GENERAL DESCRIPTION

The AD8307 is the first logarithmic amplifier made available in an 8-lead SOIC_N package. It is a complete 500 MHz monolithic demodulating logarithmic amplifier based on the progressive compression (successive detection) technique, providing a dynamic range of 92 dB to ±3 dB law conformance and 88 dB to a tight ±1 dB error bound at all frequencies up to 100 MHz. The AD8307 is extremely stable and easy to use, requiring no significant external components. A single-supply voltage of 2.7 V to 5.5 V at 7.5 mA is needed. A fast acting CMOS-compatible control pin can disable the AD8307 to a standby current of 150 μA.

The AD8307 operates over the industrial temperature range of −40°C to +85°C and is available in an 8-lead SOIC package and an 8-lead PDIP.

FEATURES

Complete multistage logarithmic amplifier

92 dB dynamic range: −75 dBm to +17 dBm to −90 dBm

using matching network

Single supply of 2.7 V minimum at 7.5 mA typical

DC to 500 MHz operation, ±1 dB linearity

Slope of 25 mV/dB, intercept of −84 dBm

Highly stable scaling over temperature

Fully differential dc-coupled signal path

100 ns power-up time, 150 μA 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 120 dB)

Signal level determination down to 20 Hz

True decibel ac mode for multimeters