ISO7762: supply voltage requirements

Xiaoying Lu

Part Number: ISO7762

Hi,

I have some uncertain design requirements for ISO7762.

I want to make sure that, if the supply voltage for VCC2 can be 3.3V when the input voltage is 5V, if yes, what's the supply current characteristics in this mode?

For the output signal, can it be connected with MCU directly, or we need add one small serial resistor? Thanks.

Regards,

Xiaoying

over 3 years ago

+1 Koteshwar Rao over 3 years ago

TI__Guru 52960 points

Hi Xiagoying,

Yes, operating VCC1 and VCC2 with different voltages is perfectly fine as the two sections of device are independently powered. Please see below FAQ for more details.

https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/732659/faq-can-a-digital-isolator-signal-voltage-be-different-from-its-power-supply-voltage

Since these two sections are independently powered, even the supply current characteristics can also referred independently. For example, if VCC1 5V and VCC2 is 3.3V then refer ICC1 from the section 6.10 titled "Supply Current Characteristics - 5V Supply" and refer ICC2 from the section 6.12 titled "Supply Current Characteristics - 3.3V Supply" of ISO7762 datasheet. Thanks.

Regards,
Koteshwar Rao

Isolation

Isolation forum

ISO7762: supply voltage requirements