PBL38541

PBL 385 41 November 1998 PBL 385 41 Universal Speech Circuit Description. PBL 38541 is a monolithic integrated speech transmission circuit for use in electronic telephones or in any other line interface application. High settable supply current for auxiliary functions, up to 6.0 mA (at high line currents). The circuit is designed to accomodate either a low impedance dynamic or an electret microphone. Microphone can be muted separately. Payphone signaling and DTMF dialling tones have a separate input that is controlled by a mute signal. A signal summing point is available at the transmitter input. An internally preset line length compensation can be adjusted with external resistors to fit into different current feed systems as for ex. 48 V, 2 x 200 ohms, 48 V, 2 x 400 ohms and 48 V, 2 x 800 ohms. The line length compensation can be shut off in either high or low gain mode. Application dependent parameters such as line balance, side tone level, transmitter and receiver gains and frequency responces are set independently by external components which means an easy adaption to various market needs. The setting of the parameters if carried out in certain order will counteract the interaction between the settings. The circuit provides four different DC - supplies to feed microphones,diallers and other more current consuming functions like handsfree systems. Pin numbers in this datasheet refer to 18-pin DIP package unless otherwhise noted. Key features. Minimum number of externa...