The LOG101 is a versatile integrated circuit that computes the logarithm or log ratio of an input current relative to a reference current.

The LOG101 is tested over a wide dynamic range of input signals. In log ratio applications, a signal current can come from a photodiode, and a reference current from a resistor in series with a precision external reference.

The output signal at V_OUT is trimmed to 1V per decade of input current allowing seven decades of input current dynamic range.

Low DC offset voltage and temperature drift allow accurate measurement of low-level signals over a wide environmental temperature range. The LOG101 is specified over the temperature range ?5°C to +75°C, with operation over ?40°C to +85°C.