FEATURES
EASY-TO-USE COMPLETE FUNCTION
OUTPUT SCALING AMPLIFIER
ON-CHIP 2.5V VOLTAGE REFERENCE
HIGH ACCURACY: 0.2% FSO Over 5 Decades
WIDE INPUT DYNAMIC RANGE:
7.5 Decades, 100pA to 3.5mA
LOW QUIESCENT CURRENT: 1.75mA
WIDE SUPPLY RANGE: ±4.5V to ±18V
PACKAGES: SO-14 (narrow) and SO-16

APPLICATIONS
LOG, LOG RATIO:
Communication, Analytical, Medical, Industrial,
Test, General Instrumentation
PHOTODIODE SIGNAL COMPRESSION AMP
ANALOG SIGNAL COMPRESSION IN FRONT
OF ANALOG-TO-DIGITAL (A/D) CONVERTER
ABSORBANCE MEASUREMENT
OPTICAL DENSITY MEASUREMENT

DESCRIPTION
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 –5°C to +75°C.