Small current-sense amp for applications in portable electronics

The MAX9634 high-side current-sense amplifier offers precision accuracy specifications of VOS less than 250µV (max) and gain error less than 0.5% (max). Quiescent supply current is an ultra-low 1µA. The MAX9634 fits in a tiny, 1mm x 1mm UCSP™ package size or a 5-pin SOT23 package, making the part ideal for applications in notebook computers, cell phones, PDAs, and all battery-operated portable devices where accuracy, low quiescent current, and small size are critical.

The MAX9634 features an input common-mode voltage range from 1.6V to 28V. These current-sense amplifiers have a voltage output and are offered in four gain versions: 25V/V (MAX9634T), 50V/V (MAX9634F), 100V/V (MAX9634H), and 200V/V (MAX9634W).

The four gain selections offer flexibility in the choice of the external current-sense resistor. The very low 250µV (max) input offset voltage allows small 25mV to 50mV full-scale VSENSE voltage for very low voltage drop at full-current measurement.

The MAX9634 is offered in tiny 4-bump UCSP (1mm x 1mm x 0.6mm footprint) and 5-pin SOT23 packages specified for operation over the -40°C to +85°C extended temperature range.