AD8309 is a 5MHz-500MHz 100dB demodulating logarithmic amplifier with limiter output
The AD8309 is a complete IF limiting amplifier that provides an accurate logarithmic (decibel) measurement of the input signal (RSSI) over a 100 dB dynamic range. It operates from 5 MHz to 500 MHz, requires a single supply of +2.7 V to +6.5 V, and consumes about 16 mA in normal operation. The device features fully differential inputs, programmable limiter gain, and a differential RSSI output that scales at 20 mV/dB.
The datasheet includes detailed specifications, absolute maximum ratings, pin descriptions, ordering information, and theory of operation. It also provides performance graphs for RSSI slope, intercept, limiter response, and supply current versus enable voltage, helping designers integrate the AD8309 into high‑performance receivers and measurement equipment.
| Frequency Range | 5 MHz – 500 MHz |
|---|---|
| Dynamic Range | 100 dB |
| Supply Voltage | +2.7 V to +6.5 V |
| RSSI Slope | 20 mV/dB |
| Differential Output Current | 10 mA |
The AD8309 operates from a single supply of +2.7 V to +6.5 V.
The device provides a 100 dB dynamic range.
The RSSI output scales at 20 mV per dB.
The AD8309 is specified for operation up to 500 MHz.