TPS54239E: Highly susceptible to ESD

Yan Pui Chan

Part Number: TPS54239E

Hi,

I am using TPS54239E in one of the project design and found out it is very susceptible to ESD. The ESD event causing the MCU to reset very often, is this a known issue? Is there any recommendations to resolve this issue?

Below is our schematic for your reference.

Thanks,

Alan

over 5 years ago

0 Iven Su over 5 years ago

TI__Expert 8245 points

Hi,

It looks like the MCU is susceptible to the ESD evnet, the converter device has a ESD protection just for itself. The device will not generate a very-high peak volatge to cause a ESD damage through the power supply, thanks.

0 Yan Pui Chan over 5 years ago in reply to Iven Su

Intellectual 500 points

Hi,

We have verified by just replacing the TPS54239E to a Linear Voltage Regulator (LM1085ISX-5.0/NOPB), the MCU reset due to ESD events have been reduced by ~50% (it was almost 100%). For my understanding, TPS54239E may false detect OVP due to ESD, so the 5V output will not stable and causing MCU to reset.

Thanks,

Alan

0 Iven Su over 5 years ago in reply to Yan Pui Chan

TI__Expert 8245 points

Hi,

Could you please clarify what's the ESD event and what point of circuit it injects? Also, could you please probe the 5Vout to see whether the output is stable? Thanks.

0 Yan Pui Chan over 5 years ago in reply to Iven Su

Intellectual 500 points

Hi,
"ESD event" is generated by the ESD gun to our product, we do +/-4kV direct connect and +/-8kV air connect. This is one of the requirement from CE certification.

0 Yan Pui Chan over 5 years ago in reply to Yan Pui Chan

Intellectual 500 points

0 Yan Pui Chan over 5 years ago in reply to Yan Pui Chan

Intellectual 500 points

Attached picture shows the 5V output dropped out due to ESD event.

0 Iven Su over 5 years ago in reply to Yan Pui Chan

TI__Expert 8245 points

Hi，

The rapid output behavior is mainly determined by the output capacitor and load, when the ESD event occurs, even if the converter stop working, the rapid output change will not happen. It looks like a very heavy current sink happens on the output capacitor. Please check with it and you can change to larger caps and the waveform will change. Thanks.

0 Yan Pui Chan over 5 years ago in reply to Iven Su

Intellectual 500 points

Hi Iven,

We found the root cause was on our side, thanks for your supports.

Thanks,

Alan

Power management

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TPS54239E: Highly susceptible to ESD