TPS61165: hardware question

Yan Pui Chan

Part Number: TPS61165

Is there any ways to increase the soft start/ramping time for the LED on the hardware side, instead of using PWM on the software side? I want to increase the timing to around 400ms, if not, what is the maximum value it can goes?

over 7 years ago

0 ivan yakimenko over 7 years ago

Prodigy 80 points

hi, its not a big problem to increase time, do you need to use PWM after soft-start?

0 Yan Pui Chan over 7 years ago in reply to ivan yakimenko

Intellectual 510 points

We don't need to at this point, we will set the EN pin high at the high.

0 ivan yakimenko over 7 years ago in reply to Yan Pui Chan

Prodigy 80 points

one of the way is to use transistor and capacitor of hundred microfarads connected to CTRL pin, when cap is full transistor short pin to high

0 Yan Pui Chan over 7 years ago in reply to ivan yakimenko

Intellectual 510 points

Can you please send me a picture of the connections for reference? For the CTRL pin, I thought it is digital input. Will it work this way? Thanks!

0 Caryss Li over 7 years ago

TI__Expert 4550 points

Hi Chan,
I think what Ivan said is valid, you could using capacitor to add delay time.

0 Yan Pui Chan over 7 years ago in reply to Caryss Li

Intellectual 510 points

Hi Caryss,
Can you please clarify by using capacitor to add delay time?
Is that means adding a RC circuit on the CTL pin?
Thanks,
Alan

0 Caryss Li over 7 years ago in reply to Yan Pui Chan

TI__Expert 4550 points

Hi Alan,
Yes, you could use someting like that, and you need to transistor NPN or PNP, to disconnet CTRL from GND or connect to EN.
This way may not be accurate, and it is suggest to use SW to add delay.