The RSA408X are high-side, current-sense amplifiers with an input voltage range that extends from 5V to 100V making them ideal for telecom, automotive, backplane, and other systems where high-voltage current monitoring is critical. The RSA4080 is designed for unidirectional current-sense applications and the RSA4081 allows bidirectional current sensing. The RSA4081 single output pin continuously monitors the transition from charge to discharge and avoids the need for a separate polarity output. The RSA4081 requires an external reference to set the zero-current output level (VSENSE = 0V). The charging current is represented by an output voltage from VREF to VCC, while discharge current is given from VREF to GND. For maximum versatility, the 100V input voltage range applies independently to both supply voltage (VCC) and common-mode input voltage (VRS+). High side current monitoring does not interfere with the ground path of the load being measured, making the RSA408X particularly useful in a wide range of high voltage systems. The combination of four gain versions (20V/V, 50V/V, 60V/V, 100V/V= A, B, C, D suffix) and a user selectable, external sense resistor sets the full-scale current reading and its proportional output voltage. The RSA408X offer a high level of integration, resulting in a simple, accurate, and compact current sense solution. The RSA408X is available in Green SOP8 and MSOP8 packages. It operates over an ambient temperature range of -40°C to 125°C.