Low Cost, DC to 500MHz, 92dB Logarithmic Amplifier
The AD8307 is the first logarithmic amplifier made available in an 8-lead (SOIC_N) package. It is a complete 500MHz monolithic demodulating logarithmic amplifier based on the progressive compression (successive detection) technique, providing a dynamic range of 92dB to +/-3dB law-conformance and 88dB to a tight +/-1dB error bound at all frequencies up to 100MHz. It is extremely stable and easy to use, requiring no significant external components. A single-supply voltage of 2.7V to 5.5V at 7.5mA is needed, corresponding to an unprecedented power consumption of only 22.5mW at 3V. A fast acting CMOScompatible control pin can disable the AD8307 to a standby current of less than 150uA.
Features
* Complete multistage logarithmic amplifier
* 92dB dynamic range: 75dBm to +17dBm to 90 dBm using matching network
* Single supply of 2.7V minimum at 7.5mA typical
* DC to 500 MHz operation, +/-1dB linearity
* Slope of 25mV/dB, intercept of -84dBm
* Highly stable scaling over temperature
* Fully differential dc-coupled signal path
* 100ns power-up time, 150uA 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 (to 120dB)
* Signal level determination down to 20Hz
* True decibel ac mode for multimeters
