through the coordination of signal protection circuits, multiple integrated circuits, voltage stabilization circuits, boost circuits, surge protection circuits, filtering circuits and GAMMA circuits, the liquid crystal display can be effectively started and stable operation can be ensured, thereby improving the overall performance and user experience of vehicle-mounted electronic products.

[0013] Further, the voltage stabilizing circuit includes a voltage stabilizing chip, a first capacitor, a first resistor, a second resistor, a first diode, a third resistor, a fourth resistor, a second capacitor, a third capacitor, a first inductor, a fourth capacitor and a fifth capacitor;

[0014] The first pin of the voltage stabilizing chip is connected to the first capacitor and the first resistor in sequence, the third pin of the voltage stabilizing chip is connected to the second resistor, the fifth pin of the voltage stabilizing chip is connected to the first diode, the third resistor and the fourth resistor in sequence, one end of the second capacitor and the third capacitor are respectively connected between the first diode and the third resistor, the other ends of the second capacitor and the third capacitor are respectively grounded, one end of the first inductor is connected between the fifth pin of the voltage stabilizing chip and the first diode, the other end of the first inductor is connected to the fourth capacitor, the sixth pin and the seventh pin of the voltage stabilizing chip are respectively connected between the fourth capacitor and the first inductor, and the eighth pin of the voltage stabilizing chip is connected to the fifth capacitor, wherein the second pin of the voltage stabilizing chip is connected between the third resistor and the fourth resistor.

[0015] Furthermore, the boost circuit includes a boost control circuit, a VGL circuit, a VGH circuit, a VSP circuit and a VSN circuit;

[0016] The boost control circuit is respectively connected to the boost control circuit, the VGL circuit, the VGH circuit, the VSP circuit and the VSN circuit through a boost chip of the boost control circuit.

[0017] Further, the boost control circuit includes a second inductor, a fifth resistor, a sixth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a seventh diode;

[0018] The seventh diode, the second inductor and the fifth resistor are connected to the first pin of the boost chip, one end of the sixth resistor is respectively connected to the fourth pin, the eighth pin and the tenth pin of the boost chip, the other end of the sixth resistor is connected between the second inductor and the fifth resistor, one end of the sixth capacitor is connected between the second inductor and the fifth resistor, the other end of the sixth capacitor is grounded, one end of the seventh capacitor is connected between the fourth pin of the boost chip and the sixth resistor, the other end of the seventh capacitor is grounded, the eighth capacitor is connected to the twenty-first pin of the boost chip, and the ninth capacitor is connected to the eighteenth pin of the boost chip.

[0019] Further, the VGL circuit includes a voltage input terminal, a seventh resistor, a ninth capacitor, a third diode, a first transistor, a seventh resistor, a tenth capacitor, an eighth resistor, a fourth diode, a ninth resistor, a tenth resistor and an eleventh capacitor;

[0020] The voltage input end is sequentially connected to the third diode, the ninth capacitor, the seventh resistor and the twenty-fourth pin of the boost chip, the first end of the third diode is respectively connected to the first transistor, the seventh resistor and the VGL voltage output end, one end of the tenth capacitor is connected between the first transistor and the third diode, the other end of the tenth capacitor is grounded, one end of the eighth resistor is connected between the first transistor and the third diode, the third end of the fourth diode is connected to the first transistor, the first end of the fourth diode is grounded, one end of the ninth resistor is connected between the third end of the fourth diode and the first transistor, one end of the ninth resistor is connected to the other end connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the third end of the fourth diode, one end of the eleventh capacitor is connected between the seventh resistor and the VGL voltage output end, wherein the second end of the fourth diode is connected between the ninth resistor and the tenth resistor, and the other end of the eighth resistor is connected to the third end of the fourth diode.

[0021] Further, the VGH circuit includes an eleventh resistor, a twelfth capacitor, a second diode, a second transistor, a twelfth resistor, a twelfth resistor, a thirteenth capacitor, a fifth diode, a fourteenth capacitor, a fifteenth capacitor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth capacitor, a sixth diode and a sixteenth capacitor;

[0022] The twenty-fourth pin of the boost chip is sequentially connected to the eleventh resistor, the twelfth capacitor, the second diode, the second transistor, the twelfth resistor and the VGH voltage output terminal;

[0023] One end of the twelfth resistor is connected to the thirteenth capacitor, the fifth diode and the first end of the second diode in sequence, the other end of the twelfth resistor is connected to the twenty-fourth pin of the boost chip, one end of the fourteenth capacitor is connected between the second end of the fifth diode and the first end of the second diode, the other end of the fourteenth capacitor is grounded, and the first end of the fifth diode is connected to the twenty-third pin of the boost chip;

[0024] One end of the thirteenth resistor is connected to the first end of the sixth diode, the other end of the thirteenth resistor is connected between the second diode and the second transistor, one end of the fourteenth resistor is connected between the second transistor and the twelfth resistor, the other end of the fourteenth resistor is connected to the fifteenth resistor, one end of the sixteenth capacitor is connected to the first end of the sixth diode, the other end of the sixteenth capacitor is connected between the fourteenth resistor and the fifteenth resistor, the second end of the sixth diode is connected between the fourteenth resistor and the fifteenth resistor, and one end of the second transistor is connected to the first end of the sixth diode.

[0025] Further, the VSP circuit includes a seventeenth capacitor, a sixteenth resistor, a VSP voltage output terminal, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, an eighteenth capacitor and a nineteenth capacitor;

[0026] The twenty-third pin of the boost chip is connected to the sixteenth resistor and the VSP voltage output terminal in sequence, one end of the seventeenth capacitor is connected to the twenty-third pin of the boost chip, the other end of the seventeenth capacitor is grounded, one end of the seventeenth resistor is connected between the twenty-third pin of the boost chip and the sixteenth resistor, the other end of the seventeenth resistor is connected to one end of the eighteenth resistor, the other end of the eighteenth resistor is grounded, one end of the nineteenth resistor is connected between the twenty-third pin of the boost chip and the sixteenth resistor, one end of the nineteenth resistor is connected to one end of the eighteenth capacitor, the other end of the eighteenth capacitor is connected between the seventeenth resistor and the eighteenth resistor and the twenty-second pin of the boost chip in sequence, one end of the nineteenth capacitor is connected between the sixteenth resistor and the VSP voltage output terminal, and the other end of the nineteenth capacitor is grounded.

[0027] Further, the VSN circuit includes a twentieth capacitor, a twentieth resistor, a twenty-first capacitor, a twenty-first resistor, a seventh diode, a twenty-second resistor, a VSN voltage output terminal, a third inductor and a twenty-second capacitor;

[0028] The seventeenth pin of the boost chip is connected to the twentieth resistor and the second-first resistor in sequence, the thirteenth pin of the boost chip is connected to the seventh diode, the second-second resistor and the VSN voltage output end in sequence, the fourteenth pin of the boost chip is connected to the third inductor, the fifteenth pin of the boost chip is connected between the seventh diode and the second-second resistor, the sixteenth pin of the boost chip is connected between the twentieth resistor and the second-first resistor and one end of the second-first capacitor in sequence, the other end of the second-first capacitor is connected between the seventh diode and the second-second resistor and the second-second capacitor in sequence, and the end of the second-first resistor away from the twentieth resistor is connected between the seventh diode and the second-second resistor.

[0029] Furthermore, a termination resistor is provided between two adjacent integrated circuits in one group, and a differential resistance termination resistor is provided between two adjacent integrated circuits in two groups.

[0030] In a second aspect, the invention provides the following technical solution: an LED display screen, comprising the above-mentioned display screen PCBA circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A circuit block diagram of a display screen PCBA circuit provided by one embodiment of the present invention;

[0033] Figure 2 A circuit layout diagram of a display screen PCBA circuit provided by one embodiment of the present invention;

[0034] Figure 3 A circuit diagram of a voltage stabilizing circuit provided in one embodiment of the present invention;

[0035] Figure 4 A circuit block diagram of a boost circuit provided in one embodiment of the present invention;

[0036] Figure 5 A circuit diagram of a voltage boost circuit provided in one embodiment of the present invention;

[0037] Figure 6 A circuit diagram of a boost control circuit provided in one embodiment of the present invention;

[0038] Figure 7A circuit diagram of a VGL circuit provided in one embodiment of the present invention;

[0039] Figure 8 A circuit diagram of a VGH circuit provided by one embodiment of the present invention;

[0040] Fig. 9 A circuit diagram of a VSP circuit provided in one embodiment of the present invention;

[0041] Fig.10 A circuit diagram of a VSN circuit provided in one embodiment of the present invention;

[0042] Fig.11 A circuit diagram of a hardware selection circuit provided in one embodiment of the present invention;

[0043] Fig.12 A circuit diagram of a surge simulation circuit provided in one embodiment of the present invention;

[0044] Fig.13 A circuit diagram of a boost control circuit provided in another embodiment of the present invention.

[0045] Explanation of main component symbols: 1. Input interface; 2. Signal protection circuit; 3. Integrated circuit; 4. Voltage stabilization circuit; 5. Boost circuit; 6. Surge protection circuit; 7. Filter circuit; 8. GAMMA circuit; 9. Termination resistor; 10. Differential resistor termination resistor; 11. Hardware selection circuit; 12. Backlight constant current circuit; 13. Boost control circuit; 14. VGL circuit; 15. VGH circuit; 16. VSP circuit; 17. VSN circuit; 18. LCD liquid crystal module 19. Connection IC; 20. PCBA board.

[0046] The embodiments of the present invention will be further described below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout are the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0048] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] In the embodiments of the present invention, please refer to Figure 1 to Figure 2 As shown, a display screen PCBA circuit includes: an input interface 1, a signal protection circuit 2, multiple integrated circuits 3, a voltage stabilizing circuit 4, a boost circuit 5, a surge protection circuit 6, a filter circuit 7 and a GAMMA circuit 8;

[0051] The input end of the signal protection circuit is connected to the input interface, and the signal protection circuit is used to protect the signal line output by the input interface from electrostatic discharge and electrical overstress;

[0052] The input end of the voltage stabilizing circuit is connected to the input interface, and the voltage stabilizing circuit is used to stabilize the voltage input by the input interface;

[0053] The input end of the boost circuit is connected to the output end of the voltage stabilizing circuit, and the boost circuit is used to increase the stabilized voltage to a specific voltage level required by the liquid crystal display;

[0054] The input end of the surge protection circuit is connected to the output end of the boost circuit, and the surge protection circuit is used to prevent voltage surges from causing damage to the circuit;

[0055] The input ends of the multiple integrated circuits are respectively connected to the signal protection circuit and the output ends of the surge protection circuit, and the multiple integrated circuits are connected in sequence. The filter circuit and the GAMMA circuit are connected between two adjacent integrated circuits. The multiple integrated circuits are responsible for coordinating and managing all circuits. The filter circuit is used to remove noise from the signal input by the input interface, and the GAMMA circuit is used to adjust the amplitude or shape of the signal.

[0056] In this embodiment, the plurality of integrated circuits include a master IC (integrated circuit) and two slave ICs (Slave1 IC and Slave2 IC). The input interface is used to receive operating voltage, signal input and backlight input. These inputs provide necessary power and signals for the circuit.

[0057] It is worth mentioning that through the cooperation of signal protection circuits, multiple integrated circuits, voltage stabilization circuits, voltage boost circuits, surge protection circuits, filtering circuits and GAMMA circuits, the stable operation of the LCD display can be effectively started and guaranteed, thereby improving the overall performance and user experience of vehicle-mounted electronic products.

[0058] See also Figure 3 As shown, specifically, the voltage stabilizing circuit includes a voltage stabilizing chip (U1, MP1542), a first capacitor (C75), a first resistor (R71), a second resistor (R72), a first diode (D12, RBI6OM), a third resistor (R73), a fourth resistor (R74), a second capacitor (C78), a third capacitor (C79), a first inductor (L7), a fourth capacitor (C77) and a fifth capacitor (C76);

[0059] The first pin of the voltage stabilizing chip is connected to the first capacitor and the first resistor in sequence, the third pin of the voltage stabilizing chip is connected to the second resistor, the fifth pin of the voltage stabilizing chip is connected to the first diode, the third resistor and the fourth resistor in sequence, one end of the second capacitor and the third capacitor is connected between the first diode and the third resistor respectively, the other end of the second capacitor and the third capacitor is grounded respectively, one end of the first inductor is connected between the fifth pin of the voltage stabilizing chip and the first diode, the other end of the first inductor is connected to the fourth capacitor, the sixth pin and the seventh pin of the voltage stabilizing chip are connected between the fourth capacitor and the first inductor respectively, the eighth pin of the voltage stabilizing chip is connected to the fifth capacitor, wherein the second pin of the voltage stabilizing chip is connected between the third resistor and the fourth resistor. VCC = VFB*(1+R73 / R74) = 1.25*(1+5.1K / 3K).

[0060] See also Figure 4 and Figure 5 As shown, specifically, the boost circuit 5 includes a boost control circuit 13, a VGL circuit 14, a VGH circuit 15, a VSP circuit 16 and a VSN circuit 17;

[0061] The boost control circuit is respectively connected to the boost control circuit, the VGL circuit, the VGH circuit, the VSP circuit and the VSN circuit through a boost chip of the boost control circuit.

[0062] See also Figure 6 As shown, more specifically, the boost control circuit includes a second inductor (L1), a fifth resistor (R33), a sixth resistor (R38), a sixth capacitor (C49), a seventh capacitor (C53), an eighth capacitor (C57), a ninth capacitor (C58) and a seventh diode (D3);

[0063] The seventh diode, the second inductor and the fifth resistor are connected to the first pin of the boost chip, one end of the sixth resistor is respectively connected to the fourth pin, the eighth pin and the tenth pin of the boost chip, the other end of the sixth resistor is connected between the second inductor and the fifth resistor, one end of the sixth capacitor is connected between the second inductor and the fifth resistor, the other end of the sixth capacitor is grounded, one end of the seventh capacitor is connected between the fourth pin of the boost chip and the sixth resistor, the other end of the seventh capacitor is grounded, the eighth capacitor is connected to the twenty-first pin of the boost chip, and the ninth capacitor is connected to the eighteenth pin of the boost chip.

[0064] See also Figure 7 As shown, more specifically, the VGL circuit includes a voltage input terminal, a seventh resistor (R8), a ninth capacitor (C40), a third diode (D1), a first transistor (Q1), a seventh resistor (R50), a tenth capacitor (C42), an eighth resistor (R11), a fourth diode (D2), a ninth resistor (R14), a tenth resistor (R27) and an eleventh capacitor (C41);

[0065] The voltage input end is sequentially connected to the third diode, the ninth capacitor, the seventh resistor and the twenty-fourth pin of the boost chip, the first end of the third diode is respectively connected to the first transistor, the seventh resistor and the VGL voltage output end, one end of the tenth capacitor is connected between the first transistor and the third diode, the other end of the tenth capacitor is grounded, one end of the eighth resistor is connected between the first transistor and the third diode, the third end of the fourth diode is connected to the first transistor, the first end of the fourth diode is grounded, one end of the ninth resistor is connected between the third end of the fourth diode and the first transistor, one end of the ninth resistor is connected to the other end connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the third end of the fourth diode, one end of the eleventh capacitor is connected between the seventh resistor and the VGL voltage output end, wherein the second end of the fourth diode is connected between the ninth resistor and the tenth resistor, and the other end of the eighth resistor is connected to the third end of the fourth diode.

[0066] See also Figure 8As shown, more specifically, the VGH circuit includes an eleventh resistor (R30), a twelfth capacitor (C43), a second diode (D4), a second transistor (Q2), a twelfth resistor (R49), a twelfth resistor (R34), a thirteenth capacitor (C46), a fifth diode (D5), a fourteenth capacitor (C48), a fifteenth capacitor (C44), a thirteenth resistor (R31), a fourteenth resistor (R32), a fifteenth resistor (R35), a sixteenth capacitor (C47), a sixth diode (D6) and a sixteenth capacitor (C45);

[0067] The twenty-fourth pin of the boost chip is sequentially connected to the eleventh resistor, the twelfth capacitor, the second diode, the second transistor, the twelfth resistor and the VGH voltage output terminal;

[0068] One end of the twelfth resistor is connected to the thirteenth capacitor, the fifth diode and the first end of the second diode in sequence, the other end of the twelfth resistor is connected to the twenty-fourth pin of the boost chip, one end of the fourteenth capacitor is connected between the second end of the fifth diode and the first end of the second diode, the other end of the fourteenth capacitor is grounded, and the first end of the fifth diode is connected to the twenty-third pin of the boost chip;

[0069] One end of the thirteenth resistor is connected to the first end of the sixth diode, the other end of the thirteenth resistor is connected between the second diode and the second transistor, one end of the fourteenth resistor is connected between the second transistor and the twelfth resistor, the other end of the fourteenth resistor is connected to the fifteenth resistor, one end of the sixteenth capacitor is connected to the first end of the sixth diode, the other end of the sixteenth capacitor is connected between the fourteenth resistor and the fifteenth resistor, the second end of the sixth diode is connected between the fourteenth resistor and the fifteenth resistor, and one end of the second transistor is connected to the first end of the sixth diode.

[0070] See also Fig. 9 As shown, more specifically, the VSP circuit includes a seventeenth capacitor (C50), a sixteenth resistor (R51), a VSP voltage output terminal, a seventeenth resistor (R36), an eighteenth resistor (R39), a nineteenth resistor (R37), an eighteenth capacitor (C52) and a nineteenth capacitor (C51);

[0071] The 23rd pin of the boost chip is connected to the 16th resistor (R51) and the VSP voltage output terminal in sequence, one end of the 17th capacitor is connected to the 23rd pin of the boost chip, the other end of the 17th capacitor is grounded, one end of the 17th resistor is connected between the 23rd pin of the boost chip and the 16th resistor, the other end of the 17th resistor is connected to one end of the 18th resistor, the other end of the 18th resistor is grounded, one end of the 19th resistor is connected between the 23rd pin of the boost chip and the 16th resistor, one end of the 19th resistor is connected to one end of the 18th capacitor, the other end of the 18th capacitor is connected between the 17th resistor and the 18th resistor and the 22nd pin of the boost chip in sequence, one end of the 19th capacitor is connected between the 16th resistor (R51) and the VSP voltage output terminal, and the other end of the 19th capacitor is grounded. The voltage of the VSP voltage output terminal is VSP=VFB*(1+R36 / R39); VFBP=1.25V.

[0072] See also Fig.10 As shown, more specifically, the VSN circuit includes a twentieth capacitor (C54), a twentieth resistor (R40), a second first capacitor (C55), a second first resistor (R41), a seventh diode (D7), a second second resistor (R7), a VSN voltage output terminal, a third inductor (L2) and a second second capacitor (C56);

[0073] The seventeenth pin of the boost chip is connected to the twentieth resistor (R40) and the second first resistor (R41) in sequence, the thirteenth pin of the boost chip is connected to the seventh diode (D7), the second second resistor (R7) and the VSN voltage output terminal in sequence, the fourteenth pin of the boost chip is connected to the third inductor, the fifteenth pin of the boost chip is connected between the seventh diode and the second second resistor, the sixteenth pin of the boost chip is connected to the twentieth resistor (R40) and the second first resistor and one end of the second first capacitor in sequence, the other end of the second first capacitor is connected to the seventh diode and the second second resistor and the second second capacitor in sequence, and the end of the second first resistor away from the twentieth resistor is connected between the seventh diode and the second second resistor. VSN = VFBN-(VREF-VFBN)*41 / R40; VFBN = 0.25V, VREF = 1.25V, VSN = -6.5V.

[0074] Furthermore, a termination resistor 9 is provided between two adjacent integrated circuits in one group, and a differential resistance termination resistor 10 is provided between two adjacent integrated circuits in the second group. The termination resistor and the differential resistance termination resistor are used to match the characteristic impedance of the transmission line, reduce signal reflection, and improve signal integrity.

[0075] In this embodiment, the PCBA assembly further includes a hardware selection circuit 11, which is connected to the main IC (integrated circuit). The hardware selection circuit initializes the circuit according to the hardware configuration, such as scanning direction, chip selection and BIST selection. The PCBA assembly further includes a backlight constant current circuit 12 connected to the input interface, which provides a stable current for the backlight module to ensure the uniformity and stability of the backlight. The filter circuit and the GAMMA circuit are arranged between the main IC and the slave IC to optimize the display effect.

[0076] The specific signal processing flow is as follows:

[0077] 1. Signal input / control PIN / VCC input: receive external signals and power;

[0078] 2. VSP / VSN / VGL / VGH boost: These are the driving voltages for the liquid crystal display (LCD). VSP (Source Positive Voltage) and VSN (Source Negative Voltage) are used to control the light transmittance of the liquid crystal, while VGH and VGL are used to control the switching state of the liquid crystal. VSP and VSN provide a positive voltage and a negative voltage to charge the capacitor that controls the light transmittance of the pixel. VGH and VGL control the opening and closing of the switch tube on the pixel. A high level of VGH turns on the switch tube, and a negative voltage of VGL turns off the switch tube.

[0079] 3.VCC voltage regulator circuit / differential signal TVS protection: The voltage regulator circuit ensures the stability of the VCC voltage to prevent fluctuations in the power supply system from affecting circuit performance. TVS (Transient Voltage Suppression) diodes are used to protect differential signals from damage by ESD (Electrostatic Discharge) and EOS (Electrical Overstress).

[0080] 4. Reset and standby circuit: This circuit is used to reset the LCD screen and select the timing of the signal start.

[0081] 5. Surge protection circuit: used to prevent voltage surges and protect circuits from voltage spikes.

[0082] 6.SOURCE circuit: This is the part of the circuit which is used to generate the VSP and VSN voltages.

[0083] 7. Differential signal enhancement circuit: enhances the strength of the differential signal and improves the signal's anti-interference ability.

[0084] 8.GATE circuit: controls VGH and VGL signals to drive the gate of the LCD display.

[0085] 9. LCD circuit: The final LCD display driver circuit receives the processed signal and controls the display of the LCD screen.

[0086] It is worth mentioning that the voltage stabilization circuit diagram is used to stabilize the input voltage (the voltage at which the IC works) 3.3V (because the power supply system may be higher or lower or exceed the specification). VGH / VGL is VGH and VGL are two voltage signals in the LCD display.

[0087] VGH (Gate High Voltage) is the driving voltage of the liquid crystal display, which is used to control the brightness and grayscale of the liquid crystal display. The VGH signal is generated by the driving circuit and is usually a positive voltage.

[0088] VGL (Gate Low Voltage) is another driving voltage of the LCD screen, which is used to control the refresh and switching of the LCD display. The VGL signal is also generated by the driving circuit and is usually a negative voltage.

[0089] The VGH and VGL signals play an important role in the driving process of the LCD display. By precisely controlling these two voltages, high-quality image display effects can be achieved.

[0090] VGH, VGL: The on / off voltage of the switch tube at the pixel point, added to the gate of the switch tube, VGH high level turns on to charge the pixel capacitor, and VGL negative voltage turns off the switch tube;

[0091] VSN, VSP: LCD driver power supply, which can charge the capacitor that controls the light transmittance of the pixel. One positive voltage and one negative voltage. Another method is to have only one positive voltage called AVDD.

[0092] The surge simulation circuit is designed to prevent ESD and EOS.

[0093] Reset and Standby: Reset the LCD screen and signal start selection.

[0094] After the differential signal comes out, it passes through the TVS tube for protection and then supplies the IC to work. The far end needs to have a differential signal resistor of 100 ohms ± 10 ohms and connect the termination resistor in the secondary IC. A 35 ohm resistor is connected in series in the differential signal to improve the eye diagram.

[0095] The PCBA layout diagram in this embodiment shows the actual physical layout, including the location, routing and connection methods of each component. The various areas in the layout diagram include the Source area, Gate area, main circuit area, differential resistor reservation, hardware selection area, surge protection area, reset and standby area, VCC voltage stabilization circuit area, VGL / VGH / VSP / VSN boost area, circuit external interface, signal electrostatic protection area and test points, all of which correspond to the functional modules in the circuit block diagram.

[0096] See also Fig.11 As shown, the hardware selection area (hardware selection circuit) includes: a 23rd resistor (R5), a 24th resistor (R6), a 25th resistor (R9), a 26th resistor (R10), a 27th resistor (R12), a 28th resistor (R13), a 29th resistor (R20), a 30th resistor (R21), a 31st resistor (R28), a 32nd resistor (R29) and a 33rd resistor (R53);

[0097] The second third resistor (R5) and the second fourth resistor (R6) are connected in series to form a combined resistor, the second fifth resistor (R9) and the second sixth resistor (R10) are connected in series to form a combined resistor, the second seventh resistor (R12) and the second eighth resistor (R13) are connected in series to form a combined resistor, the second ninth resistor (R20) and the thirtieth resistor (R21) are connected in series to form a combined resistor, the third first resistor (R28) and the third second resistor (R29) are connected in series to form a combined resistor, one end of all the combined resistors is connected in parallel to the third third resistor (R53) and grounded, and the other ends of all the combined resistors are connected in parallel to the input voltage (VCC).

[0098] See also Fig.12 As shown, the surge simulation circuit (surge protection zone) includes an eighth diode (T10), a ninth diode (T11), a tenth diode (T12), an eleventh diode (T13), a twelfth diode (T14), and a twelfth diode (T15);

[0099] One ends of the eighth diode (T10), the ninth diode (T11), the tenth diode (T12), the eleventh diode (T13), the twelfth diode (T14), and the twelfth diode (T15) are respectively connected to VCC, VSP, VSN, VCOM, VGL, VGH, and VSN, and the other ends thereof are connected in parallel and grounded.

[0100] In summary, a display PCBA circuit has the following effects:

[0101] Through the coordination of signal protection circuits, multiple integrated circuits, voltage stabilization circuits, voltage boost circuits, surge protection circuits, filtering circuits and GAMMA circuits, the LCD display can be effectively started and stable operation can be guaranteed, thereby improving the overall performance and user experience of vehicle-mounted electronic products.

[0102] See also Fig.13 As shown, another embodiment of the present invention further provides an LED display screen, which includes an LCD liquid crystal module 18, a connection IC 19 connected to the LCD liquid crystal module, a PCBA board 20 connected to the connection IC 19, and the above-mentioned display screen PCBA circuit, wherein the display screen PCBA circuit is arranged on the PCBA board 20.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A display PCBA circuit, characterized in that: include: Input interface, signal protection circuit, multiple integrated circuits, voltage stabilization circuit, boost circuit, surge protection circuit, filter circuit and GAMMA circuit; The input end of the signal protection circuit is connected to the input interface, and the signal protection circuit is used to protect the signal line output by the input interface from electrostatic discharge and electrical overstress; The input end of the voltage stabilizing circuit is connected to the input interface, and the voltage stabilizing circuit is used to stabilize the voltage input by the input interface; The input end of the boost circuit is connected to the output end of the voltage stabilizing circuit, and the boost circuit is used to increase the stabilized voltage to a specific voltage level required by the liquid crystal display; The input end of the surge protection circuit is connected to the output end of the boost circuit, and the surge protection circuit is used to prevent voltage surges from causing damage to the circuit; The input ends of the multiple integrated circuits are respectively connected to the signal protection circuit and the output ends of the surge protection circuit, and the multiple integrated circuits are connected in sequence. The filter circuit and the GAMMA circuit are connected between two adjacent integrated circuits. The multiple integrated circuits are responsible for coordinating and managing all circuits. The filter circuit is used to remove noise from the signal input by the input interface, and the GAMMA circuit is used to adjust the amplitude or shape of the signal.

2. The display screen PCBA circuit according to claim 1, characterized in that: The voltage stabilizing circuit includes a voltage stabilizing chip, a first capacitor, a first resistor, a second resistor, a first diode, a third resistor, a fourth resistor, a second capacitor, a third capacitor, a first inductor, a fourth capacitor and a fifth capacitor; The first pin of the voltage stabilizing chip is connected to the first capacitor and the first resistor in sequence, the third pin of the voltage stabilizing chip is connected to the second resistor, the fifth pin of the voltage stabilizing chip is connected to the first diode, the third resistor and the fourth resistor in sequence, one end of the second capacitor and the third capacitor are respectively connected between the first diode and the third resistor, the other ends of the second capacitor and the third capacitor are respectively grounded, one end of the first inductor is connected between the fifth pin of the voltage stabilizing chip and the first diode, the other end of the first inductor is connected to the fourth capacitor, the sixth pin and the seventh pin of the voltage stabilizing chip are respectively connected between the fourth capacitor and the first inductor, and the eighth pin of the voltage stabilizing chip is connected to the fifth capacitor, wherein the second pin of the voltage stabilizing chip is connected between the third resistor and the fourth resistor.

3. The display screen PCBA circuit according to claim 1, characterized in that: The boost circuit includes a boost control circuit, a VGL circuit, a VGH circuit, a VSP circuit and a VSN circuit; The boost control circuit is respectively connected to the boost control circuit, the VGL circuit, the VGH circuit, the VSP circuit and the VSN circuit through a boost chip of the boost control circuit.

4. The display screen PCBA circuit according to claim 3, characterized in that: The boost control circuit includes a second inductor, a fifth resistor, a sixth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a seventh diode; The seventh diode, the second inductor and the fifth resistor are connected to the first pin of the boost chip, one end of the sixth resistor is respectively connected to the fourth pin, the eighth pin and the tenth pin of the boost chip, the other end of the sixth resistor is connected between the second inductor and the fifth resistor, one end of the sixth capacitor is connected between the second inductor and the fifth resistor, the other end of the sixth capacitor is grounded, one end of the seventh capacitor is connected between the fourth pin of the boost chip and the sixth resistor, the other end of the seventh capacitor is grounded, the eighth capacitor is connected to the twenty-first pin of the boost chip, and the ninth capacitor is connected to the eighteenth pin of the boost chip.

5. The display screen PCBA circuit according to claim 3, characterized in that: The VGL circuit includes a voltage input terminal, a seventh resistor, a ninth capacitor, a third diode, a first transistor, a seventh resistor, a tenth capacitor, an eighth resistor, a fourth diode, a ninth resistor, a tenth resistor and an eleventh capacitor; The voltage input end is sequentially connected to the third diode, the ninth capacitor, the seventh resistor and the twenty-fourth pin of the boost chip, the first end of the third diode is respectively connected to the first transistor, the seventh resistor and the VGL voltage output end, one end of the tenth capacitor is connected between the first transistor and the third diode, the other end of the tenth capacitor is grounded, one end of the eighth resistor is connected between the first transistor and the third diode, the third end of the fourth diode is connected to the first transistor, the first end of the fourth diode is grounded, one end of the ninth resistor is connected between the third end of the fourth diode and the first transistor, one end of the ninth resistor is connected to the other end connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the third end of the fourth diode, one end of the eleventh capacitor is connected between the seventh resistor and the VGL voltage output end, wherein the second end of the fourth diode is connected between the ninth resistor and the tenth resistor, and the other end of the eighth resistor is connected to the third end of the fourth diode.

6. The display screen PCBA circuit according to claim 3, characterized in that: The VGH circuit includes an eleventh resistor, a twelfth capacitor, a second diode, a second transistor, a twelfth resistor, a twelfth resistor, a thirteenth capacitor, a fifth diode, a fourteenth capacitor, a fifteenth capacitor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth capacitor, a sixth diode and a sixteenth capacitor; The twenty-fourth pin of the boost chip is sequentially connected to the eleventh resistor, the twelfth capacitor, the second diode, the second transistor, the twelfth resistor and the VGH voltage output terminal; One end of the twelfth resistor is connected to the thirteenth capacitor, the fifth diode and the first end of the second diode in sequence, the other end of the twelfth resistor is connected to the twenty-fourth pin of the boost chip, one end of the fourteenth capacitor is connected between the second end of the fifth diode and the first end of the second diode, the other end of the fourteenth capacitor is grounded, and the first end of the fifth diode is connected to the twenty-third pin of the boost chip; One end of the thirteenth resistor is connected to the first end of the sixth diode, the other end of the thirteenth resistor is connected between the second diode and the second transistor, one end of the fourteenth resistor is connected between the second transistor and the twelfth resistor, the other end of the fourteenth resistor is connected to the fifteenth resistor, one end of the sixteenth capacitor is connected to the first end of the sixth diode, the other end of the sixteenth capacitor is connected between the fourteenth resistor and the fifteenth resistor, the second end of the sixth diode is connected between the fourteenth resistor and the fifteenth resistor, and one end of the second transistor is connected to the first end of the sixth diode.

7. The display screen PCBA circuit according to claim 3, characterized in that: The VSP circuit includes a seventeenth capacitor, a sixteenth resistor, a VSP voltage output terminal, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, an eighteenth capacitor and a nineteenth capacitor; The twenty-third pin of the boost chip is connected to the sixteenth resistor and the VSP voltage output terminal in sequence, one end of the seventeenth capacitor is connected to the twenty-third pin of the boost chip, the other end of the seventeenth capacitor is grounded, one end of the seventeenth resistor is connected between the twenty-third pin of the boost chip and the sixteenth resistor, the other end of the seventeenth resistor is connected to one end of the eighteenth resistor, the other end of the eighteenth resistor is grounded, one end of the nineteenth resistor is connected between the twenty-third pin of the boost chip and the sixteenth resistor, one end of the nineteenth resistor is connected to one end of the eighteenth capacitor, the other end of the eighteenth capacitor is connected between the seventeenth resistor and the eighteenth resistor and the twenty-second pin of the boost chip in sequence, one end of the nineteenth capacitor is connected between the sixteenth resistor and the VSP voltage output terminal, and the other end of the nineteenth capacitor is grounded.

8. The display screen PCBA circuit according to claim 3, characterized in that: The VSN circuit includes a 20th capacitor, a 20th resistor, a 21st capacitor, a 21st resistor, a 7th diode, a 22nd resistor, a VSN voltage output terminal, a third inductor and a 22nd capacitor; The seventeenth pin of the boost chip is connected to the twentieth resistor and the second-first resistor in sequence, the thirteenth pin of the boost chip is connected to the seventh diode, the second-second resistor and the VSN voltage output end in sequence, the fourteenth pin of the boost chip is connected to the third inductor, the fifteenth pin of the boost chip is connected between the seventh diode and the second-second resistor, the sixteenth pin of the boost chip is connected between the twentieth resistor and the second-first resistor and one end of the second-first capacitor in sequence, the other end of the second-first capacitor is connected between the seventh diode and the second-second resistor and the second-second capacitor in sequence, and the end of the second-first resistor away from the twentieth resistor is connected between the seventh diode and the second-second resistor.

9. The display screen PCBA circuit according to claim 1, characterized in that: A termination resistor is arranged between two adjacent integrated circuits in one group, and a differential resistance termination resistor is arranged between two adjacent integrated circuits in the second group.

10. An LED display screen, characterized in that: The invention comprises a display screen PCBA circuit as described in any one of claims 1 to 9.

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