100 kHz current sense amplifier for shunt-based monitoring
The MAX4070AUA+T is a single-circuit current sense amplifier from Analog Devices, designed to measure load current by amplifying the voltage drop across an external shunt resistor. Its 100 kHz -3 dB bandwidth supports dc current monitoring plus ripple or transient capture up to that frequency — fast enough for most motor-drive, solenoid, and power-supply output rails, but not for switching-node edge detection. The input offset voltage is trimmed to 80 µV, which sets the floor for measurement error at low shunt drops. With a 10 mΩ shunt, 80 µV offset corresponds to 8 mA of apparent current — acceptable for a 10 A rail but too coarse for sub-100 mA idle-current tracking. The 2.4 µA input bias current flows through the shunt and adds a small voltage drop that is common-mode, not differential, so it cancels in the amplifier's gain stage.
Supply span and quiescent current for always-on rails
The 100 µA supply current is low enough to leave the amplifier powered continuously on a battery-backed rail — the quiescent draw is 2.4 mW at 24 V, negligible in a system that already dissipates watts in the load. The 8-uMAX/uSOP package is a 3 mm × 3 mm footprint with 0.65 mm pin pitch — the same as the 8-MSOP land pattern, so the PCB layout is shared with other uMAX-packaged parts in the same BOM position.
Active production and compliance posture
The Tape & Reel (TR) packaging option is suited for automated pick-and-place assembly. The Cut Tape (CT) variant is also listed for prototype or low-volume builds.