Maxim makes an opamp, MAX44280, that has a specified input capacitance of 0.4 pF. That would be great in some apps where Cin causes noise-gain peaking.
I figured I'd give Maxim another chance, after being s*****d by them in the past.
So I went online and filled out their sample request. The process makes no sense, website runaround, but eventually I got it done.
Two days later I got an email to the effect that the sample request was waiting for a product-line manager approval. I responded and asked why, and was told that it was standard internal procedure and would take only another 24 hours.
OK, a week later I got two samples, packaged in a short tube and wrapped in a ball of sticky masking tape.
These opamps, like most Maxim parts, have nonstandard pinout. I built a test fixture to measure Cin. With power off, I measured 1.4 pF on the non-inverting input pin. I powered it up and the opamp didn't act anything like an opamp. I checked everything three times and figured the amp was blown, so I tried to replace it. It's an SC70, really tiny, and my tweezers slipped and I pogoed it into the carpet, never to be seen again.
The sales engineer emailed me to see how the samples were coming along, and I told him the situation. He promised to get me 10 more ASAP. Then he called back with a technical guy. I explained my setup. I'm using +-2.5 volt supplies, and the technical guy said that this is a single-supply opamp and might not be qualified for dual-supply operation. He said he'd contact the designers or something. I asked him how they defined and measured the 0.4 pF Cin, and he said he'd find out. They were due to call me last Monday.
So far, no more parts, no call.