A subscriber line interface circuit contains a high voltage analog
section, and a low voltage and digital signal processing section, that
monitors and controls the high voltage analog section. The high voltage
analog section includes a dual mode tip/ring amplifier unit coupled to a
subscriber loop pair, and an input signal receiving unit, that conditions
input voice and low voltage signaling and ringing signals from the mixed
signal section. Attributes of and/or enhancements to the high voltage
section are used to improve the operational performance of the subscriber
line interface circuit, in particular, low noise, low power,
wide-bandwidth and wide dynamic range characteristics.