Quad current-sense amplifier for precision rail monitoring
The MAX4378FASD+ is a quad-circuit current-sense amplifier from Analog Devices, designed to measure current on power rails by sensing the voltage drop across an external shunt resistor. Four independent amplifiers in a single 14-SOIC package let you monitor multiple supply rails or phases without multiplying the BOM count — useful in multi-voltage systems where each rail needs its own current-limit threshold. The 10V/µs slew rate and 2 MHz -3dB bandwidth mean the output tracks fast load transients, so a downstream comparator or ADC sees the real current waveform, not a filtered average.
Supply range and operating temperature for system integration
Each amplifier draws 1 mA quiescent current, so the total supply draw for all four channels is 4 mA — negligible in a power budget but worth noting for battery-powered designs where every milliamp counts. With an input bias current of 120 µA, the shunt resistor value must be chosen so the bias current does not introduce a significant offset voltage error in the measurement path.
Active lifecycle and compliance documentation
Supplied in Tube packaging, the 14-SOIC (0.154" body width) footprint is a standard industry package with wide second-source availability for the outline, though the MAX4378FASD+ is the specific ordering code for this quad current-sense variant.