The AD8244BRMZ is a low power FET input quad Unity-gain Buffer designed to isolate very large source impedances from the rest of the signal chain. The 2pA maximum bias current, near zero current noise and 10 TR input impedance introduce almost no error, even with source impedance well into the megaohms. Many traditional operational amplifier pinouts have a supply pin that is next to the non-inverting input. A guard trace must be routed between these pins to avoid leakage currents much larger than the bias current of a FET input op amp. The AD8244 solves this problem with unique pinout that physically separates the high impedance inputs from the low impedance supplies and outputs of the other buffers. The AD8244 design is focused on solving problems specific to buffers. This includes close channel-to-channel matching which allows channels of the AD8244 to be used in differential signal chains with minimal error.
Extremely high input impedance
Low noise
High DC precision - 3μV/°C maximum offset drift (B grade)
No leakage from inputs to supply pins
Provides guarding capability
Rail-to-rail output
Single-supply operation - Input range extends to ground