J
Jeroen
- Jan 1, 1970
- 0
I was playing today with a little ionization chamber amplifier,
which is an exercise in high-impedance design. My usual business
revolves around wideband RF amplifiers, so this is unfamiliar
territory for me.
I selected an LPC661 opamp which has a specified maximum Ib of
4pA, but with a typical value stated to be 2fA. That's a very
large difference, which, I guess, is motivated by the need to
minimize testing time. It takes a while to measure fA
currents with some precision.
It appears I got lucky: Its measured Ib comes out at an amazing
170aA! I'm impressed. I hadn't yet noticed some opamps had gotten
*that* good.
Jeroen Belleman
which is an exercise in high-impedance design. My usual business
revolves around wideband RF amplifiers, so this is unfamiliar
territory for me.
I selected an LPC661 opamp which has a specified maximum Ib of
4pA, but with a typical value stated to be 2fA. That's a very
large difference, which, I guess, is motivated by the need to
minimize testing time. It takes a while to measure fA
currents with some precision.
It appears I got lucky: Its measured Ib comes out at an amazing
170aA! I'm impressed. I hadn't yet noticed some opamps had gotten
*that* good.
Jeroen Belleman