GENERAL DESCRIPTION
The AD8310 is a complete, dc to 440 MHz demodulating logarithmic amplifier (log amp) with a very fast voltage mode output, capable of driving up to 25 mA into a grounded load in under 15 ns. It uses the progressive compression (successive detection) technique to provide a dynamic range of up to 95 dB to ±3 dB law conformance or 90 dB to a ±1 dB error bound up to 100 MHz. It is extremely stable and easy to use, requiring no significant external components. A single-supply voltage of 2.7 V to 5.5 V at 8 mA is needed, corresponding to a power consumption of only 24 mW at 3 V. A fast-acting CMOS compatible enable pin is provided.

FEATURES
   Multistage demodulating logarithmic amplifier
   Voltage output, rise time <15 ns
   High current capacity: 25 mA into grounded RL
   95 dB dynamic range: −91 dBV to +4 dBV
   Single supply of 2.7 V min at 8 mA typ
   DC to 440 MHz operation, ±0.4 dB linearity
   Slope of +24 mV/dB, intercept of −108 dBV
   Highly stable scaling over temperature
   Fully differential dc-coupled signal path
   100 ns power-up time, 1 mA sleep current

APPLICATIONS
   Conversion of signal level to decibel form
   Transmitter antenna power measurement
   Receiver signal strength indication (RSSI)
   Low cost radar and sonar signal processing
   Network and spectrum analyzers
   Signal-level determination down to 20 Hz
   True-decibel ac mode for multimeters