AD641 is a 250MHz demodulating logarithmic amplifier with 44dB dynamic range, 2.0nV/√Hz input noise voltage, 50µV input offset voltage, low power (9mA for +VS, 35mA for -VS) and dual polarity current outputs.
The AD641 is a demodulating logarithmic amplifier capable of 250 MHz operation with a 44 dB dynamic range in a single configuration. It provides a stable slope of 1 mA per decade and includes an on‑chip 10× attenuator, dual polarity current outputs, and onboard resistors for easy conversion to voltage.
The document lists electrical characteristics, ordering guide, thermal and absolute‑maximum ratings, and circuit description. It covers industrial (‑40 °C to +85 °C) and military (‑55 °C to +125 °C) package options, including plastic DIP, PLCC, and Cerdip, and provides typical DC and AC performance graphs.
| 3 dB Bandwidth | 250 MHz |
|---|---|
| Dynamic Range (single configuration) | 44 dB |
| Maximum Output Current | 2.3 mA |
The industrial version operates from –40 °C to +85 °C.