PRODUCT DESCRIPTION
The AD8313 is a complete multistage demodulating logarithmic amplifier, capable of accurately converting an RF signal at its differential input to an equivalent decibel-scaled value at its dc output. The AD8313 maintains a high degree of log conformance for signal frequencies from 0.1 GHz to 2.5 GHz and is useful over the range of 10 MHz to 3.5 GHz. The nominal input dynamic range is –65 dBm to 0 dBm (re: 50 Ω), and the sensitivity can be increased by 6 dB or more with a narrow band input impedance matching network or balun. Application is straightforward, requiring only a single supply of 2.7 V–5.5 V and the addition of a suitable input and supply decoupling. Operating on a 3 V supply, its 13.7 mA consumption (for TA = +25°C) amounts to only 41 mW. A power-down feature is provided; the input is taken high to initiate a low current (20 µA) sleep mode, with a threshold at half the supply voltage.

FEATURES
   Wide Bandwidth: 0.1 GHz to 2.5 GHz Min
   High Dynamic Range: 70 dB to ±3.0 dB
   High Accuracy: ±1.0 dB over 65 dB Range (@ 1.9 GHz)
   Fast Response: 40 ns Full-Scale Typical
   Controller Mode with Error Output
   Scaling Stable Over Supply and Temperature
   Wide Supply Range: +2.7 V to +5.5 V
   Low Power: 40 mW at 3 V
   Power-Down Feature: 60 μW at 3 V
   Complete and Easy to Use
  
APPLICATIONS
   RF Transmitter Power Amplifier Setpoint
      Control and Level Monitoring
   Logarithmic Amplifier for RSSI Measurement
      Cellular Base Stations, Radio Link, Radar