TWI889328B - Charge pumps, control chips and electronic devices that can reduce electromagnetic radiation - Google Patents

Abstract

A charge pump has: a capacitor circuit having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, wherein the voltage doubling operation has a first stage and a second stage. In the first stage, the first end and the second end of the first capacitor receive a first pulse voltage signal and a second pulse voltage signal respectively to perform a first charging procedure. In the second stage, the second end of the first capacitor receives a third pulse voltage signal. The switch receives a control signal to couple the stacked voltage signal to the second capacitor via a channel of the switch to establish an output voltage on the second capacitor; wherein one of the first pulse voltage signal and the second pulse voltage signal has a first slope transient period in the first phase, and the other pulse voltage signal appears after the first slope transient period.

Description

Charge pumps, control chips and electronic devices that can reduce electromagnetic radiation

The present invention relates to a DC-DC converter, and more particularly to a charge pump capable of reducing electromagnetic radiation.

A charge pump is a type of DC-DC converter that uses capacitors as energy storage elements. It is generally used to generate an output voltage that is greater than the input voltage, or to generate a negative output voltage.

Please refer to FIG. 1 and FIG. 2 together, wherein FIG. 1 is a schematic diagram of a conventional charge pump; and FIG. 2 is an operation timing diagram of the conventional charge pump. As shown in FIG. 1, the conventional charge pump includes a first switch 11, a second switch 12, a first capacitor 13, a third switch 14, a fourth switch 15, and a second capacitor 16, and performs a voltage doubling operation according to the operation timing shown in FIG. 2 based on the control of a first switch signal S1, a second switch signal S2, a first switch signal S3, and a fourth switch signal S4 to establish a voltage twice that of a voltage source VP on the second capacitor 16. In detail, the voltage doubling operation includes a first stage and a second stage. In the first stage: the first switch signal S1 and the second switch signal S2 are in an active state to turn on the first switch 11 and the second switch 12, and the third switch signal S3 and the fourth switch signal S4 are in an inactive state to disconnect the third switch 14 and the fourth switch 15, thereby establishing a cross-voltage VP between the two terminals A and B of a first capacitor 13; in the second stage: the first switch signal S1 and the second switch signal S2 are in an inactive state to disconnect the first switch 11 and the second switch 12, and the third switch signal S3 and the fourth switch signal S4 are in an active state to turn on the third switch 14 and the fourth switch 15, at this time, the terminal B is coupled to the voltage source VP so that the voltage of the terminal A is equal to VP+VP, and the terminal A is coupled to the second capacitor 16 to charge the second capacitor 16. After charging the second capacitor 16 multiple times in this way, a voltage of 2*VP can be established on the second capacitor 16.

Since charge pumps do not use inductors, the electromagnetic radiation they generate is rarely studied. However, in some applications, the electromagnetic radiation generated by the charge pump during the charging and discharging of the capacitor will affect the normal operation of the antenna. Although conductive tape can effectively isolate the interference of electromagnetic radiation, it will increase the manufacturing cost.

In detail, the instantaneous current I of the capacitor C of the charge pump can be expressed as I=C*△V/△T, where △T is the unit time and △V is the voltage change value. If △V/△T is larger (the greater the charging and discharging slope of the capacitor C), the larger the instantaneous current I will be. Excessive instantaneous current is the main cause of electromagnetic wave radiation.

In addition, when the charging and discharging slope of capacitor C is too fast, it will not only cause electromagnetic wave radiation, but also have a certain degree of impact on the touch signal-to-noise ratio (SNR) in the application of touch and drive integrated chip (TDDI).

In order to solve the above problems, a novel charge pump control mechanism is urgently needed in this field.

The main purpose of the present invention is to provide a charge pump that can effectively reduce electromagnetic radiation by first applying a ramp voltage signal to one end of a capacitor and then applying a pulse voltage to the other end of the capacitor when the ramp voltage signal reaches a predetermined voltage.

Another object of the present invention is to provide a control chip that can effectively reduce electromagnetic radiation through the aforementioned charge pump.

Another object of the present invention is to provide an information processing device that can effectively reduce electromagnetic radiation through the aforementioned control chip.

To achieve the above-mentioned purpose, a charge pump is proposed, which has: a capacitor circuit, having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation having a first stage and a second stage, in the first stage, the first end and the second end of the first capacitor correspondingly receive a first pulse voltage signal and a second pulse voltage signal to perform a first charging procedure, in the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through a channel of the switch to establish an output voltage on the second capacitor; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a first capacitor circuit; a second capacitor circuit; a voltage signal generating unit for generating the first pulse voltage signal; a second voltage signal generating unit for generating the second pulse voltage signal; a third voltage signal generating unit for generating the third pulse voltage signal; and a switch signal generating unit for generating the control signal to control the resistance value of the channel of the switch; wherein the first voltage signal A pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period.

In one embodiment, the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period.

In one embodiment, the control signal has a second slope transient period in the second phase, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period.

To achieve the above-mentioned purpose, the present invention further proposes a control chip, which has a charge pump, and the charge pump has: a capacitor circuit, having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation has a first stage and a second stage, in the first stage, the first end and the second end of the first capacitor correspondingly receive a first pulse voltage signal and a second pulse voltage signal to perform a first charging procedure, in the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through the channel of the switch to establish an input voltage on the second capacitor. a first voltage signal generating unit for generating the first pulse voltage signal; a second voltage signal generating unit for generating the second pulse voltage signal; a third voltage signal generating unit for generating the third pulse voltage signal; and a switch signal generating unit for generating the control signal to control the resistance value of the channel of the switch; wherein, A pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period.

In one embodiment, the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period.

In one embodiment, the control signal has a second slope transient period in the second phase, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period.

To achieve the above-mentioned object, the present invention further proposes an electronic device having a control chip, the control chip having a charge pump, and the charge pump having: a capacitor circuit having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation having a first stage and a second stage, in the first stage, the first terminal of the first capacitor is The first and second ends of the first capacitor receive a first pulse voltage signal and a second pulse voltage signal correspondingly to perform a first charging procedure. In the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through the channel of the switch to generate a stacking voltage signal at the second end. An output voltage is established on the capacitor; a first voltage signal generating unit is used to generate the first pulse voltage signal; a second voltage signal generating unit is used to generate the second pulse voltage signal; a third voltage signal generating unit is used to generate the third pulse voltage signal; and a switch signal generating unit is used to generate the control signal to control the resistance value of the channel of the switch; Among them, a pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period.

In one embodiment, the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period.

In one embodiment, the control signal has a second slope transient period in the second phase, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period.

In a possible embodiment, the electronic device may be a liquid crystal display, an LED display, an OLED display or an information processing device.

In order to enable the review committee to further understand the structure, features, purpose, and advantages of the present invention, the detailed description of the drawings and preferred specific embodiments is attached as follows.

11: First switch

12: Second switch

13: First capacitor

14: The third switch

15: The fourth switch

16: Second capacitor

100: Charge pump

110: Capacitor circuit

111: First capacitor

112: Second capacitor

113: Switch

121: First voltage signal generating unit

121a: Switch

122: Second voltage signal generating unit

122a: Switch

123: Third voltage signal generating unit

123a: switch

123b: switch

123c:Capacitor

123d: switch

123e: switch

124: Switching signal generating unit

200: Control chip

210: Charge pump

220: Control circuit

300: Electronic devices

310: Control chip

320: Functional module

FIG. 1 is a schematic diagram of an existing charge pump; FIG. 2 is an operation timing diagram of the charge pump of FIG. 1; FIG. 3 is a circuit diagram of an embodiment of the charge pump of the present invention; FIG. 4 is an operation timing diagram of realizing a voltage doubling operation of the charge pump of FIG. 3 by controlling the channel resistance of the switch; FIG. 5 is a circuit diagram of an embodiment of the first voltage signal generating unit, the second voltage signal generating unit and the third voltage signal generating unit of the charge pump of FIG. 3; FIG. 6 is a block diagram of an embodiment of the control chip of the present invention; and FIG. 7 is a block diagram of an embodiment of the electronic device of the present invention.

Please refer to FIG. 3, which shows a circuit diagram of an embodiment of the charge pump of the present invention. As shown in FIG. 3, a charge pump 100 has a capacitor circuit 110, a first voltage signal generating unit 121, a second voltage signal generating unit 122, a third voltage signal generating unit 123 and a switch signal generating unit 124.

The capacitor circuit 110 has a first capacitor 111, a second capacitor 112 and a switch 113 to periodically perform a voltage doubling operation, and the voltage doubling operation has a first stage and a second stage.

In the first stage, the first terminal A and the second terminal B of the first capacitor 111 receive a first pulse voltage signal _v1 and a second pulse voltage signal _v2 respectively to perform a first charging procedure; in the second stage, the second terminal B of the first capacitor 111 receives a third pulse voltage signal _v3 to generate a stacked voltage signal at the first terminal A, wherein the voltage of the stacked voltage signal is equal to the voltage of the third pulse voltage signal _v3 plus the voltage difference between the first terminal A and the second terminal B of the first capacitor 111, and the switch 113 receives a control signal S ₄ so that the stacked voltage signal is coupled to the second capacitor 112 via the channel of the switch 113 to establish an output voltage V _O on the second capacitor 112.

In addition, the first voltage signal generating unit 121 is used to generate the first pulse voltage signal v ₁ ; the second voltage signal generating unit 122 is used to generate the second pulse voltage signal v ₂ ; the third voltage signal generating unit 123 is used to generate the third pulse voltage signal v ₃ ; and the switch signal generating unit 124 is used to generate the control signal S ₄ to control the resistance of the channel of the switch 113 .

To reduce electromagnetic radiation, one of the first pulse voltage signal _v1 and the second pulse voltage signal _v2 may have a first slope transient period in the first phase, and the other pulse voltage signal provides a pulse voltage after the first slope transient period; or the third pulse voltage signal _v3 may have a second slope transient period in the second phase, and the control signal _S4 may provide a pulse voltage after the second slope transient period; or the control signal _S4 may have a second slope transient period in the second phase, and the third pulse voltage signal v ₃ provides a pulse voltage after the second slope transient period.

In addition, in order to make the first pulse voltage signal _v1 , the second pulse voltage signal _v2 , the third pulse voltage signal _v3 and the switch signal generating unit 124 generate the above-mentioned waveform and timing, the first voltage signal generating unit 121, the second voltage signal generating unit 122 and the third voltage signal generating unit 123 can each include a slope control unit and/or a delay unit to adjust the slope of the rising edge/falling edge of the generated pulse voltage and/or the output time point of the pulse voltage, and the switch signal generating unit 124 can also include a slope control unit and/or a delay unit to adjust the generated control signal S The slope of the rising edge/falling edge of _{S 4} , and/or the output timing of the control signal S ₄ .

In addition, the slope control unit and the delay unit can achieve the above waveform and timing by adjusting the control signal of a voltage source or a switch connected in series with the voltage source. Please refer to Figure 4, which is a working timing diagram of the voltage doubling operation of the charge pump of Figure 3 by controlling the channel resistance of the switch. As shown in FIG4 , control signals SW1, SW2, SW3, and SW4 are control signals of internal switches of the first voltage signal generating unit 121, the second voltage signal generating unit 122, the third voltage signal generating unit 123, and the switch signal generating unit 124, wherein SW1 has a first slope transient period td1 in the first stage, and SW2 provides a pulse voltage after the first slope transient period td1; SW3 has a second slope transient period td2 in the second stage, and SW4 provides a pulse voltage after the second slope transient period td2.

Please refer to FIG. 5, which shows a circuit diagram of an embodiment of the first voltage signal generating unit 121, the second voltage signal generating unit 122, and the third voltage signal generating unit 123 of the charge pump of FIG. 3. As shown in FIG. 5, the first voltage signal generating unit 121 has a switch 121a, and the switch 121a couples a positive voltage Vp to the first terminal A according to the control of the control signal SW1; the second voltage signal generating unit 122 has a switch 122a, and the switch 122a couples a negative voltage Vn to the second terminal B according to the control of the control signal SW2; the third voltage signal generating unit 123 has a switch 123a, a switch 123b, and a Capacitor 123c, a switch 123d and a switch 123e, wherein switch 123a couples positive voltage Vp to a terminal C according to control of control signal SW1; switch 123b couples negative voltage Vn to a terminal D according to control of control signal SW2; capacitor 123c is coupled between terminal C and terminal D; switch 123d conducts terminal C and second terminal B according to control of control signal SW4 to output a third pulse voltage signal _v3 ; switch 123e couples positive voltage Vp to terminal D according to control of control signal SW3. During operation, the peak value of the third pulse voltage signal _v3 = 2Vp-Vn, and the output voltage _V0 = 3Vp-2Vn. Since the third voltage signal generating unit 123 performs voltage doubling operation according to the control signals SW1, SW2, SW3 and SW4 shown in FIG. 4 , the current variation rate can be effectively reduced during operation.

Accordingly, the present invention can effectively reduce the current variation rate, thereby significantly reducing electromagnetic radiation.

According to the above description, the present invention further proposes a control chip. Please refer to FIG6, which shows a block diagram of an embodiment of the control chip of the present invention. As shown in FIG6, a control chip 200 has a charge pump 210 and a control circuit 220, wherein the charge pump 210 is implemented by the charge pump 100 to generate an output voltage _V0 to provide a working voltage to the control circuit 220.

According to the above description, the present invention further proposes an electronic device. Please refer to FIG. 7, which shows a block diagram of an embodiment of the electronic device of the present invention. As shown in FIG. 7, an electronic device 300 has a control chip 310 and a functional module 320, and the control chip 310 is implemented by the control chip 200 to drive the functional module 320.

In addition, the electronic device 300 may be a liquid crystal display, an LED display, an OLED display, or an information processing device.

According to the above design, the present invention has the following advantages: 1. The charge pump of the present invention can effectively reduce electromagnetic radiation by first applying a ramp voltage signal to one end of a capacitor, and applying a pulse voltage to the other end of the capacitor when the ramp voltage signal reaches a predetermined voltage; 2. The control chip of the present invention can effectively reduce electromagnetic radiation through the aforementioned charge pump; and 3. The information processing device of the present invention can effectively reduce electromagnetic radiation through the aforementioned control chip.

What is disclosed in this case is a better embodiment. Any partial changes or modifications that are derived from the technical ideas of this case and are easily inferred by people familiar with the art do not deviate from the scope of the patent rights of this case.

In summary, this case shows that it is very different from the known technology in terms of purpose, means and effect, and it is the first invention that is practical and indeed meets the patent requirements for invention. We sincerely ask the review committee to examine it carefully and grant a patent as soon as possible to benefit the society. This is our utmost prayer.

100: Charge pump

110: Capacitor circuit

111: First capacitor

112: Second capacitor

113: Switch

121: First voltage signal generating unit

122: Second voltage signal generating unit

123: Third voltage signal generating unit

124: Switching signal generating unit

Claims (10)

A charge pump, comprising: A capacitor circuit, having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation having a first stage and a second stage, in the first stage, the first end and the second end of the first capacitor correspondingly receive a first pulse voltage signal and a second pulse voltage signal to perform a first charging procedure, in the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through the channel of the switch to establish an output voltage on the second capacitor; A first voltage signal generating unit for generating the first pulse voltage signal; A second voltage signal generating unit for generating the second pulse voltage signal; A third voltage signal generating unit for generating the third pulse voltage signal; and A switch signal generating unit for generating the control signal to control the resistance value of the channel of the switch; Among them, a pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period. A charge pump as described in claim 1, wherein the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period. A charge pump as described in claim 1, wherein the control signal has a second slope transient period in the second stage, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period. A control chip has a charge pump, the charge pump has: A capacitor circuit, having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation has a first stage and a second stage, in the first stage, the first end and the second end of the first capacitor receive a first pulse voltage signal and a second pulse voltage signal correspondingly to perform a first charging procedure, in the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through the channel of the switch to establish an output voltage on the second capacitor; A first voltage signal generating unit for generating the first pulse voltage signal; A second voltage signal generating unit for generating the second pulse voltage signal; A third voltage signal generating unit for generating the third pulse voltage signal; and A switch signal generating unit for generating the control signal to control the resistance value of the channel of the switch; Among them, a pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period. A control chip as described in claim 4, wherein the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period. A control chip as described in claim 4, wherein the control signal has a second slope transient period in the second stage, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period. An electronic device having a control chip, the control chip having a charge pump, and the charge pump having: A capacitor circuit having a first capacitor, a second capacitor and a switch to periodically perform a voltage doubling operation, the voltage doubling operation having a first stage and a second stage, in the first stage, the first end and the second end of the first capacitor correspondingly receive a first pulse voltage signal and a second pulse voltage signal to perform a first charging procedure, in the second stage, the second end of the first capacitor receives a third pulse voltage signal to generate a stacking voltage signal at the first end, and the switch receives a control signal to couple the stacking voltage signal to the second capacitor through the channel of the switch to establish an output voltage on the second capacitor; A first voltage signal generating unit for generating the first pulse voltage signal; A second voltage signal generating unit for generating the second pulse voltage signal; A third voltage signal generating unit for generating the third pulse voltage signal; and A switch signal generating unit for generating the control signal to control the resistance value of the channel of the switch; Among them, a pulse voltage signal generated by one of the first voltage signal generating unit and the second voltage signal generating unit has a first slope transient period in the first phase, and the other voltage signal generating unit of the first voltage signal generating unit and the second voltage signal generating unit provides a pulse voltage signal after the first slope transient period. An electronic device as described in claim 7, wherein the third pulse voltage signal has a second slope transient period in the second stage, and the switch signal generating unit provides a pulse voltage signal after the second slope transient period. An electronic device as described in claim 7, wherein the control signal has a second slope transient period in the second phase, and the third voltage signal generating unit provides a pulse voltage signal after the second slope transient period. The electronic device as described in claim 7 is selected from the group consisting of a liquid crystal display, a LED display, an OLED display and an information processing device.

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