Short circuit prevention circuit for TP (touch panel)

Abstract

The utility model discloses a TP touchpad anti-short circuit, which comprises a control circuit and a voltage output circuit, the control circuit comprises a field effect transistor and a connector, the voltage output circuit comprises a voltage conversion chip, the voltage conversion chip is electrically connected with the input end of the field effect transistor, and the input end of the field effect transistor is electrically connected with the connector. And the connector is electrically connected with the output end of the field effect transistor and the TP touch panel respectively. By adopting the field effect transistor, the short circuit phenomenon caused by false contact of the Pin of the connector is avoided. Product damage or injury to a user when the product is used is prevented.

Description

Technical Field

[0001] The utility model belongs to the field of electronic technology, and in particular relates to a TP touch panel short circuit prevention circuit. Background Art

[0002] Most of the TP touch panels on the market now have direct voltage output, which can ensure the product's functionality. However, when the connector's pin contacts the TP touch panel by mistake, the normal circuit supply may be disrupted, resulting in damage to the chip, which in turn causes product problems. Utility Model Content

[0003] The utility model aims to provide a TP touch panel short circuit prevention circuit to solve the above problems existing in the prior art.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A TP touch panel anti-short circuit, comprising:

[0006] A control circuit and a voltage output circuit, wherein the control circuit includes a field effect tube and a connector, and the voltage output circuit includes a voltage conversion chip, wherein the voltage conversion chip is electrically connected to the input end of the field effect tube, and the connector is electrically connected to the output end of the field effect tube.

[0007] Optionally, the voltage output circuit also includes a first voltage-dividing resistor, a second voltage-dividing resistor, a first bypass capacitor and a second bypass capacitor. The model of the voltage conversion chip is APL5934, and the model of the field effect tube is WPM2026. The FB pin of the voltage conversion chip is electrically connected to the input end of the first voltage-dividing resistor and the input end of the second voltage-dividing resistor, respectively. The output end of the second voltage-dividing resistor is grounded. The common point of the output end of the first voltage-dividing resistor, the input end of the first bypass capacitor and the input end of the second bypass capacitor is electrically connected to the source of the field effect tube. The output end of the first bypass capacitor and the output end of the second bypass capacitor are grounded.

[0008] Optionally, the voltage output circuit also includes a first resistor, a second resistor and a third bypass capacitor, the GND pin of the voltage conversion chip is grounded, the EN pin of the voltage conversion chip is electrically connected to the first resistor and the second resistor respectively, and the VIN pin of the voltage conversion chip is electrically connected to the third bypass capacitor.

[0009] Optionally, the voltage output circuit further includes a fourth bypass capacitor, and the voltage conversion chip is electrically connected to the fourth bypass capacitor.

[0010] Optionally, the model of the connector (JTP2) is FPC1020-05B2-S3R, and the fifth pin, the sixth pin and the seventh pin of the connector are grounded.

[0011] Optionally, the gate of the field effect transistor is electrically connected to the fourth pin of the connector.

[0012] Optionally, the drain of the field effect transistor is electrically connected to the first pin of the connector.

[0013] Optionally, the second pin of the connector and the third pin of the connector are data transmission pins.

[0014] Beneficial effects:

[0015] This application uses field effect transistors to avoid short circuits caused by connector pins when they are accidentally touched, thereby preventing product damage or user injury when using the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A circuit diagram of a control circuit provided according to an embodiment of the present application;

[0017] Figure 2 A circuit diagram of a voltage output circuit provided according to an embodiment of the present application.

[0018] Description of reference numerals:

[0019] Q36, field effect transistor, JTP2, connector, U101, voltage conversion chip, R394, first voltage dividing resistor, R396, second voltage dividing resistor, C565, first bypass capacitor, C564, second bypass capacitor, R117, first resistor, R119, second resistor, C563, third bypass capacitor, C566, fourth bypass capacitor. DETAILED DESCRIPTION

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the utility model will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute a limitation of the utility model.

[0021] Embodiment 1:

[0022] like Figure 1As shown, this embodiment provides a circuit diagram of a control circuit, which is a connection circuit and also a control part of an anti-short circuit, including JTP2, which is a connector of a TP touch panel, Q36, which is a field effect transistor, and the power supply circuit of the TP touch panel is controlled by the field effect transistor Q36. The connector is part of the TP touch panel, and PIN4 is on the connector, and its function is to detect contact.

[0023] like Figure 2 As shown, it is a circuit diagram of a voltage output circuit provided in this embodiment, and the voltage output circuit includes a voltage conversion chip U101, the voltage conversion chip U101 is electrically connected to the input end of the field effect transistor Q36, and the connector JTP2 is electrically connected to the output end of the field effect transistor Q36. The voltage output circuit also includes a first voltage-dividing resistor R394, a second voltage-dividing resistor R396, a first bypass capacitor C565 and a second bypass capacitor C564. The model of the voltage conversion chip U101 is APL5934, and the model of the field effect transistor Q36 is WPM2026. The FB pin of the voltage conversion chip U101 is electrically connected to the input end of the first voltage-dividing resistor R394 and the input end of the second voltage-dividing resistor R396 respectively, and the output end of the second voltage-dividing resistor R396 is grounded. The common point of the output end of the first voltage-dividing resistor R394, the input end of the first bypass capacitor C565 and the input end of the second bypass capacitor C564 is electrically connected to the source of the field effect transistor Q36, and the output end of the first bypass capacitor C565 and the output end of the second bypass capacitor C564 are grounded. The voltage output circuit also includes a first resistor R117, a second resistor R119 and a third bypass capacitor C563, the GND pin of the voltage conversion chip U101 is grounded, the EN pin of the voltage conversion chip U101 is electrically connected to the first resistor R117 and the second resistor R119, respectively, and the VIN pin of the voltage conversion chip U101 is electrically connected to the third bypass capacitor C563. The voltage output circuit also includes a fourth bypass capacitor C566, and the voltage conversion chip U101 is electrically connected to the fourth bypass capacitor C566. The voltage output circuit also includes a fourth bypass capacitor C566, and the voltage conversion chip U101 is electrically connected to the fourth bypass capacitor C566. The model of the connector (JTP2) is FPC1020-05B2-S3R, and the fifth pin, the sixth pin and the seventh pin of the connector TP2 are grounded. The gate of the field effect transistor Q36 is electrically connected to the fourth pin of the connector JTP2. The drain of the field effect transistor Q36 is electrically connected to the first pin of the connector JTP2. The second pin of the connector JTP2 and the third pin of the connector JTP2 are data transmission pins.

[0024] The TP touch panel of the present application is connected to the circuit through the connector JTP2 and is powered normally. Pin1 (first pin) of the connector JTP2 is 1.5V high level, Pin2 (second pin) and Pin3 (third pin) of the connector (JTP2) are data transmission ports, and to avoid circuit short circuit, the conduction of the touch panel circuit is controlled by the field effect tube Q36. When Pin4 (fourth pin) of the connector JTP2 is normally connected to the TP touch panel, Pin-4 is low level, the field effect tube Q36 is turned on, and the TP touch panel is powered normally; when Pin4 of the connector JTP2 is not connected to the TP touch panel, Pin-4 is high level, the field effect tube Q36 is turned off, and the TP touch panel is not powered, forming a protection circuit to avoid circuit short circuit caused by accidental touch.

[0025] This application uses field effect transistors to avoid short circuits caused by connector pins when they are accidentally touched, thereby preventing product damage or user injury when using the product.

[0026] Embodiment 2:

[0027] The first resistor R117 and the second resistor R119 of the present application are both designed to be compatible with the enable pin of the APL5934 chip. The EN Pin (APL5934-Pin8) is a high enable control pin. R119 is used for forced pull-up to keep U101 in working state. R117 is a port control and can control U101 to work or shut down as required.

[0028] The voltage output circuit of the TP touch panel includes U101-voltage conversion chip and peripheral devices (multiple resistors, capacitors, etc.). The voltage conversion chip U101 is an ultra-low voltage difference linear regulator, which is used to output a stable TP-1.5V power supply. The external voltage divider resistors R394 and R396 are circuit voltage dividers, which are used to control the level of the voltage feedback pin FB of the voltage conversion chip U101 to ensure the normal operation of the control voltage conversion chip U101. The V1.8A network (V1.8A is a universal power network with a stable output of 1.8V) and the PM_TP_EN network are compatible with the enable pin of the APL5934 chip. ENPin (APL5934-Pin8) is a high enable control pin. Pin8 is the EN pin of the voltage conversion chip U101, which is used to control the operation and output of the voltage conversion chip U101; if the voltage applied and maintained on this Pin8 is lower than 0.4v, the chip will turn off the output. The first bypass capacitor C565, the second bypass capacitor C564, the third bypass capacitor C563 and the fourth bypass capacitor C566 are used for circuit decoupling to ensure voltage stability. +V5A is a universal power supply network with a stable output of 1.5V.

[0029] The voltage output circuit part of the present application is the output circuit of the TP touch panel circuit driver chip. The pull-up of Pin8 of APL5934 ensures that the chip working mode is turned on. The first voltage divider resistor R394 and the second voltage divider resistor R396 can ensure that the chip outputs a 1.5V voltage; bypass capacitors of multiple networks are used to achieve circuit decoupling to ensure a stable output voltage. The present application adopts field effect transistor Q36 to avoid short circuits caused by the Pin pin of connector JTP2 when contacted by mistake. Prevent product damage or user injury when using the product.

[0030] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A TP touch panel anti-short circuit, characterized in that: include: A control circuit and a voltage output circuit, the control circuit comprising a field effect tube (Q36) and a connector (JTP2), the voltage output circuit comprising a voltage conversion chip (U101), the voltage conversion chip (U101) being electrically connected to an input end of the field effect tube (Q36), the connector (JTP2) being electrically connected to an output end of the field effect tube (Q36), the field effect tube (Q36) being used to control whether a power supply circuit of a TP touch panel is turned on, and the model of the field effect tube (Q36) is WPM2026.

2. The TP touch panel anti-short circuit according to claim 1, characterized in that: The voltage output circuit also includes a first voltage-dividing resistor (R394), a second voltage-dividing resistor (R396), a first bypass capacitor (C565) and a second bypass capacitor (C564); the model of the voltage conversion chip (U101) is APL5934; the model of the field effect tube (Q36) is WPM2026; the FB pin of the voltage conversion chip (U101) is electrically connected to the input end of the first voltage-dividing resistor (R394) and the input end of the second voltage-dividing resistor (R396), respectively; the output end of the second voltage-dividing resistor (R396) is grounded; the common point of the output end of the first voltage-dividing resistor (R394), the input end of the first bypass capacitor (C565) and the input end of the second bypass capacitor (C564) is electrically connected to the source of the field effect tube (Q36); the output end of the first bypass capacitor (C565) and the output end of the second bypass capacitor (C564) are grounded.

3. The TP touch panel anti-short circuit according to claim 2, characterized in that: The voltage output circuit also includes a first resistor (R117), a second resistor (R119) and a third bypass capacitor (C563); a GND pin of the voltage conversion chip (U101) is grounded; an EN pin of the voltage conversion chip (U101) is electrically connected to the first resistor (R117) and the second resistor (R119), respectively; and a VIN pin of the voltage conversion chip (U101) is electrically connected to the third bypass capacitor (C563).

4. The TP touch panel anti-short circuit according to claim 3, characterized in that: The voltage output circuit also includes a fourth bypass capacitor (C566), and the voltage conversion chip (U101) is electrically connected to the fourth bypass capacitor (C566).

5. The TP touch panel anti-short circuit according to claim 1, characterized in that: The model of the connector (JTP2) is FPC1020-05B2-S3R, and the fifth pin, the sixth pin and the seventh pin of the connector (JTP2) are grounded.

6. The TP touch panel anti-short circuit according to claim 5, characterized in that: The gate of the field effect transistor (Q36) is electrically connected to the fourth pin of the connector (JTP2).

7. The TP touch panel anti-short circuit according to claim 5, characterized in that: The drain of the field effect transistor (Q36) is electrically connected to the first pin of the connector (JTP2).

8. The TP touch panel anti-short circuit according to claim 1, characterized in that: The second pin of the connector (JTP2) and the third pin of the connector (JTP2) are data transmission pins.

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