Wireless charging chip

Abstract

The embodiment of the utility model provides a wireless charging chip, comprising a pin connected with a detection end of an LC series resonance circuit in an external wireless charging system; the overvoltage protection module is connected with the pin, and an output signal of the output end of the overvoltage protection module represents an overvoltage abnormal condition; the foreign matter detection module is connected with the pin, and the foreign matter detection module detects the waveform of the pin to judge whether a foreign matter exists or not; the demodulation module is connected with the pin, and the demodulation module detects the waveform of the pin to obtain a communication code; and the overvoltage protection module, the foreign matter detection module and the demodulation module acquire corresponding electric signals from the pins. According to the wireless charging circuit, the requirements of overvoltage detection, foreign matter detection and demodulation can be met by only one pin, the number of chip pins and discrete devices needing to be arranged on a printed circuit board are reduced, and the integration level of the wireless charging circuit is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to integrated circuit technical field, concretely relates to a wireless charging chip. BACKGROUND

[0002] In the current wireless charging transmitting end drive chip, a plurality of detection circuits need to be set, each detection circuit detects the electric signal of respective pin, and the corresponding auxiliary circuit needs to be set on the PCB. Obviously, the pins occupied by the prior art are too many, which is not conducive to improving the integration of the wireless charging circuit. SUMMARY

[0003] The embodiment of the utility model aims at providing a wireless charging chip to solve the above problems.

[0004] The embodiment of the utility model realizes the above-mentioned purpose through the following technical scheme.

[0005] The embodiment of the utility model provides a wireless charging chip, which comprises a pin, a detection end of an LC series resonance circuit in an external wireless charging system is connected to the pin, an overvoltage protection module, which is connected to the pin, and the output signal of the output end of the overvoltage protection module represents an overvoltage abnormal condition, a foreign matter detection module, which is connected to the pin, the foreign matter detection module detects the waveform of the pin to determine whether there is foreign matter, a demodulation module, which is connected to the pin, the demodulation module detects the waveform of the pin to obtain a communication code, and the overvoltage protection module, the foreign matter detection module and the demodulation module obtain corresponding electric signals from the pin.

[0006] In some embodiments, the overvoltage protection module, the foreign matter detection module and the demodulation module each comprise a comparison unit, and the comparison units of at least two of the overvoltage protection module, the foreign matter detection module and the demodulation module are time-multiplexed

[0007] In some embodiments, the wireless charging chip further comprises a voltage division module, which comprises a first resistor and a second resistor connected in series between the pin and a common end, and the common connection point formed by the first resistor and the second resistor serves as a first voltage division output end; the pin, the first resistor, the first voltage division output end and the overvoltage protection module are connected in sequence;

[0008] The pin, the first resistor, the first voltage division output end and the demodulation module are connected in sequence; the pin, the first resistor, the first voltage division output end and the foreign matter detection module are connected in sequence.

[0009] In some embodiments, the demodulation module comprises: a first voltage division unit comprising a third resistor and a fourth resistor connected in series between a first voltage supply end and a common end, a common junction of the third resistor and the fourth resistor serving as a second voltage division output end; a first capacitor connected between the first voltage division output end and a second voltage division output end; a first comparison unit having a first input end connected to the second voltage division output end and a second input end connected to a first reference voltage end, and outputting a signal indicative of the communication code.

[0010] In some embodiments, the demodulation module comprises: a second voltage division unit comprising a fifth resistor and a sixth resistor connected in series between the pin and the common end, a common junction of the fifth resistor and the sixth resistor serving as a third voltage division output end; a third voltage division unit comprising a seventh resistor and an eighth resistor connected in series between the first voltage supply end and the common end, a common junction of the seventh resistor and the eighth resistor serving as a fourth voltage division output end; a second capacitor connected between the third voltage division output end and the fourth voltage division output end; a second comparison unit having a first input end connected to the fourth voltage division output end and a second input end connected to the first reference voltage end, and outputting a signal indicative of the communication code.

[0011] In some embodiments, the demodulation module further comprises: an amplifier connected between the fourth voltage division output end and the first input end of the second comparison unit.

[0012] In some embodiments, the second comparison unit is a hysteretic comparator.

[0013] In some embodiments, the foreign object detection module comprises a third comparison unit having a first input end connected to the pin, a first switch connected between a second input end of the third comparison unit and a second reference voltage end, and a second switch connected between the second input end of the third comparison unit and the first reference voltage end, the third comparison unit serving as a comparison unit of the demodulation module in a conductive state of the second switch.

[0014] In some embodiments, the wireless charging chip further comprises: a diode having an anode connected to the pin and a cathode connected to the foreign object detection module and the demodulation module; and a third capacitor and a ninth resistor connected in parallel between the cathode of the diode and the common end.

[0015] In some embodiments, the demodulation module comprises: a half-wave unit connected to the pin and outputting a half-wave waveform corresponding to an oscillation waveform of the pin; and a mean value detection unit connected to the half-wave unit and determining the communication code based on a mean value of the half-wave waveform.

[0016] The wireless charging chip provided by the embodiment comprises a pin, which is connected with a detection end of an LC series resonant circuit in an external wireless charging system; an overvoltage protection module, which is connected with the pin and outputs an output signal at an output end, the output signal representing an overvoltage abnormal condition; a foreign matter detection module, which is connected with the pin and detects a waveform of the pin to determine whether foreign matter exists; and a demodulation module, which is connected with the pin and detects a waveform of the pin to obtain a communication code; the overvoltage protection module, the foreign matter detection module and the demodulation module obtain corresponding electrical signals from the pin. Through the implementation of the embodiment, only one pin is needed to meet the requirements of overvoltage detection, foreign matter detection and demodulation, the number of chip pins and discrete devices required to be arranged on a printed circuit board are reduced, and the integration of the wireless charging circuit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0018] Figure 1 is an application diagram of the wireless charging chip in the prior art;

[0019] Figure 2 is a circuit structure diagram of the wireless charging chip provided by the embodiment;

[0020] Figure 3 is another circuit structure diagram of the wireless charging chip provided by the embodiment;

[0021] Figure 4 is a waveform diagram of the wireless charging chip provided by the embodiment;

[0022] Figure 5 is a structure diagram of the demodulation module of the wireless charging chip provided by the embodiment;

[0023] Figure 6 is a structure diagram of the foreign matter detection module of the wireless charging chip provided by the embodiment. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0025] This embodiment provides a wireless charging chip, such as Figure 2 As shown, the wireless charging chip may include: pin P, which is connected to the detection terminal M of the LC series resonant circuit in the external wireless charging system; an overvoltage protection module 11, which is connected to pin P, and whose output signal represents an overvoltage abnormality; a foreign object detection module 12, which is connected to pin P, and detects the waveform of pin P to determine whether a foreign object exists; and a demodulation module 13, which is connected to pin P, and detects the waveform of pin P to obtain the communication code; the overvoltage protection module 11, the foreign object detection module 12, and the demodulation module 13 obtain the corresponding electrical signals from pin P.

[0026] In this embodiment, as Figure 1 As shown, the external wireless charging system may include a first switch K1Q1, a second switch K2Q2, a third switch K3Q3, and a fourth switch Q4. The first switch K1Q1 and the second switch K2Q2 form a half-bridge circuit, and the third switch K3Q3 and the fourth switch Q4 form another half-bridge circuit. Between the nodes of the two half-bridge circuits, an inductor L and a capacitor C are connected in series. The inductor L and the capacitor are the detection terminal M of the LC series resonant circuit described in this embodiment, and the pin P is connected to the detection terminal M.

[0027] In this embodiment, the overvoltage protection module 11 can be used to determine whether the voltage at pin P is overvoltage. It may include a comparison unit, which compares the voltage at pin P with the corresponding voltage threshold. When the voltage at pin P is overvoltage, the output of the comparison unit can be flipped.

[0028] In this embodiment, the foreign object detection module 12 can detect the voltage waveform at pin P, count the effective waves of the voltage waveform, and determine whether there is a foreign object between the wireless charging transmitter and the wireless charging receiver based on the counting result. The wireless charging transmitter and the wireless charging receiver can communicate with each other. Specifically, the resonant waveform at the detection terminal M of the wireless charging transmitter represents the communication code, and the value of the communication code is determined by detecting the voltage at pin P.

[0029] In this embodiment, the overvoltage protection module 11, the foreign object detection module 12, and the demodulation module 13 obtain the corresponding electrical signals from pin P. In other words, through the implementation of this embodiment, only one pin P is needed to meet the requirements of overvoltage detection, foreign object detection, and demodulation, thereby reducing the number of chip pins P and the discrete components that need to be set on the printed circuit board, and improving the integration of the wireless charging circuit.

[0030] In some embodiments, the overvoltage protection module 11, the foreign matter detection module 12, and the demodulation module 13 each include a comparison unit, and the comparison units of at least two of the overvoltage protection module 11, the foreign matter detection module 12, and the demodulation module 13 are time-multiplexed. In this embodiment, the comparison unit in the foreign matter detection module 12 can be used for both the foreign matter detection process and the detection of the overvoltage detection and demodulation process.

[0031] In some embodiments, as shown in FIG. 13, the wireless charging chip can further include a voltage division module 14 including a first resistor R1 and a second resistor R2 connected in series between a pin P and a common end GND, a common junction of the first resistor R1 and the second resistor R2 serving as a first voltage division output end; the pin P, the first resistor R1, the first voltage division output end, and the overvoltage protection module 11 being connected in sequence; the pin P, the first resistor R1, the first voltage division output end, and the demodulation module 13 being connected in sequence; and the pin P, the first resistor R1, the first voltage division output end, and the foreign matter detection module 12 being connected in sequence. The voltage at the first voltage division output end can represent the voltage at the pin P. Figure 3

[0032] In some embodiments, as shown in FIG. 13, the wireless charging chip can further include a voltage division module 14 including a first resistor R1 and a second resistor R2 connected in series between a pin P and a common end GND, a common junction of the first resistor R1 and the second resistor R2 serving as a first voltage division output end; the pin P, the first resistor R1, the first voltage division output end, and the overvoltage protection module 11 being connected in sequence; the pin P, the first resistor R1, the first voltage division output end, and the demodulation module 13 being connected in sequence; and the pin P, the first resistor R1, the first voltage division output end, and the foreign matter detection module 12 being connected in sequence. The voltage at the first voltage division output end can represent the voltage at the pin P. Figure 3

[0033] In this embodiment, the first resistor R1, the second resistor R2, the first capacitor C1, the third resistor R3, and the fourth resistor R4 can constitute a forward bias circuit. The oscillation voltage of the pin P has both positive and negative relative to the voltage of the common end GND, and the oscillation voltage of the first voltage division output end also has both positive and negative relative to the voltage of the common end GND. The voltage at the second voltage division output end is overall raised by the first capacitor C1, the third resistor R3, and the fourth resistor R4, so that the voltage at the second voltage division output end can represent the voltage at the pin P, and the oscillation waveform at the second voltage division output end changes correspondingly with the oscillation waveform at the pin P. After the voltage at the first voltage division output end is overall raised, the voltage at the second voltage division output end is obtained, and the first comparison unit 132 can compare the voltage at the second voltage division output end with the voltage at the first reference voltage end Vth1, and then determine the code represented by the oscillation waveform.

[0034] ​​In the embodiment, the voltage at the pin P can be converted into a voltage easy to be detected by the voltage dividing module 14 cooperating with the first capacitor C1 and the first voltage dividing unit 131, and the design requirement of the comparison unit is low.

[0035] In some embodiments, the demodulation module 13 can further include a counting unit, which can be connected with the output end of the first comparison unit 132. The counting unit can count the high and low levels of the output end of the first comparison unit 132. Specifically, as shown in Figure 4 the high resonance voltage waveform can represent the code “1”, the low resonance voltage waveform can represent the code “0”, the detection frequency of the first comparison unit 132 can be consistent with the resonance frequency of the resonance voltage of the second voltage dividing output end, and if the output end of the first comparison unit 132 outputs the level signal representing the high resonance voltage waveform for four times in succession, the counting unit can count the level signal, and if the count reaches four, the corresponding count signal can be output, which can be used to represent the code value.

[0036] In some embodiments, as shown in Figure 5 the demodulation module 13 can include: a second voltage dividing unit 133 including a fifth resistor R5 and a sixth resistor R6 connected in series between the pin P and the common end GND, and the common connection point of the fifth resistor R5 and the sixth resistor R6 serving as a third voltage dividing output end; a third voltage dividing unit 134 including a seventh resistor R7 and an eighth resistor R8 connected in series between the first voltage supply end V1 and the common end GND, and the common connection point of the seventh resistor R7 and the eighth resistor R8 serving as a fourth voltage dividing output end; a second capacitor C2 connected between the third voltage dividing output end and the fourth voltage dividing output end; and a second comparison unit 135 having a first input end connected with the fourth voltage dividing output end and a second input end connected with the first reference voltage end Vth1, and outputting a signal representing the communication code.

[0037] In the embodiment, the fifth resistor R5, the sixth resistor R6, the second capacitor C2, the seventh resistor R7 and the eighth resistor R8 can constitute a forward bias circuit. Wherein, the oscillation voltage of the pin P has positive and negative relative to the voltage of the common end GND, and the oscillation voltage of the third voltage dividing output end also has positive and negative relative to the voltage of the common end GND, the voltage of the fourth voltage dividing output end is lifted as a whole by the second capacitor C2, the seventh resistor R7 and the eighth resistor R8, so that the voltage of the fourth voltage dividing output end can represent the voltage of the pin P, and the oscillation waveform of the fourth voltage dividing output end changes correspondingly with the oscillation waveform at the pin P. After the voltage of the third voltage dividing output end is lifted as a whole, the voltage of the fourth voltage dividing output end is obtained, and the second comparison unit 135 can compare the voltage of the fourth voltage dividing output end with the voltage of the first reference voltage end Vth1, and then determine the code represented by the oscillation waveform.

[0038] In some embodiments, the demodulation module 13 can further include an amplifier connected between the fourth voltage dividing output end and the first input end of the second comparison unit 135.

[0039] In some embodiments, the first comparison unit 132 can be a hysteresis comparator.

[0040] In some embodiments, the second comparison unit 135 can be a hysteresis comparator.

[0041] In some embodiments, as shown in FIG. 1, the foreign matter detection module 12 can include a third comparison unit 121, the first input end of the third comparison unit 121 is connected with the pin P, a first switch tube K1 is connected between the second input end of the third comparison unit 121 and the second reference voltage end Vth2, a second switch tube K2 is connected between the second input end of the third comparison unit 121 and the first reference voltage end Vth1, and the third comparison unit 121 functions as a comparison unit of the demodulation module 13 in the off state of the second switch tube K2. Figure 6

[0042] In the present embodiment, when the first switch tube K1 is on and the second switch tube K2 is off, the third comparison unit 121 can compare the voltage of the pin P with the voltage of the second reference voltage end Vth2, and at this time, the third comparison unit 121 can function as a comparison unit of the foreign matter detection module 12. When the first switch tube K1 is off and the second switch tube K2 is on, the third comparison unit 121 can compare the voltage of the pin P with the voltage of the first reference voltage end Vth1, and at this time, the third comparison unit 121 can function as a comparison unit of the demodulation module 13.

[0043] In some embodiments, as shown in FIG. 1, the third comparison unit 121 can further include a third switch tube K3 connected between the second input end of the third comparison unit 121 and the third reference voltage end Vth3, and when the third switch tube K3 is off and the first switch tube K1 and the second switch tube K2 are on, the third comparison unit 121 can compare the voltage of the pin P with the voltage of the third reference voltage end Vth3, and at this time, the third comparison unit 121 can function as a comparison unit of the overvoltage protection module. Figure 6

[0044] In some embodiments, as shown in FIG. 1, the wireless charging chip can further include a diode D, the anode of which is connected with the pin P, and the cathode of which is connected with the foreign matter detection module 12 and the demodulation module 13; and a third capacitor C3 and a ninth resistor R9 connected in parallel, which are connected between the cathode of the diode D and the common end GND. Figure 3

[0045] ​​​In the embodiment, the foreign matter detection module 12 can obtain the voltage waveform envelope of the pin P based on the voltage of the cathode of the diode D, and determine whether there is a foreign matter between the wireless charging transmitting end and the wireless charging receiving end based on the envelope. In addition, the cathode of the diode D is connected with the demodulation module 13, which can be regarded as that the cathode of the diode D can be connected with the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected with the second voltage dividing output end.

[0046] In some embodiments, the demodulation module 13 can include: a half-wave unit connected with the pin P, and outputting a half-wave waveform corresponding to the oscillation waveform of the pin P; and a mean value detection unit connected with the half-wave unit, and obtaining and determining the communication code based on the mean value of the half-wave waveform.

[0047] In the embodiment, the half-wave unit can be a half-wave rectifier circuit, and the half-wave unit can also multiply the voltage waveform of the pin P with the digital signal to obtain the half-wave waveform of the voltage waveform of the pin P. After obtaining the half-wave waveform, the mean value of the half-wave waveform can be calculated, and the meaning represented by the voltage waveform is determined based on the obtained mean value.

[0048] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A wireless charging chip, characterized in that, The application relates to a wireless charging system, which comprises the following parts: a pin connected with a detection end of an LC series resonant circuit in an external wireless charging system; an overvoltage protection module connected with the pin, wherein an output signal of an output end of the overvoltage protection module represents an overvoltage abnormal condition; a foreign matter detection module connected with the pin, wherein the foreign matter detection module detects a waveform of the pin to determine whether foreign matter exists; a demodulation module connected with the pin, wherein the demodulation module detects a waveform of the pin to obtain a communication code; the overvoltage protection module, the foreign matter detection module and the demodulation module obtain corresponding electric signals from the pin.

2. The wireless charging chip of claim 1, wherein, The overvoltage protection module, the foreign matter detection module and the demodulation module each comprise a comparison unit, and the comparison units of at least two of the overvoltage protection module, the foreign matter detection module and the demodulation module are time-multiplexed.

3. The wireless charging chip of claim 2, wherein, The application further comprises the following parts: a voltage division module comprising a first resistor and a second resistor connected in series between the pin and a common end, wherein a common junction of the first resistor and the second resistor serves as a first voltage division output end; the pin, the first resistor, the first voltage division output end and the overvoltage protection module are connected in sequence; the pin, the first resistor, the first voltage division output end and the demodulation module are connected in sequence; the pin, the first resistor, the first voltage division output end and the foreign matter detection module are connected in sequence.

4. The wireless charging chip of claim 3, wherein, The demodulation module comprises the following parts: a first voltage division unit comprising a third resistor and a fourth resistor connected in series between a first voltage supply end and a common end, wherein a common junction of the third resistor and the fourth resistor serves as a second voltage division output end; a first capacitor connected between the first voltage division output end and the second voltage division output end; a first comparison unit having a first input end connected with the second voltage division output end, a second input end connected with a first reference voltage end and an output end outputting a signal representing a communication code.

5. The wireless charging chip of claim 1, wherein, The demodulation module comprises the following parts: a second voltage division unit comprising a fifth resistor and a sixth resistor connected in series between the pin and a common end, wherein a common junction of the fifth resistor and the sixth resistor serves as a third voltage division output end; a third voltage division unit comprising a seventh resistor and an eighth resistor connected in series between a first voltage supply end and a common end, wherein a common junction of the seventh resistor and the eighth resistor serves as a fourth voltage division output end; a second capacitor connected between the third voltage division output end and the fourth voltage division output end; a second comparison unit having a first input end connected with the fourth voltage division output end, a second input end connected with a first reference voltage end and an output end outputting a signal representing a communication code.

6. The wireless charging chip of claim 5, wherein, The demodulation module further comprises the following part: an amplifier connected between the fourth voltage division output end and the first input end of the second comparison unit.

7. The wireless charging chip of claim 5, wherein, The second comparison unit is a hysteresis comparator.

8. The wireless charging chip of claim 2, wherein, The foreign matter detection module comprises a third comparison unit, a first input end of the third comparison unit is connected with the pin, a first switch tube is connected between a second input end of the third comparison unit and a second reference voltage end, and a second switch tube is connected between the second input end of the third comparison unit and a first reference voltage end, and the third comparison unit functions as a comparison unit of the demodulation module in a conductive state of the second switch tube.

9. The wireless charging chip of claim 2, wherein, Further comprising: a diode, an anode of the diode is connected with the pin, and a cathode of the diode is connected with the foreign matter detection module and the demodulation module; a third capacitor and a ninth resistor connected in parallel, and the third capacitor and the ninth resistor are connected between the cathode of the diode and a common end.

10. The wireless charging chip of claim 1, wherein, The demodulation module comprises: a half-wave unit, the half-wave unit is connected with the pin, and outputs a half-wave waveform corresponding to an oscillation waveform of the pin; a mean value detection unit, the mean value detection unit is connected with the half-wave unit, and obtains and determines the communication code based on a mean value of the half-wave waveform.

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