GENERAL DESCRIPTION
The TEA1065 is a bipolar integrated circuit which performs all speech and line interface functions that are required in fully electronic telephone sets with adjustable DC mask. The circuit performs electronic switching between dialling and speech internally.
   
FEATURES
• Current and voltage regulator mode with adjustable
    static resistances
• Provides supply for external circuitry
• Symmetrical high-impedance inputs for piezoelectric
    microphone
• Asymmetrical high-impedance input for electret
    microphone
• DTMF signal input with confidence tone
• Mute input for pulse or DTMF dialling
• Power-down input for pulse dial or register recall
• Digital pulse input to drive an external switch transistor
• Receiving amplifier for magnetic, dynamic or
    piezoelectric earpieces
• Large gain setting range on microphone and earpiece
    amplifiers
• Line loss compensation facility, line current dependent
    (on microphone and earpiece amplifiers)
• Adjustable gain control
• DC line voltage adjustment facility