The INA138 and INA168 (INA1x8) are high-side, unipolar, current shunt monitors. Wide
input common-mode voltage range, low quiescent current, and tiny SOT-23 packaging enable use in a
variety of applications.
Input common-mode and power-supply voltages are independent and can range from 2.7 V to
36 V for the INA138 and 2.7 V to 60 V for the INA168. Quiescent current is only 25 µA, which
permits connecting the power supply to either side of the current measurement shunt with minimal
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 INA138 and INA168 are available in SOT23-5 and are specified for the –40°C to
125°C temperature range.