The INA139 and INA169 are high-side, unipolar, current shunt monitors. Wide input common-mode voltage range, high-speed, low quiescent current, and tiny SOT23 packaging enable use in a variety of applications.
Input common-mode and power-supply voltages are independent and can range from 2.7V to 40V for the INA139 and 2.7V to 60V for the INA169. Quiescent current is only 60µA, which permits connecting the power supply to either side of the current measurement shunt with minimal error.
The device converts a differential input voltage to a current output. This current is converted back to a voltage with an external load resistor that sets any gain from 1 to over 100. Although designed for current shunt measurement, the circuit invites creative applications in measurement and level shifting.
Both the INA139 and INA169 are available in SOT23-5 packages and are specified for the –40°C to +85°C industrial temperature range.
COMPLETE UNIPOLAR HIGH-SIDE CURRENT MEASUREMENT CIRCUIT