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ISO6740-Q1: ISO6740QDWRQ1

Part Number: ISO6740-Q1

ISO6740QDWRQ1 is used in our design as shown below, the sense signals(INx and OUTx) are of 5V level and VCC=3.3V. According to the datasheet INx and OUTx maximum voltage rating is VCCx+0.5, but we wanted to know if INx and OUTx signals are 5V tolerant or we need to level translate sense signals in our schematic to 3.3V?


  • Adding information to above querry - The VCCx absolute maximum voltage is 6V, as per data sheet. So if VCC is biased with 3.3V. Then whether input supports 5V level input signals. (Whether inputs are 5V tolerant) 

  • Hello Kiranmayi,

    Operating outside the conditions in Table 7.1 Absolute Maximum Ratings (attached below for convenience) will cause device damage. As you have stated the datasheet INx and OUTx maximum voltage rating is VCCx+0.5, exceeding this could damage the device.

    Please also note that VCCI and VCCO do not have to be the same voltage and are completely independent, so there may not be a need to level shift separately. More information here.

    I hope this helps.



  • Thank you Andrew, so with supply voltage 3.3V we cannot connect 5V level input signal to INx as it may damage the device. Hope i inferred it correctly?

  • Kiranmayi,

    Your understanding is correct. With a 3.3V supply, 5V level input signal to INx may damage the device. The maximum input level signal to INx without damage is 3.8V (INx_max = VCCx + 0.5V = 3.3V + 0.5V).