GENERAL DESCRIPTION
The ICs UBA2050, UBA2050A, UBA2051, UBA2051A and UBA2051C contain all the functions needed to build a fully electronic telephone set.

FEATURES
Speech/transmission part
• Low DC line voltage; operates down to 1.45 V (excluding voltage drop over external polarity guard)
• Line voltage regulator with adjustable DC voltage
• Regulated 3.3 V supply (VDD) for the dialler part and peripherals compatible with:
    – Speech mode
    – Ringer mode
    – Trickle mode.
• Unregulated supply (VCC) for the transmission part and peripherals
• Transmit stage with:
    – Microphone amplifier with symmetrical high-impedance inputs
    – DTMF input with confidence tone on receive output.
• Receive stage with:
    – Receive amplifier with asymmetrical output
    – Earpiece amplifier with adjustable gain (and gain boost facility) for all types of earpieces.
• AGC: line loss compensation for microphone and receive amplifiers.
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