The INA138-Q1 and INA168-Q1 (INA1x8-Q1) devices are high-side, unidirectional, current sense amplifiers. Wide input common-mode voltage range, low quiescent current, and TSSOP and SOT-23 packaging enable use in a variety of applications. Input common-mode and power-supply voltages are independent, and range from 2.7 V to 36 V for the INA138-Q1, and 2.7 V to 60 V for the INA168-Q1. Quiescent current is only 25 µA, 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 devices are available in a TSSOP-8 package. The INA168-Q1 is also available in a SOT-23-5 package. Both devices are specified for the –40°C to +125°C temperature range.