Other Parts Discussed in Thread: TPS61150A I am seeing some unexpected behavior from a TPS61150A design with output ripple. The chip is driving 2 strings of WLEDs at 15mA ea. and approx. 20V output.
schematic is copied from the typical application on…
Dear Sean,
Thank you for the reply!
Please find my inline replies.
For the application to use the FET to change the total resistance between "ISET" and gnd, we suggest when you change the Q1 turn on or turn off, we recommend to disable the…
I am having a similar problem with the TPS61150a. I run 2 strings of 6 leds each. Channel 1 string totals 10.2 Volts for forward led voltage, the other 16.2 Volts. The current maximum is set for 12 mA for each ISET. The enables are PWM's at 30 KHz.…
Gary,
What I didn't see in your request was input supply voltage, so I will list a few alternatives which can support multi-strings in the same IC.
Boost:
TPS61150A - Dual Output Boost WLED driver (single inductor)
TPS61183 - 6 channel
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So, I have been looking at both the TPS61150 and TPS61150A Datasheets and I am still unclear as to what is the maximum current for each strand and total maximum current.
I have 2 Strands with each using 20mA. Although this has been working, Am I exceeding…
There seems to be a reliability issue with the chip if the 2 LED strings are a far mismatch of voltage drop. Two strings of 6 LEDs each. One is Red with Vf of 2.5 Volts. The other Green with Vf = 3.5 Volts. The 6 Volt total difference apparently stresses…
