About VCCD short protection

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JuIn_1625121
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About CYT2B63BAE,

Does VCCD pin have any circuit protection?

The customer is concerned about the following short.

Pin58.VCCD - Pin57.GND

Pin59. OUTPUT H - Pin58.VCCD

Best Regards,

Inoue

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Pranith
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Hello @JuIn_1625121 ,

The datasheet mentions 1.1v threshold brown out detection (BOD) is made available on VCCD. The BOD is enabled by default. This should ideally ensure protection in both scenarios ( VCCD shorted with GPIO (5.5V) or VCCD shorted with VSSD ). Any deviation from the threshold would cause the MCU to reset.

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JuIn_1625121
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100 sign-ins First solution authored 100 replies posted

Hello Pranith,

Thank you for your answer.

Will it be damaged by overvoltage or overcurrent?

Best Regards,

Inoue

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Pranith
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Hi @JuIn_1625121 ,

I have tried to summarize the scenarios below:

1. Would a short between either VCCD and GPIO (5.5V) or VCCD and VSSD cause the device to short circuit/burn out?

  • Shorting VCCD and GPIO
    •  In this case if the GPIO is input then it would read 1.1V, and the value will be based on the TTL logic levels.
  • In case if the GPIO is output,
    • Output low, then the current will sink and if there is no current limit set externally, then it results in a dead short and will damage the pin.
    • Output high, now there are two potentials 5.5V and 1.1V, and the current will flow from higher potential to lower potential. And again since there is no current limit, it is again a dead short and will cause damage.

2. As mentioned in the datasheet, 1.1V threshold Brown out detection (BOD) is provided on VCCD and is enabled by default, would this prevent the device from short circuit in the scenarios mentioned above?

  • Brownout will cause a reset if the voltage drops below the lower threshold voltage. It ensures that the system will work at the required voltage and then cause a reset if brownout is detected. This will not prevent a short circuit. If there is a short circuit, the device will fail.

In any case it is forbidden to short the pins you have mentioned.

Regards,

 

JuIn_1625121
Level 5
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100 sign-ins First solution authored 100 replies posted

Hello Pranith,

 

Thank you for your answer.

It was very easy to understand.

 

Best Regards,

Inoue

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