The PBL 3852 is an universal transmission circuit in bipolar technology that performs all the speech and line interface functions required to implement an electronic telephone set suitable for the majority of existing telephone network requirements.
Easy adaptation of the DC-mask to different line feed systems. A summing point for auxiliary signals to be transmitted like DTMF and hands-free audio signal. The PBL 3852 has a low current consumption that enables the circuit to work with reduced performance down to 2.1 volts (4.8 mA) across the circuit. The low current consumption for a speech circuit is essential in telephone line powered handsfree designs required to work at long line lengths. The PBL 3852 is especially suitable to be used with Ericsson handsfree circuits like PBL 3786, PBL 3786/2, PBL 3881 and PBL 3880 thanks to a specific interfacing arrangement.
The transmitting and receiving gains can be regulated in order to compensate for the attenuation of the signals due to increasing attenuation with increasing line length. It is also possible to limit high transmitting signal levels (soft clipping) thus preventing excessive distortion caused by signal clipping. The gain regulation is set with discrete external components.
The circuit is easily adapted to different markets by setting the application dependent parameters individually in certain order, this preventing the interaction between the same. PBL 3852 has up to four different power supplies to feed microphones, auxiliary circuits and functions.
All pin numbers in this paper refer to DIP package.
Required Field 
