Precision Logarithmic And Log Ratio Amplifier With On-Chip 2.5V Voltage Reference

The LOG112 and LOG2112 are versatile integrated circuits that compute the logarithm or log ratio of an input current relative to a reference current. VLOGOUT of the LOG112 and LOG2112 are trimmed to 0.5V per decade of input current, ensuring high precision over a wide dynamic range of input signals. The LOG112 and LOG2112 features a 2.5V Voltage Reference that may be used to generate a precision current reference using an external resistor. Low DC offset voltage and temperature drift allow accurate measurement of low-level signals over the specified temperature range of 5C to +75C. By Texas Instruments