LED frequency burst integrated circuit and fill light device

Abstract

The present invention discloses an LED flashing integrated circuit and fill light device, including an AC-DC conversion power supply, a DC-DC boost power supply, an LED power supply switching circuit, an LED strobe signal control and dimming control circuit, an LED flashing signal control and dimming control circuit, and a processor. In the present invention, the LED strobe is directly powered by the AC-DC conversion power supply, and the LED flashing is powered by the DC-DC boost power supply. At the same time, the LED strobe and flashing are controlled by current in different ways. The response time of the strobe and flashing is only related to the signal processing time of the MCU and the operational amplifier, and has nothing to do with the DC-DC boost power supply and the inductor. Therefore, the DC-DC boost power supply only needs to use a chip power inductor and electrolytic to achieve large current output, and the response time is faster than that of the control constant current chip. It can better solve the problems of poor compatibility of existing LED strobe and flashing fill lights with cameras and high cost, and meet the application requirements of different occasions.

Description

Technical Field

[0001] The invention belongs to the technical field of security and intelligent traffic equipment, and specifically relates to an LED frequency burst integrated circuit and a fill light device. Background Art

[0002] At present, LED fill light devices are mainly used to realize LED strobe and LED burst strobe functions, among which LED strobe is used to synchronize with each frame shutter of the camera to realize the fill light effect on the video; LED burst strobe is used for high-brightness fill light when the camera captures pictures, and is used to capture the details of objects. The brightness of LED strobe and LED burst strobe has a great influence on the clarity of camera recording and snapshot pictures, so the adjustment of brightness is very important. If the brightness of the fill light device is too high, it will bring safety hazards to pedestrians and vehicle drivers and passengers, and it does not meet the requirements of energy saving and environmental protection. At present, the brightness of most fill lights LED strobe and LED burst strobe on the market cannot be adjusted, or only the brightness of LED strobe can be adjusted, or the adjustment range is too small, which cannot be well adapted to the camera to meet the requirements of capturing clear images, or the cost is too high, which is not suitable for large-scale promotion and application.

[0003] The current technical solutions mainly differ in the power supply and control method of the fill light device. There are two solutions with advantages in the power supply and control method of LED fill light devices on the market:

[0004] One solution is to add a secondary DC-DC constant current to an AC-DC power supply (such as a circuit and a light-filling device for controlling LED strobe flashes provided in the Chinese patent application with publication number CN117440555A). This method outputs a stable DC voltage value V through the AC-DC power supply from the 220V mains voltage. O , V O The DC-DC step-down constant current circuit is output to the LED light source, and the camera signal controls the on and off of the DC-DC step-down constant current circuit through the control circuit to realize the stroboscopic and flashing of the LED light source. This technical solution is mainly based on the constant current method. When the LED flashes, the output current is large. To ensure the smooth output of the current, the circuit requires a large power inductor, which is large in size and high in cost. At the same time, because the energy storage of the power inductor takes time, the response time of this circuit to the camera signal is long, and the camera needs to make a long delay processing. In addition, due to the dimming range limitation of the DC-DC constant current chip and the low consistency accuracy of the chip (currently the accuracy is generally ±5%), this circuit cannot adjust the LED frequency brightness to a very low level, and the brightness of the same level between different fill lights is also quite different, which cannot meet the needs in some special applications.

[0005] Another solution is to use an AC-DC power supply plus a secondary DC-DC constant voltage solution. This method uses the AC-DC power supply to output a stable DC voltage value V O1 , V O1 Then the DC-DC boost constant voltage circuit outputs a stable DC voltage value V O2 , V O1 Power the LED strobe, V O2 When supplying power to LED flashes, due to the heating characteristics of LED light sources, the higher the temperature, the lower the VF value. The LED flash current will gradually increase as the lighting time increases. Long-term high current lighting will shorten the life of the LED. O2 Electrolytic capacitors are used to store energy, so the current when the LED flashes will be a waveform with a gradually decreasing peak value, making the camera fill light uneven. In addition, this method of LED flash power supply requires large-capacity electrolytics to output large currents and cannot be dimmed, which is costly, has a large hardware structure, and takes a long time to charge large-capacity electrolytic capacitors (tens of milliseconds), which cannot meet the application requirements of continuous flashing in a short time. Summary of the invention

[0006] In view of the above, the present invention provides an LED strobe-burst integrated circuit and fill light device, which can better solve the problems of poor compatibility of existing LED strobe and LED burst fill lights with cameras and high costs, and meet the application requirements of different occasions.

[0007] An LED frequency burst integrated circuit, comprising:

[0008] AC-DC conversion power supply, used to convert 220V mains power into strobe voltage PS_POW and working voltage VDD;

[0009] A DC-DC boost power supply, used for boosting the strobe voltage PS_POW and converting it into a burst voltage BS_POW;

[0010] The processor converts the duty cycle signal sent by the camera into a PWM signal PS_CTRL when the LED strobe is required, and converts the pulse signal sent by the camera into a pulse signal BS_CTRL and locks PS_CTRL when the LED flash is required;

[0011] LED strobe signal control and dimming control circuit, used for converting PS_CTRL into a driving signal LED_PB with an amplitude of VDD;

[0012] LED flash signal control and dimming control circuit, used to convert BS_CTRL into a power switching signal LED_BS, and compare the LED feedback voltage Vis with the flash dimming signal BS_DIM provided by the processor to generate a driving signal LED_PB;

[0013] The LED power supply switching circuit uses LED_PB to drive the switch tube to turn on the LED. When the LED needs to strobe, PS_POW is used to power the LED. When the LED needs to flash, LED_BS is used to control the switch BS_POW to power the LED.

[0014] Furthermore, the LED strobe signal control and dimming control circuit includes four resistors R29, R30, R36, R38, an NMOS tube Q5, a PMOS tube Q6 and a filter module, wherein the source of Q6 is connected to one end of R30 and connected to VDD, the other end of R30 is connected to one end of R29 and the gate of Q6, the other end of R29 is connected to the drain of Q5, the gate of Q5 is connected to one end of R36 and connected to PS_CTRL, the other end of R36 is connected to the source of Q5 and R38 One end of R38 is connected to the drain of Q6 and generates a driving signal LED_PB; the filtering module includes three resistors R21~R23 and two capacitors C14~C15, wherein one end of R23 is connected to PS_DIM, the other end of R23 is connected to one end of R22 and one end of C15, the other end of R22 is connected to one end of R21 and one end of C14, the other end of C14 is connected to the other end of C15 and grounded, and the other end of R21 generates an analog signal VF.

[0015] Furthermore, the LED power supply switching circuit includes three resistors R28, R35, R45, a diode D8, an NMOS tube M3 and a PMOS tube M2, wherein the source of M2 is connected to one end of R28 and connected to BS_POW, the other end of R28 is connected to the gate of M2 and one end of R35, the other end of R35 is connected to LED_BS, the drain of M2 is connected to the cathode of D8 and the anode of the LED, the anode of D8 is connected to PS_POW, the drain of M3 is connected to the cathode of the LED, the gate of M3 is connected to LED_PB, the source of M3 is connected to one end of R45 and generates an LED feedback voltage Vis, and the other end of R45 is grounded.

[0016] Furthermore, the processor compares the LED feedback voltage Vis with the set threshold value. If the two are inconsistent, the duty cycle of the strobe dimming signal PS_DIM is adjusted and output. The strobe dimming signal PS_DIM is converted into an analog signal VF through a filtering module in the LED strobe signal control and dimming control circuit, which is used to control the reference chip in the AC-DC conversion power supply to adjust the voltage of PS_POW to make the LED strobe current constant.

[0017] Furthermore, the LED flash signal control and dimming control circuit includes:

[0018] A pulse signal generating module, used for converting BS_CTRL into a pulse signal V1 with an amplitude of VDD;

[0019] A power switching module, used for converting BS_CTRL to generate a power switching signal LED_BS;

[0020] The dimming control module, when enabled by the pulse signal V1, compares the LED feedback voltage Vis with the flash dimming signal BS_DIM to generate a driving signal LED_PB.

[0021] Furthermore, the pulse signal generating module includes four resistors R25, R26, R27, R32, an NMOS tube Q2 and a PMOS tube Q3, wherein one end of R26 is connected to the source of Q3 and connected to VDD, the other end of R26 is connected to one end of R25 and the gate of Q3, the other end of R25 is connected to the drain of Q2, the gate of Q2 is connected to one end of R27 and connected to BS_CTRL, the other end of R27 is connected to the source of Q2 and one end of R32 and connected to ground, and the other end of R32 is connected to the drain of Q3 and generates a pulse signal V1.

[0022] Furthermore, the power switching module includes a resistor R31 and an NMOS tube Q4, wherein the gate of Q4 is connected to one end of R31 and connected to BS_CTRL, the drain of Q4 generates a power switching signal LED_BS, and the source of Q4 is connected to the other end of R31 and grounded.

[0023] Furthermore, the dimming control module includes four resistors R39, R42, R43, R44, two capacitors C19 and C20, a diode D9 and an operational amplifier U5, wherein one end of R42 is connected to BS_DIM, the other end of R42 is connected to one end of R43 and one end of C20, the other end of R43 is connected to one end of C19, one end of R44 and the positive input end of U5, the other end of C20 is connected to the other end of C19, the other end of R44 and the negative power supply of U5 and grounded, one end of R39 is connected to Vis, the other end of R39 is connected to the inverting input end of U5, the positive power supply of U5 is connected to V1, the output end of U5 is connected to the anode of D9, and the cathode of D9 generates a drive signal LED_PB.

[0024] Furthermore, when it is necessary to adjust the size of the LED stroboscopic current, the camera will send corresponding instructions to the processor, and the processor will reset the corresponding stroboscopic current feedback comparison value according to the instructions, change the duty cycle of PS_DIM, and then change the voltage of PS_POW until the LED is constant at the set stroboscopic current value; when it is necessary to adjust the size of the LED burst lightning current, the camera will send corresponding instructions to the processor, and the processor will change the duty cycle of BS_DIM to change the reference voltage at the positive input terminal of U5, and during the subsequent pulse width time of V1, the LED will burst with the reset current value.

[0025] A fill light device comprises the above-mentioned LED frequency burst integrated circuit and an LED connected to the circuit.

[0026] The present invention adopts the above innovative design, LED strobe is directly powered by AC-DC power supply, LED burst is powered by DC-DC boost power supply, and LED strobe and burst are controlled by current in different ways at the same time, the response time of LED strobe burst is only related to the signal processing time of MCU and op amp, and has nothing to do with power supply and inductance, so that the boost power supply for LED burst power supply only needs a small power inductor and electrolytic capacitor of suitable capacity to achieve a large constant current output, and can achieve the dimming of LED burst, and the response time is also faster than that of the control constant current chip. At the same time, the LED strobe power supply voltage in the present invention can be adjusted to a very low level, the dimming range of LED can be very large, and the dimming accuracy of strobe burst is only related to the output frequency accuracy of the single-chip microcomputer, and the crystal oscillator accuracy of the current single-chip microcomputer is less than 10PPM, so the brightness consistency between different fill light devices is better, which can better solve the problems of poor compatibility of existing LED strobe, LED burst fill light and camera, high cost, etc., and meet the application needs of more occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the overall structural block diagram of the LED frequency explosion integrated circuit of the present invention.

[0028] Figure 2 It is a structural diagram of the LED strobe signal control and dimming control circuit.

[0029] Figure 3 It is a structural diagram of the LED flash signal control and dimming control circuit.

[0030] Figure 4 Schematic diagram of the structure of the switching circuit for LED power supply. DETAILED DESCRIPTION

[0031] In order to describe the present invention more specifically, the technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] like Figure 1 As shown, the LED flash-sparking integrated circuit of the present invention includes an AC-DC conversion power supply, a DC-DC boost power supply, an LED power supply switching circuit, an LED strobe signal control and dimming control circuit, an LED flash signal control and dimming control circuit and an MCU (microcontroller unit), wherein the AC-DC conversion power supply converts the AC (alternating current) 220V of the mains power into a strobe voltage PS_POW, the DC-DC boost power supply converts the strobe voltage PS_POW into a flash voltage BS_POW, the BS_POW voltage is greater than the PS_POW voltage, that is, the LED flash current is greater than the strobe current; the MCU provides a PWM signal PS_CTRL and a strobe dimming signal PS_DIM to the LED strobe signal control and dimming control circuit, and provides a pulse signal BS_CTRL and a flash dimming signal BS_DIM to the LED flash signal control and dimming control circuit; the LED power supply switching circuit receives the control signals provided by the LED flash signal control and dimming control circuit and the LED strobe signal control and dimming control circuit to switch the LED light source to strobe or flash.

[0033] like Figure 2 As shown, the LED strobe signal control and dimming control circuit in this embodiment includes four resistors R29, R30, R36, R38, an NMOS tube Q5, a PMOS tube Q6 and a filter module, wherein the source of Q6 is connected to one end of R30 and connected to VDD, the other end of R30 is connected to one end of R29 and the gate of Q6, the other end of R29 is connected to the drain of Q5, the gate of Q5 is connected to one end of R36 and connected to PS_CTRL, the other end of R36 is connected to the source of Q5 and one end of R38 and is grounded, and the other end of R38 is connected to the drain of Q6 and generates a driving signal LED_PB.

[0034] MCU compares the LED feedback voltage Vis with the set threshold. If the two are inconsistent, the duty cycle of the strobe dimming signal PS_DIM is adjusted and output. PS_DIM is converted into an analog signal VF through the filter module in the LED strobe signal control and dimming control circuit, which is used to control the reference chip of the AC-DC conversion power supply to adjust the voltage of PS_POW to make the LED strobe current constant.

[0035] like Figure 2 As shown, the filtering module includes three resistors R21~R23 and two capacitors C14~C15, wherein one end of R23 is connected to PS_DIM, the other end of R23 is connected to one end of R22 and one end of C15, the other end of R22 is connected to one end of R21 and one end of C14, the other end of C14 is connected to the other end of C15 and grounded, and the other end of R21 generates an analog signal VF.

[0036] like Figure 3 As shown, the LED flash signal control and dimming control circuit in this embodiment includes a pulse signal generating module, a power switching module and a dimming control module, wherein:

[0037] The pulse signal generating module is used to convert BS_CTRL into a pulse signal V1 with an amplitude of VDD, which includes four resistors R25, R26, R27, R32, an NMOS tube Q2 and a PMOS tube Q3, wherein one end of R26 is connected to the source of Q3 and connected to VDD, the other end of R26 is connected to one end of R25 and the gate of Q3, the other end of R25 is connected to the drain of Q2, the gate of Q2 is connected to one end of R27 and connected to BS_CTRL, the other end of R27 is connected to the source of Q2 and one end of R32 and is grounded, and the other end of R32 is connected to the drain of Q3 and generates a pulse signal V1.

[0038] The power switching module is used to convert BS_CTRL to generate a power switching signal LED_BS, which includes a resistor R31 and an NMOS tube Q4, wherein the gate of Q4 is connected to one end of R31 and connected to BS_CTRL, the drain of Q4 generates the power switching signal LED_BS, and the source of Q4 is connected to the other end of R31 and grounded.

[0039] When the pulse signal V1 is enabled, the dimming control module compares the LED feedback voltage Vis with the flash dimming signal BS_DIM to generate a drive signal LED_PB, which includes four resistors R39, R42, R43, R44, two capacitors C19 and C20, a diode D9 and an operational amplifier U5, wherein one end of R42 is connected to BS_DIM, the other end of R42 is connected to one end of R43 and one end of C20, the other end of R43 is connected to one end of C19, one end of R44 and the positive input end (pin 1) of U5, the other end of C20 is connected to the other end of C19, the other end of R44 and the negative power supply of U5 (pin 2) and grounded, one end of R39 is connected to Vis, the other end of R39 is connected to the inverting input end (pin 3) of U5, the positive power supply (pin 6) of U5 is connected to V1, the output end (pin 4) of U5 is connected to the anode of D9, and the cathode of D9 generates the drive signal LED_PB.

[0040] like Figure 4As shown, the LED power supply switching circuit in this embodiment includes three resistors R28, R35, R45, a diode D8, an NMOS tube M3 and a PMOS tube M2, wherein the source of M2 is connected to one end of R28 and connected to BS_POW, the other end of R28 is connected to the gate of M2 and one end of R35, the other end of R35 is connected to LED_BS, the drain of M2 is connected to the cathode of D8 and pin 2 (i.e., LED+) of the LED terminal J2, the anode of D8 is connected to PS_POW, the drain of M3 (pin 2) is connected to pin 1 (i.e., LED-) of the LED terminal J2, the gate of M3 (pin 1) is connected to LED_PB, the source of M3 (pin 3) is connected to one end of R45 and generates an LED feedback voltage Vis, and the other end of R45 is grounded.

[0041] The principle and working mode of the LED frequency burst integrated circuit in this embodiment are as follows:

[0042] When the camera needs the LED to strobe, it sends a duty cycle signal with a fixed frequency. The MCU receives this signal and sends a corresponding PWM signal PS_CTRL. The LED strobe signal control and dimming control circuit converts the received PS_CTRL into a drive signal LED_PB with an amplitude of VDD, drives the MOS tube M3, and PS_POW supplies power to the LED through D8. The LED will flash corresponding to the signal frequency sent by the camera. At the same time, a feedback voltage signal Vis will be generated on the feedback resistor R45. Vis is input to the MCU and compared with the preset value. If it is inconsistent, the duty cycle of the output strobe dimming signal PS_DIM is adjusted. The PS_DIM signal is converted into an analog signal VF through a filter circuit to control the reference chip in the AC-DC conversion power supply to adjust the voltage of PS_POW to achieve a constant current of the LED strobe current. If the size of the LED strobe current needs to be adjusted, the camera only needs to send a corresponding instruction, and the MCU will reset the corresponding strobe current feedback comparison value, change the duty cycle of PS_DIM, and then change the voltage of PS_POW until the LED is constant at the set strobe current value.

[0043] When the camera needs the LED to flash, it will send out a pulse signal with a fixed pulse width. After receiving this signal, the MCU will send out a corresponding pulse signal BS_CTRL and stop outputting the strobe signal PS_CTRL. The LED flash signal control and dimming control circuit will convert the received BS_CTRL into a pulse signal V1 with an amplitude of VDD. At the same time, the BS_CTRL signal will turn on the MOS tube M2 in the LED power supply switching circuit through Q4, and BS_POW will power the LED through M2. At this time, V1 makes the operational amplifier chip U5 start to work. The voltage of U5's 3rd pin is 0 at the beginning, and U5 outputs 4th pin as high level. This high level LED_PB turns on the MOS tube M3, and the LED current generates feedback voltage Vis through the feedback resistor R45. Vis is re-input to U5's 3rd pin and compared with the voltage set at U5's 1st pin. When the voltage of Vis gradually increases to a value close to the reference voltage set at 1st pin, according to the virtual short and virtual break characteristics of the operational amplifier, the output voltage of U5's 4th pin will gradually decrease, causing the driving voltage LED_PB of M3 to gradually decrease, and the MOS tube M3 will enter the non-saturated working area, and its VDS ( The drain-source voltage) will gradually increase (the power consumption of the MOS tube will increase, but because this mode is only used when the LED flashes, the flash frequency is up to 9 times per second, and the pulse width is only 2ms, which will not cause overheating and damage to the MOS tube) to ensure that the LED flash current is always at a constant set value, that is, Vis always remains consistent with the set value of U5 pin 1; if the size of the LED flash current needs to be adjusted, the camera only needs to send a corresponding instruction, the MCU will change the duty cycle of BS_DIM and then change the reference voltage of U5 pin 1. During the pulse width of the subsequent LED flash pulse, the LED will flash with the reset current value.

[0044] In another set of embodiments, we provide a fill light device, which includes the above-mentioned LED frequency burst integrated circuit and an LED load connected to the circuit.

[0045] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art to the present invention based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An LED frequency burst integrated circuit, characterized in that: include: AC-DC conversion power supply, used to convert 220V mains power into strobe voltage PS_POW and working voltage VDD; A DC-DC boost power supply, used for boosting the strobe voltage PS_POW and converting it into a burst voltage BS_POW; The processor converts the duty cycle signal sent by the camera into a PWM signal PS_CTRL when the LED strobe is required, and converts the pulse signal sent by the camera into a pulse signal BS_CTRL and locks PS_CTRL when the LED flash is required; LED strobe signal control and dimming control circuit, used for converting PS_CTRL into a driving signal LED_PB with an amplitude of VDD; LED flash signal control and dimming control circuit, used to convert BS_CTRL into a power switching signal LED_BS, and compare the LED feedback voltage Vis with the flash dimming signal BS_DIM provided by the processor to generate a driving signal LED_PB; LED power supply switching circuit, using LED_PB to drive the switch tube to turn on the LED, when the LED needs to strobe, PS_POW is used to power the LED, and when the LED needs to flash, LED_BS is used to control the switch BS_POW to power the LED; The LED strobe signal control and dimming control circuit includes four resistors R29, R30, R36, R38, an NMOS tube Q5, a PMOS tube Q6 and a filter module, wherein the source of Q6 is connected to one end of R30 and connected to VDD, the other end of R30 is connected to one end of R29 and the gate of Q6, the other end of R29 is connected to the drain of Q5, the gate of Q5 is connected to one end of R36 and connected to PS_CTRL, the other end of R36 is connected to the source of Q5 and one end of R38 The other end of R38 is connected to the drain of Q6 and generates a driving signal LED_PB; the filtering module includes three resistors R21~R23 and two capacitors C14~C15, wherein one end of R23 is connected to PS_DIM, the other end of R23 is connected to one end of R22 and one end of C15, the other end of R22 is connected to one end of R21 and one end of C14, the other end of C14 is connected to the other end of C15 and grounded, and the other end of R21 generates an analog signal VF; The LED power supply switching circuit includes three resistors R28, R35, R45, a diode D8, an NMOS tube M3 and a PMOS tube M2, wherein the source of M2 is connected to one end of R28 and connected to BS_POW, the other end of R28 is connected to the gate of M2 and one end of R35, the other end of R35 is connected to LED_BS, the drain of M2 is connected to the cathode of D8 and the anode of the LED, the anode of D8 is connected to PS_POW, the drain of M3 is connected to the cathode of the LED, the gate of M3 is connected to LED_PB, the source of M3 is connected to one end of R45 and generates an LED feedback voltage Vis, and the other end of R45 is grounded; The LED flash signal control and dimming control circuit includes: A pulse signal generating module, used for converting BS_CTRL into a pulse signal V1 with an amplitude of VDD; A power switching module, used for converting BS_CTRL to generate a power switching signal LED_BS; The dimming control module, when enabled by the pulse signal V1, compares the LED feedback voltage Vis with the flash dimming signal BS_DIM to generate a driving signal LED_PB; The pulse signal generating module includes four resistors R25, R26, R27, R32, an NMOS tube Q2 and a PMOS tube Q3, wherein one end of R26 is connected to the source of Q3 and connected to VDD, the other end of R26 is connected to one end of R25 and the gate of Q3, the other end of R25 is connected to the drain of Q2, the gate of Q2 is connected to one end of R27 and connected to BS_CTRL, the other end of R27 is connected to the source of Q2 and one end of R32 and connected to ground, the other end of R32 is connected to the drain of Q3 and generates a pulse signal V1; The power switching module includes a resistor R31 and an NMOS tube Q4, wherein the gate of Q4 is connected to one end of R31 and connected to BS_CTRL, the drain of Q4 generates a power switching signal LED_BS, and the source of Q4 is connected to the other end of R31 and grounded; The dimming control module includes four resistors R39, R42, R43, R44, two capacitors C19 and C20, a diode D9 and an operational amplifier U5, wherein one end of R42 is connected to BS_DIM, the other end of R42 is connected to one end of R43 and one end of C20, the other end of R43 is connected to one end of C19, one end of R44 and the positive input end of U5, the other end of C20 is connected to the other end of C19, the other end of R44 and the negative pole of the power supply of U5 and is grounded, one end of R39 is connected to Vis, the other end of R39 is connected to the inverting input end of U5, the positive pole of the power supply of U5 is connected to V1, the output end of U5 is connected to the anode of D9, and the cathode of D9 generates a drive signal LED_PB.

2. The LED frequency burst integrated circuit according to claim 1, characterized in that: The processor compares the LED feedback voltage Vis with the set threshold value. If the two are inconsistent, the duty cycle of the strobe dimming signal PS_DIM is adjusted and output. The strobe dimming signal PS_DIM is converted into an analog signal VF through a filtering module in the LED strobe signal control and dimming control circuit, which is used to control the reference chip in the AC-DC conversion power supply to adjust the voltage of PS_POW to make the LED strobe current constant.

3. The LED frequency burst integrated circuit according to claim 1, characterized in that: When it is necessary to adjust the size of the LED stroboscopic current, the camera will send corresponding instructions to the processor. The processor will reset the corresponding stroboscopic current feedback comparison value according to the instructions, change the duty cycle of PS_DIM, and then change the voltage of PS_POW until the LED is constant at the set stroboscopic current value; when it is necessary to adjust the size of the LED burst lightning current, the camera will send corresponding instructions to the processor. The processor will change the duty cycle of BS_DIM to change the reference voltage of the positive input terminal of U5. During the pulse width time of V1, the LED will burst with the reset current value.

4. A fill light device, characterized in that: The fill light device comprises an LED frequency burst integrated circuit as described in any one of claims 1 to 3 and an LED connected to the circuit.

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