Driver circuit

Abstract

The present invention provides a driver circuit. The driver circuit is configured to drive a display panel to perform a display operation and a touch sensing operation. The driver circuit includes: a touch and display driver integrated circuit and an external circuit. The touch and display driver integrated circuit is configured to drive the display panel to perform a display operation and a touch sensing operation during a display period and a touch sensing period, respectively. The touch and display driver integrated circuit outputs a reference signal. The external circuit is disposed outside the touch and display driver integrated circuit. The external circuit is configured to output a first output voltage and a second output voltage based on the reference signal from the touch and display driver integrated circuit. The first output voltage is greater than the second output voltage.

Description

Technical Field

[0001] The present invention relates to a driver circuit, and more particularly to a driver circuit adapted to drive a display panel to perform a display operation and a touch sensing operation. Background Art

[0002] In some applications, an electronic device may have a display function and a touch sensing function to obtain a better user experience. A user can operate the electronic device by using a touch sensor to touch a display panel to perform some desired functions. For such an application, two driver chips are required to drive the display panel with a touch sensor to perform a display operation and a touch sensing operation. In the related art, in order to reduce costs, the two driver chips are integrated into a touch and display driver integration (TDDI) chip. The TDDI chip can drive the display panel with a touch sensor to perform a display operation and a touch sensing operation.

[0003] Conventional TDDI chips generally include a high-voltage device that provides a driving signal to the display panel. However, the high-voltage device may generate electromagnetic interference, and other components of the TDDI chip may be affected. In addition, the high-voltage device also increases the temperature variation of the TDDI chip. Summary of the Invention

[0004] The present invention relates to a driver circuit that can reduce the temperature variation of a TDDI chip and electromagnetic interference caused by a high-voltage device.

[0005] The present invention provides a driver circuit configured to drive a display panel to perform a display operation and a touch sensing operation. The driver circuit includes a TDDI circuit and an external circuit. The TDDI circuit is configured to drive the display panel to perform the display operation and the touch sensing operation during a display period and a touch sensing period, respectively. The TDDI circuit outputs a reference signal. The external circuit is disposed outside the TDDI circuit. The external circuit is configured to output a first output voltage and a second output voltage based on the reference signal from the TDDI circuit. The first output voltage is greater than the second output voltage.

[0006] In an embodiment of the present invention, the driver circuit further includes a power supply circuit. The power supply circuit is coupled to the external circuit. The power supply circuit is configured to output a first input voltage and a second input voltage. The external circuit receives the first input voltage and the second input voltage from the power supply circuit. The first input voltage is greater than the second input voltage.

[0007] In an embodiment of the present invention, the external circuit generates the first output voltage based on the reference signal according to the first input voltage. The external circuit generates the second output voltage based on the reference signal according to the second input voltage.

[0008] In an embodiment of the present invention, the external circuit includes a switching device controlled by a first control signal. During the display period, the switching device is turned on by the first control signal. During the touch sensing period, the switching device is turned off by the first control signal.

[0009] In an embodiment of the present invention, the switching device has a first voltage endurance, and the TDDI circuit has a second voltage endurance. The first voltage endurance is greater than the second voltage endurance.

[0010] In an embodiment of the present invention, the external circuit further includes a diode device, a first capacitor, and a second capacitor. The diode device includes a first end and a second end. The first end of the diode device is coupled to the power supply circuit. The first end of the diode device serves as an input terminal to receive the first input voltage. The second end of the diode device serves as an output terminal to output the first output voltage. The first capacitor includes a first end and a second end. The first end of the first capacitor is coupled to the second end of the diode device, and the second end of the first capacitor is coupled to the TDDI circuit to receive the reference voltage. The second capacitor includes a first end and a second end. The first end of the second capacitor is coupled to the second end of the first capacitor, and the second end of the second capacitor is coupled to the switching device. The switching device includes a first end, a second end, and a control end. The first end of the switching device is coupled to the second end of the second capacitor. The first end of the switching device serves as an output terminal to output the second output voltage. The second end of the switching device serves as an input terminal to receive the second input voltage. The control end of the switching device is coupled to the first control signal.

[0011] In an embodiment of the present invention, the switching device includes a first end, a second end, and a control end. The first end of the switching device is coupled to the power supply circuit. The first end of the switching device serves as an input end to receive the first input voltage. The second end of the switching device serves as an output end to output the first output voltage. The external circuit further includes a first capacitor, a second capacitor, and a diode device. The first capacitor includes a first end and a second end. The first end of the first capacitor is coupled to the second end of the switching device, and the second end of the first capacitor is coupled to the TDDI circuit to receive the reference voltage. The second capacitor includes a first end and a second end. The first end of the second capacitor is coupled to the second end of the first capacitor. The diode device includes a first end and a second end. The first end of the diode device is coupled to the second end of the second capacitor. The first end of the diode device serves as an output end to output the second output voltage. The second end of the diode device serves as an output end to receive the second input voltage.

[0012] In an embodiment of the present invention, the driver circuit further includes a first level shifter. The first level shifter is coupled to the TDDI circuit. The TDDI circuit outputs a second control signal to the first level shifter. The first level shifter is configured to receive the second control signal and also receive the first input voltage or the second input voltage. The first level shifter generates the first control signal based on the first input voltage or the second input voltage according to the second control signal.

[0013] In an embodiment of the present invention, the first level shifter is disposed in the external circuit.

[0014] In an embodiment of the present invention, the driver circuit further includes a second level shifter. The second level shifter is coupled to the external circuit and is disposed outside the external circuit. The second level shifter is configured to receive the first output voltage and the second output voltage from the external circuit. The first level shifter is disposed outside the external circuit and is integrated with the second level shifter to form a semiconductor chip.

[0015] In an embodiment of the present invention, the TDDI circuit and the power supply circuit are implemented as different semiconductor chips.

[0016] In an embodiment of the present invention, the reference signal is a ground voltage during the display period.

[0017] In an embodiment of the present invention, the reference signal is a synchronous drive voltage during the touch sensing period.

[0018] In an embodiment of the present invention, the first output voltage and the second output voltage have the same amplitude, phase, and frequency as the reference signal.

[0019] To make the above content easier to understand, several embodiments will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description, are used to explain the principles of the present disclosure.

[0021] Figure 1 is a schematic block diagram showing a display device according to an embodiment of the present invention.

[0022] Figure 2 is a schematic block diagram showing Figure 1 the driver circuit according to an embodiment of the present invention.

[0023] Figure 3 is a schematic block diagram showing the driver circuit according to another embodiment of the present invention.

[0024] Figure 4A is a schematic block diagram showing the driver circuit operating during display according to an embodiment of the present invention.

[0025] Figure 4B is a schematic block diagram showing the Figure 4A driver circuit operating during touch sensing according to an embodiment of the present invention.

[0026] Figure 5 is a schematic block diagram showing the driver circuit according to another embodiment of the present invention.

[0027] Figure 6 is a schematic block diagram showing the driver circuit according to another embodiment of the present invention.

[0028] Figure 7 is a schematic block diagram showing the TDDI circuit according to an embodiment of the present invention.

[0029] [DESCRIPTION OF SYMBOLS]

[0030] 100: Display device

[0031] 110, 200, 300, 500, 600: Driver circuit

[0032] 112, 700: Touch and display driver integration (TDDI) circuit

[0033] 114, 514, 614: External circuit

[0034] 120: Display panel

[0035] 211: Power supply circuit

[0036] 213_1: First level shifter

[0037] 213_2: Second level shifter

[0038] 215: Gate driver circuit

[0039] 400: Output buffer

[0040] 710: Source driver circuit

[0041] 720: Interface circuit

[0042] 730: Digital circuit

[0043] 740: Analog front-end (AFE) circuit

[0044] 750: Output buffer circuit

[0045] 760: Gate driver circuit

[0046] 800: Level shifter circuit

[0047] C1: First capacitor

[0048] C2: Second capacitor

[0049] CKV: Clock signal

[0050] D: Diode device

[0051] GCK_OUT, LS_OUT: Output

[0052] MUX: Select signal

[0053] STV: Start pulse signal

[0054] T1, T2: Switch device

[0055] TP_CON: First control signal

[0056] TP_EN: Second control signal

[0057] Vg: Ground voltage

[0058] Vs: Synchronous drive voltage

[0059] VGH: First input voltage

[0060] VGH_LS: First output voltage

[0061] VGL: Second input voltage

[0062] VGL_LS: Second output voltage

[0063] VMD: Reference signal / reference voltage

[0064] △V1, △V2: Voltage difference Detailed implementation manners

[0065] Embodiments are provided below to elaborate on the present disclosure in detail. The present disclosure is not limited to the provided embodiments, and the provided embodiments can be appropriately combined. The terms "coupling / coupled" or "connecting / connected" used in the specification (including the claims) of this application can refer to any direct or indirect connection manner. For example, "The first device is coupled to the second device" should be interpreted as "The first device is directly connected to the second device" or "The first device is indirectly connected to the second device through other devices or connection manners". Additionally, the term "signal" can refer to current, voltage, charge, temperature, data, electromagnetic waves, or any one or more of these signals.

[0066] Figure 1 is a schematic block diagram showing a display device according to an embodiment of the present invention. Referring to Figure 1 , the display device 100 of this embodiment includes a driver circuit 110 and a display panel 120. The display panel 120 includes a touch sensor and display pixels (not shown). The driver circuit 110 can be configured to be coupled to the display panel 120. The electronic circuit 110 is adapted to drive the display panel 120 to perform a display operation and a touch sensing operation.

[0067] Figure 2 is a schematic block diagram showing the Figure 1 driver circuit according to an embodiment of the present invention. Referring to Figure 2 , the driver circuit 110 is configured to drive the display panel 120 to perform a display operation and a touch sensing operation. The driver circuit 110 includes a touch and display driver integration (TDDI) circuit 112 and an external circuit 114. It can be implemented as a single semiconductor chip. The external circuit 114 is provided outside the TDDI circuit 112. In one embodiment, the TDDI circuit 112 can be implemented as a single semiconductor chip.

[0068] Specifically, the TDDI circuit 112 is configured to drive the display panel 120 to perform a display operation and a touch sensing operation during a display period and a touch sensing period, respectively. The TDDI circuit 112 outputs a reference signal VMD to the external circuit 114. The external circuit 114 is configured to output a first output voltage VGH_LS and a second output voltage VGL_LS based on the reference signal VMD from the TDDI circuit 112. In this embodiment, the first output voltage VGH_LS is greater than the second output voltage VGL_LS.

[0069] Figure 3 is a schematic block diagram showing a driver circuit according to another embodiment of the present invention. Referring to Figure 3 , the driver circuit 200 includes a TDDI circuit 112, an external circuit 114, a power supply circuit 211, a second level shifter 213_2, and a gate driver circuit 215. The power supply circuit 211 is coupled to the external circuit 114. In one embodiment, the TDDI circuit 112, the external circuit 114, the power supply circuit 211, the second level shifter 213_2, and the gate driver circuit 215 may be implemented as different semiconductor chips, but the present invention is not limited thereto.

[0070] Specifically, the power supply circuit 211 is configured to output a first input voltage VGH and a second input voltage VGL to the external circuit 114. The first input voltage VGH is greater than the second input voltage VGL. The external circuit 114 receives the first input voltage VGH and the second input voltage VGL from the power supply circuit 211. The external circuit 114 generates a first output voltage VGH_LS based on the first input voltage VGH and the reference signal VMD. The external circuit 114 generates a second output voltage VGL_LS based on the second input voltage VGL and the reference signal VMD. The external circuit 114 outputs the first output voltage VGH_LS and the second output voltage VGL_LS to the second level shifter 213_2 and the gate driver circuit 215.

[0071] The second level shifter 213_2 is coupled to the external circuit 114 and the TDDI circuit 112. The second level shifter 213_2 is disposed outside the external circuit 114. The second level shifter 213_2 is configured to receive the first output voltage VGH_LS and the second output voltage VGL_LS from the external circuit 114. The TDDI circuit 112 outputs a selection signal MUX to the second level shifter 213_2. The second level shifter 213_2 selects one of the first output voltage VGH_LS and the second output voltage VGL_LS as an output LS_OUT to drive the display panel 120. In one embodiment, the second level shifter 213_2 may be implemented as a single semiconductor chip, but the present invention is not limited thereto.

[0072] The gate driver circuit 215 is coupled to the external circuit 114 and the TDDI circuit 112. The gate driver circuit 215 is configured to receive a first output voltage VGH_LS and a second output voltage VGL_LS from the external circuit 114. The TDDI circuit 112 outputs a start pulse signal STV and a clock signal CKV to the gate driver circuit 215. The gate driver circuit 215 generates an output GCK_OUT according to the start pulse signal STV and the clock signal CKV to drive scan lines on the display panel 120. In one embodiment, the gate driver circuit 215 can be implemented as a single semiconductor chip and disposed on the display panel 120, but the present invention is not limited thereto.

[0073] Figure 4A is a schematic block diagram showing a driver circuit operating during display. Referring to Figure 4A , the driver circuit 300 includes a TDDI circuit 112, an external circuit 114, a power supply circuit 211, and a first level shifter 213_1. The first level shifter 213_1 is coupled to the TDDI circuit 112 and disposed in the external circuit 114.

[0074] The external circuit 114 includes a diode device D, a first capacitor C1, a second capacitor C2, and a switching device T1. The diode device D, the first capacitor C1, the second capacitor C2, and the switching device T1 are connected in series. Specifically, the diode device D includes a first end and a second end. The first end of the diode device D is coupled to the power supply circuit 211. The first end of the diode device D serves as an input terminal to receive a first input voltage VGH. The second end of the diode device D is coupled to the first end of the first capacitor C1. The second end of the diode device D serves as an output terminal to output a first output voltage VGH_LS. The first capacitor C1 includes a first end and a second end. The first end of the first capacitor C1 is coupled to the second end of the diode device D. The second end of the first capacitor C1 is coupled to the TDDI circuit 112 to receive a reference voltage VMD from the output buffer 400 of the TDDI circuit 112. The second capacitor C2 includes a first end and a second end. The first end of the second capacitor C2 is coupled to the second end of the first capacitor C1. The second end of the second capacitor C2 is coupled to the switching device T1.

[0075] The switching device T1 includes a first end, a second end, and a control end. The first end of the switching device T1 is coupled to the second end of the second capacitor C2. The first end of the switching device T1 serves as an output terminal to output a second output voltage VGL_LS. The second end of the switching device T1 is coupled to the power supply circuit 211. The second end of the switching device T1 serves as an input terminal to receive a second input voltage VGL. The control end of the switching device T1 is coupled to a first control signal TP_CON.

[0076] The switching device T1 is controlled by a first control signal TP_CON. The switching device T1 is turned on by the first control signal TP_CON during display, and the switching device T1 is turned off by the first control signal TP_CON during touch sensing.

[0077] The TDDI circuit 112 outputs a second control signal TP_EN to the first level shifter 213_1. The first level shifter 213_1 is configured to receive the second control signal TP_EN and a second input voltage VGL. The first level shifter 213_1 generates a first control signal TP_CON based on the second input voltage VGL according to the second control signal TP_EN.

[0078] In this embodiment, the driver circuit 300 operates during display. The TDDI circuit 112 outputs the second control signal TP_EN to control the first level shifter 213_1 to operate during display. During display, the reference signal VMD is set to the ground voltage Vg. That is, the TDDI circuit 112 outputs the ground voltage Vg as the reference signal VMD. The first output voltage VGH_LS is substantially equal to the first input voltage VGH. The voltage difference △V1 between the first output voltage VGH_LS and the first input voltage VGH is the turn-on voltage of the diode device D. In this embodiment, the diode device D can be a Schottky diode, but the present invention is not limited thereto.

[0079] On the other hand, the switching device T1 is turned on by the first control signal TP_CON during display. The second output voltage VGL_LS is substantially equal to the second input voltage VGL. The voltage difference △V2 between the second output voltage VGL_LS and the second input voltage VGL is the drain-to-source voltage of the switching device T1. In this embodiment, the switching device T1 can be a high voltage N-type metal oxide semiconductor (HVNMOS) transistor, but the present invention is not limited thereto.

[0080] Figure 4B is a schematic block diagram of a driver circuit that operates during touch sensing according to an embodiment of the present invention. Referring to Figure 4A During touch sensing, the driver circuit 300 operates. The TDDI circuit 112 outputs the second control signal TP_EN to control the first level shifter 213_1 to operate during touch sensing. During touch sensing, the reference signal VMD is the synchronous drive voltage Vs. That is, the TDDI circuit 112 outputs the synchronous drive voltage Vs as the reference signal VMD. In this embodiment, the synchronous drive voltage Vs can be as Figure 4B Figure 4B ​The triangular wave shown in [figure], but the present invention is not limited thereto. In one embodiment, the synchronous drive voltage Vs may be a square wave or a sine wave. The synchronous drive voltage Vs may be a positive voltage or a negative voltage.

[0081] Based on the first input voltage VGH and the synchronous drive voltage Vs, a first output voltage VGH_LS is generated. The first output voltage VGH_LS is also a triangular wave having a minimum reference level equal to the first input voltage VGH.

[0082] On the other hand, the switching device T1 is turned off by the first control signal TP_CON during touch sensing. Based on the second input voltage VGL and the synchronous drive voltage Vs, a second output voltage VGL_LS is generated. The first output voltage VGH_LS is also a triangular wave having a minimum reference level equal to the second input voltage VGL.

[0083] The first output voltage VGH_LS and the second output voltage VGL_LS have the same amplitude, phase, and frequency as the reference signal (i.e., the synchronous drive voltage Vs), as shown in Figure 4B [figure]. During touch sensing, when a touch sensing operation is performed, the synchronous drive voltage Vs from the TDDI circuit 112 is output to the display panel 120 to drive the scan lines and / or data lines to reduce noise.

[0084] Figure 5 is a schematic block diagram showing a driver circuit according to another embodiment of the present invention. Referring to Figure 5 , the driver circuit 500 includes a TDDI circuit 112, an external circuit 514, a power supply circuit 211, and a first level shifter 213_1. The first level shifter 213_1 is coupled to the TDDI circuit 112 and is disposed in the external circuit 514.

[0085] The external circuit 514 includes a switching device T2, a first capacitor C1, a second capacitor C2, and a diode device D. The switching device T2, the first capacitor C1, the second capacitor C2, and the diode device D are connected in series. Specifically, the switching device T2 includes a first end, a second end, and a control end. The first end of the switching device T2 is coupled to the power supply circuit 211. The first end of the switching device T2 serves as an input terminal to receive the first input voltage VGH. The second end of the switching device T2 is coupled to the first end of the first capacitor C1. The second end of the switching device T2 serves as an output terminal to output the first output voltage VGH_LS. The control end of the switching device T2 is coupled to the first control signal TP_CON.

[0086] The switching device T2 is controlled by the first control signal TP_CON. The switching device T2 is turned on by the first control signal TP_CON during display, and the switching device T1 is turned off by the first control signal TP_CON during touch sensing. In this embodiment, the switching device T2 may be a high voltage P-type metal oxide semiconductor (HVPMOS) transistor, but the present invention is not limited thereto.

[0087] The TDDI circuit 112 outputs a second control signal TP_EN to the first level shifter 213_1. The first level shifter 213_1 is configured to receive the second control signal TP_EN and the first input voltage VGH. The first level shifter 213_1 generates the first control signal TP_CON based on the first input voltage VGH according to the second control signal TP_EN.

[0088] The first capacitor C1 includes a first end and a second end. The first end of the first capacitor C1 is coupled to the second end of the switching device T2. The second end of the first capacitor C1 is coupled to the TDDI circuit 112 to receive the reference voltage VMD from the output buffer 400 of the TDDI circuit 112. The second capacitor C2 includes a first end and a second end. The first end of the second capacitor C2 is coupled to the second end of the first capacitor C1. The second end of the second capacitor C2 is coupled to the diode device D. The diode device D includes a first end and a second end. The first end of the diode device D is coupled to the second end of the second capacitor C2. The first end of the diode device D serves as an output terminal to output the second output voltage VGL_LS. The second end of the diode device D is coupled to the power supply circuit 211. The second end of the diode device D serves as an input terminal to receive the second input voltage VGL.

[0089] Figure 6 is a schematic block diagram showing a driver circuit according to another embodiment of the present invention. Refer to Figure 6 The driver circuit 600 includes a TDDI circuit 112, an external circuit 614, a power supply circuit 211, and a level shifter circuit 800. The level shifter circuit 800 includes a first level shifter 213_1 and a second level shifter 213_2. The first level shifter 213_1 is disposed outside the external circuit 614 and is integrated with the second level shifter 213_2 to form a semiconductor chip.

[0090] In this embodiment, the external circuit 614 includes a diode device D, a first capacitor C1, a second capacitor C2, and a switching device T1 connected in series. The switching device T1 is controlled by a first control signal TP_CON from a first level shifter 213_1. The switching device T1 can be a high-voltage N-type metal-oxide semiconductor (HVNMOS) transistor, but the present invention is not limited thereto.

[0091] The TDDI circuit 112 outputs a second control signal TP_EN to the first level shifter 213_1. The first level shifter 213_1 is configured to receive the second control signal TP_EN and a second input voltage VGL. The first level shifter 213_1 generates a first control signal TP_CON based on the second input voltage VGL according to the second control signal TP_EN.

[0092] Figure 7 is a schematic block diagram showing a TDDI circuit according to an embodiment of the present invention. Refer to Figure 4A and Figure 7 , Figure 4A The switching device T1 of

[0093] Specifically, the external circuit 114 includes a switching device T1, which is, for example, an HVNMOS transistor. The TDDI circuit 800 includes a source driver circuit 710, an interface circuit 720, a digital circuit 730, an analog front end (AFE) circuit 740, an output buffer circuit 750, and a gate driver circuit 760. The source driver circuit 710, the AFE circuit 740, and the output buffer circuit 750 include middle voltage (MV) devices. The interface circuit 720, the digital circuit 730, and the gate driver circuit 760 include low voltage (LV) devices.

[0094] In this embodiment, the switching device T1 is a high-voltage (HV) device. The TDDI circuit 800 includes MV devices and LV devices. Therefore, the voltage durability of the switching device T1 is greater than that of the TDDI circuit 800.

[0095] In addition, referring to the well-known common knowledge in the related art, sufficient teachings, suggestions, and example implementations of the hardware structures of the source driver circuit 710, the interface circuit 720, the digital circuit 730, the AFE circuit 740, the output buffer circuit 750, and the gate driver circuit 760 can be obtained.

[0096] In one embodiment, the output buffer circuit 750 may include a digital-to-analog converter (DAC) and an output buffer 400. The DAC receives a control signal in digital format and converts it into a control signal in analog format. The output buffer 400 amplifies the control signal in analog format to generate a reference signal VMD and outputs it to the external circuit 114.

[0097] In one embodiment, for a TDDI application, the low voltage may be a voltage between 1.0V and 1.5V, the middle voltage may be a voltage between 3.3V and 7.0V, and the high voltage may be a voltage between 8V and 32V.

[0098] In summary, in an embodiment of the present invention, the TDDI circuit provides a synchronous drive voltage of HV via an external circuit during touch sensing. The TDDI circuit includes only MV devices and / or LV devices and is thus not limited to being manufactured by an HV process. The TDDI circuit can work with a cheaper and more efficient level converter or gate driver. Since the TDDI circuit includes only MV devices and / or LV devices, the temperature variation of the chip and the electromagnetic interference caused by HV devices can be reduced, and the complexity of the TDDI circuit can be simplified.

[0099] For those skilled in the art, various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the above, the disclosure is intended to cover modifications and variations that fall within the scope of the appended claims and their equivalents.

Claims

1. A driver circuit configured to drive a display panel to perform a display operation and a touch sensing operation, the driver circuit comprising: A touch and display driver integrated circuit configured to drive the display panel to perform the display operation and the touch sensing operation during a display period and a touch sensing period respectively, wherein the touch and display driver integrated circuit outputs a reference signal; An external circuit disposed outside the touch and display driver integrated circuit and configured to output a first output voltage and a second output voltage based on the reference signal from the touch and display driver integrated circuit, wherein the first output voltage is greater than the second output voltage; And A power supply circuit coupled to the external circuit and configured to output a first input voltage and a second input voltage, wherein the external circuit receives the first input voltage and the second input voltage from the power supply circuit, and the first input voltage is greater than the second input voltage, wherein the external circuit includes a switching device controlled by a first control signal, and during the display period, the switching device is turned on by the first control signal, and during the touch sensing period, the switching device is turned off by the first control signal, wherein the external circuit further includes: A diode device including a first end and a second end, wherein the first end of the diode device is coupled to the power supply circuit and serves as an input end to receive the first input voltage, and the second end of the diode device serves as an output end to output the first output voltage; A first capacitor including a first end and a second end, wherein the first end of the first capacitor is coupled to the second end of the diode device, and the second end of the first capacitor is coupled to the touch and display driver integrated circuit to receive a reference voltage; and A second capacitor including a first end and a second end, wherein the first end of the second capacitor is coupled to the second end of the first capacitor, and the second end of the second capacitor is coupled to the switching device, wherein the switching device includes a first end, a second end, and a control end, the first end of the switching device is coupled to the second end of the second capacitor and serves as an output end to output the second output voltage, and the second end of the switching device serves as an input end to receive the second input voltage, and the control end of the switching device is coupled to the first control signal.

2. The driver circuit according to claim 1, wherein the external circuit generates the first output voltage based on the reference signal according to the first input voltage, and the external circuit generates the second output voltage based on the reference signal according to the second input voltage.

3. The driver circuit according to claim 1, wherein the switching device has a first voltage durability, and the touch and display driver integrated circuit has a second voltage durability, and the first voltage durability is greater than the second voltage durability.

4. The driver circuit according to claim 1 further includes a first level shifter coupled to the touch and display driver integrated circuit, wherein the touch and display driver integrated circuit outputs a second control signal to the first level shifter, and the first level shifter is configured to receive the second control signal and also receive the first input voltage or the second input voltage, wherein the first level shifter generates the first control signal based on the first input voltage or the second input voltage according to the second control signal.

5. The driver circuit according to claim 4, wherein the first level shifter is disposed in the external circuit.

6. The driver circuit according to claim 4 further includes: a second level shifter, coupled to the external circuit and disposed outside the external circuit, and configured to receive the first output voltage and the second output voltage from the external circuit, wherein the first level shifter is disposed outside the external circuit and is integrated with the second level shifter to form a semiconductor chip.

7. The driver circuit according to claim 1, wherein the touch and display driver integrated circuit and the power supply circuit are implemented as different semiconductor chips.

8. The driver circuit according to claim 1, wherein the reference signal is a ground voltage during the display.

9. The driver circuit according to claim 1, wherein the reference signal is a synchronous drive voltage during the touch sensing.

10. The driver circuit according to claim 9, wherein the first output voltage and the second output voltage have the same amplitude, phase, and frequency as the reference signal.

11. A driver circuit configured to drive a display panel to perform a display operation and a touch sensing operation, the driver circuit includes: a touch and display driver integrated circuit configured to drive the display panel to perform the display operation and the touch sensing operation during the display and the touch sensing respectively, wherein the touch and display driver integrated circuit outputs a reference signal; an external circuit disposed outside the touch and display driver integrated circuit and configured to output a first output voltage and a second output voltage based on the reference signal from the touch and display driver integrated circuit, wherein the first output voltage is greater than the second output voltage; and a power supply circuit coupled to the external circuit and configured to output a first input voltage and a second input voltage, wherein the external circuit receives the first input voltage and the second input voltage from the power supply circuit, and the first input voltage is greater than the second input voltage, wherein the external circuit includes a switching device controlled by a first control signal, and during the display, the switching device is turned on by the first control signal, and during the touch sensing, the switching device is turned off by the first control signal, wherein The switching device includes a first end, a second end, and a control end. The first end of the switching device is coupled to the power supply circuit and serves as an input end to receive the first input voltage, and the second end of the switching device serves as an output end to output the first output voltage. Wherein the external circuit further includes: A first capacitor, including a first end and a second end, wherein the first end of the first capacitor is coupled to the second end of the switching device, and the second end of the first capacitor is coupled to the touch and display driver integrated circuit to receive a reference voltage; A second capacitor, including a first end and a second end, wherein the first end of the second capacitor is coupled to the second end of the first capacitor; And A diode device, including a first end and a second end, wherein the first end of the diode device is coupled to the second end of the second capacitor and serves as an output end to output the second output voltage, and the second end of the diode device serves as an input end to receive the second input voltage.

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