TPS92515HV-Q1: Driver's Dimming Range 0.1%-100%

Could you provide more information about the application?

For example, application, dimming mode, dimming accuracy, output current, LED spec. If Q grade needed or not. Interface... 

Hi,

I think it so clear, I just want to one LED driver for 0.1%-100% dimmable spesifection. I got 4 led and I want to dim them 0.1%-100% with led driver from my MCU.

Regards

Please answer Xiaoguang's questions so we can recommend the appropriate device.  You need to give us the VIN (min, typ, max), ILED (min, typ max), the typical characteristics of the LED (datasheet would be good) so that we can figure out VLED range (min, typ max).  Are the 4 LEDs in series?  Are you doing PWM dimming and if so what is the PWM frequency?  You gave us the duty cycle range so that is fine.  Are you doing shunt fet dimming?  Do you have a desired switching frequency?  Do want a programmable device or an analog solution? Does it need to be automotive grade? (assume yes or you wouldn't be using this forum.  Once you give Xiaoguang that information we can recommend a device.  

-fhoude

Hi Fhoude and Xiaoguang,

First of all, I want to ask Fhoude why are talking like that? I don't like your talk with me you are in border like one side rude one side kind. I warm you about that. 

Hello Oben,  I am sorry you interpreted my reply as border line rude, it was not intended to be.  I was being direct with the questions needed to be answered so that we could efficiently give you an answer.  Our E2E forum is designed to be searchable for answers and if you put a bunch of threads on the forum it makes it harder for other customers to search the forum and it makes it harder for use to track.  I was just trying to make it more efficient and letting you know only one thread is needed.  

Secondly, if I need to answer that question again" why you want this from me instead of Xiaoguang. I talked a lot of people in this forum but you guys most not interested that's why I opened a lot of new question.

Our goal is to answer all our posts within 24 hours or at least respond within 24 hours.  I looked at your previous posts and I only saw the recent ones and I didn't see us not answering.  So your comment about us us not being interested confused me.  Unfortunately, there are delays to the fact we have team members in different parts of the world.  We do our best to help out.  Maybe I am not understanding your comment too.        

All in all, your question answers; unfortunately I can not share leds datasheet, but input of my circuit and Leds is same 24V, and max I for my Leds output is 3.75 A and my max W is 90W. Yes this is kind a automotive and ındustrıel grade. I want to see both solutıon I mean Programmable device and analog solution.

It sounds like you have some sort of power supply that generates 24V for your Vin, is that correct?  I am a bit confused about the LEDs, I believe your configuration is as follows:

Generally speaking the output voltage is a function of the output current (our drivers create constant current (CC) source) multiplied by the Vf of the diode and how many diodes that are in series.  The Vf of a diode can vary greatly due to a lot of reason, color, type, size, current going through then, etc and it is important for us to know because we will likely need a buck LED driver due to the amount of current your have specified.  3.75A is pretty large and power losses would be high and heat sinking would be a major concern.  I believe that you hope that the current will be shared equally between the two strings of 2 series diodes.  If the diodes aren't matched then that might not be true but it should be fairly close.     

If you can't share the datasheet for the LED, then can you tell us the Vf (forward voltage) of the diode at the current you expect it to be going through it.  If the current is shared precisely then I would want to know the Vf at 1.875A.  VLED would be 2xVf at 1.875A.  This is important for the buck converter that we propose to use.  Here is example of Vf vs If curve that I am talking about.  Every LED or diode datasheet will have something like this. 

If you don't want to share the information on a public forum we can either take it offline or we could get your local FAE (Field Application Engineer) to submit your questions on a separate internal forum that is not public.  

For my PWM frequency, it could be araound 400KHz-1MHz. Yes it could be shunt fet dim or not does not matter. And My Leds serial and pararel together. 2x2.

I think you are confusing the switching frequency of the LED driver with the PWM frequency.  PWM dimming frequencies are generally 30 Hz to 2-4 kHz.  I have never seen a PWM frequency of 400kHz-1MHz,  but maybe it exists, but these parts are not intended for that.  We need clarification to proceed.  If you would prefer we could do a webex meeting to go over this.  We have a lot of devices that might potentially be able to do this but in order to narrow our selection we need more information.  Designing a LED driver isn't trivial and I would rather get as much information up front so that we are more likely to give you a solution that will work the first time.  

Finally, I am waiting quick response.

Regards

Hello Oben,

Here is a link to general training about how to drive LEDs.  It covers a wide variety of information and it would be good to learn the common terminology used with respect to driving LEDs.

https://www.ti.com/video/series/led-driver-basics.html 

I would also like to know more about your end equipment so that I can understand how your using the LED driver.  If this is proprietary then you can message me privately.

-fhoude

Hello Fhoude,

Thank you for all.

Regards

Hello Oben,

Let me know what you find out about the clarification of our questions with respect to design specifications so that we can guide you to component selection and help with design recommendation.

-Francis Houde