What is the likely power consumption for the SP3070EEN RS422 Transceiver under normal operating conditions?

Question

I am designing with the SP3070EEN.

SP3070 Datasheet

I've tried to calculate the power consumption that this IC is likely to use when transmitting under normal conditions. I ended up with 5mW but in the datasheet the spec for total power dissipation is given as 667mW so I think I'm undercalculating how much power the IC would possibly be using.

What would be a more realistic estimate for the power draw of this IC? Any comments on how you calculated it would be greatly appreciated.

Edit: RS422 Load Power Dissipation Doc

Answer 1

The 667 mW number is the maximum allowable power dissipation for this device. This spec is probably based on the maximum die temperature and the thermal resistance of the package. That doesn't mean that it actually will consume that much power.

It looks like you need to allow for 1.5 mA at your maximum supply voltage, plus the power dissipated in the load.