PBL38814

The PBL 388 14 contains all the necessary circuitry, amplifiers, detectors, comparator and control functions to implement a high performance voice switched handsfree two- way communication system. The gain dynamics of PBL38814 (attenuation between channels) is selectable (25dB or 50dB) via a separate pin. A background noise detector of PBL38814 in the transmitting channel reduces the influence of continuous external noise  signals to the switching .

The PBL 388 14 is designed for mains powered handsfree telephones, vehicular mobile telephone handsfree systems and handsfree intercom systems. Automatic volume attenuation in the power amplifier extends the operating range at low supply currents. The PBL38814 has two special features, the power amplifiers volume control can be implemented either as an ac. potentiometer control or as a digital control by a m- processor (dc. control) and that the feedback loop of the power amplifier PBL38814 is accessible thus making it possible to add a simple external power stage driving low impedance loudspeakers up to several watts.

Filtering is possible of both, the audio and the speech switching control signals of PBL38814 , in both transmitter and receiver channels.