LOG100

Features:

·ACCURACY
   0.37% FSO max Total Error
   Over 5 Decades
·LINEARITY
   0.1% max Log Conformity
   Over 5 Decades
·EASY TO USE
   Pin-selectable Gains
   Internal Laser-trimmed Resistors
·WIDE INPUT DYNAMIC RANGE
   6 Decades, 1nA to 1mA
·HERMETIC CERAMIC DIP

Application

· LOG, LOG RATIO AND ANTILOG COMPUTATIONS
· ABSORBANCE MEASUREMENTS
· DATA COMPRESSION
·OPTICAL DENSITY MEASUREMENTS
· DATA LINEARIZATION
· CURRENT AND VOLTAGE INPUTS


Specifications

Supply ................................................................................................ ±18V
Internal Power Dissipation .............................................................. .600mV
Input Current ..................................................................................... 10mA
Input Voltage Range .......................................................................... ±18V
Storage Temperature Range ........................................... ..40  to +85
Lead Temperature (soldering, 10s) ............................................... ..+300
Output Short-circuit Duration .................................. .Continuous to ground
Junction Temperature ........................................................................ 175


Description

·The LOG100 uses advanced integrated circuit technologies to achieve high accuracy, ease of use, low cost, and small size. It is the logical choice for your logarithmic-type computations. The amplifier has guaranteed maximum error specifications over the full sixdecade input range (1nA to 1mA) and for all possible combinations of I₁ and I₂. Total error is guaranteed so that involved error computations are not necessary.

·The circuit uses a specially designed compatible thinfilm monolithic integrated circuit which contains amplifiers, logging transistors, and low drift thin-filmresistors. The resistors are laser-trimmed for maximum
precision. FET input transistors are used for the amplifiers whose low bias currents (1pA typical) permit signal currents as low as 1nA while maintaining guaranteed total errors of 0.37% FSO maximum.

·Because scaling resistors are self-contained, scale factors of 1V, 3V or 5V per decade are obtained simply by pin selections. No other resistors are required for log ratio applications. The LOG100 will meet its guaranteed accuracy with no user trimming.

·Provisions are made for simple adjustments of scale factor, offset voltage, and bias current if enhanced performance is desired.