Log Amp Delivers Wide Dynamic Range

With both logarithmic and limiter outputs, the AD8309 logarithmic amplifier provides accurate phase detection in phase-shift keying and frequency-shift keying applications including CDMA and GSM. The 500-MHz, 100-dB device detects the RF envelope of the signal so that engineers need not design demodulating circuitry around it. The limiter outputs provide a hard-limited signal as a differential current from open-collector outputs. The output buffer provides an adjustable output that's stable over temperature.The amplifier's 500-MHz bandwidth, high accuracy and temperature stability make it suitable for high-speed signal strength measurement in RF/IF applications such as cell phones and radar.