AN1082

Application

As worldwide demand for inexpensive Voice over Internet Protocol telephony grows, so will the need for Integrated Circuits that are specialized to enable compatibility between new telephony systems and older telephones based on analog standards. Analog ring signal generation and off hook loop current supply are two analog functions that are performed by Subscriber Line Interface Circuits (SLICs). This application note discusses the special power supply implementation to generate the high negative voltages needed by SLICs.