AD8655 gain bug?

[pinkfloyd11]

Hi

I'm not professional user but sometimes I try to compare real hardware with simulator.

In this case I have simulated AD8655:

test AD8655.jpg (293.84 KiB) Viewed 2499 times

The real one have R19=270 and R20=270K

For obtain value like the real one, I had modified value to 340K

Please check because this could be a bug

[Ettore]

I quickly calculated by hand that output voltage with R19=R20=270k and R7 connected is 546.1mV and 370mV with R7 unconnected.
Simulation results are consistent with those calculation.

R7 connected.jpg (100.59 KiB) Viewed 2475 times

R7 unconnected.jpg (98.59 KiB) Viewed 2475 times

So, it can be safely said that simulation of the AD8655 gain is definitely correct.

However, you didn't post full schematic, so if you want us to check then you should post the entire Proteus .pdsprj file, or send it to me by PM.