KR20170037339A - Wireless power transmitter - Google Patents

Abstract

A power wireless transmitter capable of wirelessly charging a wireless power receiver, includes a differential signal generating unit which generates a differential signal, a PA driver which includes a plurality of transistors, a first inductor which is arranged between the plurality of transistors and a driving voltage input terminal, and a second inductor which is arranged between the plurality of transistors and a ground terminal, and removes the noise of the differential signal; an amplifier which amplifies the noise-removed differential signal by a preset gain; and a resonant unit which transmits the amplified differential signal to the wireless power receiver. Accordingly, the present invention can remove the noise of the differential signal or a single-ended signal.

Description

[0001] WIRELESS POWER TRANSMITTER [0002]

The present invention relates to a wireless power transmitter, and more particularly to a wireless power transmitter for wirelessly transmitting power to at least one wireless power receiver.

BACKGROUND ART A mobile terminal such as a mobile phone or a PDA (Personal Digital Assistants) is driven by a rechargeable battery. In order to charge the battery, a separate charging device is used to supply electric energy to the battery of the mobile terminal. Typically, the charging device and the battery are each provided with a separate contact terminal on the outside thereof, which are in contact with each other to electrically connect the charging device and the battery.

However, in the contact type charging method, since the contact terminal protrudes to the outside, contamination by foreign matter is easy, and battery charging may not be performed properly for this reason. Also, even if the contact terminal is exposed to moisture, charging may not be performed properly.

In order to solve these problems, wireless charging or non-contact charging technology has recently been developed and used in many electronic devices.

This wireless charging technique uses wireless power transmission and reception, for example, a system in which a battery can be automatically charged by simply placing a cellular phone on a charging pad without connecting a separate charging connector. It is generally known to the general public as a wireless electric toothbrush or a wireless electric shaver. Such wireless charging technology can enhance the waterproof function by charging the electronic products wirelessly, and it is advantageous to increase the portability of the electronic devices since the wired charger is not required, and the related technology is expected to greatly develop in the upcoming electric car era .

Such wireless charging techniques include an electromagnetic induction method using a coil, a resonance method using resonance, and a radio frequency (RF) / microwave radiation (RF) method in which electric energy is converted into a microwave.

Currently, electromagnetic induction is the main method. However, in recent years, experiments have been successfully conducted to transmit electric power wirelessly from a distance of several tens of meters using microwaves at home and abroad. In the near future, The world seems to be opened.

The power transmission method by electromagnetic induction is a method of transmitting power between the primary coil and the secondary coil. When a magnet is moved to a coil, an induced current is generated, which generates a magnetic field at the transmitting end and induces a current according to the change of the magnetic field at the receiving end to generate energy. This phenomenon is called magnetic induction phenomenon, and the power transmission method using the phenomenon is excellent in energy transmission efficiency.

In 2005, Professor Soljacic of MIT announced Coupled Mode Theory, a system in which electricity is delivered wirelessly, even at distances of a few meters (m) from the charging device, using resonant power transmission principles. The MIT team's wireless charging system uses resonance (resonance), which uses a physics concept that resonates at the same frequency as a wine bottle next to the tuning fork. Instead of resonating the sound, the researchers resonated electromagnetic waves that contained electrical energy. The resonant electrical energy is transmitted directly only when there is a device with a resonant frequency, and unused portions are not re-absorbed into the air, but are reabsorbed into the electromagnetic field. Therefore, unlike other electromagnetic waves, they will not affect the surrounding machine or body .

Conventional wireless power transmitters and wireless power receivers can generate a differential signal or a single-ended signal and input / output between the devices. In addition, a wireless power transmitter uses a switching power amplifier such as a class E / D for high efficiency. In this case, a differential signal or a single-ended signal supplied to the power amplifier is close to a square wave, so that a noise of a very high harmonic signal may occur. In addition, when a circuit structure such as a single-ended structure is used, power consumption is also increased and the driving voltage is instantaneously detected at the rising edge or the falling edge of the current peak in the case of a spherical file due to the single- Resulting in a large EMI (electro magnetic interference) signal emission of a high frequency. EMI emissions can act as noise sources at various frequencies in a module or system, affecting other circuits or modules, which can degrade performance and cause malfunctions.

According to various embodiments of the present invention, a wireless power transmitter and a wireless power receiver and a PA driver may be provided to eliminate noise in differential or single-ended signals.

According to various embodiments of the present invention, a wireless power transmitter for wirelessly charging a wireless power receiver includes a differential signal generator for generating a differential signal, a plurality of transistors, a plurality of transistors disposed between the plurality of transistors and the drive voltage input A PA driver that includes a first inductor, a second inductor disposed between the plurality of transistors and a ground terminal, and removes noise of the differential signal, an amplifier that amplifies the noise canceled differential signal by a predetermined gain, And a resonance unit for transmitting the amplified differential signal to the wireless power receiver.

According to various embodiments of the present invention, a wireless power transmitter for wirelessly charging a wireless power receiver includes a signal generator for generating a single-ended signal, a plurality of transistors, a plurality of transistors disposed between the plurality of transistors and the driving voltage input A PA driver includes a first inductor, a second inductor disposed between the plurality of transistors and a ground terminal, and configured to remove noise of the single-ended signal. The PA driver amplifies the single- An amplifier, and a resonator for transmitting the amplified single-ended signal to the wireless power receiver.

According to various embodiments of the present invention, an integrated circuit (IC) for eliminating noise of a differential signal supplied to an amplifier for amplifying a differential signal for wireless power transmission includes an integrated circuit A first N-MOSFET and a first P-MOSFET supplied with a signal through respective gates, a second N-MOSFET and a second P-MOSFET supplied with a second signal included in the differential signal through respective gates, A first inductor disposed between the first P-MOSFET and the second P-MOSFET and a driving voltage input terminal, and a second inductor disposed between the first N-MOSFET and the second N-MOSFET and the ground terminal can do.

In accordance with various embodiments of the present invention, the elimination of harmonics generated in the wireless power transmitter increases the wireless charging efficiency and EMI can be reduced.

In addition, according to various embodiments of the present invention, a low-power output circuit can be constituted by configuring the output or drive circuit of the inverter structure using complementary elements such as CMOS.

1 is a conceptual diagram for explaining overall operation of a wireless charging system.
2 is a block diagram of a wireless power transmitter and a wireless power receiver in accordance with an embodiment of the present invention.
Figures 3A-3C show block diagrams of a wireless power transmitter in accordance with various embodiments of the present invention.
4 shows a block diagram of a modulator according to various embodiments of the present invention.
5 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention.
6 shows a conceptual diagram of a signal generator and a phase controller according to various embodiments of the present invention.
7 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention.
8 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention.
Figure 9A shows the time delay, or phase delay, of a square wave at a wireless power transmitter including elements of a CMOS process according to various embodiments of the present invention at a resonant frequency of 6.78Mhz.
FIG. 9B shows measurement results for explaining FIG. 9A.
Figures 10A-10G show circuit diagrams of a PA driver in accordance with various embodiments of the present invention.
11 shows waveforms of signals before and after noise cancellation through a PA driver according to various embodiments of the present invention.
12 is a diagram illustrating a method for sensing a position change of a wireless power receiver on a wireless power transmitter according to various embodiments of the present invention.
13A to 13C show signal waveforms according to comparative examples.
14A and 14B are diagrams illustrating a method for indicating that a position of a wireless power receiver on a wireless power transmitter is out of a predetermined position according to various embodiments of the present invention.
15 is a configuration diagram of a current sensing circuit of a differential structure according to various embodiments of the present invention.
16 is a configuration diagram of an amplifier circuit connected to the current sensing circuit according to various embodiments of the present invention.
17 is a configuration diagram of a rectifier circuit according to various embodiments of the present invention.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. It should be understood, however, that this invention is not intended to be limited to the particular embodiments described herein but includes various modifications, equivalents, and / or alternatives of the embodiments of this document . In connection with the description of the drawings, like reference numerals may be used for similar components.

In this document, the expressions "having," " having, "" comprising," or &Quot;, and does not exclude the presence of additional features.

In this document, the expressions "A or B," "at least one of A or / and B," or "one or more of A and / or B," etc. may include all possible combinations of the listed items . For example, "A or B," "at least one of A and B," or "at least one of A or B" includes (1) at least one A, (2) Or (3) at least one A and at least one B all together.

As used herein, the terms "first," "second," "first," or "second," and the like may denote various components, regardless of their order and / or importance, But is used to distinguish it from other components and does not limit the components. For example, the first user equipment and the second user equipment may represent different user equipment, regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component can be named as the second component, and similarly the second component can also be named as the first component.

(Or functionally or communicatively) coupled with / to "another component (eg, a second component), or a component (eg, a second component) Quot; connected to ", it is to be understood that any such element may be directly connected to the other element or may be connected through another element (e.g., a third element). On the other hand, when it is mentioned that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component) It can be understood that there is no other component (e.g., a third component) between other components.

As used herein, the phrase " configured to " (or set) to be "configured according to circumstances may include, for example, having the capacity to, To be designed to, "" adapted to, "" made to, "or" capable of ". The term " configured to (or set up) "may not necessarily mean" specifically designed to "in hardware. Instead, in some situations, the expression "configured to" may mean that the device can "do " with other devices or components. For example, a processor configured (or configured) to perform the phrases "A, B, and C" may be implemented by executing one or more software programs stored in a memory device or a dedicated processor (e.g., an embedded processor) , And a generic-purpose processor (e.g., a CPU or an application processor) capable of performing the corresponding operations.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. The general predefined terms used in this document may be interpreted in the same or similar sense as the contextual meanings of the related art and, unless expressly defined in this document, include ideally or excessively formal meanings . In some cases, even the terms defined in this document can not be construed as excluding the embodiments of this document.

1 is a conceptual diagram for explaining overall operation of a wireless charging system. As shown in FIG. 1, the wireless charging system includes a wireless power transmitter 100 and at least one wireless power receiver 110-1, 110-2, 110-n.

The wireless power transmitter 100 may transmit power (1-1, 1-2, 1-n) wirelessly to at least one wireless power receiver (110-1, 110-2, 110-n).

The wireless power transmitter 100 may form an electrical connection with the wireless power receivers 110-1, 110-2, and 110-n. For example, the wireless power transmitter 100 may transmit wireless power by emitting an electromagnetic field or a magnetic field. Here, the wireless power transmitter 100 may transmit wireless power based on an inductive or resonant scheme.

Meanwhile, the wireless power transmitter 100 may perform bidirectional communication with the wireless power receivers 110-1, 110-2, and 110-n. The wireless power transmitter 100 and the wireless power receivers 110-1, 110-2 and 110-n transmit packets 2-1, 2-2, 2- n can be processed or transmitted / received. The wireless power receiver may be implemented in a mobile communication terminal, a PDA, a PMP, a smart phone, a wearable electronic device, or the like. The wireless power receiver 110-1, 110-2, and 110-n may perform load modulation when communicating in an in-band manner, (110-1, 110-2, 110-n).

The wireless power transmitter 100 may provide power wirelessly to a plurality of wireless power receivers 110-1, 110-2, and 110-n. For example, the wireless power transmitter 100 may transmit power to a plurality of wireless power receivers 110-1, 110-2, and 110-n through a resonance method. If the wireless power transmitter 100 employs a resonant mode, the distance between the wireless power transmitter 100 and the plurality of wireless power receivers 110-1, 110-2, 110-n may be a distance that operates in an indoor environment . Also, if the wireless power transmitter 100 employs an electromagnetic induction scheme, the distance between the wireless power transmitter 100 and the plurality of wireless power receivers 110-1, 110-2, 110-n may preferably be less than 10 cm .

The wireless power receivers 110-1, 110-2, and 110-n may receive wireless power from the wireless power transmitter 100 to perform charging of the battery included therein. Also, the wireless power receivers 110-1, 110-2, and 110-n may transmit signals requesting wireless power transmission, information required for wireless power reception, wireless power receiver status information or wireless power transmitter 100 control information, To the wireless power transmitter (100).

The wireless power receivers 110-1, 110-2, and 110-n may also transmit messages indicating their respective charging states to the wireless power transmitter 100 in an in-band or out-band manner.

The wireless power transmitter 100 may include a display means such as a display and may be coupled to the wireless power receivers 110-1 and 110-2 based on messages received from each of the wireless power receivers 110-1, 110-2, and 110-n, respectively. In addition, the wireless power transmitter 100 may display together the time that each wireless power receiver 110-1, 110-2, 110-n is expected to complete charging.

2 is a block diagram of a wireless power transmitter and a wireless power receiver in accordance with an embodiment of the present invention.

2, the wireless power transmitter 200 may include a power transmitter 211, a controller 212, and a communication module 213. The wireless power receiver 250 may also include a power receiver 251, a controller 252, and a communication module 253.

The power transmitter 211 may provide the power required by the wireless power receiver 200 and may provide power to the wireless power receiver 250 wirelessly. Here, the power transmission unit 211 may supply power in the form of an AC waveform, and may supply power in the form of a DC waveform while converting it into an AC waveform using an inverter, and supply the AC waveform in the form of an AC waveform.

In addition, the power transmitter 211 may provide an alternating current waveform to the wireless power receiver 250. The power transmitting unit 211 may further include a resonant circuit or an induction circuit, and thus can transmit or receive a predetermined electromagnetic wave. When the power transmitting section 211 is implemented as a resonant circuit, the inductance L of the loop coil of the resonant circuit may be changeable. Those skilled in the art will readily understand that the power transmitting unit 211 is not limited as long as it can transmit an electromagnetic field or a magnetic field.

The control unit 212 may control the entire operation of the wireless power transmitter 200. [ The control unit 212 or the control unit 252 can control the overall operation of the wireless power transmitter 200 or the wireless power receiver 250 using an algorithm, a program or an application required for the control read from the memory (not shown) have.

Communication module 213 may communicate in any manner with wireless power receiver 250 or another electronic device. The communication module 213 is connected to the communication module 253 of the wireless power receiver 250 through a communication network such as an NFC (Near Field Communication), a Zigbee communication, an infrared communication, a visible light communication, a Bluetooth communication, a bluetooth low energy secure transfer method, or the like. Meanwhile, the above-described communication method is merely an example, and the embodiments of the present invention are not limited to the specific communication method performed by the communication module 213.

The power receiving unit 251 can receive the wireless power from the power transmitting unit 211 based on the induction method or the resonance method.

Figures 3A-3C show block diagrams of a wireless power transmitter in accordance with various embodiments of the present invention.

3A, the wireless power transmitter 300 may include a signal adjustment unit 310, an amplifier 320, a matching unit 330, and a resonance unit 340.

The signal adjusting unit 310 includes a current sensing circuit 311, a voltage sensing circuit 312, ADCs 313 and 314, a control unit 315, a modulation unit 316, a PA (power amplifier) driver 317, (318). ≪ / RTI > The signal adjusting unit 310 may be implemented by an IC (integrated circuit), but there is no limitation on the implementation type.

In the embodiment of FIG. 3A, the signal adjustment unit 310 can generate a differential signal using the signal generation unit 318 and output the generated differential signal to the amplifier 320. FIG. For example, the signal generator 318 may include power providing means capable of generating a single-ended signal. The power providing means may be implemented with a battery included in the wireless power transmitter 300 or may be implemented with a power interface that receives power from the outside. When the power providing means is implemented by a battery, the signal generating unit 318 may further include an inverter for converting the DC power output from the battery into AC. In the case where the power providing means is implemented as a power interface, the power providing means may receive the AC power from the outside, or may receive the power of the DC and convert it to AC, in which case it may further comprise an inverter have.

On the other hand, the signal generator 318 can generate a differential signal from the single-ended signal. The signal generator 318 may include, for example, a branch rail connected in parallel to a rail that receives a single-ended signal, and may include an inverted signal generator such as an inverter located on the branch rail. Accordingly, a first signal having the same phase as that of the single-ended signal can be output on one rail of the signal generating unit 318, and a phase difference of 180 degrees with respect to the single- The second signal can be output. Accordingly, the signal generator 318 can generate a differential signal composed of a first signal and a second signal having a phase difference of 180 degrees from each other.

The modulator 316 can adjust at least one of the differential signals. The modulating unit 316 can adjust at least one of the amplitude and the phase of at least one of the differential signals. In one embodiment, the modulating unit 316 can adjust the phase of at least one of the differential signals by delaying at least one of the differential signals. The modulating unit 316 may include a DC / DC converting means or a voltage divider, and so on, so that the amplitude of at least one of the differential signals can be adjusted. On the other hand, in another embodiment, the amplitude of at least one of the differential signals may be adjusted by adjusting the driving voltage VDD of the amplifier 320 instead of the modulation unit 316. [ In this case, a DC / DC converting means or a voltage divider may be disposed on the rail to which the driving voltage VDD of the amplifier 320 is applied.

The PA driver 317 can perform current pumping with respect to the differential signal output from the modulator 316. This shortens the On / Off delay time of the input signal of the amplifier 320, And the noise canceled input signal can be amplified to a predetermined gain. In various embodiments of the invention, the input signal may be a differential signal or a single-ended signal.

In various embodiments of the present invention, the PA driver 317 may include at least one inductor. The inductor can prevent an abrupt change in the current so that the PA driver 17 can output the peak when the peak of the input differential signal is included . As will be described in more detail below, the relative position of the wireless power receiver with respect to the wireless power transmitter may be varied. Because the wireless power receiver can also include an inductor, the wireless power transmitter and the wireless power receiver can be coupled in a circuit, so that the impedance due to the relative position change can be changed. A peak may be included in the differential signal input to the PA driver 317 in accordance with the impedance change, and a peak can be prevented by the inductor included in the PA driver 317. In addition, when the wireless power transmitter operates based on, for example, the A4WP standard method, a relatively high frequency of 6.78 MHz can be used as the resonant frequency. Alternatively, even when the performance is changed in accordance with the impedance of the resonance part, the antenna, or the load, the PA driver 317 including the inductor has the characteristic of being robust against change, and more stable signal amplification is possible. In various embodiments of the present invention, the PA driver 317 may further include an inductor as well as an additional capacitor or FET device, and various embodiments will be described in more detail with reference to Figures 10a-10g.

The amplifier 320 can amplify the differential signal output from the PA driver 317 with a predetermined gain. The amplifier 320 may be implemented, for example, with an amplifier of Class-D or Class-E. The amplifier 320 may perform amplification using the driving voltage VDD. On the other hand, as described above, in one embodiment, the driving voltage VDD can be changed. For example, the wireless power transmitter 300 may include a voltage-modifiable element, such as a DC / DC converter or voltage divider, disposed on a rail that provides a driving voltage VDD to the amplifier 320. The wireless power transmitter 300 may operate the DC / DC converter or voltage divider to change the gain of the amplifier 320 when it is determined that it is necessary to adjust the amplitude of the differential signal output from the amplifier 320, The amplitude of the differential signal can be adjusted.

The matching unit 330 may include at least one of various elements for impedance matching, for example, at least one inductor and at least one capacitor. As described above, the relative position of the wireless power receiver with respect to the wireless power transmitter is variable, and thus, if the wireless power receiver is located on a wireless power transmitter, it can have various impedances. The wireless power transmitter 300 can increase wireless charging efficiency through impedance matching.

The resonator 340 generates an electromagnetic field using the differential signal from the amplifier 320 and emits the electromagnetic field to the outside. In the case where the wireless power transmitter 300 operates based on the A4WP scheme, the resonator 340 can be designed to have a resonance frequency of 6.78 MHz, and an electromagnetic field having a resonance frequency can be generated and radiated to the outside . The resonator 340 may include at least one inductor and at least one capacitor that constitute a resonant circuit.

The current sensing circuit 311 can sense the electrical characteristics of the first signal at the first input of the resonator 340, e.g., a current value. The voltage sensing circuit 312 may sense the electrical characteristics of the second signal at the second input of the resonator 340, e.g., a voltage value. Meanwhile, in various embodiments of the present invention, the current sensing circuit 311 may be coupled to the second input of the resonator 340 and the voltage sensing circuit 312 may be coupled to the first input of the resonator 340 . Further, in another embodiment of the present invention, each of the two current sensing circuits may be connected to the first input terminal and the second input terminal of the resonance part 340, respectively, and each of the two voltage sensing circuits may be connected to the resonance part 340 And may be connected to the first input terminal and the second input terminal, respectively.

The ADC 313 may convert the analog value of the current sensed by the current sensing circuit 311 into a digital value and output the digital value to the control unit 315. The ADC 314 may convert the analog value of the voltage sensed by the voltage sensing circuit 312 into a digital value and output the digital value to the control unit 315. [

The control unit 315 can determine the modulation information of the signal using the current value of the first signal and the voltage value of the second signal. For example, the controller 315 may determine the phase difference between the first signal and the second signal using the current value of the first signal and the voltage value of the second signal. The control unit 315 can determine that the phase difference between the first signal and the second signal is, for example, 183 degrees. The control unit 315 may determine the modulation information of the signal for maintaining the phase difference between the first signal and the second signal at 180 degrees. For example, the control unit 315 can determine modulation information that delays the second signal by t. The control unit 315 can output the control signal corresponding to the determined modulation information to the modulation unit 316. [ The modulation section 316 can delay the second signal by t based on the input control signal so that the phase difference between the first signal and the second signal can be maintained at a predetermined value, have. In another embodiment, the controller 315 may determine from the digital value from the ADC 314 that, for example, the amplitude of the second signal is A '. The control unit 315 can determine the modulation information that allows the amplitude of the second signal to be adjusted to A, and output the corresponding control signal. For example, when the modulation section 316 adjusts the amplitude, the control section 315 can output a control signal for adjusting the amplitude to the modulation section 316. [ In another example, when the amplifier 320 adjusts the amplitude, the control unit 315 supplies a control signal to the device such as a DC / DC converter, a voltage divider, or the like disposed on the rail to which the drive voltage of the amplifier 320 is applied. Can be output. Accordingly, the wireless power transmitter can monitor and control the change of the impedance, the mismatch of the differential signal, or the distortion of the signal in real time, thereby increasing the charging efficiency and decreasing the EMI.

According to the above description, the modulating unit 316 may be configured so that the phase difference between the first signal and the second signal maintains a predetermined value or at least one of the first signal and the second signal maintains a predetermined value, The differential signal can be adjusted. Accordingly, the first signal and the second signal constituting the differential signal have waveforms that are not distorted while having a predetermined phase difference despite the impedance change, so that relatively low EMI and high charging efficiency can be created .

When the amplifier 320 adopts the switching method of the class D, E or F, the amplifier 320 can use a square wave signal capable of turning on / off the power element with the input signal. The differential signal of the square wave should keep the two signals monotonic, continuous phase difference. The number of digital control bits varies depending on the maximum range of the phase difference to be varied and the minimum variation range of the phase difference. If the maximum range is large and the minimum variation is very small and the sophisticated case has many phase steps, the number of control bits is large. Conversely, when the maximum range is small and the minimum variation width is relatively large, Phase control should be continuous, monotonic, or monotonic. If it is forged, the state of discontinuity or control instability will not occur when controlling the phase difference by adjusting the cord in digital control. In addition, for phase control, a low power circuit must be designed for power efficiency of the entire transmitter while still being able to fully drive the input of the amplifier 320. Accordingly, a signal adjusting unit 310 may be provided for outputting a rectangular wave whose phase is controlled only by digital circuits for low-power characteristics, while the phase is controlled to be continuous and monotonically increased. In addition, the signal adjusting unit 310 that maximizes the efficiency of the amplifier 320 by adjusting the power of a logic circuit such as an inverter that PWM-generates the amplitude of the PWM signal, which is an input signal that greatly affects the efficiency of the amplifier 320 Can be provided.

In various embodiments of the present invention, the amplifier 320, the matching unit 330, and the resonator unit 340 may be disposed outside the signal adjustment unit 310. Also, the power supplier 318 may be disposed outside the signal controller 310 or may be included in the signal controller 310 according to the embodiment. More specifically, when the power supplier 318 is implemented as a battery, the power supplier 318 may be disposed outside the signal adjuster 310. When the power supplier 318 is implemented as a power interface, the power supplier 318 may be included in the signal coordinator 310. [ An element disposed outside the signal adjustment unit 310 may be implemented as an analog element. Meanwhile, in various embodiments of the present invention, the wireless power transmitter may sense not only the input of the resonator 340 but also current and voltage values at various locations.

Figure 3B shows a block diagram of a wireless power transmitter using a single-ended signal according to various embodiments of the present invention.

3B, the wireless power transmitter 300 may include a signal adjusting unit 350, an amplifier 360, a matching unit 370, and a resonator unit 380.

The signal adjusting unit 350 may include a sensing circuit 351, an ADC 353, a control unit 355, a modulating unit 356, a PA (power amplifier) driver 357 and a signal generating unit 358. The signal adjusting unit 350 may be implemented by an integrated circuit (IC), but there is no limitation on the implementation type.

In the embodiment of FIG. 3B, the signal conditioning unit 350 may generate a single-ended signal and output the generated single-ended signal to the amplifier 360. FIG. The signal generator 358 may generate a single-ended signal. For example, the signal generator 358 may include power providing means capable of generating a single-ended signal. The power providing means may be implemented with a battery included in the wireless power transmitter 300 or may be implemented with a power interface that receives power from the outside. When the power providing means is implemented as a battery, the signal generating unit 358 may further include an inverter for converting the power of DC output from the battery into AC. In the case where the power providing means is implemented as a power interface, the power providing means may receive the AC power from the outside, or may receive the power of the DC and convert it to AC, in which case it may further comprise an inverter have.

The modulation unit 356 can adjust the single-ended signal. The modulator 356 can adjust at least one of the amplitude and the phase of the single-ended signal. In one embodiment, the modulator 356 can adjust the phase of the single-ended signal by delaying the single-ended signal. The modulating unit 356 may include a DC / DC converting means or a voltage divider and the like, thereby adjusting the amplitude of the single-ended signal. On the other hand, in another embodiment, the amplitude of the single-ended signal may be adjusted by adjusting the driving voltage VDD of the amplifier 360 instead of the modulation unit 356. [ In this case, the DC / DC converting means or the voltage divider may be disposed on the rail to which the driving voltage VDD of the amplifier 360 is applied.

The PA driver 357 can perform current pumping with respect to the differential signal output from the modulator 356. This shortens the On / Off Delay time of the input signal of the amplifier 360, And the noise canceled input signal can be amplified to a predetermined gain. In various embodiments of the invention, the input signal may be a differential signal or a single-ended signal.

In various embodiments of the present invention, the PA driver 357 may include at least one inductor. The inductor can prevent an abrupt change in the current so that the PA driver 357 can output the peak when the peak of the input differential signal is included .

The amplifier 360 can amplify the single-ended signal output from the PA driver 357 with a predetermined gain. The amplifier 360 may be implemented, for example, with an amplifier of class-D or class-E. The amplifier 360 may perform amplification using the driving voltage VDD. On the other hand, as described above, in one embodiment, the driving voltage VDD can be changed. For example, the wireless power transmitter 300 may include a voltage-modifiable element, such as a DC / DC converter or voltage divider, disposed on a rail that provides a driving voltage VDD to the amplifier 360. The wireless power transmitter 300 may operate the DC / DC converter or voltage divider to change the gain of the amplifier 360 if it is determined that it is necessary to adjust the amplitude of the single-ended signal output from the amplifier 360 The amplitude of the outputted single-ended signal can be adjusted.

The matching portion 370 may include at least one of various elements for impedance matching, for example, at least one inductor and at least one capacitor. As described above, the relative position of the wireless power receiver with respect to the wireless power transmitter is variable, and thus, if the wireless power receiver is located on a wireless power transmitter, it can have various impedances. The wireless power transmitter 300 can increase wireless charging efficiency through impedance matching.

The resonance unit 380 can generate an electromagnetic field using the single-ended signal from the amplifier 360 and radiate it to the outside. When the wireless power transmitter 300 operates based on the A4WP scheme, the resonator unit 380 may be designed to have a resonance frequency of 6.78 MHz, and an electromagnetic field having a resonance frequency may be generated and radiated to the outside . The resonator portion 380 may include at least one inductor and at least one capacitor that constitute a resonant circuit.

The sensing circuit 351 may sense at least one of the electrical characteristics of the single-ended signal at the input of the resonator 380, for example, the current value and the voltage value.

The ADC 353 converts at least one analog value among the current value and the voltage value sensed by the current sensing circuit 351 into a digital value and outputs the digital value to the control unit 355.

The control unit 355 can determine the modulation information of the signal using at least one of the current value and the voltage value of the single-ended signal. For example, the control unit 355 may determine the phase of the single-ended signal using at least one of the current value and the voltage value of the single-ended signal. The control unit 355 can determine the modulation information of the signal for maintaining the phase of the single-ended signal at a predetermined value. For example, the control unit 355 can determine modulation information that delays the single-ended signal by t. The control unit 355 can output the control signal corresponding to the determined modulation information to the modulation unit 356. [ The modulator 356 can delay the single-ended signal by t based on the input control signal, so that the phase of the single-ended signal can be maintained at a predetermined value. In another embodiment, the controller 355 may determine from the digital value from the ADC 354 that the amplitude of the single-ended signal is A ', for example. The control unit 355 can determine the modulation information for adjusting the amplitude of the single-ended signal to A, and output the corresponding control signal. For example, when the modulation section 356 adjusts the amplitude, the control section 355 can output a control signal for adjusting the amplitude to the modulation section 356. [ In another example, when the amplifier 360 adjusts the amplitude, the control unit 355 supplies a control signal to the device such as a DC / DC converter, a voltage divider, or the like disposed on the rail to which the driving voltage of the amplifier 360 is applied. Can be output.

According to the above description, the modulating unit 356 can adjust the single-ended signal so that the phase of the single-ended signal maintains a predetermined value or the amplitude of the single-ended signal maintains the predetermined value.

In various embodiments of the present invention, the amplifier 360, the matching unit 370, and the resonator unit 380 may be disposed outside the signal conditioning unit 350. The signal generating unit 358 may be disposed outside the signal adjusting unit 350 or may be included in the signal adjusting unit 350 according to the embodiment. More specifically, when the power supply unit 358 is implemented as a battery, the power supply unit 358 may be disposed outside the signal adjustment unit 350. When the power supplier 358 is implemented as a power interface, the power provider 358 may be included in the signal coordinator 350.

3C, the wireless power transmitter 300 includes a current sensing circuit 311, a voltage sensing circuit 312, ADCs 313 and 314, a controller 315, a modulator 316, a PA (power amplifier) A driver 317, a signal generator 318, an amplifier 320, a matching unit 330, and a resonator 340.

As illustrated in FIG. 3A, at least one configuration included in the wireless power transmitter 300 may be implemented through one IC, such as one of the signal adjusters 310. FIG. In addition, as shown in FIG. 3C, each may be implemented as separate hardware (e.g., analog device, IC (integrated circuit), etc.). For example, the modulation unit 316 or the PA driver 317 and the like may be configured with hardware such as a separate IC.

In addition, although not shown, each component included in the wireless power transmitter using the single-ended signal shown in FIG. 3B may also be implemented as separate hardware.

The components shown in FIG. 3C are the same as those described with reference to FIG. 3A, and a detailed description thereof will be omitted.

4 shows a block diagram of a modulator according to various embodiments of the present invention.

The modulation unit 410 may include a voltage adjustment unit 411, an amplitude control unit 412, and a phase control unit 413. In various embodiments of the present invention, the modulator 410 can digitally control the phase of the differential signal, enabling the application of various digital control algorithms via the MCU or FPGA, Can be guaranteed.

The phase control unit 413 can adjust the phase of at least one of the differential signals. In various embodiments of the present invention, the phase control section 413 may include a delay element capable of delaying at least one signal. The phase control unit 413 may delay at least one signal during the determined delay time based on the control signal from the control unit. For example, FIG. 5 illustrates a conceptual diagram of a phase control unit according to various embodiments of the present invention. Referring to FIG. 5, the phase control unit 500 may include a plurality of delay elements 511 to 515. Some delay elements of the plurality of delay elements 511 to 515 can be controlled to be on-state, and the signal can be delayed by the delay time? T. The control unit can determine the delay time? T, and can determine the number of delay elements to be controlled to be on-state based on the determined delay time? T and output a control signal. Accordingly, the phase control unit 413 can determine a first delay element corresponding to the determined number of the delay elements among the plurality of delay elements 511 to 515. The phase control unit 413 can output the output of the first delay element to adjust the phase of the signal by delaying the signal by the determined delay time? T.

In various embodiments of the present invention, the phase control section 413 may delay at least one of the first signal or the second signal, and the phase difference between the first signal and the second signal may be maintained at 180 degrees .

Alternatively, when the wireless power transmitter uses a single-ended signal rather than a differential signal, the control unit may output a control signal that causes the phase of the single-ended signal to have a predetermined value. The phase control unit 413 can control at least a part of the delay element to be on-state based on the control signal, and the single-ended signal is delayed by the delay time? T so that the single- .

The amplitude controller 413 can adjust the amplitude of at least one signal of the differential signal using the driving voltage input from the voltage adjuster 411. For example, the amplitude controller 413 can adjust the amplitude of at least one signal of the differential signal based on the magnitude of the driving voltage input from the voltage adjuster 411. For example, the control unit may determine that the amplitude of at least one signal has a difference from the predetermined value, and thus output a control signal such that the amplitude of at least one signal has a predetermined value. The voltage adjustment unit 411 can adjust the amplitude of the differential signal or the single-ended signal output from the amplitude control unit 412 by adjusting the drive voltage of the amplitude control unit 412 based on the control signal output from the control unit.

According to the above description, the modulating unit 410 can adjust at least one of the phase and the amplitude of the differential signal or the single-ended signal.

The amplifier 420 may be implemented, for example, with an amplifier of class D or E, and may include inductors 421 and 422 and FETs 423 and 424, as shown. A first signal modulated from the modulator 410 may be input to the gate of the FET 423 and a second signal modulated from the modulator 410 may be input to the gate of the FET 414. Inductors 421 and 422 may be connected to the output terminal of the amplifier 420 and each of the inductors 421 and 422 may be connected to the drain of each of the FETs 423 and 424. [

4, after the phase of the differential signal input to the modulator 410 is adjusted through the phase controller 413, the amplitude of the phase-adjusted differential signal is adjusted through the amplitude controller 412, But is not limited thereto. After the amplitude of the differential signal input to the modulator 410 is adjusted through the amplitude controller 412, the phase of the differential signal whose amplitude is adjusted may be adjusted through the phase controller 413. Each of the signals included in the differential signal in which at least one of the phase and the amplitude is adjusted through the modulation unit 410 may be output to the input of the amplifier 420.

6 shows a conceptual diagram of a signal generator and a phase controller according to various embodiments of the present invention.

Referring to FIG. 6, the phase controller may include a first phase delay circuit 630, a second phase delay circuit 631, a first buffer 640, and a second buffer 641. The signal generator for outputting a differential signal to the phase controller may include a differential signal generator 610, a first comparator 620, and a second comparator 621.

The differential signal generator 610 may receive a single-ended signal and output a differential signal. For example, the differential signal generator 610 may include a single to differential (S2D) circuit, and may generate and output a differential signal using the S2D circuit. The first signal and the second signal constituting the differential signal may have a phase difference of 180 degrees.

Each of the first and second signals constituting the generated differential signal may be converted into a square wave through a first comparator 620 and a second comparator 621. Since the input signal is a differential signal having a difference of 180 degrees, the output of the two comparators 620 and 621 becomes a differential square wave having a phase difference of 180 degrees.

The phase control unit may include a first phase control unit and a second phase control unit for adjusting phases of the first signal and the second signal for supplying the differential signal. The first phase control unit may include a first phase delay circuit 630 and a first buffer 640 and the second phase control unit may include a second phase delay circuit 631 and a second buffer 641. have.

The first phase delay circuit 630 and the second phase delay circuit 631 may be configured such that at least one delay element is connected in series. For example, the first phase delay circuit 630 may be configured such that at least one first delay element among a plurality of delay elements included in the phase control section is connected in series, and the at least one first delay element The phase of the first signal can be adjusted by delaying the phase of the first signal. Wherein the second phase delay circuit (631) comprises at least one second delay element among a plurality of delay elements included in the phase control section connected in series, and the second phase delay circuit The phase of the second signal can be adjusted by delaying the phase of the signal.

The first phase delay circuit 630 and the second phase delay circuit 631 may delay at least one of a square wave of the first signal and a square wave of the second signal. In various embodiments of the present invention, the first phase delay circuit 630 and the second phase delay circuit 631 may be driven at the digital level and may be driven in a continuous, monotonic increasing or decreasing manner according to an external digital control input The phase can be controlled. In the embodiment of FIG. 6, the first phase delay circuit 630 and the second phase delay circuit 631 may be implemented with a structure including an analog switch. The number of delay elements operating in the ON state in each of the first phase delay circuit 630 and the second phase delay circuit 631 can be determined depending on the position where the analog switches are connected, Can be determined.

The first buffer 640 and the second buffer 641 may temporarily store the first and second signals whose phases are adjusted, and then output the temporarily stored first and second signals. Each of the phase-adjusted first and second signals may be output to the input of the amplifier or may be output to an amplitude controller for adjusting the amplitude of the differential signal.

If the voltage Vref, which is a comparison voltage of the comparators 620 and 621, is adjusted, the duty cycle of the rectangular wave can be adjusted by changing the voltage of '1' and the reference voltage moving to '0'.

7 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention.

7 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention. 7, the phase control unit 710 may include at least one inverter 711, 712, and 713 and a multiplexer 720. As shown in FIG. If the number of inverters 711, 712, and 713 is N, the number of channels of the multiplexer may be N-1. The multiplexer 720 can determine an inverter to be controlled to be on-state based on an input control signal and output the determined inverter output.

Hereinafter, it is assumed that the first signal is adjusted by the first phase control unit and the second signal is adjusted by the second phase control unit. The first phase control unit may include at least one first inverter and a first multiplexer, and the second phase control unit may include at least one second inverter and a second multiplexer. It is also assumed that the first phase control unit controls the m th first inverter to the ON state based on the control signal and the second phase control unit controls the n th second inverter to the ON state based on the control signal.

When the delay time of each of the first inverter and the second inverter is td, the output of the mth first inverter becomes a signal having a time delay of m x td with respect to the input signal. The first signal may pass through m inverters so that the first signal may have a time delay of m x td. Further, the output of the m-th inverter corresponding to the first signal delayed by m x td may be outputted through the multiplexer.

In addition, the second signal may be passed through n inverters so that the second signal may have a time delay of n x td. the output of the n-th inverter corresponding to the second signal delayed by n x td may be output through the multiplexer. In this case, the time difference between the output (Vout, p) of the first phase control unit, which is the output of the mth inverter, and the output (Vout, n), which is the output of the second phase control unit, (Nm) td / T) × 360 ° in addition to the time difference of (nm) × td in addition to the time difference of T / 2 + (nm) It is possible to generate a differential signal composed of the first signal and the second signal. At this time, if n and m are controlled by the digital control, a differential signal of phase difference that continuously increases or decreases monotonously can be generated. Here, the maximum range of the phase control is the difference between the case where the output of the first phase control unit is the minimum delay and the output of the second phase control unit is the maximum delay and vice versa, so (2Ntd / T) x 360 deg. This is the phase difference control range that can be controlled to the maximum. Here, N is the number of inverters included in the phase control unit, and it is assumed that the number of inverters included in each of the first phase control unit and the second phase control unit is equal to N. [ Even when the number of inverters included in each of the first and second phase controllers is different, a phase difference control range that can be controlled to the maximum in the same manner can be determined.

If the number of inverters is large, the phase control precision becomes high and becomes td / T × 360 °. That is, it is possible to determine the phase control accuracy by adjusting the time delay of the inverter and to adjust the maximum phase control range by adjusting the number of inverters. In order to perform N control, input the k bit control signal from the external to the multiplexer. Then, the N outputs of the inverters can be selectively outputted through the multiplexer.

8 shows a conceptual diagram of a phase control unit according to various embodiments of the present invention.

As shown in FIG. 8, the phase control unit may include at least one inverter 810, 811. 8 may include a capacitor disposed between the output terminal of the inverter 810 and the input terminal of the inverter 811 and the ground terminal. For example, the inverter 810 may include a capacitor 820 having one end connected between the inverter 810 and the inverter 811 and the other end grounded. The capacitor 820 can perform charging and discharging, and can further delay the signal. Meanwhile, in various embodiments of the present invention, the capacitor 820 may be implemented as a variable capacitor.

The capacitance of the capacitor may be adjusted based on a control signal generated in the control unit. The phase control unit determines one inverter of at least one inverter based on the control signal, outputs the output of the determined inverter, adjusts the capacitance of the capacitor, and controls the phase of the differential signal more precisely .

Figure 9A shows the time delay, or phase delay, of a square wave at a wireless power transmitter including elements of a CMOS process according to various embodiments of the present invention at a resonant frequency of 6.78Mhz.

Figure 9A illustrates the time delay, or phase delay, of a square wave at a wireless power transmitter including elements of a CMOS process according to various embodiments of the present invention at a resonant frequency of 6.78 MHz. It can be seen that the efficiency of the amplifier is affected not only by the power VDD and phase of the amplifier but also by the amplitude of the PWM signal, which is the input signal of the amplifier.

9A is a graph showing a magnitude variation of each of the differential output voltages according to the control of the phase difference. In Fig. 9A, the correlation between the phase difference control code and the differential output voltages VTXP and VTXN (where P is positive and N is negative) is shown. Here, the phase difference control code may mean a digital code capable of controlling the phase difference between the outputs of the differential.

Referring to FIG. 9A, it can be seen that as the phase difference control code increases, the VTXP increases and the VTXN decreases. As the phase difference control code decreases, the VTXP decreases and the VTXN increases. Accordingly, the size of the VTXP and the VTXN are sensed, and the control unit performs the phase difference control according to each size, so that the symmetry of the output differential signal can be guaranteed.

FIG. 9B shows measurement results for explaining FIG. 9A. Referring to FIG. 9B, it can be seen that the efficiency of the amplifier changes as the PWM amplitude is changed to 3V / 3.2V / 3.4V. Therefore, it is necessary to optimize the power efficiency by controlling the amplitude of the PWM signal. In order to realize this, a logic circuit such as an invertor or an EXOR can be used to generate a PWM signal of a power amplifier. By optimizing VDD as a power source of these logic circuits by a DC-DC converter or the like, the efficiency of a power amplifier can be maximized . In other words, the power of the logic circuit is also controlled at the same time as the phase control to optimize the efficiency of the power amplifier.

9B is a graph showing that the efficiency of the amplifier is changed according to the amplitude of the driving voltage. Referring to FIG. 9B, since there is an optimum amplitude for obtaining a relatively high power efficiency, the wireless power transmitter can process the signal to have an optimum amplitude. More specifically, when the amplitude of the detected signal does not correspond to the optimum amplitude, the control section can adjust the amplitude of the differential signal or the single-ended signal to be outputted by performing the amplitude control.

Figures 10A-10G show circuit diagrams of a PA driver in accordance with various embodiments of the present invention. In various embodiments of the invention, instantaneous peak current in a wireless power transmitter can be attenuated in the inductor to reduce EMI emissions when high harmonics are generated. Further, when a MOS or BJT circuit is included in a wireless power transmitter, a capacitor is disposed between the gate-drain or the base-collector of the current source circuit, and feedback is enabled, so that the peak current of harmonics can be mitigated . In addition, the wireless power transmitter may include complementary elements such as CMOS, and may operate at low power by complementary elements of NMOS and PMOS. For example, when an output of an inverter structure or a driving circuit is constituted so that no signal is inputted, current can be prevented from flowing and operation at low power can be possible.

Referring to FIG. 10A, the PA driver may include a plurality of transistors 1010, 1011, 1020, and 1021 and inductors 1030 and 1031. For example, the drain terminal of the first P-MOSFET 1011 is connected to the drain terminal of the first N-MOSFET 1010 and the first N-MOSFET 1010 and the first P-MOSFET 1011 are connected to the drain terminal of the first N- The first signal of the differential signal can be input through the gate. Also, the first N-MOSFET 1010 and the first P-MOSFET 1011 can process the first signal and output a signal having a voltage of V0 +.

The drain terminal of the second P-MOSFET 1021 is connected to the drain terminal of the second N-MOSFET 1020 and the second N-MOSFET 1020 and the second P-MOSFET 1021 are connected to the drain terminal of the second N- And a second signal of the differential signal can be received. The second N-MOSFET 1020 and the second P-MOSFET 1021 may process the second signal and output a signal having a voltage of V0-.

A source of the first P-MOSFET 1011 and a source of the second P-MOSFET 1021 may be coupled to a first inductor 1031 and the source of the first N-MOSFET 1010 and the second N- A second inductor 1030 may be coupled to the source of the MOSFET 1020.

In general, a wireless power transmitter transmits a relatively large amount of power, so that a relatively large voltage swing and a current swing may occur in the wireless power transmitter. Accordingly, a large AC current flows instantaneously in the wireless power transmitter, thereby causing a problem that a large noise signal of a high frequency is radiated or conducted. Particularly, when a class D or E amplifier in which a wireless power transmitter operates by switching is used, a peak current having a relatively large magnitude can be generated because the voltage signal transits from 0V to VDD or VDD to 0V as a square wave. The generated peak current may flow to the ground terminal or the drive power input terminal for grounding of the PA driver, and power noise may be transmitted on other circuits and substrates, thereby increasing the noise problem.

Since the source or emitter terminals of the plurality of transistors 1010, 1011, 1020, and 1021 are connected to each other to be common to each other, peak currents of opposite signs occur in the instantaneous transition of the input voltage and they can be canceled, The signal can be cut off from being transmitted to the ground terminal or the drive power input terminal of the PA driver. The peak current can be removed by the inductors 1030 and 1031 connected in series to the ground terminal and the drive power input terminal of the PA driver, respectively.

Figures 10B-10D show a circuit diagram of a PA driver further comprising a transistor current source. 10B, a third N-MOSFET 1040 may be disposed between the 1N-MOSFET 1010 and the second N-MOSFET 1020. In the embodiment of FIG. For example, the source of the first N-MOSFET 1010 and the second N-MOSFET 1020 may be connected to the drain of the third N-MOSFET 1040. A second inductor 1030 may be coupled to the source of the third N-MOSFET 1040. In the embodiment of FIG. 10C, a third P-MOSFET 1041 may be disposed between the first P-MOSFET 1011 and the second P-MOSFET 1021. For example, it may be connected to the source of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively, at the drain of the third P-MOSFET 1041. A first inductor 1031 may be connected to the source of the third P-MOSFET 1041. [ 10d, the source of the first N-MOSFET 1010 and the source of the second N-MOSFET 1020 may be connected to the drain of the third N-MOSFET 1040. [ A second inductor 1030 may be coupled to the source of the third N-MOSFET 1040. And may be connected to the sources of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively, at the drain of the third P-MOSFET 1041. A first inductor 1031 may be connected to the source of the third P-MOSFET 1041. [

Figures 10E through 10G show a circuit diagram of a PA driver further comprising a transistor current source and a capacitor. 10E, the source of the first N-MOSFET 1010 and the source of the second N-MOSFET 1020 may be connected to the drain of the third N-MOSFET 1040. A second inductor 1030 may be coupled to the source of the third N-MOSFET 1040. On the other hand, a first capacitor 1050 may be disposed between the source of each of the first N-MOSFET 1010 and the second N-MOSFET and the gate of the third N-MOSFET 1040. For example, the source of the first N-MOSFET 1010 and the second N-MOSFET 1020 may be connected to one end of the first capacitor 1050. The gate of the third MOSFET 1040 may be connected to the other end of the first capacitor 1050. 10F, the drain of the third P-MOSFET 1041 may be connected to the sources of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively. A first inductor 1031 may be connected to the source of the third P-MOSFET 1041. [ On the other hand, the second capacitor 1051 may be disposed between the source of each of the first P-MOSFET 1011 and the second P-MOSFET 1021 and the gate of the third P-MOSFET. For example, one end of the second capacitor 1051 may be connected to the sources of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively. And the gate of the third P-MOSFET 1041 may be connected to the other end of the capacitor 1051. In the embodiment of FIG. 10G, the sources of the first N-MOSFET 1010 and the second N-MOSFET 1020 may be connected to the drain of the third N-MOSFET 1040. A second inductor 1030 may be coupled to the source of the third N-MOSFET 1040. A source of the first N-MOSFET 1010 and the second N-MOSFET 1020 may be connected to one end of the first capacitor 1050. The gate of the third N-MOSFET 1040 may be connected to the other end of the first capacitor 1050. May be connected to the sources of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively, at the drain of the third P-MOSFET 1041. A first inductor 1031 may be connected to the source of the third P-MOSFET 1041. [ On the other hand, one end of the second capacitor 1051 may be connected to the sources of the first P-MOSFET 1011 and the second P-MOSFET 1021, respectively. The gate of the third P-MOSFET 1041 may be connected to the other end of the second capacitor 1051. As the capacitor is additionally included, the peak current can be mitigated.

The instantaneous peak current can instantaneously raise the drain voltage of the MOSFET, but at this time the MOSFET's impedance can be reduced as the gate voltage increases. In this case, the magnitude of the instantaneous peak current and the voltage can be reduced by the resistance caused by the parasitic circuit or the capacitor, and the spike type harmonic current, which is transmitted to the ground or the driving power input terminal of the PA driver, Voltage noise can be reduced.

A signal is output to an amplifier through the PA driver shown in FIGS. 10A to 10G, and the amplifier can amplify the noise canceled signal through the PA driver.

10A to 10G illustrate a PA driver for a differential signal. However, the present invention is not limited thereto, and the PA driver may be implemented as a single-ended signal. For example, in the case of a single-ended signal, the second N-MOSFET 1020 and the second P-MOSFET 1021 may be removed in Figures 10A-10G.

In addition, although FIGS. 10A to 10G are shown as CMOS transistors, they are only for illustrative purposes and can be implemented in the same manner through other types of transistors such as bipolar junction transistors (BJTs) Lt; / RTI >

11 shows waveforms of signals before and after noise cancellation through a PA driver according to various embodiments of the present invention.

11 (a) shows the waveform of the signal before the noise is removed through the PA driver. As with the waveform of the signal shown in Figure 11 (a), the wireless power transmitter transmits a relatively large amount of power, so that a relatively large voltage swing and current swing can occur in the wireless power transmitter. Particularly, when a class D or E amplifier in which a wireless power transmitter operates in a switching mode is used, a voltage signal shifts from 0 V to VDD or from VDD to 0 V as a square wave, The waveform of the signal shown in FIG.

11 (b) shows the waveform of the signal before noise is removed through the PA driver. As shown in the waveform of the signal shown in FIG. 11 (b), when harmonics with high instantaneous peak current are generated in the wireless power transmitter, it is possible to attenuate in the inductor to reduce EMI emission. When a MOS or BJT circuit is included in the wireless power transmitter, a capacitor is disposed between the gate-drain or the base-collector of the current source circuit so that feedback can be performed, the waveform of the signal shown in Fig.

12 is a diagram illustrating a method for sensing a position change of a wireless power receiver on a wireless power transmitter according to various embodiments of the present invention.

According to various embodiments of the present invention, the wireless power transmitter 1200 may sense a change in position of the wireless power receiver. The wireless power transmitter 1200 may sense a change in resonant impedance due to a relative position change with the wireless power receiver. As such, the wireless power transmitter 1200 may sense a change in resonant impedance and sense a change in position of the wireless power receiver based on a change in the sensed resonant impedance.

For example, when a wireless power receiver is moved from a first position 1210 to a second position 1211, the wireless power transmitter 1200 senses a change in resonance impedance and, based on the sensed resonance impedance change, To detect that the wireless power transmitter has been moved from the first position 1210 to the second position 1211. [

13A to 13C show signal waveforms according to comparative examples.

13A shows a first waveform 1312 and a second waveform 1313 for a first signal and a second signal, respectively, constituting a differential signal amplified through an amplifier. The first waveform 1312 of the first signal may have the form of a square wave and the second waveform 1313 of the second signal may have the form of a square wave. As described above, it can be seen that the first signal and the second signal may have a phase difference of 180 degrees, so that the first waveform 1312 and the second waveform 1313 are shown as having a phase difference of 180 degrees have.

On the other hand, when the resonance impedance of the wireless power transmitter changes due to the environment around the resonator or the environment around the antenna, such as for example changing the position of the wireless power receiver, the phase difference between the first signal and the second signal is 180 degrees May not be maintained. 13B, it can be seen that the second waveform 1314 corresponding to the second signal has moved to the right in comparison with FIG. 13A. Accordingly, it can be seen that the first waveform 1312 and the second waveform 1314 can not maintain a phase difference of 180 degrees. As the first waveform 1312 and the second waveform 1314 do not maintain a phase difference of 180 degrees, portions of the first waveform 1312 and portions of the second waveform 1314 overlap at portions 1321, 1322, 1323 may occur. As portions of the first waveform 1312 and portions of the second waveform 1314 overlap, the EMI can be increased and the overall wireless charging efficiency can be reduced.

In addition, when the resonant impedance of the wireless power transmitter changes due to the environment around the resonator or the environment around the antenna, such as the change of the position of the wireless power receiver, the amplitudes of the amplitudes of the first signal and the second signal may be different. As shown in FIG. 13C, it can be seen that the amplitude of the second waveform 1331 corresponding to the second signal is smaller than that of FIG. 13A. This confirms that the amplitudes of the first waveform 1312 and the second waveform 1331 are different. The wireless charging efficiency of the wireless power transmitter changes according to the amplitudes of the first and second signals and as the amplitudes of the first waveform 1312 and the second waveform 1331 differ, .

14A and 14B are diagrams illustrating a method for indicating that a position of a wireless power receiver on a wireless power transmitter is out of a predetermined position according to various embodiments of the present invention.

As described in FIG. 12, the wireless power transmitter 1400 may sense a change in position of the wireless power receiver. Accordingly, the wireless power transmitter 1400 may provide a notification to the user when the location of the wireless power receiver is outside of a predetermined location 1411 to be optimized for wireless charging efficiency. For example, when the position of the wireless power receiver is moved out of the predetermined position 1411 to the first position 1412, the resonant impedance of the wireless power transmitter 1400 is changed and accordingly the wireless power transmitter 1400 Can be reduced. Accordingly, the wireless power transmitter 1400 may provide a notification to the user that the position of the wireless power receiver has deviated from the predetermined location 1411 when the location of the wireless power receiver is outside the predetermined location 1411, And to move the position of the wireless power receiver to the predetermined position 141. [

14A, when the position of the wireless power receiver deviates from the predetermined position 1411, the wireless power transmitter 1400 transmits a wireless power (e.g., a power) to the user through the display unit 1401 included in the wireless power transmitter 1400, It is possible to provide a notification indicating that the position of the receiver deviates from the predetermined position 1411. For example, the wireless power transmitter 1400 can provide a notification to a user by lighting the LED lamp 1401 in a specific color or blinking the LED lamp 1401.

14B, when the position of the wireless power receiver is out of the predetermined position 1411, the wireless power transmitter 1400 transmits a signal to the wireless power receiver 1400 indicating that the wireless power receiver has deviated from the predetermined position 1411, As shown in FIG. When receiving the signal, the wireless power receiver may provide an indication to the user via the display, such as a display, that the location of the wireless power receiver has left the predetermined location 1411.

In addition, the wireless power transmitter 1400 may transmit the signal to the wireless power receiver, and may also provide a notification to the user through the display 1401 included in the wireless power transmitter 1400.

15 is a configuration diagram of a current sensing circuit of a differential structure according to various embodiments of the present invention.

15, the current sensing circuit may include a power amplifier 1500, a first current sensing resistor 1530, a second current sensing resistor 1535, and a load resistor 1505 for load sensing. have. The current sensing circuit of FIG. 15 includes a current detecting resistor arranged in series in a signal path for measuring AC / RF current outputted from the power amplifier 1500 or transmitted to a resonator, and a voltage And the difference between them is measured. In particular, in the differential structure, two current detecting resistors are disposed in the same positive and negative directions, and both ends of the current detecting resistors, that is, four voltage points are crossed and sampled. At this time, the cross method is configured such that the common mode is reduced and the asymmetry effect is canceled.

The power amplifier 1500 applies a first output voltage to one end of the load 1505 and a second output voltage opposite to the first output voltage to the other end of the load 1505. At this time, the second output voltage is opposite to the polarity of the first output voltage. The power amplifier 1500 according to various embodiments of the present invention may be a class D or E amplifier. Here, the load 1505 may be a load corresponding to the antenna or the resonator.

The load resistor 1505 may be denoted as " R _{L &} quot ;, and may be implemented with two first resistors and a second resistor as shown in FIG. 4 to express the asymmetry in terms of a differential circuit. In this case, the first resistor and the second resistor are different by ΔR _L , in which case the first resistor may be expressed as '0.5R _L + ΔR _L ' and the second resistor may be expressed as '0.5R _{L -} ΔR _L ' have. A middle portion between the first resistor and the second resistor is grounded.

The first current detecting resistor 1530 and the second current detecting resistor 1535 may be denoted by 'R _S ', respectively. The current sensing circuit is for obtaining a voltage 'V _RS ' across both ends of the first current detecting resistor 1530. When this 'V _RS ' is obtained, it can be amplified in the circuit connected to the current sensing circuit and used to sense the current magnitude. However, in the case of a current sensing circuit in which one current detecting resistor is disposed, a difference between voltages across the resistor is very large, which may cause a problem of the common mode. Therefore, when the voltage swing of a signal to be sensed is very large, two current detecting resistors are arranged in the current sensing circuit according to various embodiments of the present invention so as not to be affected by a common mode of the internal circuit, a problem caused by asymmetry,

These two current detection resistors 1530 and 1535 are changed as the load impedance changes when the voltage and current signals output from the power amplifier 1500 are applied to a load such as an antenna or a resonator, And can be used to control the operational amplifier by measuring the current signal I _RF .

The first current detection resistor 1530 is disposed between the first output of the power amplifier 1500 and the load 1505 and the second current detection resistor 1535 is disposed between the first output of the power amplifier 1500 and the load 1505, 2 output and the load 1505, as shown in FIG.

The first voltage V ₁ 1510 is a voltage applied to the front end of the first current detection resistor 1530 and the second voltage V ₂ 1515 is a voltage applied to the first current detection resistor 1530 It is the voltage applied to the rear end. The third voltage V ₃ 1520 is a voltage applied to the front end of the second current detection resistor 1535 and the fourth voltage V ₄ 1525 is a voltage applied to the rear end of the second current detection resistor 1535 .

The current sensing circuit can obtain the voltages input to the operational amplifier 1600 of FIG. 16 based on the following equations (1) and (2).

In the above Equations 1 and 2, V _P and V _N are positive and negative voltages of the signal voltage across the load 1505, respectively. In various embodiments of the present invention, V _P is referred to as a first reference voltage, and V _N may be referred to as a second reference voltage. In Equations (1) and (2), V _RS is a voltage applied to the first current detecting resistor 1530 and the second current detecting resistor 1535, respectively. This V _RS is a very small voltage as a product of the current I _RF to be sensed and the resistance R _S. That is, V _RS can be expressed as in Equation (3) below.

According to Equation 1, the fifth voltage V ₅ can be obtained by adding the first voltage V ₁ 1510 and the fourth voltage V ₄ 1525. According to Equation 2, the sixth voltage V ₆ can be obtained by adding the second voltage V ₂ 1515 and the third voltage V ₃ 1520.

This is realized as a circuit as shown in FIG.

16 is a configuration diagram of an amplifier circuit connected to the current sensing circuit according to various embodiments of the present invention.

Voltages V _1, V ₂ , V ₃ , and V ₄ applied to both ends of the first current detecting resistor 1530 and the second current detecting resistor 1535 in FIG. May be added to each other in the form of a cross voltage via a voltage divider and output in the form of a fifth voltage (V ₅ ) and a sixth voltage (V ₆ ). The first voltage divider divides the first voltage V ₁ applied to the front end of the first current detection resistor 1530 and the fourth voltage V ₄ applied to the rear end of the second current detection resistor 1535, Can be combined. The second voltage divider further includes a second voltage V ₂ applied to the rear end of the first current detection resistor 1530 and a third voltage V ₃ applied to the front end of the second current detection resistor 1535, Can be combined. The first voltage divider and the second voltage divider may be connected to the front end of the operational amplifier 1600.

In the fifth voltage (V ₅₎ and the sixth voltage (V ₆₎ are calculated and input to the amplifier 1600, such an operational amplifier 1600, the fifth voltage (V ₅₎ and the sixth voltage (V ₆₎ through, depending Can be obtained. The output voltage V _O obtained through the subtraction circuit using the operational amplifier 1600 can be expressed by Equation (4). At this time, the operational amplifier 1600 performs a function of amplifying the difference between the fifth voltage V ₅ and the sixth voltage V ₆ by the gain A.

In Equation (4), A represents a gain in the operational amplifier 1600 with a predetermined gain.

According to Equation (4), the output voltage V _O output from the operational amplifier 1600 is not affected by V _P and V _N , that is, a voltage that is not affected by the load 1505 'R _L ' Can be output.

As described above, the output voltage (V _O ) 2A * V _RS that is not affected by the change of 'R _L ' which is the load 1505 according to various embodiments of the present invention can be obtained.

In addition, the above equations can be applied even when the magnitudes of V _P and V _N are different from each other in the asymmetry of the differential structure, thereby improving the detection performance by asymmetry. In addition, the common mode problem is also calculated as viewed from the input V ₅ and V ₆ of the amplifier 1600 is V _{P -} because it is expressed as V _N, if asymmetry is not severe that is, the size difference between V _P and V _N predetermined range The magnitude of the voltage swings V _P and V _N that are significantly reduced from the absolute magnitude of the load voltage swing is applied in the common mode and the problem that the desired signal is not seen due to the output size of the common mode signal can be solved.

On the other hand, the output voltage V _O output from the operational amplifier 1600 needs to be converted from a signal of the AC type to a constant voltage of the DC type in order to be input to the control unit and the communication units 312 and 313. For this, a rectifying circuit portion 1700 for DC leveling can be realized as shown in FIG.

Accordingly, the control unit and the communication unit of the wireless power transmitter can generate the control signal based on the output voltage (V _O ) provided from the sensing circuit. Accordingly, the signal generating unit can generate power based on the control signal provided from the control unit.

As described above, the sensing circuit according to various embodiments of the present invention can be configured to include the above-described FIG. 15 and FIG. 16, and the output voltage V _O can be supplied to the control unit and the communication unit, And may further include a rectifying circuit portion 1700.

If the sensing circuit is implemented to include the configurations of Figs. 15 and 16, the sensing circuit supplies the first output voltage to one end of the load, and the second output voltage, which is opposite to the first output voltage, A first current detecting resistor disposed between the first output of the first amplifier and the load and a second current detecting resistor disposed between the second output of the first amplifier and the load; A fifth voltage obtained by adding a first voltage across the first end of the first current detection resistor and a fourth voltage across the rear end of the second current detection resistor, Detecting a sixth voltage which is a sum of a second voltage applied and a third voltage applied to a front end of the second current detecting resistor and outputs an output voltage proportional to a difference between the fifth voltage and the sixth voltage, . ≪ / RTI >

Each of the components described in this document may be composed of one or more components, and the name of the component may be changed according to the type of the electronic device. In various embodiments, the electronic device may comprise at least one of the components described herein, some components may be omitted, or may further include additional other components. In addition, some of the components of the electronic device according to various embodiments may be combined into one entity, so that the functions of the components before being combined can be performed in the same manner.

As used in this document, the term "module" may refer to a unit comprising, for example, one or a combination of two or more of hardware, software or firmware. A "module" may be interchangeably used with terms such as, for example, unit, logic, logical block, component, or circuit. A "module" may be a minimum unit or a portion of an integrally constructed component. A "module" may be a minimum unit or a portion thereof that performs one or more functions. "Modules" may be implemented either mechanically or electronically. For example, a "module" may be an application-specific integrated circuit (ASIC) chip, field-programmable gate arrays (FPGAs) or programmable-logic devices And may include at least one.

At least a portion of a device (e.g., modules or functions thereof) or a method (e.g., operations) according to various embodiments may include, for example, computer-readable storage media in the form of program modules, As shown in FIG. When the instruction is executed by a processor, the one or more processors may perform a function corresponding to the instruction. The computer readable storage medium may be, for example, a memory.

The computer readable recording medium may be a hard disk, a floppy disk, a magnetic media (e.g., a magnetic tape), an optical media (e.g., a compact disc read only memory (CD-ROM) digital versatile discs, magneto-optical media such as floptical disks, hardware devices such as read only memory (ROM), random access memory (RAM) Etc. The program instructions may also include machine language code such as those produced by a compiler, as well as high-level language code that may be executed by a computer using an interpreter, etc. The above- May be configured to operate as one or more software modules to perform the operations of the embodiment, and vice versa.

Modules or program modules according to various embodiments may include at least one or more of the elements described above, some of which may be omitted, or may further include additional other elements. Operations performed by modules, program modules, or other components in accordance with various embodiments may be performed in a sequential, parallel, iterative, or heuristic manner. Also, some operations may be performed in a different order, omitted, or other operations may be added.

According to various embodiments, in a storage medium storing instructions, the instructions may be configured to cause the at least one processor to perform at least one operation when executed by at least one processor.

And the embodiments disclosed in this document are presented for the purpose of explanation and understanding of the disclosed technology and do not limit the scope of the technology described in this document. Accordingly, the scope of this document should be interpreted to include all modifications based on the technical idea of this document or various other embodiments.

Claims (21)

1. A wireless power transmitter for wirelessly charging a wireless power receiver,
A differential signal generator for generating a differential signal;
A plurality of transistors, a first inductor disposed between the plurality of transistors and the driving voltage input terminal, and a second inductor disposed between the plurality of transistors and the ground terminal, driver;
An amplifier for amplifying the noise-removed differential signal to a predetermined gain; And
And a resonance part for transmitting the amplified differential signal to the wireless power receiver
Gt; The method according to claim 1,
The plurality of transistors including:
A first N-MOSFET and a first P-MOSFET that are supplied with a first signal included in the differential signal through respective gates; And
And a second N-MOSFET supplied with a second signal included in the differential signal through each of the gates and the second P-MOSFET
Gt; wherein < / RTI > 3. The method of claim 2,
A drain of the first P-MOSFET is connected to a drain of the first N-MOSFET,
And a drain of the second P-MOSFET is coupled to a drain of the second N-MOSFET. The method of claim 3,
A source of the first P-MOSFET and a source of the second P-MOSFET are connected to the first inductor,
Wherein a source of the first N-MOSFET and a source of the second N-MOSFET are coupled to the second inductor. The method of claim 3,
The PA driver,
And a third N-MOSFET disposed between the first N-MOSFET and the second N-MOSFET and the second inductor.
≪ / RTI > 6. The method of claim 5,
Wherein a drain of the third N-MOSFET is connected to a source of the first N-MOSFET and a source of the second N-MOSFET, and a source of the third N-MOSFET is coupled to the second inductor. . The method according to claim 6,
The PA driver,
A first capacitor disposed between the source of each of the first N-MOSFET and the second N-MOSFET and the third N-MOSFET,
A first capacitor disposed between a gate of the third N-MOSFET and a source of the first N-MOSFET and a source of the second N-
Further comprising a wireless power transmitter. 6. The method according to any one of claims 3 to 5,
The PA driver,
And a third P-MOSFET disposed between the first P-MOSFET and the second P-MOSFET and the first inductor.
≪ / RTI > 8. The method of claim 7,
Wherein a drain of the third P-MOSFET is connected to a source of the first P-MOSFET and a source of the second P-MOSFET, and a source of the third P-MOSFET is connected to the first inductor. . 10. The method of claim 9,
The PA driver,
A second capacitor disposed between a gate of the third P-MOSFET and a source of the first P-MOSFET and a source of the second P-MOSFET;
Further comprising a wireless power transmitter. 1. A wireless power transmitter for wirelessly charging a wireless power receiver,
A signal generator for generating a single-ended signal;
A plurality of transistors, a first inductor disposed between the plurality of transistors and the driving voltage input terminal, and a second inductor disposed between the plurality of transistors and the ground terminal, PA driver;
An amplifier for amplifying the noise-removed single-ended signal with a predetermined gain; And
And for transmitting the amplified single ended signal to the wireless power receiver,
Gt; 12. The method of claim 11,
The plurality of transistors including:
The first N-MOSFET and the first P-MOSFET, which receive the single-ended signal through respective gates,
Gt; wherein < / RTI > 13. The method of claim 12,
And a drain of the first P-MOSFET is coupled to a drain of the first N-MOSFET. 14. The method of claim 13,
A source of the first P-MOSFET is connected to the first inductor,
And a source of the first N-MOSFET is coupled to the second inductor. 14. The method of claim 13,
The PA driver,
And a second N-MOSFET disposed between the first N-MOSFET and the second inductor.
≪ / RTI > 16. The method of claim 15,
Wherein the drain of the second N-MOSFET is connected to the source of the first N-MOSFET and the source of the second N-MOSFET is connected to the second inductor. 17. The method of claim 16,
The PA driver,
A first capacitor disposed between the gate of the second N-MOSFET and the source of the first N-
Further comprising a wireless power transmitter. 16. The method according to any one of claims 13 to 15,
The PA driver,
And a second P-MOSFET disposed between the first P-MOSFET and the first inductor.
≪ / RTI > 18. The method of claim 17,
Wherein the drain of the second P-MOSFET is connected to the source of the first P-MOSFET and the source of the second P-MOSFET is connected to the first inductor. 20. The method of claim 19,
The PA driver,
A second capacitor disposed between the gate of the second P-MOSFET and the source of the first P-MOSFET;
Further comprising a wireless power transmitter. An integrated circuit (IC) for eliminating noise of a differential signal supplied to an amplifier for amplifying a differential signal for wireless power transmission,
A first N-MOSFET and a first P-MOSFET that receive a first signal included in a differential signal supplied to the IC through respective gates;
A second N-MOSFET and a second P-MOSFET that receive a second signal included in the differential signal through respective gates;
A first inductor disposed between the first P-MOSFET and the second P-MOSFET and a driving voltage input terminal; And
And a second inductor disposed between the first N-MOSFET and the second N-MOSFET and a ground terminal,
≪ / RTI >

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