200 kHz GBW at 4 µA — the power-speed trade-off for battery rails
The MAX44265EWT+T is a single-channel general-purpose op-amp from Maxim Integrated, built for applications where supply current is the binding constraint. Gain-bandwidth product is 200 kHz with a supply current of just 4 µA — that ratio places it in the nano-power class, suited for always-on sensor conditioning, battery-monitor front-ends, and threshold-detection loops that cannot spare a milliampere. The rail-to-rail output preserves dynamic range at low supply voltages — a 1.8 V rail still swings within millivolts of both rails, which matters when the ADC reference is the same supply.
Input bias and offset — what 1 pA and 200 µV mean for the signal chain
Input bias current is 1 pA typical, low enough that a 10 MΩ source resistor contributes only 10 µV of offset error — negligible for most precision loops. Input offset voltage is 200 µV; for a gain-of-100 stage that translates to 20 mV of DC error at the output, which is acceptable for 8-bit systems but worth budgeting in a 12-bit path. Slew rate is 0.1 V/µs, which sets the large-signal bandwidth to roughly 16 kHz at 2 Vpp output. For audio or fast transient edges the amplifier will slew-limit before the 200 kHz GBW suggests — the small-signal bandwidth is available only for signals below about 50 mVpp. Output current capability is 15 mA per channel, enough to drive a 10 kΩ load to rail or charge a 100 pF sampling capacitor on a SAR ADC input within one microsecond.
6-WLP package — board-fit and rework considerations
The part comes in a 6-ball WLP (wafer-level package) measuring 1.24 x 0.84 mm, with a 0.4 mm ball pitch typical of Maxim's WLP family. The package is surface-mount only and ships on tape and reel or cut tape. The 0.4 mm pitch demands a controlled solder-paste stencil and a reflow profile matched to the board thickness — standard JEDEC profiles for lead-free apply. Store the reels dry — WLP packages are moisture-sensitive and require bake before reflow if the moisture-barrier bag is breached.