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Category: LEDs & Optoelectronics

Find all the optoelectronic devices your electronic system needs from our optoelectronics LEDs & displays range. Optoelectronic components are needed to convert electrical signals into light signals. LEDs, discrete LEDs, display modules, illumination, lamps, lasers, LED displays, and other components are available from Volt.Tech. Our main focus has always been in the area of application solutions to optimize your products performance. Our team of design engineers and R&D scientist are committed to providing you with unsurpassed technical support. Please post any questions relating to LEDs, LCDs, IR, Laser, OLED or any other optoelectronics devices in this section.

volt.tech Latest Questions

vikas Nagpal
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vikas Nagpal
Asked: March 6, 2023In:
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Hello, After looking over all the documentation I could find (datasheet, source primer, etc.), I couldn’t easily find how I’m meant to connect IR LED (s) for Ir DA communication with an STM32WB55. The image I attached is a screenshot from ...Read more

Hello,

After looking over all the documentation I could find (datasheet, source primer, etc.), I couldn’t easily find how I’m meant to connect IR LED (s) for Ir DA communication with an STM32WB55. The image I attached is a screenshot from the reference primer, which implies that there may be IrDA_OUT and, IN pins (I am interpreting this as being separate from the TX and RX pins). Am I supposed to add some intermediate IC for Ir DA, or can the STM32WB55 actually output signals for driving/ reading IR LEDs photodiodes?

I am aware of the actuality of the IR_OUT pins, but that’s its own separate thing. In the IR_OUT documentation, they use only timers (TIM16 & TIM17), not the US ART supplemental.

Thanks and Regards

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datasheethardwareirdaledsphotodiodesstm32wb55
  1. Julian White

    Hello, IrDA has hardly been used for a long time, which is also marked in discontinued IrDA transceivers. However, since basically everything except the TIA and visual factors is included in the STM32 IrDA SIR ENDEC, it's possible to recreate IrDA with an IR LED plus driver transistor and an IR photRead more

    Hello,

    IrDA has hardly been used for a long time, which is also marked in discontinued IrDA transceivers. However, since basically everything except the TIA and visual factors is included in the STM32 IrDA SIR ENDEC, it’s possible to recreate IrDA with

    • an IR LED plus driver transistor and
    • an IR photodiode plus TIA.

    RX and TX are switched to the IrDA function so that the LED driver and TIA can be connected directly.

    Regards

    Julian White

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Alex thomas
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Alex thomas
Asked: February 8, 2023In:
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Hi, I have an IC on the side which is written” HVLED01A” on it and I want to know its output number. I wonder is equal to the” HVLED001A” output number or if it’s another IC? Thank you in advance.

Hi, I have an IC on the side which is written” HVLED01A” on it and I want to know its output number.

I wonder is equal to the” HVLED001A” output number or if it’s another IC?

Thank you in advance.

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codehvled01aICledoptoelectronics
  1. vikas Nagpal

    Welcome, to the community! yes, I can confirm the HVLED001A uses the device marking HVLED01A. Good luck! If the problem is resolved, please mark this content as answered by selecting Select as best,  This will help other users find that answer faster. Thank You

    Welcome, to the community!

    yes, I can confirm the HVLED001A uses the device marking HVLED01A.

    Good luck!

    If the problem is resolved, please mark this content as answered by selecting Select as best,  This will help other users find that answer faster.

    Thank You

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vikas Nagpal
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vikas Nagpal
Asked: January 30, 2023In:
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Hello, Can LED2472G be applied as a shift register to drive signal relays with a coil current of <30mA? Can they be applied as general shift registers too? Thanks!

Hello,

Can LED2472G be applied as a shift register to drive signal relays with a coil current of <30mA? Can they be applied as general shift registers too?

Thanks!

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ledled2472goptoelectronicsregistersignal relays
  1. Alex thomas

    Welcome, to the community! Well, LED2472G is a move register, but it can simply be used as similar to a limited extent the individual outputs (bits) are actually constant-current LED drivers, so they aren't actually able for sense purposes. But of course, you can control the loads connected to the iRead more

    Welcome, to the community!

    Well, LED2472G is a move register, but it can simply be used as similar to a limited extent the individual outputs (bits) are actually constant-current LED drivers, so they aren’t actually able for sense purposes. But of course, you can control the loads connected to the individual outputs logically in the same way as a shift register. Only the serial output is directly similar to a classic shift register.

    Still, one could imagine using LED2472G to drive 30mA relays, indeed if this doesn’t correspond to the original purpose. But you mustn’t forget the usual free-wheeling diodes, which due to the unspecified avalanche energy should better be Schottky diodes because only they’re fast enough. Evenultra-fast diodes with a blocking time of 10.20 ns are probably too slow not to damage the respective LED driver- at least nothing guarantees that.

    Does it answer your question?

    Regards

    Alex

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nidhi singh
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nidhi singh
Asked: December 1, 2022In:
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Hello, What is the difference between Parts L9826 and Parts E-L9826？ I can not see the difference between them from the datasheets. Thank you in Advance

Hello,

What is the difference between Parts L9826 and Parts E-L9826？ I can not see the difference between them from the datasheets.

Thank you in Advance

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datasheetse-l9826l9826ledsopteolectronicspower management
  1. ashishgawade

    There's no technical difference between L9826 and E-L9826. At the time, the version with the prefix E- indicated the more environmentally friendly Eco version, which has been standard for a long time. still, please mark this thread as answered by selecting Select as best, as also explained then, IfRead more

    There’s no technical difference between L9826 and E-L9826. At the time, the version with the prefix E- indicated the more environmentally friendly Eco version, which has been standard for a long time.

    still, please mark this thread as answered by selecting Select as best, as also explained then, If the problem is solved. This will help other users find that answer faster.
    Regards

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Alex thomas
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Alex thomas
Asked: November 25, 2022In:
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Hello, I am new to STM32 and trying to learn exciting stuff. I want to light a single LED from my WS2812B strip. For example, I’ll choose the 6th LED on my computer, and the 6th LED on the strip will light ...Read more

Hello,

I am new to STM32 and trying to learn exciting stuff. I want to light a single LED from my WS2812B strip.

For example, I’ll choose the 6th LED on my computer, and the 6th LED on the strip will light up.

But I am not sure where to start. How can I access to single LED address? And how to get it to work with STM32?

Thanks in advance.

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ledoptoelectronicsstm32stripws2812b
  1. vikas Nagpal

    Welcome, to the community! The question of WS2812 has already been discussed here many times. The thread How to use HAL DMA to generate PWM on P- NUCLEO- WB, for example, also deals with it and refers to a Github driver from Tilen Majerle and a HAL example from Martin Willner. Maybe that will help yRead more

    Welcome, to the community!

    The question of WS2812 has already been discussed here many times. The thread How to use HAL DMA to generate PWM on P- NUCLEO- WB, for example, also deals with it and refers to a Github driver from Tilen Majerle and a HAL example from Martin Willner.

    Maybe that will help you?

    Regards

    Vikas

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Alex thomas
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Alex thomas
Asked: October 4, 2022In:
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I’ve read quite a bit about needing a resistor when powering a 5 mm LED from an esp32 GPIO pin, still, other experts say that if a LED is powered right, it will not need a resistor at all will ...Read more

I’ve read quite a bit about needing a resistor when powering a 5 mm LED from an esp32 GPIO pin, still, other experts say that if a LED is powered right, it will not need a resistor at all will not burn out.

1. Is it as easy as purchasing a LED that’s powered properly for an esp32 GPIO pin so that it will not probably burn out in a reasonable amount of time( years)?
2. Still, what’s the current on each GPIO pin? ( I know that the voltage on each GPIO pin is 3, If so.3 V)
3. Rather than adding a resistor, I can add a second LED parallel to add resistance and meet the power requirements, right?

Thanks!

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esp32gpioledspin
  1. nidhi singh

    The maximum power per pin is 40mA. You shouldn't push more than 150 mA through all your output pins( and probably less than that to avoid overheating). You can find the correct resistor value using any led resistor calculator online and the datasheet for your led. I do not see how parallel resistorsRead more

    The maximum power per pin is 40mA. You shouldn’t push more than 150 mA through all your output pins( and probably less than that to avoid overheating). You can find the correct resistor value using any led resistor calculator online and the datasheet for your led. I do not see how parallel resistors will be useful if you’re powering directly through the pin, and you do not have to get the exact resistance calculated. However, you should have a transistor gating a separate power supply for the light, If you need more than milliamps.

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Alex thomas
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Alex thomas
Asked: September 24, 2022In:
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Internal Low-Side Switch in LED5000?

What’s the purpose of the internal low-side switch in LED5000? Is it a synchronous converter? If so, also why is an external Schottky shown in the application diagrams?

What’s the purpose of the internal low-side switch in LED5000? Is it a synchronous converter? If so, also why is an external Schottky shown in the application diagrams?

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led5000ledsoptoelectronics
  1. Best Answer
    ashishgawade

    Yes, it works in synchronous mode. still, after the low-side FET has been switched off, there's always a specific dead time while the inductor still drives current. That current would flow through the body diode of the low-side FET, reducing effectiveness and increasing the radiated noise. This behaRead more

    Yes, it works in synchronous mode.

    still, after the low-side FET has been switched off, there’s always a specific dead time while the inductor still drives current. That current would flow through the body diode of the low-side FET, reducing effectiveness and increasing the radiated noise. This behavior can be improved by using a Schottky that takes over the current during the dead time.

    When your question is answered, please close this content by choosing Select as Best. This will help other users find that answer faster.

    Good luck!

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ashishgawade
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ashishgawade
Asked: September 19, 2022In:
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We’re using the L6920 to drive a 1-watt LED. We’re trying to apply the under voltage cut-off ( lockout) too. We chose the values of the voltage ground connected to the LBI pin similar that the value that comes to say ...Read more

We’re using the L6920 to drive a 1-watt LED.

We’re trying to apply the under voltage cut-off ( lockout) too. We chose the values of the voltage ground connected to the LBI pin similar that the value that comes to say 3V. Still, the IC didn’t shut off at 3V.
We also tried connecting the LBO to Vout with a 200K resistor in between. Even this didn’t work.

Can someone help apply this circuit?
Thanks!

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circuitdriveICl6920ledsoptoelectronics
  1. Best Answer
    Alex thomas

    Hi Ashish, However, you would notice that LBI input is connected to LBO output and that's the only purpose of this input, If you look into the block diagram of L6920 in its datasheet. LBI input doesn't shut down the output! Still, you need to use LBO output to shut down accordingly, If you require tRead more

    Hi Ashish,

    However, you would notice that LBI input is connected to LBO output and that’s the only purpose of this input, If you look into the block diagram of L6920 in its datasheet. LBI input doesn’t shut down the output!
    Still, you need to use LBO output to shut down accordingly, If you require to shut down the output.

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nidhi singh
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nidhi singh
Asked: September 7, 2022In:
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Hello I’m developing an operation that does led control with a button, I use a counter for this, but every time I hold the button, the counter increases further than 1 So indeed if I hold the button down, I want ...Read more

Hello

I’m developing an operation that does led control with a button, I use a counter for this, but every time I hold the button, the counter increases further than 1 So indeed if I hold the button down, I want it to increase once.

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buttoncontroldevelopingledsoptoelectronics
  1. vikas Nagpal

    Perhaps you should debounce the button, as mechanical buttons bounce, i.e. may produce more than one pulse per button press. There are several techniques to do that, one of the easiest is to connect some small capacitor in parallel to the button, which together with the pull resistor forms some lowRead more

    Perhaps you should debounce the button, as mechanical buttons bounce, i.e. may produce more than one pulse per button press.

    There are several techniques to do that, one of the easiest is to connect some small capacitor in parallel to the button, which together with the pull resistor forms some low pass filter. The time constant of that filter should be slightly lower than the period of the maximum speed to press that button(e.g.100.200 ms). You’ll find this solution also at the NUCLEO or DISCOVERY boards.

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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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