Analog Devices AD8310
95 dB Logarithmic Amplifier
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 currentAPPLICATIONS
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 FUNCTIONAL BLOCK DIAGRAM SUPPLY +INPUT –INPUT COMMON VPOS 5 8mA BAND GAP REFERENCE AND BIASING AD8310 ENBL 7 ENABLE INHI 8 1.0kΩ 1 INLO 3 SIX 14.3dB 900MHz AMPLIFIER STAGES MIRROR 2μA /dB NINE D