I have a circuit that needs to pass 22 analog signals through a buffer amplifier before feeding them into an ADC (due to the relatively high impedance on the analog signals). I plan to use non-inverting op-amps in unity gain configuration for this. All signals are under 3.3V and low-frequency.
PCB space is at a premium. General-purpose op-amp ICs use 3 pins per op-amp, but since I know I will be in unity-gain configuration, I am hoping there are some specialized ICs that do what I need and need fewer pins per signal.
Q1: Do you know if there are buffer amplifier ICs that use only 2 pins (total — 1 in and 1 out) per amplified signal? For example, maybe there is an op-amp IC that is internally configured for unity-gain?
Q2: Can you suggest search terms I could drop into a parametric search to look for such things? I'd also take suggestions for specific ICs, because I can work my way backwards from that to a parametric search.
For what it's worth, my prototypes will be hand-assembled, and I am comfortable with soldering SMD IC by hand as long as it's a gull-wing package (down to 0.5mm lead pitch), but a no-leads or a BGA package wouldn't be viable at this time.