Communication ICs Speech network BA6566 / BA6566F / BA6566FP The BA6566, BA6566F, and BA6566FP are speech network ICs which possess the basic functions required for handset communications. In addition to amplifying signals from a transmitter and sending them to a telephone line, they amplify only reception signals from a telephone line and drive the receiver. They also compensate for fluctuation in the volume at which signals are transmitted and received, caused by the length of the telephone line (AGC). Applications Telephones and telephone equipment Features 1) Can accommodate both dynamic and piezoelectric 3) Erroneous operation caused by high-frequency elec- receivers, simply by changing the circuit constant for trical wave interference is minimized. a wide dynamic reception range. 4) An HSOP package is used, eliminating the need for 2) Automatic gain control (AGC) is used, based on the an attached transistor to dissipate heat. This means transmission and reception telephone line current, that a common circuit can be shared when a DIP for easier compliance with communications stan- package is used (BA6566FP). dards. Block diagram 217Communication ICs BA6566 / BA6566F / BA6566FP Absolute maximum ratings (Ta=25 C) 218