TPS61196: TPS61196PWPT Current Output

Hi Tyrique,

TPS61196 can only support up to 200mA continuous current if all 6 channels are used. The limit is due to the power dissipation of the package.

BR

Patrick

I am only currently using 4 channels. the other two are tied down as directed through 36k res

Hi Tyrique,

Understood, so may I have a look at your schematic? You can send it to me through private message if you have confidential concern.

BR

Patrick

I will send over a private message with a capture of the schematic. Thank you for your help.

Hi Tyrique,

I will give you feedback after reviewing it.

BR

Patrick

Hi Tyrique,

What is the LED string voltage? And will the output current be larger than 200mA if you only connect 3 LED strings or less?

BR

Patrick

A string is comprised of 15, 3V LEDs (45V), there are 4 strings in the assembly.

An additional finding is that if the 12V input is boosted to 15V I get the correct 250mA per string.

Hi Tyrique,

Have you tried conditions between the 15V*4 strings and 45V*4 stings?

BR

Patrick

For clarification, the system has a 12V input and generates the 45V boost. I cranked the input voltage to 15V and was able to see the correct current per string. To my knowledge, the boost is not dependent on the input voltage (the efficiency is but I did not see the voltage affecting the boost from the data sheet.)

The system is always driving 4 strings of 15 LEDs (60 LEDs) total.  The main issue is that I am going to eventually use an off the shelf 12V PS vs a bench top variable power supply. I am trying to understand why the current MAX is not increasing even if the current limiting resistors are changed.

Hi Tyrique,

Thanks for the clarification, so have you checked when you applied the 12V Vin, will the input current reach to its limit? From my side, looks like this issue is more likely due to the input power limit.

BR

Patrick

I will test with a higher wattage 12V and see what I find, I will also try to take a reading on the "Vin" line and report back my findings or IF this is the solution. 

Hi Tyrique,

OK, I will wait for your update.

BR

Patrick

Thank you for your patience Patrick. This is a circuit that is part of a larger project, and I will update as soon as I can.

Hi Tyrique,

Understood.

BR

Patrick