Detection device of LVDS (Low Voltage Differential Signaling) matching resistor

Abstract

The utility model discloses a detection device of an LVDS (Low Voltage Differential Signaling) matching resistor, comprising a comparison circuit module which is used for comparing an LVDS signal of a display with a reference signal and outputting a corresponding comparison signal according to a comparison result and is provided with a detection input port, a reference input port and a comparison output port; the interface circuit module is used for being connected with an LVDS signal line of the display so as to obtain an LVDS signal of the display and providing the LVDS signal to the comparison circuit module, and the interface circuit module is electrically connected to a detection input port of the comparison circuit module; the reference circuit module is used for providing the reference signal for the comparison circuit module and is electrically connected to a reference input port of the comparison circuit module; and the indicating circuit module is used for controlling the brightness of an indicating lamp according to the comparison signal output by the comparison circuit module, and is electrically connected to a comparison output port of the comparison circuit module. The detection device is used for detecting and judging whether the matched resistor in the LVDS fails or not.

Description

Technical Field

[0001] The utility model relates to display technology, in particular to a detection device for LVDS matching resistance. Background Art

[0002] LVDS (Low Voltage Differential Signaling) is a differential signal technology used for high-speed data transmission. It transmits data through two complementary signal lines (one positive and one negative). This differential signal transmission method can effectively suppress common-mode noise and improve the anti-interference ability of signal transmission. It is widely used in display drivers, automotive electronics, industrial automation, medical electronics, communications, consumer electronics and other fields.

[0003] In terms of display driving, LVDS technology is widely used to connect data transmission between display panels and motherboards. It can convert digital signals on the motherboard into analog signals suitable for the display panel and achieve high-speed and stable data transmission.

[0004] In LVDS transmission, impedance matching of resistors is very important. It can ensure the transmission effect (reduce signal reflection and interference) and stability (avoid excessive signal reflection). When the matching resistor in LVDS fails, the entire display will display abnormally. Therefore, it is particularly important to test the display before shipment to determine whether the matching resistor in LVDS fails, so as to avoid defective products from flowing to customers and reduce customer complaints and claims. Utility Model Content

[0005] In order to solve the above-mentioned deficiencies in the prior art, the utility model provides a detection device for LVDS matching resistors, which is used to detect and determine whether the matching resistors in the LVDS are invalid.

[0006] The technical problem to be solved by the utility model is achieved through the following technical solutions:

[0007] A detection device for LVDS matching resistance, comprising:

[0008] A comparison circuit module, used for comparing the LVDS signal of the display with the reference signal and outputting a corresponding comparison signal according to the comparison result, having a detection input port, a reference input port and a comparison output port;

[0009] An interface circuit module, used to connect to the LVDS signal line of the display to obtain the LVDS signal of the display and provide it to the comparison circuit module, and electrically connected to the detection input port of the comparison circuit module;

[0010] A reference circuit module, used for providing the reference signal to the comparison circuit module, and electrically connected to a reference input port of the comparison circuit module;

[0011] The indicating circuit module is used to control the brightness of the indicating light according to the comparison signal output by the comparing circuit module, and is electrically connected to the comparison output port of the comparing circuit module.

[0012] Furthermore, the LVDS signal line includes a differential clock line group and multiple differential data line groups, the differential clock line group includes a complementary first clock line and a second clock line, and each differential data line group includes a complementary first data line and a second data line; the matching resistor is connected between the first clock line and the second clock line of the differential clock line group, and between the first data line and the second data line of each differential data line group.

[0013] Furthermore, the interface circuit module includes a first ground terminal and a plurality of connecting circuit units, each connecting circuit unit corresponding to the first clock line and each first data line respectively; the first ground terminal is electrically connected to the second clock line and each second data line at the same time; each connecting circuit unit is electrically connected between the first clock line, each first data line and the comparison circuit module respectively.

[0014] Furthermore, the comparison circuit module includes multiple comparators, each comparator has a detection input port, a reference input port and a comparison output port, and one comparator corresponds to a connection circuit unit; each connection circuit unit electrically connects the first clock line and each first data line to the detection input port of the corresponding comparator.

[0015] Furthermore, the reference circuit module includes a plurality of reference circuit units, one reference circuit unit corresponds to one comparator, and each reference circuit unit is electrically connected to a reference input port of the corresponding comparator.

[0016] Furthermore, the indicating circuit module includes a plurality of indicating circuit units, one indicating circuit unit corresponds to one comparator, and each indicating circuit unit is electrically connected to a comparison output port of the corresponding comparator.

[0017] Furthermore, the connection circuit unit includes a first resistor, a second resistor and a third resistor, one end of the first resistor is connected to the first clock line or the corresponding first data line, and the other end is connected in series with the second resistor and then connected to the detection input of the corresponding comparator; one end of the third resistor is connected to the power supply, and the other end is connected to the detection input of the corresponding comparator.

[0018] Furthermore, the reference circuit unit includes a fourth resistor and a fifth resistor, one end of the fourth resistor is connected to the second ground terminal, and the other end is connected to the reference input terminal of the corresponding comparator; one end of the fifth resistor is connected to the power supply, and the other end is connected to the reference input terminal of the corresponding comparator.

[0019] Furthermore, the indication circuit unit includes a MOS tube, a sixth resistor and an indicator light, the gate end of the MOS tube is connected to the comparison output end of the corresponding comparator, the source end of the MOS tube is connected to the third ground terminal, the drain end of the MOS tube is connected to one end of the sixth resistor, the other end of the sixth resistor is connected to one end of the indicator light, and the other end of the indicator light is connected to a power supply.

[0020] Furthermore, the MOS tube is an N-type MOS tube.

[0021] The utility model has the following beneficial effects: the detection device of the utility model is first connected to the LVDS signal line of the display through the interface circuit module to obtain the LVDS signal of the display, and provides the LVDS signal to the comparison circuit module, and then compares the LVDS signal provided by the interface circuit module with the reference signal provided by the reference circuit module through the comparison circuit module, and outputs a corresponding comparison signal to the indication circuit module according to the comparison result, and finally controls the brightness of the indicator light through the indication circuit module according to the comparison signal output by the comparison circuit module to inform the detection personnel whether the matching resistor has failed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an existing display.

[0023] Figure 2 This is a circuit principle block diagram of the detection device provided by the utility model.

[0024] Figure 3 The utility model provides a circuit schematic diagram of a circuit unit, a comparator and a reference circuit unit in the detection device.

[0025] Figure 4 This is a circuit principle diagram of the indicating circuit unit in the detection device provided by the utility model. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent 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 present invention, and should not be construed as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Embodiment 1

[0031] A detection device for LVDS matching resistor 22 is used to detect the matching resistor 22 of LVDS in a display to determine whether the matching resistor 22 in the LVDS is invalid. Figure 1 As shown, the display includes a display panel 1 and a flexible circuit board 2, the display panel 1 is provided with an LVDS receiver 11, the flexible circuit board 2 is provided with a matching resistor 22 and an LVDS signal line 21, and after the flexible circuit board 2 is bound and connected to the display panel 1, the LVDS signal line 21 is electrically connected to the LVDS receiver 11.

[0032] like Figure 2 As shown, the detection device comprises:

[0033] A comparison circuit module, used for comparing the LVDS signal of the display with a reference signal and outputting a corresponding comparison signal according to the comparison result, and having a detection input port, a reference input port and a comparison output port;

[0034] An interface circuit module, used to connect to the LVDS signal line 21 of the display to obtain the LVDS signal of the display and provide it to the comparison circuit module, and electrically connected to the detection input port of the comparison circuit module;

[0035] A reference circuit module, used for providing the reference signal to the comparison circuit module, and electrically connected to a reference input port of the comparison circuit module;

[0036] The indicating circuit module is used to control the brightness of the indicating light according to the comparison signal output by the comparing circuit module, and is electrically connected to the comparison output port of the comparing circuit module.

[0037] The detection device of the utility model is first connected to the LVDS signal line 21 of the display through the interface circuit module to obtain the LVDS signal of the display, and provides the LVDS signal to the comparison circuit module, and then compares the LVDS signal provided by the interface circuit module with the reference signal provided by the reference circuit module through the comparison circuit module, and outputs a corresponding comparison signal to the indication circuit module according to the comparison result, and finally controls the brightness of the indicator light according to the comparison signal output by the comparison circuit module through the indication circuit module to inform the detection personnel whether the matching resistor 22 fails.

[0038] The LVDS signal line 21 includes a differential clock line group and multiple differential data line groups, the differential clock line group includes complementary first clock lines CLKN and second clock lines CLKP, and each differential data line group includes complementary first data lines D0N, D1N, D2N, D3N and second data lines D0P, D1P, D2P, D3P; the matching resistor 22 is connected between the first clock line CLKN and the second clock line CLKP of the differential clock line group, and between the first data line D0N, D1N, D2N, D3N and the second data line D0P, D1P, D2P, D3P of each differential data line group.

[0039] Among them, one of the first clock line CLKN and the second clock line CLKP is a positive clock line, and the other is a negative clock line, and one of the first data lines D0N, D1N, D2N, D3N and the second data lines D0P, D1P, D2P, D3P is a positive signal line, and the other is a negative signal line.

[0040] The interface circuit module includes a first ground terminal GND and a plurality of connection circuit units, each of which corresponds to the first clock line CLKN and each of the first data lines D0N, D1N, D2N, and D3N; the first ground terminal GND is electrically connected to the second clock line CLKP and each of the second data lines D0P, D1P, D2P, and D3P at the same time, so as to simultaneously perform grounding processing on the second clock line CLKP and each of the second data lines D0P, D1P, D2P, and D3P; each of the connection circuit units is electrically connected between the first clock line CLK, each of the first data lines D0N, D1N, D2N, and D3N and the comparison circuit module, so as to respectively connect the first clock line CLKN and each of the first data lines D0N, D1N, D2N, and D3N to the comparison circuit module.

[0041] The comparison circuit module includes multiple comparators A, each comparator A has a detection input port A-, a reference input port A+ and a comparison output port OUTA, and one comparator A corresponds to one connection circuit unit; each connection circuit unit electrically connects the first clock line CLKN and each first data line D0N, D1N, D2N, D3N to the detection input port A- of the corresponding comparator A, so as to provide each comparator A with a corresponding LVDS signal of the differential data line group.

[0042] In this embodiment, the comparison circuit module may be, but is not limited to, an LM2802 chip produced by Texas Instruments, which has multiple comparators A integrated therein.

[0043] The reference circuit module includes a plurality of reference circuit units, one reference circuit unit corresponds to one comparator A, and each reference circuit unit is electrically connected to a reference input port A+ of the corresponding comparator A to provide each comparator A with the reference signal separately.

[0044] The indicating circuit module includes a plurality of indicating circuit units, one indicating circuit unit corresponds to a comparator A, and each indicating circuit unit is electrically connected to a comparison output port OUTA of the corresponding comparator A to individually control the brightness of the indicating light according to a comparison signal output by the corresponding comparator A.

[0045] like Figure 3 As shown, the connection circuit unit includes a first resistor R1, a second resistor R2 and a third resistor R3, one end of the first resistor R1 is connected to the first clock line CLKN or the corresponding first data lines D0N, D1N, D2N, D3N, and the other end is connected in series with the second resistor R2 and then connected to the corresponding detection input terminal A- of the comparator A; one end of the third resistor R3 is connected to the power supply VDD, and the other end is connected to the corresponding detection input terminal A- of the comparator A.

[0046] The reference circuit unit includes a fourth resistor R4 and a fifth resistor R5, one end of the fourth resistor R4 is connected to the second ground terminal GND2, and the other end is connected to the reference input terminal A+ of the corresponding comparator A; one end of the fifth resistor R5 is connected to the power supply VDD, and the other end is connected to the reference input terminal A+ of the corresponding comparator A.

[0047] like Figure 4 As shown, the indicating circuit unit includes a MOS tube Q, a sixth resistor R6 and an indicator light L, the gate terminal G of the MOS tube Q is connected to the comparison output terminal OUTA of the corresponding comparator A, the source terminal S of the MOS tube Q is connected to the third ground terminal GND3, the drain terminal D of the MOS tube Q is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to one end of the indicator light L, and the other end of the indicator light L is connected to the power supply VDD.

[0048] When the matching resistor 22 of the differential clock line group or a pair of differential data line groups fails, the voltage value of the LVDS signal output by the differential clock line group or the differential data line group to the comparator A through the connecting circuit unit is lower than the voltage value of the reference signal provided by the reference circuit unit to the comparator A, and the comparator A outputs a low-level comparison signal to the MOS tube Q of the indicating circuit unit. The MOS tube Q is in a disconnected state under the low-level comparison signal, and the source terminal S and the drain terminal D of the MOS tube Q are disconnected, and one end of the corresponding indicator light L is disconnected from the power supply VDD, and the indicator light L is extinguished; When the matching resistor 22 of the differential clock line group or a pair of differential data line groups is effective, the voltage value of the LVDS signal output by the differential clock line group or the differential data line group to the comparator A through the connecting circuit unit is higher than the voltage value of the reference signal provided by the reference circuit unit to the comparator A, and the comparator A outputs a high-level comparison signal to the MOS tube Q of the indicating circuit unit. The MOS tube Q is in the on state under the high-level comparison signal, the source terminal S and the drain terminal D of the MOS tube Q are connected, both ends of the indicator light L are connected to the power supply VDD, and the indicator light L is lit.

[0049] In this embodiment, the MOS tube Q is an N-type MOS tube, and its model is AP2302GN.

[0050] During detection, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 and the voltage value of the power supply VDD are designed according to the resistance value of the matching resistor 22. In this embodiment, a common 100Ω matching resistor 22 is taken as an example, the voltage value of the power supply VDD is 3.3V, and the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are 0Ω, 11.8KΩ, 10KΩ, 12KΩ and 10KΩ respectively.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the utility model rather than to limit them. Although the embodiments of the utility model are described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the embodiments of the utility model can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A detection device for LVDS matching resistance, characterized in that: include: A comparison circuit module, used for comparing the LVDS signal of the display with the reference signal and outputting a corresponding comparison signal according to the comparison result, having a detection input port, a reference input port and a comparison output port; An interface circuit module, used to connect to the LVDS signal line of the display to obtain the LVDS signal of the display and provide it to the comparison circuit module, and electrically connected to the detection input port of the comparison circuit module; A reference circuit module, used for providing the reference signal to the comparison circuit module, and electrically connected to a reference input port of the comparison circuit module; The indicating circuit module is used to control the brightness of the indicating light according to the comparison signal output by the comparing circuit module, and is electrically connected to the comparison output port of the comparing circuit module.

2. The detection device according to claim 1, characterized in that: The LVDS signal line includes a differential clock line group and multiple differential data line groups, the differential clock line group includes a complementary first clock line and a second clock line, and each differential data line group includes a complementary first data line and a second data line; the matching resistor is connected between the first clock line and the second clock line of the differential clock line group, and between the first data line and the second data line of each differential data line group.

3. The detection device according to claim 2, characterized in that: The interface circuit module includes a first ground terminal and a plurality of connection circuit units, each connection circuit unit corresponds to the first clock line and each first data line respectively; the first ground terminal is electrically connected to the second clock line and each second data line at the same time; each connection circuit unit is electrically connected between the first clock line, each first data line and the comparison circuit module respectively.

4. The detection device according to claim 3, characterized in that: The comparison circuit module includes multiple comparators, each comparator has a detection input port, a reference input port and a comparison output port, and one comparator corresponds to one connection circuit unit; each connection circuit unit electrically connects the first clock line and each first data line to the detection input port of the corresponding comparator.

5. The detection device according to claim 4, characterized in that: The reference circuit module includes a plurality of reference circuit units, one reference circuit unit corresponds to one comparator, and each reference circuit unit is electrically connected to a reference input port of the corresponding comparator.

6. The detection device according to claim 5, characterized in that: The indicating circuit module includes a plurality of indicating circuit units, one indicating circuit unit corresponds to one comparator, and each indicating circuit unit is electrically connected to a comparison output port of the corresponding comparator.

7. The detection device according to claim 4, characterized in that: The connection circuit unit includes a first resistor, a second resistor and a third resistor, one end of the first resistor is connected to the first clock line or the corresponding first data line, and the other end is connected in series with the second resistor and then connected to the detection input end of the corresponding comparator; one end of the third resistor is connected to the power supply, and the other end is connected to the detection input end of the corresponding comparator.

8. The detection device according to claim 5, characterized in that: The reference circuit unit includes a fourth resistor and a fifth resistor, one end of the fourth resistor is connected to the second ground terminal, and the other end is connected to the reference input terminal of the corresponding comparator; one end of the fifth resistor is connected to the power supply, and the other end is connected to the reference input terminal of the corresponding comparator.

9. The detection device according to claim 6, characterized in that: The indicating circuit unit includes a MOS tube, a sixth resistor and an indicator light, the gate end of the MOS tube is connected to the comparison output end of the corresponding comparator, the source end of the MOS tube is connected to the third ground terminal, the drain end of the MOS tube is connected to one end of the sixth resistor, the other end of the sixth resistor is connected to one end of the indicator light, and the other end of the indicator light is connected to a power supply.

10. The detection device according to claim 9, characterized in that: The MOS tube is an N-type MOS tube.

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