Subscriber line interface circuit with intra-operational state selectable supply

摘要

A method of generating a plurality of supply voltages for a plurality of subscriber line channels includes generating a first target VBAT value for a first associated linefeed driver from a first VBAT control. A second target VBAT value for a second associated linefeed driver is generated from a second VBAT control. A selected target VBAT value is generated based upon the first and second target VBAT values. A magnitude of the selected target VBAT value is not less than any maximum of a magnitude of the first and second target VBAT values. A switching regulator is controlled to provide a first generated VBAT corresponding to the selected target VBAT value, wherein the switching regulator provides a second generated VBAT having a pre-determined proportional relationship (p) to the first generated VBAT.