The LOG102 is a versatile integrated circuit that computes the logarithm or log ratio of an input current relative to a reference current.
●The LOG102 is tested over a wide dynamic range of input signals. In log ratio applications, a signal current can be generated by a photodiode, and a reference current from a resistor in series with a precision external voltage reference.
●In the block diagram shown below, A3 and A4 are identical, uncommitted op amps that can be used for a variety of functions, such as filtering, offsetting, adding gain or as a comparator to detect loss of signal.
●The output signal at VLOG OUT is trimmed to 1V per decade of input current. It can be scaled with an output amplifier, either A3 or A4.
●Low dc offset voltage and temperature drift allow accurate measurement of low-level signals over a wide environmental temperature range. The LOG102 is specified over the temperature range, 0°C to +70°C, with operation over 40°C to +85°C.
● EASY-TO-USE COMPLETE LOG RATIO FUNCTION
● OUTPUT AMPLIFIERS FOR SCALING AND SIGNAL LOSS INDICATION
● HIGH ACCURACY: 0.15% FSO Total Error Over 6 Decades
● WIDE INPUT DYNAMIC RANGE:
● 6 Decades, 1nA to 1mA
● LOW QUIESCENT CURRENT: 1.25mA
● SO-14 PACKAGE
● APPLICATIONS
● ONET, OPTICAL POWER METERS
● LOG, LOG RATIO COMPUTATION: Communication, Analytical, Medical, Industrial, Test, General Instrumentation
● PHOTODIODE SIGNAL COMPRESSION AMP
● ANALOG SIGNAL COMPRESSION IN FRONT OF A/D CONVERTER
● ABSORBANCE MEASUREMENT
● OPTICAL DENSITY MEASUREMENT
●NOTE: U.S. Patent Pending.
●All trademarks are the property of their respective owners.