The AD640 is a monolithic laser-trimmed multi-stage logarithmic amplifier ("log amp")–a complete, calibrated measurement system comprising five 10-dB stages with paralleled current outputs that produce a device output precisely proportional to the logarithm of the input voltage. Deviating only ±0.6 dB from the ideal function, the AD640 is designed from the outset to exhibit high stability with temperature through the use of accurate nonlinear-circuit design principles. Read full article