TPS65265: TPS65265RHBR

Karthikeya RAM

Prodigy 70 points

Part Number: TPS65265

Hello,

I have used "TPS65265RHBR triple channel DC to DC regulator in my project.

I need to follow the power sequence as "BUCK1-<BUCK3->BUCK2".

so I have followed the same configuration given in the datasheet as mentioned below.

but I am not receiving a signal as i mentioned "BUCK1-<BUCK3->BUCK2".

one more issue is I was trying to introduce "sequential delay" between each buck1 convertor but ,i could not see any delay between each buck.(i have monitored these signals in scope so, i don't find any delay between them).

please, someone, suggest to me what circuit modification I have to do to get "BUCK1-<BUCK3->BUCK2".

note:-

CURRENTLY, I HAVE SOLDERED CAPACITOR TO GIVE DELAY OF 2msec at "sequential delay" C16.

Regards

NIKHIL

over 2 years ago

0 Zhao Ma over 2 years ago

TI__Genius 15135 points

Hi, Nikhil

Please pull MODE pin to high, then test again.

0 Karthikeya RAM over 2 years ago in reply to Zhao Ma

Prodigy 70 points

thank you for your reply.

i tried pulling MODE pin HIGH also but same result no change.

And also to check power sequence waveform tried to introduce delay of around 2msec but this delay also not introduced in between each buck rails.

Regards

NIKHIL

0 Zhao Ma over 2 years ago in reply to Karthikeya RAM

TI__Genius 15135 points

Hi, Nikhil

EN3 should be later than EN1 and EN2, so we cannot connect them together .

0 Karthikeya RAM over 2 years ago in reply to Zhao Ma

Prodigy 70 points

Yeah, i tried that as per the datasheet by giving EN1 and EN2 directly pull up and EN3, i gave with 2 mili seconds delay.
So initially EN1 and EN2 will be given to IC after that 2 milliseconds EN3 will be feed to IC.

but still, there is no change in sequence.

still, it's Buck1 -> buck 2-> buck 3 sequences only occurring.

but i need Buck1-> buck3-> buck2.

Also, i would like to know why the sequential delay is not introduced in between each buck output rails.

regards

NIKHIL

0 Zhao Ma over 2 years ago in reply to Karthikeya RAM

TI__Genius 15135 points

Hi, NIKHIL

Could you measure some waveforms? I want to check the sequence.

Please probe the EN1/EN2, EN3, and MODE pin voltage.

Power management

Power management forum

TPS65265: TPS65265RHBR