Power control circuit for a line driver

Abstract

The present invention is generally directed to a power control circuit for a line driver circuit in a central office. In a broad sense, the present invention operates to power-down line driver circuitry when it is not in use, and apply power to the line driver circuitry when transmissions are requested by a customer (e.g., customer premises). This reduces the power consumption of the line driver by eliminating the quiescent current draw when the line driver is idle. Recognizing that the typical line driver is in an idle state the vast majority of the time, compounded by the vast number of line drivers that exist within a central office environment, it will be appreciated that the overall power savings may be tremendous. In accordance with one aspect of the invention a circuit is provided for controllably applying power to a line driver. The circuit includes an isolation circuit disposed to receive a power control signal, the isolation circuit configured to generate a pair of output signals that are electrically isolated from the power control signal, each of the output signals having a state that is determined by the power control signal. The circuit also includes a power application circuit having a first and second input and a first and second output, wherein the first input is coupled to a first output of the isolation circuit and the second input is coupled to a second output of the isolation circuit, and wherein the first output is disposed to be coupled to a positive power input of the line driver and the second is disposed to be coupled to a negative power input of the line driver. A related method is also provided.