MAX9934

19-5011; Rev 0; 10/09 KIT ATION EVALU LE B A IL A AV High-Precision, Low-Voltage, Current-Sense Amplifier with Current Output and Chip Select for Multiplexing General Description The MAX9934** high-precision, low-voltage, high-side current-sense amplifier is ideal for both bidirectional (charge/discharge) and unidirectional current measurements in battery-powered portable and laptop devices. Input offset voltage (VOS) is a low 10µV (max) at +25°C across the -0.1V to 5.5V input common-mode voltage range, and is independent of VCC. Its precision input specification allows the use of very small sense voltages (typically ±10mV full-scale) for minimally invasive current sensing. The output of the MAX9934 is a current proportional to input V SENSE and is available in either 25µA/mV or 5µA/mV gain options (GM) with gain accuracy better than 0.25% (max) at +25°C. A chip select (CS) allows multiplexing of several MAX9934 current outputs to a single microcontroller ADC channel (see the Typical Operating Circuit). CS is compatible with 1.8V and 3.3V logic systems. The MAX9934 is designed to operate from a 2.5V to 3.6V VCC supply, and draws just 120µA (typ) quiescent current. When powered down (VCC = 0), RS+ and RSdraw less than 0.1nA (typ) leakage current to reduce battery load. The MAX9934 is robust and protected from input faults of up to ±6V input differential voltage between RS+ and RS-. The MAX9934 is specified for operation over the -40°C to +125°C temperature range and is avail...