Part Number: TPS2546
Hi,
This is a laptop project using TPS2546 at their USB type-A port as BC1.2 host, and the issue is related to TPS2546/OUT unexpectedly drop to 0V when there’s a device plugged in.
The laptop could function in DC mode (battery only) or AC mode (charging adapter connected)
TPS2546/OUT behavior is normal under below scenarios.
- CTL1/ CTL2/ CTL3/ ILIM_SEL = “1111” when laptop is in DC mode
- CTL1/ CTL2/ CTL3/ ILIM_SEL = “0111” when laptop is in AC mode
But, there’s an issue when CTL1/ CTL2/ CTL3/ ILIM_SEL = “0111” when laptop is in DC mode with waveform screenshot as below.
CH1: CTL1 CH2: CTL3 CH3:OUT CH4: STATUS
We’ve confirmed following items when the issue happens
- EN is high
- CTL1/ CTL2/ CTL3/ ILIM_SEL = “0111”
- FAULT is not measurable
- IN does not drop when OUT drop
- If we connect OUT to an electronic load (instead of a real USB device), it would drop when electronic load draw over ~0.2A
May you suggest what else we can check to continue the debugging?
Thanks!
Antony
