Low power current sense amplifier for overcurrent protection

Texas Instruments INA191 Current Sense Amplifier is a low-power, voltage-output, current-shunt monitor (additionally called a current-sense amplifier). This amplifier is generally used for overcurrent protection, the precision-current measurement for system optimisation or in closed-loop feedback circuits. It can sense drops over shunts at common-mode voltages from –0.2V to +40V, independent of the supply voltage. The low input bias current of the INA191 allows the use of larger current-sense resistors and therefore offers accurate current measurements in the µA range. Five fixed gains are offered: 25V/V, 50V/V, 100V/V, 200V/V, or 500V/V. The low offset voltage of the zero-drift architecture increases the dynamic range of the current measurement. This also provides for smaller sense resistors with lower power loss while still giving accurate current measurements.

The device runs from a single 1.7V to 5.5V power supply, drawing a maximum of 65µA of supply current when enabled and just 100nA when disabled. The device is specified over the operating temperature range of –40C to +125C and offered in a DSBGA-6 package.

Typical applications include notebook computers, cell phones, battery-powered devices, telecom equipment, power management, and battery chargers.