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QuickSilver
Associate II
August 20, 2024
Solved

STSPIN240 Logic input voltage

  • August 20, 2024
  • 1 reply
  • 1403 views

Hi, the STSPIN240 datasheet states that the absolute maximum ratings for logic input voltage should be between -0.3V and 5.5V. However, it is unclear whether the logic input voltage can exceed VS.

Can the logic input voltage exceed VS?

Thanks,

Best answer by Peter BENSCH

Oh, now I understand your question.

Yes, the maximum voltage at VIN also applies to a lower voltage at VS, i.e. also in your example of VIN=5V and VS=4V.

Please note that although a maximum voltage of 5.5V may be applied to VIN, the recommended voltage is between 0...5V.

Please also note that the logic IOs are not fully TTL compatible: VIH with 1.6V is within the TTL level of 2.4V, but VIL with max 0.6V is slightly out of tolerance (TTL can have 0.8V). Depending on the microcontroller driving the STSPIN240, you may need to provide level shifters.

Good luck!
/Peter

1 reply

Peter BENSCH
Technical Moderator
August 20, 2024

No. The data sheet clearly states for the absolute max rating: VIN max 5.5V.

This is the absolute maximum voltage up to which the function of the device is guaranteed. Even the smallest exceedance of this maximum value will result in irreversible damage to the component. It is the developer's responsibility to ensure compliance with these parameters in an appropriate manner.

Hope that answers your question?

Regards
/Peter

QuickSilver
Associate II
August 20, 2024

Hi Peter, thank you for your response.

Yes, I understand and agree with your comment.

However, considering that the STSPIN240 has a supply voltage pin "VS" which can be powered with a voltage ranging from -0.3V to 11V, it is unclear whether the maximum VIN for any logic input could exceed VS without surpassing 5.5V. For instance, if the device is powered by 4V through VS (dc motor power) and the logic inputs are driven by a microcontroller with 5V outputs, it does not exceed the 5.5V maximum rating, but it does exceed VS. Is this permissible?

 

 

Peter BENSCH
Peter BENSCHBest answer
Technical Moderator
August 21, 2024

Oh, now I understand your question.

Yes, the maximum voltage at VIN also applies to a lower voltage at VS, i.e. also in your example of VIN=5V and VS=4V.

Please note that although a maximum voltage of 5.5V may be applied to VIN, the recommended voltage is between 0...5V.

Please also note that the logic IOs are not fully TTL compatible: VIH with 1.6V is within the TTL level of 2.4V, but VIL with max 0.6V is slightly out of tolerance (TTL can have 0.8V). Depending on the microcontroller driving the STSPIN240, you may need to provide level shifters.

Good luck!
/Peter