The ADL5315 is a wide input current range, precision high-side current mirror featuring a stable and user-adjustable input voltage. It is optimized for use with PIN photodiodes, but its flexibility and wide operating range make it suitable for a broad array of additional applications. Over the 3 nA to 3 mA range, the current sourced from the INPT pin is accurately mirrored with a 1:1 ratio and sourced from the IOUT output pin. In a typical photodiode application, the output drives a current-input logarithmic amplifier to produce a linear-in-dB output representing the optical power incident upon the photodiode. For linear voltage output, a single resistor to ground is all that is required. The photodiode anode can be connected to a high speed transimpedance amplifier for the extraction of the data stream. The voltage at the INPT pin is temperature stable with respect to the voltage at the VSET input pin, which it tracks. A temperature stable reference voltage is provided at the SREF pin, which, when tied to VSET, fixes the voltage at INPT 1.0 V below VPOS. VSET can also be driven from an external source.