DESCRIPTION
The UTC TEA1110Ais a versatile telephone transmission circuit providing full speech and line interface functions in electronic telephone sets. This device works at a line voltage which can be as low as 1.6V DC (with reduced  performance) to enable parallel connection of telephone sets. It also realizes electronic switching between speeches and dialling.

FEATURES
* Low DC line voltage; operates downto 1.6V (excluding voltage drop over external polarity guard)
* Voltage regulator with adjustable DC voltage
* Provides a supply for external circuits
* Symmetrical high impedance inputs (64kΩ) for dynamic, magnetic or piezo-electric microphones
* Asymmetrical high impedance input (32kΩ) for electric microphones
* DTMF input with confidence tone
* MUTE input for pulse or DTMF dialling
* Receiving amplifier for dynamic, magnetic or piezo-electric earpieces
* AGC line loss compensation for microphone and earpiece amplifiers.