The MAX4004/MAX4006 precision, high-side, current monitors are specifically designed for monitoring photodiode current in fiber applications. They offer a connection point for the reference current and a monitor output that produces a signal proportional to the reference current. The monitor output of the MAX4004 is a current proportional to the reference current. The monitor output of the MAX4006 is a voltage proportional to the reference current. The current monitors have six decades of dynamic range and monitor reference current of 250nA to 2.5mA with better than 5% accuracy. The photodiode current can be monitored from 10nA to 10mA with reduced accuracy.