DESCRIPTION
The GR581 is a level-sensitive, adaptive highpass filter comprised of a current controlled highpass filter, a half- wave rectifier, a voltage regulator for microphone bias and a separate preamplifier.

FEATURES
• unity gain 12 dB/oct. highpass Butterworth filter
• adaptive frequency range from 200 Hz to 2 kHz
• rectifier threshold set to 82 dBSPL (adjustable)
• low noise, typically 2.6 µV
• 300 µA typical current drain
• operates from 1.1 to 3 VDC
• preamplifier with 56 dB open loop gain

PACKAGING
• 10 pin MICROpac
• 10 pin PLID®
• Chip (73 x 59 mils)