GENERAL DESCRIPTION
The TEA1066T is a bipolar integrated circuit that performs all speech and line interface functions required in fully electronic telephone sets. The circuit performs electronic switching between dialling and speech.

FEATURES
• Voltage regulator with adjustable static resistance
• Provides supply for external circuitry
• Symmetrical low-impedance inputs for dynamic and magnetic microphones
• Symmetrical high-impedance inputs for piezoelectric microphone
• Asymmetrical high-impedance input for electret microphone
• Dual-tone multi-frequency (DTMF) signal input with confidence tone
• Mute input for pulse or DTMF dialling
• Power down input for pulse dial or register recall
• Receiving amplifier for magnetic, dynamic or piezoelectric earpieces
• Large gain setting range on microphone and earpiece amplifiers
• Line loss compensation facility, line current dependent (microphone and earpiece amplifiers)
• Gain control adaptable to exchange supply
• DC line voltage adjustment facility.