Function: Low Voltage Transmission Circuit with Dialer Interface
Features: <br /> Low DC line voltage; operates down to 1.6 V<br /> Line operation current range 10…140 mA<br /> Icc £ 1.35 mA<br /> Voltage gain range:<br /> microphone amplifier 11…52 dB<br /> telephone amplifier 20…31 dB<br /> Voltage regulator with adjustable static resistance<br /> Provides supply for external circuits<br /> Symmetrical high-impedance inputs<br /> (64 kW) for dynamic, magnetic or piezoelectric microphones<br /> Asymmetrical high-impedance inputs (32 kW) for electret microphones<br /> DTMF signal input with confidence tone<br /> ¨ Mute input for pulse or DTMF dialing<br /> Receiving amplifier for dynamic, magnetic or piezoelectric earpieces<br /> Large gain setting range on microphone and earpiece amplifiers<br />