Discharge device and discharge method for PD chip

Abstract

The present application provides a discharge device for a PD chip and a discharge method thereof. The discharge device includes a temperature detection circuit, a discharge current selection module and a discharge mode selection module. The temperature detection circuit is used to detect the temperature of the PD chip. The discharge current selection module is used to select a corresponding discharge current according to a discharge voltage to be discharged by the PD chip. The discharge mode selection module is used to select a discharge mode corresponding to the discharge current according to the detected temperature of the PD chip. The discharge method includes: detecting the temperature of the PD chip; selecting a corresponding discharge current according to the discharge voltage to be discharged by the PD chip; and selecting a discharge mode corresponding to the discharge current according to the detected temperature of the PD chip. The discharge current of the present application can adapt to different discharge voltages to be discharged by the PD chip, and different discharge modes can be selected according to the detected temperature of the PD chip, so as to achieve optimal performance and safety.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of discharge technology, and in particular to a discharge device and a discharge method for a PD chip. Background Art

[0002] The new specification released by USB PD (Universal Serial Bus Power Delivery) extends the power range to a higher level. The maximum output power increases from 100W to 240W. The output voltage is extended to above 20V, including new specifications such as 24V, 36V, and 48V. The output voltage is higher, and at the same current level, such as a maximum of 5A, the output power can be as high as 120W to 240W.

[0003] These voltages are needed in higher voltage battery applications such as the e-bike, power tool market or other possible battery powered applications. The higher the charging power, the faster the charging speed.

[0004] In the USB PD specification, the output voltage can vary from a lower initial voltage to a higher voltage defined in the specification protocol. Within the previously defined nominal power range, 3.3V or 5V is generally considered a typical initial output voltage, while 20V is the maximum output voltage. For the extended power range specification, the lower initial voltage can be 15V, and the higher power output voltage can reach 48V. These output voltage ranges may be extended to higher levels in the future due to newly defined battery-powered applications. Figure 1 The variation curve of the output voltage Vout of the PD chip is revealed. Figure 1 As shown in the figure, when the output voltage Vout changes from one level to another, the voltage change rate and voltage stabilization time t settle There are certain restrictions.

[0005] For example, the rate at which the voltage rises and falls is There is a defined maximum allowed V slew levels to ensure that the system can handle the voltage changes without too many over- or under-voltage spikes.

[0006] At the same time, the voltage stabilization time also has a maximum allowable time to ensure that the regulated voltage level is reached within a reasonable time frame. A certain voltage change rate is defined as the minimum value during the voltage conversion process.

[0007] A large capacitor is usually connected to the power output port. Depending on the application voltage transient requirements, the typical size can range from 1uF (microfarad) to 100uF or larger. When the voltage rises, it needs to pass the bus voltage V busThe output capacitor is charged. The charging energy comes from the load current provided by the power supply. In the case of voltage reduction, the output load is usually reduced to a smaller level and then quickly removed due to the opening of the switch connected between the power supply and the load path.

[0008] When the output load is removed (the load path is disconnected), the voltage on the bus capacitor remains high due to the lack of a discharge path. Discharging the bus capacitor is a long-term task, especially in no-load conditions with large bus capacitance.

[0009] To solve this problem, the interface protocol IC has a discharge capability, which can discharge the capacitor voltage on the bus when the bus changes from high to low, or the load is disconnected from the bus, or the bus voltage exceeds the preset value (overvoltage condition), that is, the bus voltage V bus .

[0010] However, in current design, these discharge currents are a fixed current source with a pre-designed value connected to the design pin (VIN or VOUT pin). Regardless of the voltage variation range, the strong discharge current (which can be 5-10mA (milliamps)) will remain constant.

[0011] For example, if the bus voltage changes from 20V to 5V, the discharge current is I dis (For example, 10mA). When the bus voltage changes from 9V to 5V, in a common design, if the discharge current remains unchanged, it is still I dis In this case, when 9V becomes 5V, the discharge time will be proportionally shorter than when 20V becomes 5V.

[0012] As the power range of USB PD is extended, the output voltage range is extended to a maximum of 48V, and meeting the requirements of voltage change rate and voltage stabilization time will become increasingly challenging.

[0013] For example, when the voltage changes from 20V to 5V, the output capacitor is 100uF, and the designed discharge current is 10mA, the discharge time can be calculated according to the following formula, as shown below:

[0014] C×(V2-V1)=I dis *t dis

[0015] Where C is the output capacitor, V2 and V1 are the voltage values ​​before and after discharge, I dis is the discharge current, t dis is the discharge time.

[0016] t dis =100uF×(20V-5V) / 10mA=150ms

[0017] When the voltage changes from 48V to 5V, the discharge time will become:

[0018] t dis =100uF×(48V-5V) / 10mA=430ms

[0019] Comparing the above examples, it can be seen that the higher the voltage change, the longer the discharge time. Most importantly, if a larger output capacitor is selected to stabilize a higher output voltage, the discharge time will be further extended, and it is not easy to meet the discharge time specification and voltage conversion rate requirements in a single design.

[0020] For example, if the output capacitance is extended to 1000uF, the discharge time will become:

[0021] t dis =1000uF×(48V-5V) / 10mA=4300ms

[0022] Increasing the discharge current will proportionally shorten the discharge time, but this solution has thermal penalties. Higher discharge currents will result in more losses in the discharge chip (IC). This means that there is a third factor in this trade-off: the choice of higher discharge currents is limited due to thermal constraints.

[0023] The power loss can be calculated according to the following formula:

[0024] P loss =Vout×I dis

[0025] Among them, P loss is the power loss and Vout is the output voltage.

[0026] For example, a 48V output voltage and a 10mA discharge current will result in a maximum loss of 480mW in the protocol interface IC, which is undoubtedly a thermal challenge for the IC.

[0027] The trade-off between voltage change settling time and thermal issues is difficult to meet for high output voltage applications.

[0028] For applications with a wider voltage variation range, it is difficult to find a solution with fast enough voltage variation settling time and controllable thermal performance at a single discharge current. Summary of the invention

[0029] The purpose of the embodiments of the present application is to provide a discharge device and a discharge method for a PD chip, aiming to solve at least one technical problem mentioned in the prior art.

[0030] One aspect of an embodiment of the present application provides a discharge device for a PD chip. The discharge device includes a temperature detection circuit, a discharge current selection module, and a discharge mode selection module. The temperature detection circuit is used to detect the temperature of the PD chip. The discharge current selection module is used to select a corresponding discharge current according to a discharge voltage to be discharged by the PD chip. The discharge mode selection module is used to select a discharge mode corresponding to the discharge current according to the detected temperature of the PD chip.

[0031] Another aspect of the embodiment of the present application also provides a discharge method for a PD chip. The discharge method includes: detecting the temperature of the PD chip; selecting a corresponding discharge current according to the discharge voltage to be discharged by the PD chip; and selecting a discharge mode corresponding to the discharge current according to the detected temperature of the PD chip.

[0032] The discharge device and discharge method for a PD chip according to one or more embodiments of the present application can achieve at least one of the following beneficial technical effects:

[0033] (1) Different discharge currents can be selected according to the discharge voltage to be discharged by the PD chip. When the discharge voltage to be discharged is high, the discharge speed is fast;

[0034] (2) The discharge voltage to be discharged by the PD chip can reach the set level faster;

[0035] (3) Able to sense the temperature of the PD chip and define different thermal modes to provide faster and safer protection, thereby achieving optimal performance and safety;

[0036] (4) The thermal problem of the PD chip can be improved by adjusting the on and off of the discharge current (controlled by a PWM signal). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a curve diagram of the output voltage change of the PD chip.

[0038] Figure 2 This is an overall schematic diagram of a discharge device for a PD chip according to an embodiment of the present application.

[0039] Figure 3 Schematic diagram of the relationship between the discharge current and the temperature of the PD chip in four discharge modes according to an embodiment of the present application.

[0040] Figure 4 FIG. 1 is a schematic diagram of a curve showing a change in discharge current over time in a second discharge mode according to an embodiment of the present application.

[0041] Figure 5This is a schematic diagram of the structure of a PWM output control module and the implementation of its PWM discharge mode according to an embodiment of the present application.

[0042] Figure 6 This is a flow chart of a discharge method for a PD chip according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0044] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the specification and claims of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limit, but indicate that there is at least one. "Multiple" or "several" means two and more than two. Unless otherwise specified, similar words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation, and are not limited to a position or a spatial orientation. Similar words such as "include" or "include" mean that the elements or objects appearing in front of "include" or "include" include the elements or objects listed after "include" or "include" and their equivalents, and do not exclude other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect. The singular forms "a", "said" and "the" used in this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0045] An embodiment of the present application provides a discharge device for a PD chip. Figure 2The overall schematic diagram of a discharge device 1 for a PD chip according to an embodiment of the present application is disclosed. The PD chip has an input terminal VIN and an output terminal VOUT. The discharge device 1 can reasonably discharge the discharge voltage when the PD chip needs to discharge the voltage. In one embodiment, the situation in which the PD chip needs to discharge the voltage may include the situation in which the input terminal VIN of the PD chip needs to discharge the voltage. For example, when the charger is unplugged, the charging switch Q is disconnected, and the input terminal VIN and the output terminal VOUT of the PD chip are disconnected. At this time, the discharge device 1 is connected to the input terminal VIN of the PD chip, and the input voltage of the input terminal VIN of the PD chip can be discharged. In another embodiment, the situation in which the PD chip needs to discharge the voltage may include the situation in which the output terminal VOUT of the PD chip needs to discharge the voltage. For example, when the load is unplugged, the bus voltage terminal VBUS is disconnected from the load. At this time, the discharge device 1 is connected to the output terminal VOUT of the PD chip, and the output voltage Vout of the output terminal VOUT of the PD chip can be discharged.

[0046] like Figure 2 As shown, a discharge device 1 for a PD chip according to an embodiment of the present application includes a temperature detection circuit 11, a discharge current selection module 12 and a discharge mode selection module 13. The temperature detection circuit 11 can be used to detect the temperature T of the PD chip. The discharge current selection module 12 can select a discharge voltage V to be discharged by the PD chip. dis To select the corresponding discharge current I dis When the input end of the PD chip needs to discharge voltage, the discharge voltage V dis Including the input voltage of the PD chip; when the output end of the PD chip needs to discharge voltage, the discharge voltage V dis Including the output voltage Vout of the PD chip. The discharge mode selection module 13 can select a discharge mode corresponding to the discharge current according to the detected temperature T of the PD chip.

[0047] The discharge device 1 for the PD chip of the present application can be used according to the discharge voltage V to be discharged by the PD chip. dis Provides adaptive discharge current I dis , and an adaptive discharge mode can be selected according to the temperature T of the PD chip, thereby helping to meet the regulatory requirements for discharge time and thermal issues. In the embodiment illustrated in the present application, the output terminal VOUT of the PD chip needs to discharge voltage, that is, the discharge voltage V disThe output voltage Vout of the PD chip is used as an example for schematic illustration. It can be understood that the overall architecture of the discharge device 1 for the PD chip of the present application can also be applied to the case where the input terminal VIN of the PD chip needs to discharge voltage, that is, the discharge voltage V dis Including the input voltage of the PD chip.

[0048] In some embodiments, the discharge current selection module 12 includes a plurality of discharge current branches 121-124 and a current source switch control module 120. Each discharge current branch 121 / 122 / 123 / 124 includes a current source A1 / A2 / A3 / A4 for outputting different discharge currents and a current source selection switch S1 / S2 / S3 / S4 correspondingly connected to the current source A1 / A2 / A3 / A4. For example, in the embodiment illustrated in the present application, the discharge current selection module 12 includes four discharge current branches, namely a first discharge current branch 121, a second discharge current branch 122, a third discharge current branch 123, and a fourth discharge current branch 124. The first discharge current branch 121 includes a current source A1 and a current source selection switch S1, the second discharge current branch 122 includes a current source A2 and a current source selection switch S2, the third discharge current branch 123 includes a current source A3 and a current source selection switch S3, and the fourth discharge current branch 124 includes a current source A4 and a current source selection switch S4. The current source switch control module 120 can be configured to control the discharge voltage V dis To trigger the current source selection switch in the corresponding discharge current branch to close to output the corresponding discharge current.

[0049] For example, the discharge voltage V dis Set to four gears, namely V dis ≤20V, 20V <V dis ≤30V, 30V <V dis ≤40V, 40V <V dis ≤50V. It can be based on the discharge voltage V dis , to select the corresponding discharge current branch. For example, when the discharge voltage V dis When the voltage is less than or equal to 20V, the first discharge current branch 121 can be selected, and the current source switch control module 120 can trigger the current source selection switch S1 in the first discharge current branch 121 to close. At this time, the current source A1 outputs the first discharge current I dis1 ; When the discharge voltage of the PD chip meets 20V <V disWhen the voltage is less than or equal to 30V, the second discharge current branch 122 can be selected, and the current source switch control module 120 can trigger the current source selection switch S2 in the second discharge current branch 122 to close. At this time, the current source A2 outputs the second discharge current I dis2 ; When the discharge voltage of the PD chip meets 30V <V dis When the voltage is less than or equal to 40V, the third discharge current branch 123 can be selected, and the current source switch control module 120 can trigger the current source selection switch S3 in the third discharge current branch 123 to close. At this time, the current source A3 outputs the third discharge current I dis3 ; When the discharge voltage of the PD chip meets 40V <V dis When the voltage is less than or equal to 50V, the fourth discharge current branch 124 can be selected, and the current source switch control module 120 can trigger the current source selection switch S4 in the fourth discharge current branch 124 to close. At this time, the current source A4 outputs the fourth discharge current I dis4 It can be understood that the discharge voltage V dis The setting of the gear position and the number of corresponding discharge current branches is not limited to that shown in the attached figure. In practical applications, reasonable selection can be made according to the actual PD chip. dis The designs for selecting the corresponding discharge current branches are all within the protection scope of the discharge current selection module 12 of the present application.

[0050] In some embodiments, the discharge device 1 for a PD chip of the present application may further include a discharge voltage feedback module 14. The discharge voltage feedback module 14 may be used to detect the discharge voltage V to be discharged by the PD chip. dis , and the discharge voltage V dis The output signal is fed back to the discharge current selection module 12 .

[0051] Continue to refer to Figure 2In some embodiments, the discharge mode selection module 13 of the present application includes a plurality of duty cycle selection switches K1-K4 and a PWM output control module 130. The plurality of duty cycle selection switches K1-K4 are respectively connected in series in the plurality of discharge current branches 121-124. For example, in the embodiment illustrated in the present application, the discharge current selection module 12 includes four duty cycle selection switches K1, K2, K3 and K4, wherein the duty cycle selection switch K1 is connected in series in the first discharge current branch 121; the duty cycle selection switch K2 is connected in series in the second discharge current branch 122; the duty cycle selection switch K3 is connected in series in the third discharge current branch 123; and the duty cycle selection switch K4 is connected in series in the fourth discharge current branch 124. The PWM output control module 130 can output a PWM signal with a corresponding duty cycle according to the temperature T of the PD chip detected by the temperature detection circuit 11, and can control the on and off time of the plurality of duty cycle selection switches K1-K4 based on the PWM signal with the corresponding duty cycle.

[0052] Among them, when the temperature T of the PD chip detected by the temperature detection circuit 11 is higher, the duty cycle of the PWM signal output by the PWM output control module 130 is lower; when the temperature T of the PD chip detected by the temperature detection circuit 11 is lower, the duty cycle of the PWM signal output by the PWM output control module 130 is higher.

[0053] The discharge device 1 for a PD chip of the present application can further improve the discharge function according to the temperature T of the PD chip. In some embodiments, the discharge mode selection module 13 of the present application stores a plurality of different discharge modes, wherein the plurality of different discharge modes correspond to a plurality of temperature ranges of the PD chip, respectively. The discharge mode selection module 13 can select a corresponding discharge mode based on the temperature range in which the temperature T of the PD chip detected by the temperature detection circuit 11 falls.

[0054] In some embodiments, the multiple different discharge modes may include, for example, four discharge modes, namely, a first discharge mode, a second discharge mode, a third discharge mode, and a fourth discharge mode.

[0055] Figure 3 The following is a schematic diagram showing the relationship between the discharge current and the temperature T of the PD chip in four discharge modes of an embodiment of the present application. Figure 3 The following describes in detail how the discharge device 1 for a PD chip of the present application selects a corresponding discharge mode according to the temperature T of the PD chip.

[0056] like Figure 3 As shown, in order to protect the PD chip, the temperature T of the PD chip is set to three key temperature thresholds, which are respectively the predetermined second over-temperature protection threshold T OTP2, the predetermined first over-temperature protection threshold T OTP1 and a predetermined high temperature threshold T H , where the second over-temperature protection threshold T OTP2 Greater than the first over-temperature protection threshold T OTP1 , the first over-temperature protection threshold T OTP1 Greater than the high temperature threshold T H , that is, T OTP2 >T OTP1 >T H In one embodiment, the second over-temperature protection threshold T OTP2 For example, it can be 160°C, and the first over-temperature protection threshold T OTP1 It can be 140℃, the high temperature threshold T H It can be 100°C. Of course, it can be understood that the second over-temperature protection threshold T OTP2 , the first over-temperature protection threshold T OTP1 and high temperature threshold T H It is not limited to this, and its specific numerical value can be reasonably set according to the actual PD chip, and this application does not impose any limitation.

[0057] When the temperature T of the PD chip is higher than the predetermined second over-temperature protection threshold T OTP2 , that is, T ≥ T OTP2 When , the discharge mode selection module 13 can select the first discharge mode.

[0058] In one embodiment, the first discharge mode may include, for example: immediately turning off the discharge current to stop the discharge. In another embodiment, the first discharge mode may also include: discharging with a predetermined extremely small discharge current.

[0059] When the temperature T of the PD chip is higher than the second over-temperature protection threshold T OTP2 For example, when it is 160°C, it means that the temperature T of the PD chip is very high. Heat may be a dangerous factor and may cause damage to the PD chip. Therefore, at this time, protecting the safety of the PD chip is a priority issue. The OTP (Over Temperature Protection) protection function needs to be triggered immediately to reduce the temperature T of the PD chip as soon as possible. Therefore, the discharge mode selection module 13 of the present application will select the first discharge mode.

[0060] When the temperature T of the PD chip is higher than the predetermined first over-temperature protection threshold T OTP1 But not higher than the second over-temperature protection threshold T OTP2 , that is, T OTP1 ≤T <T OTP2 When , the discharge mode selection module 13 can select the second discharge mode.

[0061] Figure 4 The following is a schematic diagram of a curve showing the change of the discharge current over time in the second discharge mode of an embodiment of the present application. Figure 4 As shown, in one embodiment, the second discharge mode is a low discharge mode, which includes: discharging at a predetermined low percentage of the selected discharge current until the discharge voltage V dis The voltage drops to a predetermined low voltage threshold and then the discharge current is completely shut down.

[0062] When the temperature T of the PD chip is higher than the predetermined first over-temperature protection threshold T OTP1 But not higher than the second over-temperature protection threshold T OTP2 , it means that the temperature T of the PD chip is a bit high, and the OTP protection function needs to be triggered to lower the temperature T of the PD chip, but low current discharge is still possible at this time. Figure 4 As shown at time t1 in FIG. 1 , the discharge current can be reduced to, for example, about 10% of the original discharge current level for discharge, and the discharge time is predetermined, for example, 10 ms (milliseconds). Figure 4 As shown in the moment t2 in the figure, when the PD chip is about to discharge the discharge voltage V dis Below a given low voltage threshold level, such as 5V or 10V, the discharge current is then completely shut off.

[0063] It is understandable that the curve of the discharge current changing with time in the second discharge mode of the present application is not limited to Figure 4 As shown, in other embodiments, the curve of the discharge current changing with time in the second discharge mode may also vary.

[0064] When the temperature T of the PD chip is higher than the predetermined high temperature threshold T H But not higher than the first over-temperature protection threshold T OTP1 , that is, T H ≤T <T OTP1 When , the discharge mode selection module 13 can select the third discharge mode.

[0065] In one embodiment, the third discharge mode is a PWM discharge mode, which includes: controlling the selected discharge current to be periodically turned on and off.

[0066] When the temperature T of the PD chip is higher than the predetermined high temperature threshold T H But not higher than the first over-temperature protection threshold T OTP1, indicating that the temperature T of the PD chip is not destructively high at this time, and the discharge function can still be retained. However, unlike the second discharge mode, the third discharge mode does not use a fixed discharge current for discharge, but improves the discharge current to be periodically turned on and off, like a PWM signal with different duty cycles. When the PWM signal is high, the discharge is turned on and the discharge current is output; when the PWM signal is low, the discharge is turned off and the discharge current is stopped. When the PWM signal is high, the PD chip is heated; when the PWM signal is low, the PD chip releases heat.

[0067] Figure 5 The present invention discloses the structure of the PWM output control module 130 and the schematic diagram of the implementation of the PWM discharge mode. Figure 5 The following describes in detail how the discharge device 1 for the PD chip of the present application implements the PWM discharge mode.

[0068] like Figure 5 As shown, in some embodiments, the PWM output control module 130 may include a voltage providing module 131 and a comparator 132. The comparator 132 has a positive input terminal (+), a negative input terminal (-) and an output terminal.

[0069] The voltage providing module 131 may provide a corresponding detection voltage Vtemp according to the detected temperature T of the PD chip. The provided detection voltage Vtemp increases as the detected temperature T of the PD chip increases.

[0070] The positive input terminal of the comparator 132 can be connected to a signal generator to receive the sawtooth wave signal Vs; the negative input terminal of the comparator 132 is connected to the voltage providing module 131 to receive the detection voltage Vtemp provided by the voltage providing module 131 .

[0071] The comparator 132 may compare the received sawtooth wave signal Vs with the amplitude of the provided detection voltage Vtemp and output a PWM signal based on the comparison result. Figure 5 As shown in the waveform in, the higher the detection voltage Vtemp provided, the smaller the duty cycle of the output PWM signal; the lower the detection voltage Vtemp provided, the larger the duty cycle of the output PWM signal.

[0072] Combined with reference Figure 2 The discharge mode selection module 13 can control the on and off time of the duty cycle selection switch connected in series in the corresponding discharge current branch by outputting PWM signals with different duty cycles, thereby controlling the selected discharge current to be periodically turned on and off.

[0073] like Figure 3As shown, the discharge current in the third discharge mode decreases linearly with the increase of the temperature T of the PD chip. Optionally, the minimum discharge current in the third discharge mode is greater than the discharge current in the second discharge mode.

[0074] When the temperature T of the PD chip is not higher than the high temperature threshold T H , that is, T <T H When , the discharge mode selection module 13 can select the fourth discharge mode.

[0075] In one embodiment, the fourth discharge mode is a high discharge mode, which includes: performing continuous discharge at a selected discharge current.

[0076] Another embodiment of the present application also provides a discharge method for a PD chip. Figure 6 A flow chart of a discharge method for a PD chip according to an embodiment of the present application is disclosed. Figure 6 As shown, a discharge method for a PD chip according to an embodiment of the present application may include steps S1 to S3.

[0077] In step S1 , the temperature T of the PD chip is detected.

[0078] In step S2, the discharge voltage V dis To select the corresponding discharge current.

[0079] In step S3, a discharge mode corresponding to the discharge current may be selected according to the detected temperature T of the PD chip.

[0080] In some embodiments, the discharge method for a PD chip of the present application may further include step S4. In step S4, the discharge voltage V to be discharged by the PD chip is detected and fed back. dis In step S2, the discharge voltage V to be discharged by the PD chip can be fed back. dis To control and select the corresponding discharge current.

[0081] In some embodiments, step S3 may further include steps S31 to S34.

[0082] In step S31, when the detected temperature T of the PD chip is higher than the predetermined second over-temperature protection threshold T OTP2 When , the control selects the first discharge mode.

[0083] The control to select the first discharge mode in step S31 may include: controlling to immediately turn off the discharge current; or controlling to discharge with a predetermined extremely small discharge current.

[0084] In step S32, when the detected temperature T of the PD chip is higher than the predetermined first over-temperature protection threshold TOTP1 But not higher than the second over-temperature protection threshold T OTP2 When , the control selects the second discharge mode.

[0085] The control in step S32 to select the second discharge mode may include: controlling the discharge to be performed at a predetermined low percentage of the selected discharge current until the discharge voltage V dis The voltage drops to a predetermined low voltage threshold and then the discharge current is completely shut down.

[0086] In step S33, when the detected temperature T of the PD chip is higher than the predetermined high temperature threshold T H But not higher than the first over-temperature protection threshold T OTP1 When , the control selects the third discharge mode.

[0087] The controlling and selecting the third discharge mode in step S33 may include: controlling the selected discharge current to be periodically switched on and off.

[0088] The on and off time of the selected discharge current can be controlled by outputting PWM signals with different duty ratios, thereby controlling the periodic on and off of the discharge current.

[0089] In step S34, when the detected temperature T of the PD chip is not higher than the high temperature threshold T H , the control selects the fourth discharge mode.

[0090] Among them, the second over-temperature protection threshold T OTP2 Greater than the first over-temperature protection threshold T OTP1 , the first over-temperature protection threshold T OTP1 Greater than the high temperature threshold T H .

[0091] The controlling to select the fourth discharge mode in step S34 may include: controlling to perform continuous discharge with the selected discharge current.

[0092] The discharge device 1 for a PD chip and the discharge method thereof according to one or more embodiments of the present application can achieve at least one of the following beneficial technical effects:

[0093] (1) According to the discharge voltage V that the PD chip needs to discharge dis Choose different discharge currents and discharge voltage V dis When it is high, the discharge speed is fast;

[0094] (2) The discharge voltage V that the PD chip needs to discharge dis You can reach your set level faster;

[0095] (3) Able to sense the temperature T of the PD chip and define different thermal modes, providing faster and safer protection;

[0096] (4) The thermal problem of the PD chip can be solved by adjusting the discharge current I dis This can be improved by turning on and off (controlled by PWM signals).

[0097] In addition, it should be noted that the above application uses the PD chip as an example to illustrate the composition and implementation of its discharge device and discharge method. However, the application is not limited to the discharge of the PD chip. In other embodiments, the concept of the discharge device and discharge method of the present application can be fully applicable to the discharge voltage of any specified circuit chip in the charger product, for example, it can also be applicable to but not limited to the AC-DC (alternating current - direct current) converter chip in the charger product.

[0098] The above is a detailed introduction to the discharge device and discharge method for PD chip provided in the embodiment of the present application. This article uses specific examples to illustrate the discharge device and discharge method for PD chip in the embodiment of the present application. The description of the above embodiment is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A discharge device for a PD chip, characterized in that: It includes: Temperature detection circuit, used to detect the temperature of the PD chip; A discharge current selection module is used to select a corresponding discharge current according to a discharge voltage to be discharged by the PD chip, wherein the higher the discharge voltage to be discharged by the PD chip, the greater the discharge current selected by the discharge current selection module, and the discharge current selection module includes: a plurality of discharge current branches, each of the discharge current branches comprising a current source for outputting different discharge currents and a current source selection switch connected to the current source; and A current source switch control module, configured to trigger the current source selection switch in the corresponding discharge current branch to close according to the discharge voltage to be discharged by the PD chip to output the corresponding discharge current; and A discharge mode selection module is used to select a discharge mode corresponding to the discharge current according to the detected temperature of the PD chip. The discharge mode selection module stores a plurality of different discharge modes, and the plurality of different discharge modes correspond to a plurality of temperature ranges of the PD chip, respectively. The discharge mode selection module selects a corresponding discharge mode based on the temperature range in which the detected temperature of the PD chip falls, wherein: The multiple different discharge modes include a first discharge mode, a second discharge mode, a third discharge mode and a fourth discharge mode, When the temperature of the PD chip is higher than a predetermined second over-temperature protection threshold, the discharge mode selection module selects the first discharge mode; When the temperature of the PD chip is higher than a predetermined first over-temperature protection threshold but not higher than the second over-temperature protection threshold, the discharge mode selection module selects the second discharge mode; When the temperature of the PD chip is higher than a predetermined high temperature threshold but not higher than the first over-temperature protection threshold, the discharge mode selection module selects the third discharge mode; and When the temperature of the PD chip is not higher than the high temperature threshold, the discharge mode selection module selects the fourth discharge mode. Among them, the second over-temperature protection threshold is greater than the first over-temperature protection threshold, and the first over-temperature protection threshold is greater than the high temperature threshold.

2. The discharge device according to claim 1, characterized in that: Also includes: The discharge voltage feedback module is used to detect the discharge voltage to be discharged by the PD chip, and feed back the detected discharge voltage to be discharged to the discharge current selection module.

3. The discharge device according to claim 1, characterized in that: The discharge mode selection module comprises: A plurality of duty cycle selection switches are respectively connected in series in the plurality of discharge current branches; The PWM output control module is used to output a PWM signal with a corresponding duty cycle according to the detected temperature of the PD chip, and to control the on and off time of the plurality of duty cycle selection switches based on the PWM signal with the corresponding duty cycle.

4. The discharge device according to claim 3, characterized in that: The higher the detected temperature of the PD chip, the lower the duty cycle of the PWM signal output by the PWM output control module; the lower the detected temperature of the PD chip, the higher the duty cycle of the PWM signal output by the PWM output control module.

5. The discharge device according to claim 1, characterized in that: The first discharge mode includes: Immediately shut off the discharge current; or, discharge at a predetermined extremely small discharge current.

6. The discharge device according to claim 1, characterized in that: The second discharge mode is a low discharge mode, which includes: Discharging is performed at a predetermined low percentage of the selected discharge current until the discharge voltage to be discharged by the PD chip decreases to a predetermined low voltage threshold, and then the discharge current is completely turned off.

7. The discharge device according to claim 3, characterized in that: The third discharge mode is a PWM discharge mode, which includes: The selected discharge current is controlled to be switched on and off periodically.

8. The discharge device according to claim 7, characterized in that: The discharge mode selection module is used to control the on and off time of the duty ratio selection switch connected in series in the corresponding discharge current branch by outputting PWM signals with different duty ratios to control the periodic on and off of the selected discharge current.

9. The discharge device according to claim 7, characterized in that: The discharge current in the third discharge mode decreases linearly with the increase of the temperature of the PD chip.

10. The discharge device according to claim 9, characterized in that: A minimum discharge current in the third discharge mode is greater than a discharge current in the second discharge mode.

11. The discharge device according to claim 1, characterized in that: The fourth discharge mode is a high discharge mode, which includes: Continuous discharge is performed at the selected discharge current.

12. The discharge device according to claim 3, characterized in that: The PWM output control module comprises: a voltage providing module, configured to provide a corresponding detection voltage according to the detected temperature of the PD chip, wherein the provided detection voltage increases as the detected temperature of the PD chip increases; and A comparator, wherein the positive input terminal of the comparator is used to receive the sawtooth wave signal, and the negative input terminal of the comparator is connected to the voltage providing module to receive the detection voltage. The comparator is used to compare the received sawtooth wave signal with the amplitude of the provided detection voltage and output the PWM signal based on the comparison result, wherein the higher the provided detection voltage is, the smaller the duty cycle of the output PWM signal is; and the lower the provided detection voltage is, the larger the duty cycle of the output PWM signal is.

13. The discharge device according to any one of claims 1 to 12, characterized in that: The PD chip has an input end and an output end. When the input end of the PD chip needs to discharge voltage, the discharge device is connected to the input end of the PD chip, and the discharge voltage to be discharged by the PD chip includes the input voltage of the PD chip; when the output end of the PD chip needs to discharge voltage, the discharge device is connected to the output end of the PD chip, and the discharge voltage to be discharged by the PD chip includes the output voltage of the PD chip.

14. A discharge method for a PD chip, characterized in that: It includes: Detect the temperature of the PD chip; Selecting a corresponding discharge current according to a discharge voltage to be discharged by the PD chip, wherein the higher the discharge voltage to be discharged by the PD chip, the larger the selected discharge current; and The discharge mode corresponding to the discharge current is selected according to the detected temperature of the PD chip, The discharge method further includes: pre-storing a plurality of different discharge modes, wherein the plurality of different discharge modes correspond to a plurality of temperature ranges of the PD chip, respectively; The step of selecting the discharge mode corresponding to the discharge current according to the detected temperature of the PD chip includes: selecting the corresponding discharge mode based on the temperature range within which the detected temperature of the PD chip falls. The step of selecting the discharge mode corresponding to the discharge current according to the detected temperature of the PD chip includes: When the detected temperature of the PD chip is higher than a predetermined second over-temperature protection threshold, the first discharge mode is controlled to be selected; When the detected temperature of the PD chip is higher than a predetermined first over-temperature protection threshold but not higher than the second over-temperature protection threshold, controlling to select the second discharge mode; When the detected temperature of the PD chip is higher than a predetermined high temperature threshold but not higher than the first over-temperature protection threshold, controlling to select a third discharge mode; and When the detected temperature of the PD chip is not higher than the high temperature threshold, the fourth discharge mode is controlled to be selected. Among them, the second over-temperature protection threshold is greater than the first over-temperature protection threshold, and the first over-temperature protection threshold is greater than the high temperature threshold.

15. The discharge method according to claim 14, characterized in that: Also includes: Detecting and feeding back the discharge voltage to be discharged by the PD chip; Wherein, the corresponding discharge current is controlled and selected according to the fed-back discharge voltage to be discharged.

16. The discharge method according to claim 14, characterized in that: The controlling and selecting the first discharge mode comprises: The discharge current is immediately turned off through control; or, the discharge is performed at a predetermined extremely small discharge current.

17. The discharge method according to claim 14, characterized in that: The controlling and selecting the second discharge mode comprises: The discharge is controlled to be performed at a predetermined low percentage of the selected discharge current until the discharge voltage to be discharged by the PD chip decreases to a predetermined low voltage threshold, and then the discharge current is completely turned off.

18. The discharge method according to claim 14, characterized in that: The controlling and selecting the third discharge mode comprises: The selected discharge current is controlled to be switched on and off periodically.

19. The discharge method according to claim 18, characterized in that: The controlling selected discharge current periodically interrupts the discharge current including: The on and off time of the selected discharge current is controlled by outputting a PWM signal with different duty ratios.

20. The discharge method according to claim 14, characterized in that: The controlling and selecting the fourth discharge mode comprises: The selected discharge current is controlled to be continuously discharged.

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