Patent Number: 7,103,178

Title: Speech amplifier-resident mechanism for controllably supplying power to a line circuit

Abstract: A voltage-coupling and loop current supply mechanism controllably turns on an output transistor within the tip amplifier circuitry portion of the speech amplifier to controllably apply a prescribed voltage to the telephone line during on-hook/standby mode. This controllably applied voltage serves as a source of loop current when the phone goes off-hook. The ring lead portion of the tip/ring wireline pair is connected to a controlled current sink, which is coupled to the output of a voltage regulator referenced to the battery voltage. This controlled current sink is used to sink a prescribed loop current from the tip/ring pair when the phone goes off-hook. When the phone goes off-hook and loop current is detected, the voltage-supply mechanism provided by the tip amplifier's output transistor is terminated, and the speech amplifier is placed in its normal speech amplifier mode.

Inventors: Youngblood; Douglas L. (Palm Bay, FL)

Assignee: Intersil Americas Inc.

International Classification: H04M 19/00 (20060101)

Expiration Date: 9/05/02018