WO2021139653A1 - 一种闪光灯驱动电路 - Google Patents

一种闪光灯驱动电路 Download PDF

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Publication number
WO2021139653A1
WO2021139653A1 PCT/CN2021/070335 CN2021070335W WO2021139653A1 WO 2021139653 A1 WO2021139653 A1 WO 2021139653A1 CN 2021070335 W CN2021070335 W CN 2021070335W WO 2021139653 A1 WO2021139653 A1 WO 2021139653A1
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Prior art keywords
circuit
current
voltage
flashlight
flash
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PCT/CN2021/070335
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English (en)
French (fr)
Inventor
贾玉虎
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Oppo广东移动通信有限公司
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Publication of WO2021139653A1 publication Critical patent/WO2021139653A1/zh

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/34—Voltage stabilisation; Maintaining constant voltage

Definitions

  • This application relates to the field of flash drive technology, and relates to but not limited to a flash drive circuit.
  • a metal oxide semiconductor (MOS tube) is added to the path of the charging circuit integrated chip (charger) of the input power supply and the switching power supply to connect the power supply and the ground.
  • the external MOS tube When a high temperature event in the charging path is detected, the external MOS tube is turned on to generate a short-term high current on the charging path, which triggers the over-current protection of the external adapter that supplies the switching power supply to turn off the output, thereby avoiding the equipment on the path Withstands a long time short-circuit current and heats up and burns; however, due to the additional MOS tube, the material cost needs to be increased, and the circuit area is also increased, which squeezes the valuable space of electronic products.
  • an exemplary embodiment of the present application provides a flash drive circuit in order to solve at least one problem existing in the related art.
  • An exemplary embodiment of the present application provides a flash drive circuit, including:
  • the flash drive circuit includes at least a flash, a drive chip and a power supply, wherein:
  • the driving chip is connected to the flash lamp, and is configured to activate the boost circuit in the driving chip when a photographing instruction is received;
  • the boost circuit is configured to provide a voltage to the flash lamp when the forward voltage of the flash lamp is higher than the power supply voltage of the power supply, so that the flash lamp flashes.
  • the driving chip further includes:
  • the interface and control module is configured to adjust the current working mode to the through mode when the forward voltage of the flash lamp is lower than the power supply voltage, disconnect the boost circuit, and send the high power in the drive chip
  • the light-emitting diode drive module sends out control commands
  • the high-power light-emitting diode driving module is configured to adjust the current of the flash lamp in response to the received control instruction, so that the current of the flash lamp is less than a preset current threshold.
  • the driving chip further includes:
  • the short-circuit protection module connected to the voltage output terminal of the flashlight is configured to monitor the output voltage of the flashlight, and when the output voltage is less than the short-circuit protection threshold, control the fault register to be set, disconnect the path of the flashlight, and Clear the fault register bit;
  • An overvoltage protection module connected to the voltage output terminal of the flashlight is configured to monitor the output voltage of the flashlight, and when the output voltage is greater than or equal to an overvoltage protection threshold, disconnect the path of the flashlight.
  • the overvoltage protection module is further configured to adjust the voltage of the modulation controller in the flashlight driving circuit when the output voltage is less than the overvoltage protection threshold, so as to increase the voltage of the flashlight.
  • the output voltage is further configured to adjust the voltage of the modulation controller in the flashlight driving circuit when the output voltage is less than the overvoltage protection threshold, so as to increase the voltage of the flashlight. The output voltage.
  • the boost circuit further includes:
  • the inductor current protection module is configured to clamp the inductor current and set the fault register when the peak current of the inductor current monitored by the boost circuit is greater than the inductor current threshold.
  • the boost circuit is respectively connected to a first capacitor, an inductor, and a second capacitor, so that the current at the output terminal of the boost circuit is a constant current; the output terminal of the boost current is connected to the flash lamp And use battery power to supply power to the boost circuit; wherein, the first capacitor is an input capacitor, and the second capacitor is an output capacitor.
  • the driving chip further includes:
  • the input and output port is configured to be connected with an external controller. During the flashing of the flashlight, if it is detected that the external controller is in a working state, the flash current of the flashlight is reduced.
  • the distance between the battery power supply, the first capacitor and the second capacitor, respectively, and the interface and the control module is set to be less than a distance threshold
  • the surface layers of the first capacitor and the second capacitor are connected to a common ground and connected to the main ground through a through hole.
  • the area of the metal ground within the preset range of each component in the layout of the circuit board is greater than the preset area; wherein, the metal ground within the preset range is connected to the ground through a plurality of through holes. .
  • a connecting wire with a preset width is used to connect the battery power source and the inductor to the boost circuit
  • the area of the metal ground within the preset range of the pad to which each flasher belongs is set to be greater than the preset area threshold, and a preset number is placed on the metal ground within the preset range of the pad Of heat dissipation holes.
  • An exemplary embodiment of the present application provides a flashlight driving circuit, wherein the flashlight driving circuit at least includes a flashlight, a driving chip, and a power supply, wherein: the driving chip is connected to the flashlight and is configured to receive a photo When instructed, the boost circuit in the drive chip is activated; the boost circuit is configured to provide a voltage to the flash lamp when the forward voltage of the flash lamp is higher than the power supply voltage, so that the flash lamp Flash; In this way, when the flash function needs to be activated, the booster circuit in the driver chip is activated to provide voltage to the flash to make the flash flash. In this way, using such a driver chip to control the flash of the flash can improve the control accuracy and conversion efficiency. .
  • FIG. 1 is a schematic diagram of the structure of a flash drive circuit according to an exemplary embodiment of the application
  • 2A is a schematic diagram of another composition structure of a flash drive circuit according to an exemplary embodiment of the application.
  • 2B is a schematic diagram of another composition structure of a flash drive circuit according to an exemplary embodiment of this application.
  • Fig. 3 is a functional block diagram of a driving chip according to an exemplary embodiment of the application.
  • Fig. 4 is a driving principle diagram of a flashlight provided by an exemplary embodiment of the application.
  • FIG. 5 is a PCB layout diagram of a driving circuit of a flashlight provided by an exemplary embodiment of the application.
  • FIG. 1 is a schematic diagram of the structure of the flash drive circuit of an exemplary embodiment of the present application.
  • the circuit 10 at least includes a flash 101, a driving chip 102 and a power supply 103, where:
  • the driving chip 102 is connected to the flash 101 and is configured to activate the boost circuit 121 in the driving chip 102 when a photographing instruction is received.
  • the driving chip 102 is a soft start, and the driving chip 102 also includes a short circuit protection module, an overvoltage protection module, an inductive current protection module, etc.; and when the interface and control module in the driving chip 102 receive a photographing instruction, according to the chip
  • the voltage fed back by the amplifier in the chip adjusts the voltage of the boost circuit in the chip.
  • the boost circuit 121 is configured to make the output voltage of the flash lamp higher than the input voltage.
  • the flash 101 may be composed of any type of photodiode, for example, an LED flash.
  • the driving chip 102 has a soft start function, the maximum soft start time is 1200 microseconds (us), the switching frequency is 100 megahertz (MHz), and the operating frequency can be set to 50 MHz through software.
  • the boost circuit 121 is configured to provide a voltage to the flash lamp when the forward voltage of the flash lamp 101 is higher than the power supply voltage of the power supply 103 to make the flash lamp flash.
  • the power source 103 may be a battery power source or a power source connected to AC power through a jack.
  • the boost circuit 121 includes at least an inductor, a capacitor, a MOS tube, etc., when the forward voltage of the flash 101 is higher than the power supply voltage, the driving chip 102 starts the boost circuit to make the boost circuit work . Provides forward voltage for the flash lamp according to the demand of the internal current source. In this way, when the flash function needs to be activated, the booster circuit in the driver chip is activated to provide voltage to the flash lamp to make the flash lamp flash. Using such a driver chip to control the flash of the flash lamp can improve the control accuracy and conversion efficiency.
  • the driver chip 102 further includes an interface and control module and a high-power light-emitting diode drive module:
  • the interface and control module is configured to adjust the current working mode to the pass-through mode when the forward voltage of the flash lamp is lower than the power supply voltage, disconnect the boost circuit, and send the high-power light-emitting diode drive module in the drive chip Issue control commands.
  • the boost circuit does not work, and the interface and control module work in a pass-through mode.
  • Diode DRIVER, HPLED DRIVER to adjust the flash current.
  • the high-power LED driving module is configured to adjust the current of the flash lamp in response to the received control instruction, so that the current of the flash lamp is less than a preset current threshold.
  • the high-power LED driving module can adjust the current of the flash lamp to make the current of the flash lamp smaller, and the preset current threshold is the current when the flash lamp is working normally.
  • the flash lamp can work normally.
  • the driving chip 102 in order to improve the conversion efficiency of the input voltage and the output voltage, the driving chip 102 further includes a short-circuit protection module 201 and an over-voltage protection module 202, as shown in FIG. 2A, which is an example of this application.
  • FIG. 2A Another structural schematic diagram of the flash drive circuit of the embodiment is described below with reference to FIG. 1:
  • the short-circuit protection module 201 connected to the voltage output terminal of the flashlight is configured to monitor the output voltage of the flashlight, and when the output voltage is less than the short-circuit protection threshold, control the fault register to be set to disconnect the path of the flashlight, And clear the fault register bit.
  • the driver chip has a variety of safety protection functions, such as short-circuit protection, over-voltage protection, and inductor current protection.
  • the short-circuit protection module 201 monitors the output voltage (LED_OUT voltage) of the flashlight. When the flashlight is short-circuited, the level of the LED_OUT pin will change. When it is detected that the voltage of the flashlight is lower than the short-circuit protection threshold (for example, 1.2V (maximum 1.3V)), it is determined that the flashlight is short-circuited, the corresponding fault register bit will be set, and the path will be disconnected until the register is cleared Bit; this increases the software control mechanism, which can more sensitively monitor whether the circuit is short-circuited.
  • the short-circuit protection threshold for example, 1.2V (maximum 1.3V)
  • the overvoltage protection module 202 connected to the voltage output terminal of the flashlight is configured to monitor the output voltage of the flashlight, and when the output voltage is greater than or equal to an overvoltage protection threshold, disconnect the path of the flashlight.
  • the overvoltage protection module 202 monitors the output voltage of the flashlight, and when the output voltage is greater than the overvoltage protection threshold (for example, greater than 5.5V), the path of the flashlight is disconnected, thereby realizing the protection of the flashlight circuit.
  • the overvoltage protection threshold for example, greater than 5.5V
  • the overvoltage protection module 202 is further configured to adjust the voltage of the modulation controller in the flash drive circuit to increase the output voltage when the output voltage is less than the overvoltage protection threshold. The output voltage of the flash lamp; thereby increasing the current control range.
  • the constant current source inside the circuit will adjust the modulation controller to continuously boost the voltage.
  • the overvoltage protection module monitors the voltage at the output terminal. When the voltage at the output terminal reaches 5.5V, it is judged to be overvoltage and disconnected. The pathway.
  • the driver chip further includes:
  • the input and output port is configured to be connected with an external controller. During the flashing of the flashlight, if it is detected that the external controller is in a working state, the flash current of the flashlight is reduced.
  • the (General-purpose input/output2, GPIO2) signal of the input and output port is usually used as the transmit mask (TxMask) function, which can be connected to the enable signal of the external controller, which is triggered if the external controller works during the flashing process , Turn on the TxMask function to reduce the flash current to prevent excessive power supply voltage from affecting the normal operation of the system. If the port is not used, the pin of the port is left floating; in this way, the current control range is increased.
  • TxMask transmit mask
  • the driver chip 102 also has an inductive current protection function, and an inductive current protection module is also provided in the boost circuit, as shown in FIG. 2B, which is an exemplary embodiment of the application.
  • FIG. 2A Another schematic diagram of the structure of the flash drive circuit is described below in conjunction with FIG. 2A:
  • the inductor current protection module 221 is configured to clamp the inductor current and set the fault register when the peak current of the inductor current monitored by the boost circuit is greater than the inductor current threshold.
  • the inductor current protection module in the boost circuit monitors the inductor current. When the inductor peak current reaches the inductor current threshold set by the drive chip, the current is limited within this threshold range and will not increase further, and the corresponding fault register location Bit.
  • a thermal sensor is also provided in the driver chip, which is configured to monitor the temperature in the circuit. When the temperature in the circuit is detected to be too high, such as higher than a certain temperature threshold, the circuit is disconnected to protect the components of the circuit in time. Device.
  • the boost circuit in order to adjust the output voltage and current of the flash lamp more accurately, is respectively connected to a first capacitor, an inductor, and a second capacitor, so that the current at the output terminal of the boost circuit is a constant current;
  • the output terminal of the boost current is connected to the flash lamp, and a battery power supply is used to supply power to the boost circuit.
  • the VIN, SW, and VOUT pins of the boost circuit are respectively connected to a first capacitor, an inductor, and a second capacitor.
  • the first capacitor is an input capacitor
  • the second capacitor is an output capacitor to ensure that the boost circuit
  • the current at the output terminal is a constant current.
  • the boost circuit is powered by battery voltage, and the output terminal (LED_OUT) of the boost circuit is a constant current output, and the output terminal is connected to a flashlight, which ensures that the voltage provided for the flashlight is a constant voltage.
  • the battery power source, the first capacitor, and the second capacitor are set to be connected to the interface and The distance of the control module is less than the distance threshold.
  • the driver chip is a boost circuit.
  • the inductor, the first capacitor and the second capacitor are placed as close to the interface and the control module as possible, and the wiring is as close as possible Short, so as to prevent these components from working at high switching frequencies, and the wiring is too long to cause antenna effects; this wiring makes the driver chip wiring short, easy to layout, simple wiring, and strong anti-interference ability.
  • the surface layers of the first capacitor and the second capacitor are connected to the common ground and connected to the main ground through a through hole.
  • the surface of the input and output capacitors are connected to the common ground and connected to the main ground through a single via hole to reduce the DC/DC loop and interference to other circuits.
  • the area of the metal ground within the preset range of each component in the layout of the PCB is greater than the preset area.
  • the metal ground in the preset range is connected to the ground plane through a plurality of through holes, and the preset range can be understood as the range around the component.
  • the metal ground area around the component is enlarged to help heat dissipation;
  • the metal ground around the component is connected to the ground plane through a plurality of vias, reducing noise interference to sensitive circuits.
  • a connecting line with a width greater than a preset width is used to connect the battery power source and the inductor to the boost circuit.
  • the use of a wider connecting wire to connect the battery power supply and the inductor to the boost circuit can withstand the larger current flowing through the inductor to the switch node line.
  • the current may reach about 1.4 A (A).
  • the area of the metal ground within the preset range of the pad to which each flasher belongs is set to be greater than the preset area threshold, and a preset number of heat dissipation holes are made on the metal ground within the preset range of the pad .
  • the heat dissipation area of the LED is increased in the PCB layout.
  • the heat dissipation area of a single flash is 70 to 80 square millimeters. Try to increase the metal area around each pad and make more heat dissipation holes.
  • the distance between the flash and the camera should not exceed 13 mm. If two lights are used, the distance between the flash should be within 4 to 10 mm (for example, the effect is better when the distance is close to 4 mm). In this way, the wiring in the driving chip is shorter and the anti-interference ability is strong, thereby improving the luminous efficiency, reducing the temperature rise, and having reliable performance.
  • FIG. 3 is a functional block diagram of a driver chip of an exemplary embodiment of the present application. As shown in FIG. 3, the following description will be given:
  • the driving chip 31 is a driving scheme using a synchronous boost (BOOST) circuit and has a soft-start function.
  • the maximum soft-start time is 1200 microseconds
  • the switching frequency is 100 MHz
  • the operating frequency can be set to 50 MHz through software.
  • the BOOST circuit starts to work and provides the forward voltage of the LED according to the demand of the internal current source. If the battery voltage is higher than the forward voltage drop of the LED, the BOOST circuit does not work, and the interface and control module (INTERFACE AND CONTROL, IC) 312 works in the Pass-through mode, and the flash current is adjusted by the internal high-power flash diode drive.
  • an inductor (L1), a capacitor (C1), a switch (SW), a MOS tube 313, and a MOS tube 314 form the boost circuit.
  • the capacitor C1 is the input capacitor, which can be set to 10 microfarads. And set the input voltage to 2.7 volts (V) to 5V.
  • the driver chip 31 has a variety of safety protection functions:
  • the short-circuit protection module 301 monitors the output voltage (LED_OUT) 302 of the flash. When the LED is short-circuited, the level of the LED_OUT pin will be pulled down. When the detected voltage is lower than the short-circuit protection threshold 1.2V (maximum 1.3V), it is judged as a short-circuit, The fault register (fault register) 303 bit will be set, and the path will be disconnected until the AP clears the register bit; finally, the current through the light-emitting diode (LED) 317 remains between 25 mA and 1.54 amperes.
  • the output (VOUT) 306 terminal provides a voltage for the high-power LED driver 315 (HPLED driver), so that current flows through the HPLED driver 315 to the short-circuit protection module 301 and the high-power LED current control module 316.
  • the overvoltage protection module 305 when the circuit is open, the internal constant current source will adjust the modulation controller 304 (for example, pulse width modulation controller, PWM CONTROLLER) to continuously boost the voltage, and the overvoltage protection module 305 monitors the voltage of the voltage output terminal (VOUT) 306, When it reaches 5.5V, it is judged to be an overvoltage, and the path is disconnected.
  • the modulation controller 304 for example, pulse width modulation controller, PWM CONTROLLER
  • VOUT voltage output terminal
  • VOUT 306 is connected to capacitor Cout 307, and capacitor Cout 307 is grounded to ensure the stability of the output voltage.
  • the capacitance of the capacitor Cout can be set to 10 microfarads ( ⁇ F).
  • the boost circuit monitors the inductor (L1) current. When the peak current reaches the threshold set by the software, the current is limited to this threshold and will not increase further, and the corresponding register 303 is set.
  • the inductance L1 can be set to 1 microfarad.
  • the amplifier 311 serves as a feedback circuit to feed the current back to the IC 312, and the interface and control module adjust the current through the modulation controller 304.
  • the enable signal is input to the modulation controller 304 through the enable (EN) 319 pin.
  • the SCL pin 320 and the SDA pin 321 are respectively the clock and data of the serial transmission bus protocol (Inter-Integrated Circuit, I2C) protocol .
  • STOBE 322 is a strobe input signal, which can be directly connected to the interface and control module, or connected to the main system. When a photo is to be captured, this signal is triggered to activate the flash function.
  • I/O port 1 GPIO1
  • I/O port 2 GPIO2
  • the signal will be triggered, and the TxMask function will be turned on to reduce the flash current to prevent excessive power supply voltage. The normal operation of the system is affected.
  • a thermal sensor 318 is also provided, which is configured to monitor the temperature in the circuit. When the temperature is too high, the circuit is disconnected and the fault register 303 is set.
  • FIG. 4 is a driving principle diagram of a flashlight provided by an exemplary embodiment of this application, as shown in FIG. 4 for the following description:
  • U1001 is the driver chip shown in Figure 3.
  • the input voltage (VIN) 401, the switch (SW) 402 and the output voltage (VOUT) 403 form a BOOST boost circuit, which is powered by a battery (VBAT) 404, respectively Connect the input capacitor (C1001), inductor (L1001) and output capacitor (C1002), LED_OUT 405 is a constant current output, connected to flash 1001;
  • EN 407 is an enable signal, high effective, connected to the pull-down resistor of R1001 (100 k ⁇ );
  • the I2C signal is connected to the I2C interface of the main system, that is, the clock pin SCL408 and the data pin SDA409 of the I2C interface are connected to R1002 and R1003 respectively (R1002 and R1003 are 2.2K kiloohm pull-up resistors) (pull up The level is 1.8V.
  • STOBE 410 is a strobe input signal, which can be directly connected to the sensor or to the main system. This signal is triggered when the photo is taken to turn on the flash function.
  • EN 407 receives the input LED flash memory enable signal (LED_FLASH_EN) 471
  • the clock pin SCL 408 receives the input LED flash memory clock signal (LED_FLASH_SCL) 481
  • the data pin SDA409 receives the input LED flash memory data signal (LED_FLASH_SDA) 491
  • STOBE 410 receives the input LED flash strobe signal (LED_FLASH_STROBE) 492.
  • the GPIO1 signal and GPIO2 signal are usually used as the TxMask function, which can be connected to the enable signal of the external controller. If the external controller works during the flashing process, the signal will be triggered, and the TxMask function will be turned on to reduce the flash current to prevent excessive VBAT 404 voltage from affecting the system normal work. If not used, this pin is left floating.
  • GPIO1 receives the input LED flash memory touch signal (LED_FLASH_TORCH) 493.
  • the flash can be realized by LED1001.
  • FIG. 5 is a PCB layout diagram of a driving circuit of a flashlight provided by an exemplary embodiment of this application, as shown in FIG. 5 for the following description:
  • LED4501 represents a flashlight
  • U2004 is a driver chip
  • U2006 is a chip connected to a communication network
  • U2002 is an integrated stream chip
  • U2101, U3002, U2704, and U2702 are antenna switches of different radio frequencies
  • C3013, C3020, C3019, and C3027 They represent capacitors of different capacities
  • L3005, L3003, and L3004 represent inductors of different capacities respectively
  • CN2703, CN2704, and CN2701 respectively represent the corners of the camera table and the connection line of the PCB
  • SH3213 represents the position of the camera in the PCB.
  • the BOOST boost circuit is used in the driver chip.
  • the inductor, input capacitor and output capacitor are placed as close to the IC as possible, and the traces are as short as possible. These components work at high switching frequencies, and the traces may be too long.
  • Antenna effect; the surface of the input and output capacitors are connected to the common ground and connected to the main ground with separate through holes to reduce the DC/DC loop and interference to other circuits; try to increase the metal ground area around the component to help heat dissipation; the metal ground around the component Connect to the ground plane through multiple vias to reduce noise interference to sensitive circuits; the current from VBAT to the SW node line through the inductor is relatively large.
  • the flashing moment may reach about 1.4A, and the wiring needs to be widened as much as possible.
  • the LED part mainly considers heat dissipation and light efficiency.
  • the PCB layout should increase the heat dissipation area of the LED as much as possible. It is recommended that the heat dissipation area of a single lamp is 70 to 80mm2, and the pads should be enlarged as much as possible. Use more heat dissipation holes for the surrounding metal area.
  • the distance between the LED and the camera should not exceed 13mm. If two lights are used, the distance between the LEDs should be within 4 to 10mm. For example, set the LEC pitch close to 4mm.
  • the PCB layout in FIG. 5 strictly follows the above-mentioned layout rules. It can be seen from FIG. 5 that the traces of the driving circuit of an exemplary embodiment of the present application are relatively short. In this way, the driving current can be controlled, and the traces are short, and the anti-interference ability is Strong; in such a PCB layout, the layout is easier, and the wiring is simplified, which can save costs.
  • the core of chip driving performance is efficiency conversion.
  • the test data is shown in Table 1.
  • the conversion efficiency of the input and output relationship of the driving chip provided by an exemplary embodiment of the present application is as high as 90% or more, which greatly improves the luminous efficiency, reduces the temperature rise, and has reliable performance. Therefore, the use of the driver chip improves the performance of the product and makes the control accuracy high; due to the high conversion efficiency, the power loss is low; in this way, according to the current mobile phone's demand for flash drive performance, the design is optimized and the overall performance is improved.
  • formulating corresponding schematic diagrams and PCB rules is of great practical value and low cost.
  • one embodiment or “an embodiment” mentioned throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present application. Therefore, the appearances of "in one embodiment” or “in an embodiment” in various places throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not be an example of this application. The implementation process of the exemplary embodiment constitutes any limitation. The serial number of an exemplary embodiment of the present application described above is only for description, and does not represent the superiority or inferiority of the embodiment.
  • the disclosed device and method may be implemented in other ways.
  • the device embodiments described above are merely illustrative.
  • the division of the units is only a logical function division, and there may be other divisions in actual implementation, such as: multiple units or components can be combined, or It can be integrated into another system, or some features can be ignored or not implemented.
  • the coupling, or direct coupling, or communication connection between the components shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms. of.
  • the units described above as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of an exemplary embodiment of the present application.
  • the functional units in the embodiments of the present application can be all integrated into one processing unit, or each unit can be individually used as a unit, or two or more units can be integrated into one unit;
  • the unit can be implemented in the form of hardware, or in the form of hardware plus software functional units.
  • the flash drive circuit includes at least: a flash, a drive chip, and a power supply.
  • the drive chip is connected to the flash and is configured to activate the boost circuit in the drive chip when a photographing instruction is received.
  • the boost circuit is configured to provide a voltage for the flash lamp when the forward voltage of the flash lamp is higher than the power supply voltage to make the flash lamp flash.

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Abstract

一种闪光灯驱动电路（10），该闪光灯驱动电路（10）至少包括：闪光灯（101）、驱动芯片（102）和电源（103），其中：该驱动芯片（102）与该闪光灯（101）相连，配置为当接收到拍照指令时，启动该驱动芯片（102）中的升压电路（121）；该升压电路（121），配置为当该闪光灯（101）的正向电压高于该电源（103）的电源电压时，为该闪光灯（101）提供电压，以使该闪光灯（101）闪光。

Description

一种闪光灯驱动电路
相关申请的交叉引用
本申请基于申请号为202010023830.1、申请日为2020年1月9日的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此引入本申请作为参考。
技术领域
本申请涉及闪光灯驱动技术领域，涉及但不限于一种闪光灯驱动电路。
背景技术
在相关技术中，在手机和移动电源上，在输入电源和开关电源的充电电路集成芯片(charger)的通路上外加一颗金属氧化物半导体(metal oxide semiconductor，MOS管)连接电源和接地，在检测到充电通路高温事件时，打开外加的MOS管，在充电通路上产生一个短时间大电流，触发为开关电源供电的外部适配器的过流保护，令其关断输出，从而避免通路上的设备经受较长时间的短路电流而发热烧毁；但是这样由于外加MOS管，需要增加物料成本，同时也增大了电路面积，挤占电子产品宝贵的空间。
发明内容
有鉴于此，本申请一示例性实施例为解决相关技术中存在的至少一个问题而提供一种闪光灯驱动电路。
本申请一示例性实施例的技术方案是这样实现的：
本申请一示例性实施例提供了一种闪光灯驱动电路，包括：
所述闪光灯驱动电路至少包括：闪光灯、驱动芯片和电源，其中：
所述驱动芯片与所述闪光灯相连，配置为当接收到拍照指令时，启动所述驱动芯片中的升压电路；
所述升压电路，配置为当所述闪光灯的正向电压高于所述电源的电源电压时，为所述闪光灯提供电压，以使所述闪光灯闪光。
在上述电路中，所述驱动芯片还包括：
界面与控制模块，配置为当所述闪光灯的正向电压低于所述电源电压时，将当前工作模式调整至直通模式，断开所述升压电路，并向所述驱动芯片中的高功率发光二极管驱动模块发出控制指令；
所述高功率发光二极管驱动模块，配置为响应于接收到的所述控制指令，调整所述闪光灯的电流，以使所述闪光灯的电流小于预设电流阈值。
在上述电路中，所述驱动芯片还包括：
与所述闪光灯的电压输出端相连的短路保护模块，配置为监测所述闪光灯的输出电压，当所述输出电压小于短路保护阈值时，控制故障寄存器位置位，断开所述闪光灯的通路，并清除所述故障寄存器位；
与所述闪光灯的电压输出端相连的过压保护模块，配置为监测所述闪光灯的输出电压，当所述输出电压大于或等于过压保护阈值时，断开所述闪光灯的通路。
在上述电路中，所述过压保护模块，还配置为当所述输出电压小于所述过压保护阈值时，调整所述闪光灯驱动电路中的调制控制器的电压，以增大所述闪光灯的输出电压。
在上述电路中，所述升压电路还包括：
电感电流保护模块，配置为当所述升压电路监测到的电感电流的峰值电流大于电感电流阈值时，钳制所述电感电流，并将所述故障寄存器位置位。
在上述电路中，所述升压电路分别与第一电容、电感和第二电容相连，以使所述升 压电路的输出端的电流为恒定电流；所述升压电流的输出端与所述闪光灯相连，并采用电池电源为所述升压电路供电；其中，所述第一电容为输入电容，所述第二电容为输出电容。
在上述电路中，所述驱动芯片，还包括：
输入输出端口，配置为与外部控制器相连接，在所述闪光灯闪光的过程中，如果检测到所述外部控制器处于工作状态，降低所述闪光灯的闪光电流。
在上述电路中，在所述驱动芯片所属的电路板的布局中，设置所述电池电源、所述第一电容和所述第二电容分别与所述界面与控制模块的距离小于距离阈值；
在所述电路板的布局中，所述第一电容和所述第二电容的表层共地连接并通过通孔连接到主地。
在上述电路中，在所述电路板的布局中每一元器件的预设范围内的金属地的面积大于预设面积；其中，所述预设范围内的金属地通过多个通孔连接到地。
在上述电路中，在所述电路板的布局中，采用预设宽度的连接线，将所述电池电源和所述电感连接至所述升压电路；
在所述电路板布局中，设置每一闪光灯所属的焊盘在预设范围内的金属地的面积大于预设面积阈值，且在所述焊盘在预设范围内的金属地上打预设数量的散热孔。
本申请一示例性实施例提供一种闪光灯驱动电路，其中，所述述闪光灯驱动电路至少包括：闪光灯、驱动芯片和电源，其中：所述驱动芯片与所述闪光灯相连，配置为当接收到拍照指令时，启动所述驱动芯片中的升压电路；所述升压电路，配置为当所述闪光灯的正向电压高于所述电源电压时，为所述闪光灯提供电压，以使所述闪光灯闪光；如此，当需要启动闪光功能时，通过启动驱动芯片中的升压电路，为闪光灯提供电压，以使闪光灯闪光，这样，使用这样的驱动芯片控制闪光灯的闪光，能够提高控制精度以及转化效率。
附图说明
此处的附图被并入说明书中并构成本说明书的一部分，这些附图示出了符合本申请的实施例，并与说明书一起用于说明本申请的技术方案。
图1为本申请一示例性实施例闪光灯驱动电路的组成结构示意图；
图2A为本申请一示例性实施例闪光灯驱动电路的另一组成结构示意图；
图2B为本申请一示例性实施例闪光灯驱动电路的又一组成结构示意图；
图3为本申请一示例性实施例驱动芯片的功能框图；
图4为本申请一示例性实施例提供的闪光灯的驱动原理图；
图5为本申请一示例性实施例提供的闪光灯的驱动电路的PCB布局图。
具体实施方式
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述，所描述的实施例不应视为对本申请的限制，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本申请保护的范围。
下面将结合本申请一示例性实施例中的附图，对本申请一示例性实施例中的技术方案进行清楚、完整地描述。
本申请一示例性实施例提供一种闪光灯驱动电路，应用于手机、平板电脑、移动电源等具有拍照功能的电子设备中；图1为本申请一示例性实施例闪光灯驱动电路的组成结构示意图，如图1所示，所述电路10至少包括：闪光灯101、驱动芯片102和电源103，其中：
所述驱动芯片102与所述闪光灯101相连，配置为当接收到拍照指令时，启动所述驱 动芯片102中的升压电路121。
这里，驱动芯片102为软启动，驱动芯片102中还包括短路保护模块、过压保护模块和电感电流保护模块等；而且当驱动芯片102中的界面与控制模块接收到拍照指令时，根据该芯片中的放大器反馈的电压调整该芯片中升压电路的电压。升压电路121，配置为使得闪光灯的输出电压高于输入电压。闪光灯101可以是由任意类型的光电二极管组成，比如，LED闪光灯。驱动芯片102具有软启动功能，最大软启动时间为1200微秒(us)，开关频率100兆赫兹(MHz)，可通过软件设置工作频率为50MHz。
所述升压电路121，配置为当所述闪光灯101的正向电压高于电源103的电源电压时，为所述闪光灯提供电压，以使所述闪光灯闪光。
这里，电源103可以是电池电源还可以是通过插孔连接交流电的电源等。升压电路121中至少包括：电感、电容和MOS管等，当所述闪光灯101的正向电压高于所述电源电压时，驱动芯片102启动该升压电路，以使升压电路处于工作状态。根据内部电流源需求为闪光灯提供正向电压。如此，当需要启动闪光功能时，通过启动驱动芯片中的升压电路，为闪光灯提供电压，以使闪光灯闪光，使用这样的驱动芯片控制闪光灯的闪光，能够提高控制精度以及转化效率。
在一些实施例中，为了提高驱动芯片对闪光灯的电压电流的控制精度，所述驱动芯片102还包括界面与控制模块和高功率发光二极管驱动模块：
界面与控制模块，配置为当所述闪光灯的正向电压低于电源电压时，将当前工作模式调整至直通模式，断开升压电路，并向所述驱动芯片中的高功率发光二极管驱动模块发出控制指令。
这里，当所述闪光灯的正向电压低于所述电源电压时，升压电路不工作，界面与控制模块工作在直通(Pass-through)模式，通过内部的高功率发光二极管(High Power Light Emitting Diode DRIVER，HPLED DRIVER)来调整闪光灯电流。
所述高功率发光二极管驱动模块，配置为响应于接收到的控制指令，调整所述闪光灯的电流，以使所述闪光灯的电流小于预设电流阈值。
这里，高功率发光二极管驱动模块能够调整闪光灯的电流，以使闪光灯的电流较小，该预设电流阈值为闪光灯正常工作时的电流。通过采用高功率发光二极管驱动模块调整所述闪光灯的电流，使得闪光灯能够正常工作。
在一些实施例中，为了提高输入电压和输出电压的转化效率高，所述驱动芯片102还包括短路保护模块201和过压保护模块202，如图2A所示，图2A为本申请一示例性实施例闪光灯驱动电路的另一组成结构示意图，结合图1进行以下说明：
与所述闪光灯的电压输出端相连的短路保护模块201，配置为监测所述闪光灯的输出电压，当所述输出电压小于短路保护阈值时，控制故障寄存器位置位，断开所述闪光灯的通路，并清除所述故障寄存器位。
这里，驱动芯片具有多种安全保护功能，比如，短路保护、过压保护和电感电流保护等，其中，短路保护模块201监测闪光灯的输出电压(LED_OUT电压)，闪光灯短路时LED_OUT引脚电平会被拉低，当检测到闪光灯的电压低于短路保护阈值(比如，1.2V(最大1.3V))时，判定为闪光灯短路，相应的故障寄存器位会置位，断开通路，直到清除该寄存器位；这样增加了软件的控制机制，能够更加灵敏地监测电路是否短路。
与所述闪光灯的电压输出端相连的过压保护模块202，配置为监测所述闪光灯的输出电压，当所述输出电压大于等于过压保护阈值时，断开所述闪光灯的通路。
这里，过压保护模块202监测所述闪光灯的输出电压，当输出电压大于过压保护阈值(比如，大于5.5V)时，断开所述闪光灯的通路，实现了对闪光灯电路的保护。
在一些可能的实现方式中，过压保护模块202，还配置为当所述输出电压小于所述过压保护阈值时，调整所述闪光灯驱动电路中的调制控制器的电压，以增大所述闪光灯的 输出电压；从而增大电流控制范围。
比如，在接通该驱动电路的情况下，电路内部恒流源会调整调制控制器不断升压，过压保护模块监测输出端的电压，当输出端的电压到达5.5V时判定为过压，断开该通路。
在一些实施例中，所述驱动芯片，还包括：
输入输出端口，配置为与外部控制器相连接，在所述闪光灯闪光的过程中，如果检测到所述外部控制器处于工作状态，降低所述闪光灯的闪光电流。
这里，输入输出端口的(General-purpose input/output2，GPIO2)信号通常用作发射掩码(TxMask)功能，可连接外部控制器的使能信号，闪光过程中如果外部控制器工作则触发该信号，开启TxMask功能，降低闪光电流防止拉电源电压过多影响***正常工作。如果不使用该端口，将该端口的引脚悬空；如此，增大了电流控制范围。
在本申请一示例性实施例中，该驱动芯片102还具有电感电流保护功能，在升压电路中还设置有电感电流保护模块，如图2B所示，图2B为本申请一示例性实施例闪光灯驱动电路的又一组成结构示意图，结合图2A进行以下说明：
电感电流保护模块221，配置为当所述升压电路监测到的电感电流的峰值电流大于电感电流阈值时，钳制所述电感电流，并将所述故障寄存器位置位。
这里，升压电路中的电感电流保护模块，监测电感电流，当电感峰值电流达到驱动芯片设置的电感电流阈值时，电流被限制在此阈值范围内，不会进一步增加，同时相应的故障寄存器位置位。
在一些实施例中，驱动芯片中还设置了热感测，配置为监测电路中的温度，当监测到电路中温度过高，比如高于特定温度阈值时，断开电路，及时保护电路的元器件。
在一些实施例中，为了更加精确的调整闪光灯的输出电压电流，所述升压电路分别与第一电容、电感和第二电容相连，以使所述升压电路的输出端的电流为恒定电流；所述升压电流的输出端与所述闪光灯相连，并采用电池电源为所述升压电路供电。
这里，升压电路的VIN、SW和VOUT引脚分别连接第一电容、电感和第二电容，所述第一电容为输入电容，所述第二电容为输出电容，以保证所述升压电路的输出端的电流为恒定电流。
该升压电路采用电池电压供电，升压电路的输出端(LED_OUT)为恒流输出，该输出端连接闪光灯，这样保证了为闪光灯提供的电压为恒压。
在一些实施例中，在所述驱动芯片的印制电路板(Printed Circuit Board，PCB)的布局中，设置所述电池电源、所述第一电容和所述第二电容分别与所述界面与控制模块的距离小于距离阈值。
这里，驱动芯片为升压电路，根据直流-直流转换器(Direct current-Direct current converter，DC/DC)要求，电感、第一电容和第二电容都尽量靠近界面与控制模块放置，走线尽量短，从而避免这些元件工作在高开关频率下，走线过长引起天线效应；这样布线使得驱动芯片走线短，布局容易，走线精简，而且抗干扰能力强。
在PCB的布局中，所述第一电容和所述第二电容的表层共地连接并通过通孔连接到主地。
这里，输入输出电容表层共地连接并单独打过孔连接到主地，减小DC/DC回路以及对其它电路的干扰。
在一些可能的实现方式中，在所述PCB的布局中每一元器件的预设范围内的金属地的面积大于预设面积。
这里，所述预设范围内的金属地通过多个通孔连接到地平面，所述预设范围可以理解为是元器件周边的范围，这样，加大元件周边的金属地面积以帮助散热；而且元件周边金属地通过多个过孔连接到地平面，减小对敏感电路的噪声干扰。
在一些可能的实现方式中，在所述PCB的布局中，采用宽度大于预设宽度的连接线， 将所述电池电源和所述电感连接至所述升压电路。
这里，这样采用较宽的连接线将电池电源和电感连接至升压电路，能够承受电流经过电感到开关节点线路的较大电流。比如，在效率较低时闪光瞬间，该电流可能达到1.4安(A)左右。
在PCB布局中，设置每一闪光灯所属的焊盘在预设范围内的金属地的面积大于预设面积阈值，且在所述焊盘在预设范围内的金属地上打预设数量的散热孔。
这里，闪光灯在温度上升时灯效会降低，超过结温工作时会损坏闪光灯，所以在PCB布局中加大LED的散热面积。比如，单颗闪光灯的散热面积在70～80平方毫米，尽量加大各焊盘周边的金属面积，多打散热孔。为保证灯效，闪光灯据相机距离不超过13毫米，若使用两颗灯，闪光灯间距保证在4至10毫米以内(比如，距离接近4毫米时效果较好)。如此，使得驱动芯片中走线较短，抗干扰能力强，从而提高了发光效率，降低了温升，性能可靠。
本申请一示例性实施例提供一种闪光灯驱动电路，图3为本申请一示例性实施例驱动芯片的功能框图，如图3所示，进行以下说明：
驱动芯片31是一颗采用同步升压(BOOST)电路的驱动方案，具有软启动功能，最大软启动时间为1200微秒，开关频率为100兆赫兹，可通过软件设置工作频率为50MHz。当LED的正向电压高于电池电压时，BOOST电路开始工作，根据内部电流源需求提供LED正向电压。如果电池电压高于LED的正向压降，BOOST电路不工作，界面与控制模块(INTERFACE AND CONTROL，IC)312工作在Pass-through模式，通过内部高功率闪光二极管驱动来调整闪光灯电流。
在该驱动芯片中，电感(L1)、电容(C1)、开关(SW)、MOS管313和MOS管314，组成该升压电路。其中，电容C1为输入电容，可以设置为10微法。并设定输入电压为2.7伏(V)至5V。
驱动芯片31具有多种安全保护功能：
短路保护模块301监测闪光灯的输出电压(LED_OUT)302，LED短路时LED_OUT引脚电平会被拉低，当检测到电压低于短路保护阈值1.2V(最大1.3V)时，判定为短路，相应的故障寄存器(fault register)303位会置位，断开通路，直到AP清除该寄存器位；最终，经过发光二极管(LED)317的电流保持在25毫安至1.54安之间。
这里，输出(VOUT)306端为高功率发光二极管驱动315(HPLED驱动)提供电压，以使电流通过HPLED驱动315流向短路保护模块301和高功率发光二极管电流控制模块316。
过压保护模块305，开路时内部恒流源会调整调制控制器304(比如，脉冲宽度调制控制器，PWM CONTROLLER)不断升压，过压保护模块305监测电压输出端(VOUT)306的电压，当到达5.5V时判定为过压，断开通路。
这里，VOUT 306与电容Cout 307相连，电容Cout 307接地，以保证输出电压的平稳。电容Cout的容量可以设置为10微法(μF)。
电感电流保护模块：升压电路监测电感(L1)电流，当峰值电流达到软件设置阈值时，电流被限制在此阈值，不会进一步增加，同时相应寄存器303置位。
这里，电感L1可以设置为1微法。
在该驱动芯片中，放大器311作为反馈电路，将电流反馈至IC 312，界面与控制模块通过调制控制器304调整电流。使能信号通过使能(enable，EN)319引脚输入该调制控制器304，SCL引脚320和SDA引脚321分别是串行传输总线协议(Inter-Integrated Circuit，I2C)协议的时钟和数据。STOBE 322为选通输入信号，可以直接连接到界面与控制模块上，也可以连接到主***上，当要抓取照片时触发该信号开启闪光功能。
输入输出端口1(GPIO1)和输入输出端口2(GPIO2)可连接外部控制器的使能信号，闪光过程中如果外部控制器工作则触发该信号，开启TxMask功能，降低闪光电流防止拉电源电压过多影响***正常工作。
在该驱动芯片中，还设置有热感测318，配置为监测电路中的温度，当温度过高时，断开电路，并将故障寄存器303置位。
图4为本申请一示例性实施例提供的闪光灯的驱动原理图，如图4所示进行以下说明：
U1001为图3所示的驱动芯片，在该驱动芯片中，输入电压(VIN)401、开关(SW)402和输出电压(VOUT)403组成BOOST升压电路，采用电池(VBAT)404供电，分别连接输入电容(C1001)、电感(L1001)和输出电容(C1002)，LED_OUT 405为恒流输出，连接闪光灯1001；EN 407为使能信号，高有效，连接R1001(100千欧)的下拉电阻；I2C信号连接到主***的I2C接口，即在I2C接口的时钟引脚SCL 408和数据引脚SDA 409的外部分别接R1002和R1003(R1002和R1003为2.2K千欧的上拉电阻)(上拉电平为1.8V，如果其它电平可以考虑使用不同阻值，满足***要求和I2C规范)；STOBE 410为选通输入信号，可以直接连接到传感器上，也可以连接到主***，当要抓取照片时触发该信号开启闪光功能。其中，EN 407接收输入的LED闪存使能信号(LED_FLASH_EN)471，时钟引脚SCL 408接收输入的LED闪存时钟信号(LED_FLASH_SCL)481，数据引脚SDA409接收输入的LED闪存数据信号(LED_FLASH_SDA)491，STOBE 410接收输入的LED闪存选通信号(LED_FLASH_STROBE)492。
GPIO1信号和GPIO2信号通常用作TxMask功能，可连接外部控制器的使能信号，闪光过程中如果外部控制器工作则触发该信号，开启TxMask功能，降低闪光电流防止拉VBAT 404电压过多影响***正常工作。如果不使用，该引脚悬空。GPIO1接收输入的LED闪存触摸信号(LED_FLASH_TORCH)493。
在该电路中，闪光灯可以采用LED1001来实现。
图5为本申请一示例性实施例提供的闪光灯的驱动电路的PCB布局图，如图5所示进行以下说明：
在图5中，LED4501表示闪光灯，U2004是驱动芯片，U2006为连接通信网络的芯片，U2002为集成流芯片，U2101、U3002、U2704和U2702分别是不同射频的天线开关；C3013、C3020、C3019和C3027分别表示不同容量的电容；L3005、L3003和L3004分别表示不同容量的电感；CN2703、CN2704和CN2701，分别表示摄像头的桌角，表示PCB的连接线；SH3213表示摄像头在PCB中的位置。
在该驱动芯片中采用BOOST升压电路，根据DC/DC要求，电感、输入电容和输出电容都尽量靠近IC放置，走线尽量短，这些元件工作在高开关频率下，走线过长可能引起天线效应；输入输出电容表层共地连接并单独打过孔连接到主地，减小DC/DC回路以及对其它电路的干扰；尽量加大元件周边的金属地面积以帮助散热；元件周边金属地通过多个过孔连接到地平面，减小对敏感电路的噪声干扰；VBAT经过电感到SW节点线路的电流较大，效率较低时闪光瞬间可能达到1.4A左右，走线需要尽量加宽。
LED部分主要考虑散热和灯效。闪光灯在温度上升时灯效会降低，超过结温工作时会损坏LED，PCB布局时要尽可能加大LED的散热面积，建议单颗灯的散热面积在70至80mm2，尽量加大各焊盘周边的金属面积，多打散热孔。为保证灯效，LED距相机的距离不超过13mm，若使用两颗灯，LED间距保证在4至10mm以内。比如，设定LEC间距接近4mm。
图5中的PCB布局严格遵循上述布局规则，从图5可以看出，本申请一示例性实施例的驱动电路的走线较短，如此，能够控制驱动电流，而且走线短，抗干扰能力强；在这样的PCB布局中布局更加容易，走线精简，从而能够节省成本。
在一些实施例中红，芯片驱动性能的核心是效率转化，针对该性能，测试数据如表1 所示。
表1驱动芯片的转换性能测试数据
Figure PCTCN2021070335-appb-000001
从表1可以看出，本申请一示例性实施例提供的驱动芯片的输入与输出的关系，转化效率高达90％以上，极大的提高了发光效率，降低了温升，性能可靠。从而，采用驱动芯片，提升了产品的性能，使得控制精度高；由于转化效率高，使得功耗损失低；这样，针对目前手机对闪光灯驱动性能要求，优化设计，提高整体性能。针对驱动芯片，制定对应的原理图和PCB规则，非常有实用价值，而且成本低。
这里需要指出的是：对于本申请电路实施例中未披露的技术细节，请参照本申请电路实施例的描述而理解。
应理解，说明书通篇中提到的“一个实施例”或“一实施例”意味着与实施例有关的特定特征、结构或特性包括在本申请的至少一个实施例中。因此，在整个说明书各处出现的“在一个实施例中”或“在一实施例中”未必一定指相同的实施例。此外，这些特定的特征、结构或特性可以任意适合的方式结合在一个或多个实施例中。应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请一示例性实施例的实施过程构成任何限定。上述本申请一示例性实施例序号仅仅为了描述，不代表实施例的优劣。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”“具体示例”或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构或者特点包含于本申请的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不一定指的是相同的实施例或示例。而且，描述的具体特征、结构或者特点可以在任何的一个或多个实施例或示例中以合适的方式结合。
需要说明的是，在本文中，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者装置不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者装置所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括该要素的过程、方法、物品或者装置中还存在另外的相同要素。
在本申请所提供的几个实施例中，应该理解到，所揭露的设备和方法，可以通过其它的方式实现。以上所描述的设备实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，如：多个单元或组件可以结合，或可以集成到另一个***，或一些特征可以忽略，或不执行。另外，所显示或讨论的各组成部分相互之间的耦合、或直接耦合、或通信连接可以是通过一些接口，设备或单元的间接耦合或通信连接，可以是电性的、机械的或其它形式的。
上述作为分离部件说明的单元可以是、或也可以不是物理上分开的，作为单元显示的部件可以是、或也可以不是物理单元；既可以位于一个地方，也可以分布到多个网络单元上；可以根据实际的需要选择其中的部分或全部单元来实现本申请一示例性实施例方案的目的。
另外，在本申请各实施例中的各功能单元可以全部集成在一个处理单元中，也可以是各单元分别单独作为一个单元，也可以两个或两个以上单元集成在一个单元中；上述集成的单元既可以采用硬件的形式实现，也可以采用硬件加软件功能单元的形式实现。
以上所述，仅为本申请的实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。
工业实用性
本申请实施例中，闪光灯驱动电路至少包括：闪光灯、驱动芯片和电源，其中：所述驱动芯片与所述闪光灯相连，配置为当接收到拍照指令时，启动所述驱动芯片中的升压电路；所述升压电路，配置为当所述闪光灯的正向电压高于所述电源电压时，为所述闪光灯提供电压，以使所述闪光灯闪光。

Claims (10)

  1. 一种闪光灯驱动电路，其中，所述闪光灯驱动电路至少包括：闪光灯、驱动芯片和电源，其中：
    所述驱动芯片与所述闪光灯相连，配置为当接收到拍照指令时，启动所述驱动芯片中的升压电路；
    所述升压电路，配置为当所述闪光灯的正向电压高于所述电源的电源电压时，为所述闪光灯提供电压，以使所述闪光灯闪光。
  2. 根据权利要求1所述的电路，其中，所述驱动芯片还包括：
    界面与控制模块，配置为当所述闪光灯的正向电压低于所述电源电压时，将当前工作模式调整至直通模式，断开所述升压电路，并向所述驱动芯片中的高功率发光二极管驱动模块发送控制指令；
    所述高功率发光二极管驱动模块，配置为响应于接收到的所述控制指令，调整所述闪光灯的电流，以使所述闪光灯的电流小于预设电流阈值。
  3. 根据权利要求1所述的电路，其中，所述驱动芯片还包括：
    与所述闪光灯的电压输出端相连的短路保护模块，配置为监测所述闪光灯的输出电压，当所述输出电压小于短路保护阈值时，控制故障寄存器位置位，断开所述闪光灯的通路，并清除所述故障寄存器位；
    与所述闪光灯的电压输出端相连的过压保护模块，配置为监测所述闪光灯的输出电压，当所述输出电压大于或等于过压保护阈值时，断开所述闪光灯的通路。
  4. 根据权利要求3所述的电路，其中，所述过压保护模块，还配置为当所述输出电压小于所述过压保护阈值时，调整所述闪光灯驱动电路中的调制控制器的电压，以增大所述闪光灯的输出电压。
  5. 根据权利要求1所述的电路，其中，所述升压电路还包括：
    电感电流保护模块，配置为当所述升压电路监测到的电感电流的峰值电流大于电感电流阈值时，钳制所述电感电流，并将所述故障寄存器位置位。
  6. 根据权利要求1至5任一项所述的电路，其中，所述升压电路分别与第一电容、电感和第二电容相连，以使所述升压电路的输出端的电流为恒定电流；所述升压电流的输出端与所述闪光灯相连，并采用电池电源为所述升压电路供电；其中，所述第一电容为输入电容，所述第二电容为输出电容。
  7. 根据权利要求1至5任一项所述的电路，其中，所述驱动芯片，还包括：
    输入输出端口，配置为与外部控制器相连接，在所述闪光灯闪光的过程中，如果检测到所述外部控制器处于工作状态，降低所述闪光灯的闪光电流。
  8. 根据权利要求6所述的电路，其中，在所述驱动芯片的电路板的布局中，设置所述电池电源、所述第一电容和所述第二电容分别与所述界面与控制模块的距离小于距离阈值；
    在所述电路板的布局中，所述第一电容和所述第二电容的表层共地连接并通过通孔连接到主地。
  9. 根据权利要求8所述的电路，其中，在所述电路板的布局中每一元器件的预设范围内的金属地的面积大于预设面积；其中，所述预设范围内的金属地通过多个通孔连接到地。
  10. 根据权利要求8所述的电路，其中，在所述电路板的布局中，采用宽度大于预设宽度的连接线，将所述电池电源和所述电感连接至所述升压电路；
    在所述电路板布局中，设置每一闪光灯所属的焊盘在预设范围内的金属地的面积大于预设面积阈值，且在所述焊盘在预设范围内的金属地上打预设数量的散热孔。
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