The TP5700A is a linear bipolar device which includes all the functions required to build the speech circuit of a telephone It replaces the hybrid transformer compensation circuit and sidetone network used in traditional designs When used with an electret microphone (with integral FET buffer) and dynamic receiver superior audio linearity distortion and noise performance are obtained Loop attenuation compensation is also included The low voltage design enables the circuit to work over a wide range of operating conditions including long loops extension telephones and subscriber carrier applications Operating power is derived from the telephone line