Datasheet Summary
September 1997
PBL 385 70 Universal Speech Circuit
Description.
PBL 38570 is a monolithic integrated speech transmission circuit for use in electronic telephones. It is designed to acodate either a low impedance dynamic or an electret microphone. A separate input for DTMF dialling tones that is controlled by a mute signal, and a signal summing point at the transmitter input, are available. An internally preset line length pensation 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 pensation can be shut off in either high or low gain mode. Application...