• Resolved

ISO7742: Could be ISO774x powered with different values: VCC1 is 3.3V, and VCC2 is 5V?

Part Number: ISO7742

Dears:

Could you kindly help to check whether the solution is OK as below:

 ISO7742 is powered with different values: VCC1 is 3.3V, and VCC2 is 5V.

Since we are replacing the ADI's PN(ADUM1412), and ADI support the function.

From our datasheet I can see ISO774X support 2.25-V to 5.5-V Level Translation, however, there is no Supply Current Characteristics about the customer's application.

Could you kindly help to check it?

Thanks a lot!

Best regards

Luck Wu

  • Hi Luck Wu,

    Yes, ISO7742 can be powered up using different values. Example : VCC1 = 3.3V and VCC2 = 5V.
    Figure 9 of datasheet shows the supply current characteristics at 3.3V and 5V. Since the ISO7742 is a symmetric configuration (2 forward channels and 2 reverse channels), the supply currents ICC1 and ICC2 will be the same at same supply voltage.
    This makes the ICC1 and ICC2 lines overlap and only 3 lines are visible instead of 6 lines as seen in ISO7741 characteristics (Figure 7).

    VCC1 and VCC2 are not dependent on each other and the individual ICC values (ICC1 and ICC2) for different supply levels can be calculated for specific data rates from Figure 9 of datasheet.

    Let me know if this helps solve your query. Thanks.

    Regards,
    Anand Reghunathan