The LOG114 is specifically designed for measuring low-level and wide dynamic range currents in communications, lasers, medical, and industrial systems. The device computes the logarithm or log-ratio of an input current or voltage relative to a reference current or voltage (logarithmic transimpedance amplifier). High precision is verified over a wide dynamic range of input signals on either bipolar (±5V) or single (5V) supply. Special temperature drift compensation circuitry is included on-chip. In log-ratio applications, the signal current can be from a high impedance source such as a photodiode or resistor in series with a low impedance voltage source. The reference current is provided by a resistor in series with a precision internal voltage reference, photo diode, or active current source. The output signal at VLOGOUT has a scale factor of 0.375V/decade of input current, which limits the output so that the output fits within a 5V or 10V range. The output can be scaled and offset with one of the available additional amplifiers, so the output matches a wide variety of ADC input ranges. Stable DC performance allows accurate measurement of low-level signals over a wide temperature range. The LOG114 is specified over a −5°C to 75°C temperature range and can operate from −40°C to 85°C.