The Maxim Integrated MAX9634WEUK+T is a single-channel current sense amplifier from the nanoPower series, designed for ultra-low-power monitoring of load current in battery-operated and energy-harvesting systems. It draws only 1.1 µA supply current while delivering a gain-bandwidth product of 125 kHz, making it suitable for sensing fast load transients without draining the battery. Input offset voltage is 100 µV, which sets the floor for DC measurement accuracy at small shunt drops. Packaged in a SOT-23-5 — the same footprint as many general-purpose op-amps — it fits into compact, power-constrained designs.
1.1 µA supply — what it means for system power
At 1.1 µA quiescent current, this part is in the nanoPower class. In a battery-powered system drawing 100 µA total, the MAX9634WEUK+T adds about 1 % overhead — negligible for most designs. The trade-off is bandwidth: 125 kHz GBW is enough to capture load steps on a DC-DC output or motor current envelope, but not for high-frequency ripple above that corner. If your sense node needs sub-microsecond response, you trade supply current for a faster amplifier.
Package and mounting
Surface-mount in SOT-23-5. The single-channel pinout is standard for current-sense amplifiers in this footprint. No special pad layout beyond the usual SOT-23 land pattern. It is ROHS3 compliant, so it passes reflow without exemption issues.
Temperature range and environment
Rated for -40°C to 85°C — industrial temperature grade.