Power control circuit for a line driver

• US 6,353,347 B1
• Filed: 09/15/2000
• Issued: 03/05/2002
• Est. Priority Date: 09/15/2000
• Status: Expired due to Term

• Current Assignee: Synaptics Incorporated
• Original Assignee: Globespan Inc. (Synaptics Incorporated)
• Inventors: deBrigard, Thomas H.
• Primary Examiner(s): TON, MY TRANG
• Application Number:
  US09/663,280
• Time in Patent Office: 536 Days
• Field of Search: 327/143, 327/146, 327/155, 327/198, 327/51, 327/54, 327/142, 326/30, 379/396, 379/398, 370/14, 370/15, 370/17
• US Class Current: 327/142
• CPC Class Codes: H04M 19/001 Current supply source at the exchanger providing current to substations

Abstract

The present invention is generally directed to a method for controlling the application of power to a line driver. The method operates by sensing a request from a customer premises for a transmission exchange across a local loop, applying power to a line driver circuit, in response to the request for transmission, determining when the transmission exchange has terminated, and then terminating the application of power to the line driver circuit.

Claims

1. A method for controlling the application of power to a line driver comprising the steps of:

sensing a request from a customer premises for a transmission exchange across a local loop;

applying power to a line driver circuit, in response to the request for transmission;

determining when the transmission exchange has terminated; and

terminating the application of power to the line driver circuit.

2. The method as defined in claim 1, wherein the step of sensing a request includes sensing a start up poll signal from the customer premises.

3. The method as defined in claim 1, further including the step of matching a line impedance when the application of power to the line driver is terminated.

4. The method as defined in claim 1, wherein the step of determining when the transmission exchange has terminated further includes the step of measuring a time period of inactivity over the local loop.