The AD8313 is a complete multistage demodulating logarithmic amplifier that can accurately convert an RF signal at its 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. Application is straightforward， requiring only a single supply of 2.7 V to 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） is 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. The AD8313 is fabricated on Analog Devices， Inc.， advanced 25 GHz silicon bipolar IC process and is available in an 8-lead MSOP package. The operating temperature range is ?40°C to +85°C.