TPS2546: Will TPS2546 discharge Vbus in below condition?

Max Guan

Intellectual 1350 points

Part Number: TPS2546

Hi team,

My customer reported an issue that the PC system mode (MS/S3/S0) is not stable possibly due to the USB port feature.

As they measure the waveforms, only CTL1 is toggling while seems the mode for 2546 keeps at SDP1:

Customer pulled CTL2 and ILIM2 to 5V and control the CTL1 and CTL3.

Seems changing the CTL1 will lead to a Vbus discharge although the mode is not actually switched. Is this an expected behavior and what is the reason for this discharge.

I'm checking with customer why a CTL1 toggling will happen while I need your help to confirm whether the Vbus discharge make sense here.

Thanks for your help.

Max

over 5 years ago

0 Adam Mc Gaffin over 5 years ago

TI__Mastermind 30000 points

Hello Max,

Yes, this is expected behavior. If you look at Table 2 of the datasheet, you will see that the two charging modes have different power states and wake functionality.

Having CTL1 line toggled is not expected behavior, so work with your customer to determine what could cause that toggling.

0 Max Guan over 5 years ago in reply to Adam Mc Gaffin

TI__Intellectual 1350 points

Thank you Adam.

Power management

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TPS2546: Will TPS2546 discharge Vbus in below condition?