The AD640 is a complete monolithic logarithmic amplifier. It has five stages, each with 10 dB gain and 350 MHz bandwidth. It features a direct-coupled fully differential signal path. The logarithmic slope, intercept, and AC response are stable over the full military temperature range. It has dual polarity current outputs scaled at 1 mA/decade. It operates at low power (typically 220 mW at -5 V). Low-cost plastic packages are also available.
The AD640 provides a complete monolithic logarithmic amplification solution with five cascaded dc‑coupled stages, each delivering 10 dB gain and a 350 MHz -3 dB bandwidth. It features a fully differential signal path, low power consumption (≈220 mW at 5 V) and selectable voltage‑slope options for versatile applications such as radar, sonar, audio and precision instrumentation.
Specifications include a supply voltage range of +4.5 V to +7.5 V, small‑signal gain of 50 dB, peak differential output of ±180 mV, and a maximum output current of 2.3 mA. The device is offered in multiple package options (ceramic DIP, LCC, plastic DIP, PLCC) and temperature grades ranging from -55 °C to +125 °C.
| Supply Voltage Range | +4.5 V to +7.5 V |
|---|---|
| Input Resistance (Differential) | 500 Ω |
The AD640 operates from +4.5 V to +7.5 V.
The differential input resistance is 500 Ω.