The INA138 and INA168 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 2.7V to 36V for the
INA138 and 2.7V to 60V for the INA168. Both
models draw only 25mA quiescent current, which also
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 INA138 and INA168 are available in
SOT23-5 and are specified for the –40°C to +85°C
industrial temperature range.