Patent ID: 6744888
Filing Date: 2004-06-01
Classification: H04M

Abstract:
A telephone line interface circuit coupled between a telephone line source and a host device, said telephone line source providing input signals to said line interface circuit, said input signals comprising actual data signals and noise signals, said line interface circuit switchable between a low power mode, a medium power mode, and a full power mode, said line interface circuit comprising:an event detection circuit for detecting an actual data signal and for providing an event-detect signal to said host device only when an actual data signal is detected, comprising: an event transmitter for receiving said input signal from said telephone line source and generating output pulses in response to said input signal; and an event receiver for receiving said output pulses from said event transmitter, detecting whether said output pulses represent said actual data signal and generating an event-detect signal if said actual data signal has been detected; whereby upon receipt of said event-detect signal by said host device, said line interface circuit is switched to the full power mode.