LOG101
LOG
101 SBOS242B – MAY 2002 – REVISED JUNE 2004 Precision
LOGARITHMIC AND LOG RATIO AMPLIFIER
FEATURES DESCRIPTION в—Џ EASY-TO-USE COMPLETE CORE FUNCTION The LOG101 is a versatile integrated circuit that computes
the logarithm or log ratio of an input current relative to a
reference current. в—Џ HIGH ACCURACY: 0.01% FSO Over 5 Decades
в—Џ WIDE INPUT DYNAMIC RANGE:
7.5 Decades, 100pA to 3.5mA
в—Џ LOW QUIESCENT CURRENT: 1mA 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. в—Џ WIDE SUPPLY RANGE: В±4.5V to В±18V The output signal at VOUT is trimmed to 1V per decade of input
current allowing seven decades of input current dynamic
range. APPLICATIONS
в—Џ LOG, LOG RATIO COMPUTATION:
Communication, Analytical, Medical, Industrial,
Test, and General Instrumentation
в—Џ PHOTODIODE SIGNAL COMPRESSION AMPS
в—Џ ANALOG SIGNAL COMPRESSION IN FRONT
OF ANALOG-TO-DIGITAL (A/D) CONVERTERS I2 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 –5В°C to +75В°C, with operation over …
