AS2520 Overview
The AS2520/21/20B/21B are CMOS integrated circuits that contain all the audio functions needed to form a high fort, line-powered telephone. The devices incorporate line adaptation, speech circuit, loudhearing and handsfree - all supervised by the novel voice and power control circuit. A switching converter is also provided for converting the ring signal. The interface to a dialler/controller is made very simple to allow easy adaptation to a tele microcontroller. The AS2520 series incorporate volume control for the earpiece and the loudspeaker (AS2520 digital with +/keys and AS2521 analogue with potentiometer). The volume control circuit automatically pensates the loop gain to ensure acoustic stability. Typical Application
AS2520 Key Features
- 72 dBmp) u Real or plex impedance adjustable u NET 4 patible u Dynamically controlled voice switching u Same monitor amp
- all supervised by the novel voice and power control circuit. A switching converter is also provided for converting the r