1. when vin=0.4V, the output current is about 60uA, but the ideal value should be 100*0.4/20=2mA. Why? What's the range of R1 and R2? I do not find the specification in datasheet. R1 should equal to ...

Great question! I can provide what I've seen a few devices survive, but please understand this isn't TI guaranteeing that all devices will be able to handle these HDM and CDM levels. It's possible not ...