PSOC5Lp Burn out after external EMP

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PaSv_1652016
Level 2
Level 2
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I have a device based on CY8C5888LTQ-LP097. Everything works great while I have it on my desk.

But in combat conditions, the MCU burns immediately or in a few days.

Only MCU burns down.
HighVoltage parts , all  TVS , All  zener , mosfet and LDO   - all surrounding components are operational.

MCU  burned after  external Spark ~ about 2m from device. My device fully insulated with double EMC\ESD shild .

MCU suplied from 2x  5v LDO  (one for Analog and One for Digital )

HV part fully  isolated

i found only one layout error : Vccd1 and Vccd2 not  connected  together + maybe capacitor on vccd1 & vccd2 10uF instead of recommended 1Uf.
May this cause problemm  ?

Could you please have a look and check if there is anything wrong? have anyone an idea what can be the problem?

Thanks in advance,

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1 Solution
Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hello Pavel,

Vccd pins must be shorted using a short trace and the de-couping capacitor of 1uF is recommend for those pins. The specs guaranteed in the datasheet are met when the design guidelines are followed. Additionally we recommend you to place smaller values of decoupling capacitors closer to the controller as they can respond to high frequency current requirements faster. You can also use place smaller capacitors in parallel with larger capacitors to increase the frequency response range.

The following documents can be helpful for EMC/EMI issues.

PSoC® EMI Design Considerations

Design Considerations for Electrical Fast Transient (EFT) Immunity

Best Regards,
Vasanth

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2 Replies
PaSv_1652016
Level 2
Level 2
10 likes given 5 likes given First like received

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Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hello Pavel,

Vccd pins must be shorted using a short trace and the de-couping capacitor of 1uF is recommend for those pins. The specs guaranteed in the datasheet are met when the design guidelines are followed. Additionally we recommend you to place smaller values of decoupling capacitors closer to the controller as they can respond to high frequency current requirements faster. You can also use place smaller capacitors in parallel with larger capacitors to increase the frequency response range.

The following documents can be helpful for EMC/EMI issues.

PSoC® EMI Design Considerations

Design Considerations for Electrical Fast Transient (EFT) Immunity

Best Regards,
Vasanth

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