TPS65631W: TPS65631W turns off immediately

Kenneth Jackson

Part Number: TPS65631W

I'm using the TPS65631W in a design with AMOLED display. The 4.6V comes up and then immediately turns off in about 100us. I don't think it is the Short-Circuit During Start-up since it doesn't kick-in until 10ms. With no load (AMOLED), both voltages come up fine (4.6 and the programmed -2.4). The display consumes about 20mA during normal operation (NON-Startup). I have perform several tests with the displays and I believe they are operational.

I'm looking for any advice on how I should proceed.

over 5 years ago

0 Aaron Goodson over 5 years ago

TI__Expert 6330 points

Hi Kenneth,

I have notified our expert regarding this topic. Please expect a response by 2/8/19.

Thanks,
Aaron

0 Liaqat Khan over 5 years ago

TI__Mastermind 18550 points

Hello Kenneth,

Have you checked input supply to the device at the same time that 4.6V comes up and shuts down within 100us? One reason for device shutting down can be if input supply falls below UVLO level (under voltage lockout). I would suggest to have VPOS, VNEG, VIN and load current on the same scope plots to see if it can provide some clues. May be steady state current of the display is 20mA but at startup it is consuming much higher current which will ultimately come from input supply hence causing a glitch below UVLO level. What is the input supply voltage level to TPS65631W in your application?

Kind Regards,
Liaqat

0 Liaqat Khan over 5 years ago in reply to Liaqat Khan

TI__Mastermind 18550 points

Hello,
I hope that my explanation was helpful in debugging the issue. I am closing this thread but if you have further questions, please feel free to open another thread or reply to this one.
Kind Regards,
Liaqat

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TPS65631W: TPS65631W turns off immediately