M-985-01S Overview
The M-985-01 is an integrated circuit precise tone detector for call progress and special information tones (SIT), as defined by CCITT. The use of integrated circuit techniques allows the M-985-01 to pack the eight filters for call progress detection into a single 22-pin DIP or a 20-pin SOIC. A 3.58 MHz crystal-controlled time base guarantees accuracy and repeatability.