PRODUCT DESCRIPTION
The AD641 is a 250 MHz, demodulating logarithmic amplifier with an accuracy of ±2.0 dB and 44 dB dynamic range. The AD641 uses a successive detection architecture to provide an output current that is logarithmically proportional to its input voltage.

FEATURES
    Logarithmic Amplifier Performance
        Usable to 250 MHz
        44 dB Dynamic Range
        ±2.0 dB Log Conformance
        37.5 mV/√dB Voltage Output
        Stable Slope and Intercepts
    2.0 nV/√Hz Input Noise Voltage
    50 μV Input Offset Voltage
    Low Power
        ±5 V Supply Operation
        9 mA (+VS), 35 mA (–VS) Quiescent Current
    Onboard Resistors
    Onboard 103x Attenuator
    Dual Polarity Current Outputs
    Direct Coupled Differential Signal Path

APPLICATIONS
    IF/RF Signal Processing
    Received Signal Strength Indicator (RSSI)
    High Speed Signal Compression
    High Speed Spectrum Analyzer
    ECM/Radar