Voltage control circuit and voltage generation device

Abstract

The invention provides a voltage control circuit and a voltage generating device, the voltage control circuit comprises a first voltage end, a second voltage end and a voltage regulating unit, the first voltage end provides a first voltage, the second voltage end provides a second voltage, the first voltage end and the second voltage end are coupled with a capacitor in a charging stage, and the capacitor is coupled with the first voltage end and the second voltage end. The capacitor receives a first voltage and a second voltage, the voltage regulating unit regulates the voltage of the capacitor in an output stage, and the voltage control circuit generates a plurality of times of the first voltage or a plurality of times of the second voltage in the output stage through the capacitor. The voltage generating device comprises a first voltage generating circuit, a second voltage generating circuit, a capacitor and a voltage control circuit.

Description

Technical Field

[0001] This invention relates to a voltage control circuit and a voltage generating device, and more particularly to a voltage control circuit and a voltage generating device for a display panel. Background Technology

[0002] Voltage output devices used for display panels need to provide the voltage required to drive the display elements on the display panel to display, such as providing multiple times the system voltage. When the voltage output device provides multiple times the system voltage, it may exceed the process voltage tolerance limit of the internal electronic components of the voltage output device, causing damage or failure.

[0003] Please refer to Figure 1 This is a schematic diagram of a voltage generation circuit in the prior art. The voltage generation circuit 1 includes charge pump circuits P1, P2, and P3, each containing capacitors C1, C2, and C3. Based on the voltage required for the display panel to operate, the voltage generation circuit 1 generates low, medium, and high voltages to an external storage capacitor CS by connecting the capacitors C1, C2, and C3 within the charge pump circuits P1, P2, and P3 in series. For example, it generates the high voltage required to drive the display elements on the display panel. In this embodiment, for example, each capacitor can store twice the system voltage VDD. By connecting capacitors C1, C2, and C3 in series, six times the system voltage VDD (6VDD) can be provided to the storage capacitor CS, providing the display panel with the power to drive the display elements to display an image. However, generating high voltage by connecting multiple capacitors in series not only significantly occupies internal circuit space but also reduces the equivalent capacitance value, resulting in a correspondingly smaller amount of charge that can be stored. Furthermore, when the generated high voltage exceeds the process withstand voltage of the internal components, it can cause damage or malfunction to the internal circuit components.

[0004] Based on the above, the present invention provides a voltage control circuit and a voltage output device to solve the various technical problems mentioned above. Summary of the Invention

[0005] One object of the present invention is to provide a voltage control circuit, which includes a first voltage terminal, a second voltage terminal and a voltage regulation unit. During the charging stage, the first voltage terminal and the second voltage terminal are coupled to a capacitor, so that the capacitor receives the first voltage and the second voltage. The capacitor is disposed outside the voltage control circuit. During the output stage, the voltage control circuit generates a plurality of times the first voltage or a plurality of times the second voltage through the capacitor.

[0006] One objective of this invention is to provide a voltage control circuit, which includes a first voltage terminal, a second voltage terminal, and a voltage regulation unit. Through operation in the charging and output phases, the voltage control circuit outputs a positive or negative voltage exceeding the process voltage of the internal electronic components via a capacitor disposed outside the voltage control circuit, without causing damage or malfunction to the internal electronic components, and meets the voltage withstand specifications of the components, thereby achieving the technical effect of outputting the required positive or negative voltage at different time points.

[0007] One object of the present invention is to provide a voltage generating device comprising a first voltage generating circuit, a second voltage generating circuit, a capacitor, and a voltage control circuit. The first voltage generating circuit provides a first voltage, the second voltage generating circuit provides a second voltage, the capacitor receives the first voltage and the second voltage during the charging phase, and the voltage control circuit adjusts the voltage of the capacitor during the output phase. The voltage control circuit generates a plurality of times the first voltage or a plurality of times the second voltage through the capacitor during the output phase. The capacitor is disposed outside the voltage generating device.

[0008] One object of the present invention is to provide a voltage generating device, which includes a first voltage generating circuit, a second voltage generating circuit, a capacitor and a voltage control circuit. The device outputs a positive or negative voltage exceeding the process voltage of the internal electronic components through a capacitor disposed outside the voltage generating device, without causing damage or failure to the internal electronic components, and meets the voltage withstand specifications of the components, thereby achieving the technical effect of outputting the required positive or negative voltage at different time points. Attached Figure Description

[0009] Figure 1 It is a schematic diagram of a voltage generating device based on conventional technology; Figure 2 This is a block diagram of the voltage generating device of the present invention; Figure 3 This is a schematic diagram of the operation of a voltage control circuit during the charging stage according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the operation of a voltage control circuit in the output stage according to an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the operation of the voltage control circuit during the charging phase, according to another embodiment of the present invention. Figure 6 This is a schematic diagram of the operation of the voltage control circuit in the output stage according to another embodiment of the present invention. [Figure Number Reference Guide] 1, 2: Voltage generating device 210: First voltage generation circuit 220: Second voltage generation circuit 230: Voltage control circuit 231: First switching circuit 232: Second switching circuit 233: Third switching circuit 234: Fourth switching circuit 235: Fifth switching circuit 236: Sixth switching circuit 240: Voltage Regulation Unit P1: First charge pump circuit P2: Second charge pump circuit P3: Third charge pump circuit C1~C3, CF: Capacitors CS: Storage capacitor Vpos: First voltage Vneg: Second voltage Vref: Reference voltage Vfb: Feedback voltage VDD: System voltage Detailed Implementation

[0010] To provide a better understanding of the structural features and effects achieved by the present invention, preferred embodiments and detailed descriptions are provided below:

[0011] Certain terms are used in the specification and claims to refer to specific elements. However, those skilled in the art will understand that manufacturers may use different names to refer to the same element. Furthermore, this specification and claims do not distinguish elements by differences in name, but rather by differences in the overall technical aspects of the elements. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." Moreover, the term "coupled" here includes any direct and indirect means of connection. Therefore, if a first device is described as coupled to a second device, it means that the first device can be directly connected to the second device, or can be indirectly connected to the second device through other devices or other means of connection.

[0012] Please see Figure 2This is a block diagram of the voltage generating device of the present invention. The voltage generating device 2 of the present invention is used to provide voltage to a display panel to supply the voltage required for the display panel to operate, for example, providing a high voltage to the display elements on the display panel to drive the display elements to display images. The display panel is, for example, a Super Twisted Nematic (STN), LTPS (Low Temperature Polysilicon), other LCD (Liquid Crystal Display), or OLED (Organic Light Emitting Diode) display panel. The voltage generating device 2 includes a first voltage generating circuit 210, a second voltage generating circuit 220, and a voltage control circuit 230. The first voltage generating circuit 210 provides a first voltage Vpos, the second voltage generating circuit 220 provides a second voltage Vneg, and the voltage control circuit 230 receives the first voltage Vpos and the second voltage Vneg. A capacitor CF and a storage capacitor CS are coupled to the voltage control circuit 230, and the capacitor CF and the storage capacitor CS are disposed outside the voltage control circuit 230. Figure 2 The dashed lines indicate that the components are located on the outside. In this embodiment, the capacitor CF is a flying capacitor, which provides functions such as voltage boosting, energy storage, and energy transmission for the voltage generating device 2. The first voltage generating circuit 210 and the second voltage generating circuit 220 are charge pump circuits.

[0013] In this embodiment, the first voltage Vpos provided by the first voltage generating circuit 210 is a positive voltage, and the second voltage Vneg provided by the second voltage generating circuit 220 is a negative voltage. The first voltage Vpos is, for example, twice the positive system voltage. The first voltage generating circuit 210 receives the system voltage and boosts the system voltage to twice the positive voltage through an internal capacitor to provide the first voltage Vpos. The second voltage Vneg is, for example, twice the negative system voltage. The first voltage generating circuit 210 receives the system voltage and converts the system voltage to twice the negative voltage through an internal capacitor to provide the second voltage Vneg.

[0014] Please see Figure 3This is a schematic diagram of the operation of a voltage control circuit during the charging phase according to an embodiment of the present invention. The voltage control circuit 230 includes a first voltage terminal, a second voltage terminal, a first switching switch 231, a second switching switch 232, a third switching switch 233, a fourth switching switch 234, and a voltage regulation unit 240. The capacitor CF and the storage capacitor CS each have a first terminal and a second terminal. The first switching switch 231 is coupled to the first voltage terminal and the first terminal of the capacitor CF, and the second switching switch 232 is coupled to the second voltage terminal and the second terminal of the capacitor CF. During the charging phase, the first switching switch 231 and the second switching switch 232 are turned on, and the third switching switch 233 and the fourth switching switch 234 are turned off. The capacitor CF receives the voltage Vpos from the first voltage terminal through the turn-on of the first switching switch 231, and the capacitor CF receives the voltage Vneg from the second voltage terminal through the turn-on of the second switching switch 232. In this embodiment, the voltage Vpos is positive twice the system voltage, and the voltage Vneg is negative twice the system voltage; therefore, during the charging phase, the capacitor CF stores four times the system voltage.

[0015] Please see Figure 4 This is a schematic diagram of the operation of a voltage control circuit in the output stage according to an embodiment of the present invention. A third switch 233 is coupled to the first terminal of capacitor CF and the first terminal of storage capacitor CS, and a fourth switch 234 is coupled to the second terminal of capacitor CF and voltage regulation unit 240. In the output stage, the third switch 233 and the fourth switch 234 are turned on, and the first switch 231 and the second switch 232 are turned off. The first terminal of storage capacitor CS receives the voltage of the first terminal of capacitor CF through the turn-on of the third switch 233, and the voltage regulation unit 240 receives the voltage of capacitor CF through the turn-on of the fourth switch 234. In the output stage, since the first terminal of storage capacitor CS receives twice the system positive voltage of the first terminal of capacitor CF, plus the four times the system voltage stored by capacitor CF during the charging stage, the voltage of the first terminal of storage capacitor CS becomes six times the system positive voltage in the output stage, allowing storage capacitor CS to store six times the system positive voltage to provide the high voltage required for the operation of the display panel. Through the operation of the charging and output stages described above, the voltage control circuit 230 can output a high voltage exceeding the process voltage of the internal electronic components via an externally located capacitor CF, without causing damage or malfunction to the internal electronic components, thus meeting the voltage withstand specifications of the components.

[0016] The voltage regulation unit 240 includes a first input terminal, a second input terminal, and an output terminal. During the output phase, the first input terminal receives a reference voltage Vref, the second input terminal receives a feedback voltage Vfb, and the output terminal is coupled to the second terminal of the capacitor CF. According to actual output requirements, the voltage control circuit 230 adjusts the voltage of the capacitor CF through the voltage regulation unit 240. The voltage control circuit 230 sets the reference voltage Vref and the feedback voltage Vfb according to the output voltage requirements. In one embodiment, the required voltage of the capacitor CF is 15V, the reference voltage is set to 1.5V, and the feedback voltage Vfb is a portion of the voltage of the capacitor CF, for example, one-tenth of the capacitor CF voltage, or it can be set to other proportions, such as one-half of the capacitor CF voltage. In this embodiment, the portion of the capacitor CF voltage is a portion of the voltage at the second terminal of the capacitor CF. After receiving the reference voltage Vref and the feedback voltage Vfb, the voltage regulation unit 240 outputs a voltage to the capacitor CF based on the voltage difference between the two. For example, when the reference voltage Vref is greater than the feedback voltage Vfb, the output of the voltage regulation unit 240 outputs a positive voltage to the capacitor CF, increasing the voltage of the capacitor CF and thus increasing the voltage of the feedback voltage Vfb. Conversely, when the reference voltage Vref is less than the feedback voltage Vfb, the output of the voltage regulation unit 240 outputs a negative voltage to the capacitor CF, decreasing the voltage of the capacitor CF and thus decreasing the voltage of the feedback voltage Vfb. This operation of the voltage regulation unit 240 continues until the feedback voltage Vfb equals the reference voltage Vref. When the feedback voltage Vfb equals the reference voltage Vref, in the above embodiment, the voltage of the feedback voltage Vfb is 1.5V, which means that the voltage of the capacitor CF is 15V, which is the required voltage. In this embodiment, the voltage regulation unit 240 is an operational amplifier (OPA).

[0017] Please see Figure 5This is a schematic diagram illustrating the operation of a voltage control circuit during the charging phase, according to another embodiment of the present invention. The voltage control circuit 230 includes a first voltage terminal, a second voltage terminal, a first switching switch 231, a second switching switch 232, a fifth switching switch 235, a sixth switching switch 236, and a voltage regulation unit 240. The capacitor CF and the storage capacitor CS each have a first terminal and a second terminal. The first switching switch 231 is coupled to the first voltage terminal and the first terminal of the capacitor CF, and the second switching switch 232 is coupled to the second voltage terminal and the second terminal of the capacitor CF. During the charging phase, the first switching switch 231 and the second switching switch 232 are turned on, while the fifth switching switch 235 and the sixth switching switch 236 are turned off. The capacitor CF receives the voltage Vpos from the first voltage terminal through the turn-on of the first switching switch 231, and the capacitor CF receives the voltage Vneg from the second voltage terminal through the turn-on of the second switching switch 232. In this embodiment, the voltage Vpos is twice the positive system voltage, and the voltage Vneg is twice the negative system voltage; therefore, during the charging phase, the capacitor CF stores four times the system voltage.

[0018] Please see Figure 6 This is a schematic diagram illustrating the operation of a voltage control circuit in the output phase according to another embodiment of the present invention. A fifth switch 233 is coupled to the second terminal of capacitor CF and the second terminal of storage capacitor CS, and a sixth switch 236 is coupled to the first terminal of capacitor CF and voltage regulation unit 240. In the output phase, the fifth switch 235 and the sixth switch 236 are turned on, and the first switch 231 and the second switch 232 are turned off. The second terminal of storage capacitor CS receives the voltage of the second terminal of capacitor CF through the turn-on of the fifth switch 235, and the voltage regulation unit 240 receives the voltage of capacitor CF through the turn-on of the sixth switch 236. In the output phase, since the second terminal of storage capacitor CS receives twice the system negative voltage of the second terminal of capacitor CF, plus the four times system voltage stored in capacitor CF during the charging phase, the voltage of the second terminal of storage capacitor CS becomes six times the system negative voltage during the output phase. This allows storage capacitor CS to store six times the system negative voltage to provide the negative voltage required for the operation of the display panel. Through the operation of the charging and output stages described above, the voltage control circuit 230 outputs a negative voltage exceeding the process voltage of the internal electronic components via an externally located capacitor CF, without causing damage or malfunction to the internal electronic components, thus meeting the voltage withstand specifications of the components.

[0019] In one embodiment, the system voltage is 3V. The voltage generating device 2 generates the high voltage required for the display panel to operate, for example, generating 6 times the system positive voltage and negative voltage, 18V and -18V, to provide high voltage so that the display elements on the display panel can display normally.

[0020] Furthermore, since the capacitor CF is located externally to the voltage generating device 2, it not only saves internal circuit space but also allows for the selection of a larger capacitance value to store more charge. In other words, the capacitance of capacitor CF can be much larger than the internal capacitance of the voltage generating device 2. For example, if the internal capacitance of the voltage generating device 2 is 1 nF, then capacitor CF can be 1 uF, a difference of 1000 times. Moreover, the high voltage generated by the voltage generating device 2 is generated by the external capacitor CF and will not affect the internal electronic components of the voltage generating device 2. This allows the voltage generating device 2 to operate within the process withstand voltage range, such as twice the system voltage, while higher voltages exceeding the process withstand voltage are operated through the external capacitor CF, such as six times the system voltage.

[0021] Through the voltage control circuit and voltage generating device of this invention, an externally mounted capacitor outputs a high voltage exceeding the process voltage of the internal electronic components without causing damage or malfunction to the internal electronic components, thus meeting the component's withstand voltage specifications. Compared to conventional technology that uses series capacitors inside the voltage generating device to generate high voltage, this invention significantly saves internal circuit space by placing the capacitor externally, and also increases the selectivity of the capacitor. A capacitance value much larger than that inside the voltage generating device can be selected according to actual needs, improving the practicality and safety of the voltage generating device.

[0022] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent variations and modifications made in accordance with the shape, structure, features and spirit described in the claims of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A voltage control circuit, characterized in that, It includes: A first voltage terminal provides a first voltage; A second voltage terminal provides a second voltage. During a charging phase, the first voltage terminal and the second voltage terminal are coupled to a capacitor, allowing the capacitor to receive the first voltage and the second voltage. A voltage regulation unit adjusts the voltage of the capacitor in an output phase, wherein the voltage control circuit generates a multiple of the first voltage or a multiple of the second voltage through the capacitor in the output phase.

2. The voltage control circuit as described in claim 1, characterized in that, The voltage regulation unit receives a portion of the capacitor's voltage and a reference voltage during the output phase. When the portion of the capacitor's voltage is different from the reference voltage, the voltage regulation unit adjusts the capacitor's voltage.

3. The voltage control circuit as described in claim 1, characterized in that, The capacitor is an external capacitor, located outside the voltage control circuit, and includes a first terminal and a second terminal.

4. The voltage control circuit as described in claim 3, characterized in that, It also includes: A first switching circuit is coupled to the first terminal of the capacitor, and during the charging phase, the first terminal of the capacitor receives the first voltage through the first switching circuit; and A second switching circuit is coupled to the second terminal of the capacitor, and during the charging phase, the second terminal of the capacitor receives the second voltage through the second switching circuit.

5. The voltage control circuit as described in claim 3, characterized in that, It also includes: A third switching circuit is coupled to the first terminal of the capacitor. During the output stage, the voltage control circuit outputs the first voltage or a multiple of the first voltage through the third switching circuit. as well as A fourth switching circuit is coupled to the voltage regulation unit, and during the output stage, the voltage regulation unit receives the voltage of the capacitor through the fourth switching circuit.

6. The voltage control circuit as described in claim 3, characterized in that, It also includes: A fifth switching circuit is coupled to the second terminal of the capacitor. During the output phase, the voltage control circuit outputs the second voltage or a multiple of the second voltage through the fifth switching circuit. as well as A sixth switching circuit is coupled to the voltage regulation unit, and during the output stage, the voltage regulation unit receives the voltage of the capacitor through the sixth switching circuit.

7. The voltage control circuit as described in claim 1, characterized in that, It also includes: A storage capacitor, during the output phase, outputs a multiple of the first voltage or a multiple of the second voltage to the storage capacitor.

8. The voltage control circuit as described in claim 1, characterized in that, The first voltage is a positive voltage, and the second voltage is a negative voltage.

9. The voltage control circuit as described in claim 1, characterized in that, The voltage control circuit is used to drive the display panel.

10. A voltage generating device, characterized in that, Include: A first voltage generating circuit provides a first voltage; A second voltage generating circuit provides a second voltage; A capacitor, receiving the first voltage and the second voltage during a charging phase; and A voltage control circuit adjusts the voltage of the capacitor in an output phase, wherein the voltage control circuit generates a multiple of the first voltage or a multiple of the second voltage through the capacitor in the output phase.

11. The voltage output device as claimed in claim 10, characterized in that, The capacitor is located outside the voltage control circuit.

12. The voltage output device as claimed in claim 10, characterized in that, It also includes a storage capacitor coupled to the voltage control circuit, which generates a multiple of the first voltage or a multiple of the second voltage to the storage capacitor during the output phase through the capacitor.

13. The voltage output device as claimed in claim 10, characterized in that, The voltage control circuit includes a voltage regulation unit that receives a portion of the capacitor's voltage and a reference voltage during the output phase. When the portion of the capacitor's voltage differs from the reference voltage, the voltage regulation unit adjusts the capacitor's voltage.

14. The voltage output device as claimed in claim 10, characterized in that, The first voltage is a positive voltage, and the second voltage is a negative voltage.

15. The voltage output device as claimed in claim 10, characterized in that, The voltage output device is used to drive the display panel.

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