TPS650832 VR3 OVP and emergency shutdown

Antony Lin

Hi,

Customer is doing some test to short VBUS with USB/D+ on purpose, and this will generate a 3.6V @ VR3 output. If I understood it correctly, it will cause VR3 fault, and trigger emergnecy shudown. After the 3.6V is removed from the board, customer can see VR3 back to normal. (LDO3V as ENVR3 is always normal.) Is it a normal behavior? I don't understand what is the event trigger the PMIC out of emergency shutdown mode at this case. Can you explain it?

Related waveform is shown as below.

CH1: USB Port1

CH2: V6_3V3_DSW

CH3: LDO3V

CH4: DPWROK

over 9 years ago

0 Kevin LaRosa over 9 years ago

TI__Genius 17380 points

Hi Antony,

Are they seeing any voltage change on the ACOK or PWRBTNIN pin? Both can trigger a restart.

0 Antony Lin over 9 years ago in reply to Kevin LaRosa

TI__Genius 13480 points

Hi,

After further checking today, customer confirm this only happens in AC mode which means ACOK is high. So, we can explain this situation.

One further question is, are we able to disable this behavior that ACOK can get PMIC out of emergency mode?

Thanks.

Antony

0 Kevin LaRosa over 9 years ago in reply to Antony Lin

TI__Genius 17380 points

Hi Antony,

Are they seeing glitches on the ACOK line? It should not trigger unless there is an edge here.

MACOK bit will not mask the power on event, it just effects the interrupt.

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TPS650832 VR3 OVP and emergency shutdown