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LED(Light Emitting Diode) is a simple diode that emits light when current goes through it

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dev krishnan
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dev krishnan
Asked: September 2, 2022In:
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Hi everyone I’m going to use STLD40D Driver IC for my TFT LCD. For driving LCD backlight, I’v chosen this Driver from ST. But I can’t figure out the function theory of this driver. could you please explain for me the STLD40D ...Read more

Hi everyone

I’m going to use STLD40D Driver IC for my TFT LCD. For driving LCD backlight, I’v chosen this Driver from ST. But I can’t figure out the function theory of this driver.

could you please explain for me the STLD40D function theory and how to use that?

thank you in advance.

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driverICledstld40d
  1. vikas Nagpal

    Well, the STLD40D is a boost converter. The function is also described in the data sheet, section5.1. It must be taken into account that the converter not only has a min off time, but also a maximum on time. The switch- on moment is particularly interesting firstly there's no FB signal, so the powerRead more

    Well, the STLD40D is a boost converter. The function is also described in the data sheet, section5.1.

    It must be taken into account that the converter not only has a min off time, but also a maximum on time.
    The switch- on moment is particularly interesting firstly there’s no FB signal, so the power stage is switched on( SW to GND), which charges the boost inductor. As there isn’t yet enough affair voltage to drive a current through the LEDs, pin FB remains zero. still, the maximum on time now kicks in and switches the power stage off again, whereby the energy stored in the boost inductor is delivered to the LEDs at a high voltage and results in a corresponding current and a signal to FB. From now on, FB can regulate normally.

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Alex thomas
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Alex thomas
Asked: August 26, 2022In:
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I’ve a design. I’ve 13 switch and these switches control to leds. For example when i click first button, first led will be on( likewise when i click again, it’ll be out). So microcontroller want to knows everything about it. ...Read more

I’ve a design. I’ve 13 switch and these switches control to leds. For example when i click first button, first led will be on( likewise when i click again, it’ll be out). So microcontroller want to knows everything about it. But how can i control these leds? Because i want 36 * 3 io pins( RGB). Similarly after i want to control lightness of all leds with dimmer.

Do you have any IC hints for leds control & leds pwm controller?

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dimmerICledlighting and ledoptoelectronicsrgbstm32 mcusstm32f7switch
  1. vikas Nagpal

    There are numerous LED drivers also from STMicroelectronics, e.g. LED1202 LED1642GW etc ( see LED Array Drivers STMicroelectronics) Of course, the correct type depends on several factors, e.g. how you want to control the LEDs( I2C, SPI, etc). With RGB LEDs you'll clearly only switch one LED per chanRead more

    There are numerous LED drivers also from STMicroelectronics, e.g.

    LED1202
    LED1642GW
    etc ( see LED Array Drivers STMicroelectronics)

    Of course, the correct type depends on several factors, e.g. how you want to control the LEDs( I2C, SPI, etc). With RGB LEDs you’ll clearly only switch one LED per channel, so you should be suitable to get by with one LED driver for 5V.

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vsharma
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vsharma
Asked: July 25, 2022In:
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I have a 8S4P LiFePO4 pack being controlled by the ISL94202 but our BMS board doesn’t use a MCU so it’s dependent on the 94202 chip.  Currently we have a LED controlled by the /SD line.  If there’s an error ...Read more

I have a 8S4P LiFePO4 pack being controlled by the ISL94202 but our BMS board doesn’t use a MCU so it’s dependent on the 94202 chip.  Currently we have a LED controlled by the /SD line.  If there’s an error the LED lights and let’s the end user know something is wrong.

The issue is why does the /SD line go active when the unit goes into SLEEP mode?  We need the chip go go into a low current state to keep the battery from going low when the unit isn’t being used.  But since the /SD line is active during SLEEP mode we can’t use that to control the error LED.

Is there any way to be able to indicate to the end user that an error has occurred but not during SLEEP mode?

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bms boardisl94202ledmcuSLEEP mode
  1. pallavi sharma

    The purpose of the SD pin is to provide an alert to the user that the power FETs have been turned off by the device. The PSD pin can be linked to fatal faults such as OVLO, UVLO and DVCF and be used to drive an external circuit that alerts the user to these faults, and/or blows a fuse.  If either piRead more

    The purpose of the SD pin is to provide an alert to the user that the power FETs have been turned off by the device.

    The PSD pin can be linked to fatal faults such as OVLO, UVLO and DVCF and be used to drive an external circuit that alerts the user to these faults, and/or blows a fuse. 

    If either pin is used to drive an external circuit care must be taken to prevent complete discharge of the cells.

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Jagmohan rawat
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Jagmohan rawat
Asked: May 27, 2022In:
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We are making 10 watt flood light with sic IC  and we are facing issue with 4kv and 440volt because if we use mov 561 then surge pass 4kv and high voltage pass only 400volt and if we use mov ...Read more

We are making 10 watt flood light with sic IC  and we are facing issue with 4kv and 440volt because if we use mov 561 then surge pass 4kv and high voltage pass only 400volt and if we use mov 621 then surge fail at 3.5kv and high voltage pass 440volt , please suggest the mov which one can use those we can achieve 4kv and 440volt pass both parameter .

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Flood lighthigh voltageledsurge passvoltage
  1. Sandeep kumar

    Hi ,   There is only issue with MOV tolerance if you use less tolerance mov or High Surge MOV your issue will be solve Thanks sandeep

    Hi ,

     

    There is only issue with MOV tolerance if you use less tolerance mov or High Surge MOV your issue will be solve

    Thanks

    sandeep

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Anonymous
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Anonymous
Asked: May 11, 2022In:
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While we are using the BP3338A IC and using it for multiple projects like down light , street light, flood light etc. But we don’t know how to calculate the transformer winding , wire gauge , inductance if any specs is ...Read more

While we are using the BP3338A IC and using it for multiple projects like down light , street light, flood light etc.

But we don’t know how to calculate the transformer winding , wire gauge , inductance if any specs is changed. We want to do own calculation please help to provide the formula or solution .

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BP3338A ICInductanceledLED Drivertransformer windingwire guage
  1. Sandeep kumar

    Dear Rakesh, please find the enclosed reference design tool it will be helpful for the calculation of all transformer-related data, and for formulas, which you can see in the excel sheet. Thanks Sandeep

    Dear Rakesh,

    please find the enclosed reference design tool it will be helpful for the calculation of all transformer-related data, and for formulas, which you can see in the excel sheet.

    Thanks

    Sandeep

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    Attachment

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nidhi singh
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nidhi singh
Asked: April 20, 2022In:
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I have Renesas RH850F1K (R7F701649) microcontroller and using CS+ IDE. How to set the LED1,if it is connected to P0_11? I want to toggle this LED1.

I have Renesas RH850F1K (R7F701649) microcontroller and using CS+ IDE. How to set the LED1,if it is connected to P0_11? I want to toggle this LED1.

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gpio pinsledRenesas MicrocontrollerRenesas RH850F1KRH850F1K(R7F701649)
  1. dev krishnan

    The hardware User Manual contains the information required to access I/O and peripherals among other things. RH850/F1KM, RH850/F1KH User's Manual: Hardware (R01UH0684EJ0110) Sample code is available to demonstrate many of the concepts.  

    The hardware User Manual contains the information required to access I/O and peripherals among other things. RH850/F1KM, RH850/F1KH User’s Manual: Hardware (R01UH0684EJ0110) Sample code is available to demonstrate many of the concepts.

     

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