| 摘要 |
A digital device for controlling the DC line current on a telephone line which includes a digital device that utilizes a digital filter for setting the DC line current. By controlling the DC line current digitally, software can be used to set the DC line current in accordance with predefined characteristics. Predefined characteristics can be set to accommodate varying country specifications instead of using switches to control resistors and capacitors. In addition, changes in a country's requirements can be accomplished through software, instead of changing components or redesigning a circuit board. The device also incorporates a method for maintaining DC current level during changes in digital filter characteristics. The use of software results in increased flexibility by allowing an infinite number of settings via software or software updates, and allowing changes to be made quickly and easily throughout the world.
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