FEATURES
EASY-TO-USE COMPLETE CORE FUNCTION
HIGH ACCURACY: 0.01% FSO Over 5 Decades
WIDE INPUT DYNAMIC RANGE:
Decades, 100pA to 3.5mA
LOW QUIESCENT CURRENT: 1mA
WIDE SUPPLY RANGE: ±4.5V to ±18V

APPLICATIONS
LOG, LOG RATIO COMPUTATION:
Communication, Analytical, Medical, Industrial,
Test, and General Instrumentation
PHOTODIODE SIGNAL COMPRESSION AMPS
ANALOG SIGNAL COMPRESSION IN FRONT
OF ANALOG-TO-DIGITAL (A/D) CONVERTERS

DESCRIPTION
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 VOUT 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.