PRODUCT DESCRIPTION

The AD640 is a complete monolithic logarithmic amplifier. A single AD640 provides up to 50 dB of dynamic range for frequencies from dc to 120 MHz. Two AD640s in cascade can provide up to 95 dB of dynamic range at reduced bandwidth. The AD640 uses a successive detection scheme to provide an output current proportional to the logarithm of the input voltage. It is laser calibrated to close tolerances and maintains high accuracy over the full military temperature range using supply voltages from ±4.5 V to ±7.5 V.

FEATURES

Complete, Fully Calibrated Monolithic System

Five Stages, Each Having 10 dB Gain, 350 MHz BW

Direct Coupled Fully Differential Signal Path

Logarithmic Slope, Intercept and AC Response are

Stable Over Full Military Temperature Range

Dual Polarity Current Outputs Scaled 1 mA/Decade

Voltage Slope Options (1 V/Decade, 100 mV/dB, etc.)

Low Power Operation (Typically 220 mW at ±5 V)

Low Cost Plastic Packages Also Available

APPLICATIONS

Radar, Sonar, Ultrasonic and Audio Systems

Precision Instrumentation from DC to 120 MHz

Power Measurement with Absolute Calibration

Wide Range High Accuracy Signal Compression

Alternative to Discrete and Hybrid IF Strips

Replaces Several Discrete Log Amp ICs