Description
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

Key Features
• Generates its own supply from the telephone line
• Adaptive to all types of telephone line feeding systems (i.e. 48V 2x200Ω, 60V 2x 600Ω, 48V 2x800Ω)
• Operates down to 2.1V (excl. polarity bridge)
• Adjustable DC-characteristic to the line
• Few inexpensive external components to function
• Easy adaptation for various market needs
• Dialler interface with DC-supply, mute, power -down and DTMF-input
• Confidence tone in the receiver at DTMF-dialling
• ”Soft clipping” that prevents distortion at high transmit signal levels
• Balanced microphone input for dynamic, and electret microphones
• Balanced receiver output for dynamic and magnetic receiver elements
• Transmitter and receiver gain regulation for automatic loop loss compensation (disabled in mute mode)
• Four separate DC supplies for different requirements
• High gain of the receiver facilitates volume control function
• Microphone cut-off function possible by a switch
• All gain and frequency setting networks in Rx, Tx and side tone are referred to ground
• Excellent RFI performance