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BTS7040_1EPA: Why should the R_SENSE not be lower than 820 Ω?

BTS7040_1EPA: Why should the R_SENSE not be lower than 820 Ω?

Infineon_Team
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The reason for this limitation is related to the maximum power dissipation allowed inside the circuitry connected between IS and VS pins. In normal operation (IIS(FAULT), IIS(SAT)) the current is generated by the device and it is limited to the value specified, therefore the power dissipation can be calculated as follows: P = IIS * (VS - RSENSE*IIS) 
In Reverse Battery condition, the current is limited only by RSENSE, therefore P = (VS - 0.7V) * 0.7V / RSENSE
The Reverse Battery condition is a more stringent one, therefore for all applications where this could happen (therefore without a central Reverse Battery protection that would block current flowing during Reverse Battery) RSENSE must be higher than 820 Ω. Otherwise, 400 Ω are sufficient according to our estimations.

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