Hi team,
How to calculate power dissipation of an isolator?
It seems like power dissipation is related to frequency and VCC, what's the equation of it?
Thanks,
Charles
Hi Charles,
The power ratings that are provided in section 7.5 of ISO7741 datasheet are the maximum power dissipation ratings that a given package of ISO7741 can support. On the other hand, to calculate power dissipation for a given operating conditions, you can simply multiply VCC1 * ICC1 to get PD1 which is the dissipation of ISO7741 on Side1. Similarly, VCC2 and ICC2 should yield you PD2 for Side2 of device. The total power dissipation in device would be PD = PD1 + PD2.
As an example, let's consider the following operating conditions for ISO7741.
VCC1 = VCC2 = 5V
All INx = 1Mbps clock
All OUTx have a max load cap of, CL = 15pF
Referring to below supply current characteristics table from section 7.10 of ISO7741 datasheet,
typical ICC1 = 3.2mA and ICC2 = 2.8mA, hence,
typical PD = PD1 + PD2 = (VCC1 * ICC1) + (VCC2 * ICC2) = 16mW + 14mW = 30mW.
Regards,
Koteshwar Rao
