9 kHz GBWP, 450 nA — the always-on amplifier
The Microchip MCP6441T-E/OT is a single-channel, general-purpose op-amp designed for applications where supply current is the binding constraint. With a gain-bandwidth product of 9 kHz and supply current of 450 nA, it fits into battery-powered sensor interfaces, wearable health monitors, and remote IoT nodes that run for years on a coin cell. The rail-to-rail output stage lets it swing close to the supply rails in single-supply designs from 1.4 V to 6 V.
450 nA supply — the battery-life decision
At 450 nA quiescent, this part draws less than many op-amps' input bias current. In a 3 V system with a 200 mAh coin cell, the amplifier alone adds under 0.5% annual drain — negligible for a continuous-monitoring loop. The trade-off is bandwidth: the 9 kHz GBWP limits the part to DC-precise amplification, sub-audio filtering, and low-frequency signal conditioning. For a thermistor bridge or a photodiode front-end sampling at a few Hz, it is a natural fit.
1 pA input bias — high-impedance sensor front-end
The 1 pA typical input bias current preserves signal integrity from high-source-impedance sensors like pH probes, pyroelectric detectors, and capacitive humidity elements. Combined with the 4.5 mV input offset voltage, the part can resolve microvolt-level changes when used with a precision reference and appropriate gain staging.
The SOT-23-5 package keeps board area small, and the surface-mount footprint suits automated assembly lines.
ROHS3 compliant for global regulatory coverage.