tim's journal

A conversation with Analog Devices

I spoke with Tim at Analog Devices regarding my requirements, essentially, at 0.01 - 100Hz, noise below 100 nV/&sqrt;Hz, and fA input bias current. We first looked at the AD549, which has 60 fA input bias current, but really high 1/f noise. Then we looked tat the AD8551, a CMOS chopper architecture with pA input bias current. He said that he could not do both chopper and fA input bias current. Finally, we looked at the AD8605, which seemed to be a good compromise between the two. I'll have to look in more detail. Recall the LMC622 has 2 fA input bias current, but rather high noise... what I really need is a chart comparing everything.