A communication system is provided which draws virtually no loop current during
a ringing burst and only draws on-hook loop current during the caller ID field.
More particularly, ringer burst circuitry may be powered from the user powered
circuitry by the transmission of power across the isolation barrier rather than
being powered from the phone line. Thus, loop current need not be drawn from the
TIP/RING lines during ringer bursts. The isolation barrier may be a capacitive
isolation barrier which allows bidirectional communication and extraction of power
from signals transmitted across the barrier.