Patent ID: 6408059
Filing Date: 2002-06-18
Classification: H04M

Abstract:
A system comprising:a modem microprocessor responsive to predetermined signals to access a country code table, extracting information relating to the predetermined signals and using said information to generate configuration signals representative of a country telecommunication standard; a ring detect circuit operatively coupled to said microprocessor, said ring detect circuit including a first digital-to-analog converter, responsive to the configuration signal, operatively coupled to the microprocessor; a second digital-to-analog converter, responsive to the configuration signal, operatively coupled to the microprocessor; a first rectifying circuit; a capacitor operatively coupling the rectifying circuit to a first terminal; a conductor operatively coupling the rectifying circuit to a second terminal; a variable resistor operatively coupled to the rectifying circuit and the first digital-to-analog converter; a variable voltage source operatively coupled to the rectifying circuit and the second digital-to-analog converter; an operational amplifier connected to the rectifying circuit, the variable resistor and the variable voltage source; and a feedback loop interconnecting the operational amplifier to the modem microprocessor.