Patent ID: 7068019
Filing Date: 2006-06-27
Classification: G05F,H03F

Abstract:
1. A switchable linear regulator for providing a selectable output voltage, the switchable linear regulator comprising: a constant voltage source; a differential amplifier having a first input terminal coupled to the constant voltage source and a second input terminal connected to a first node; a transistor with a first terminal controlled by the differential amplifier and a second terminal coupled to a supply voltage and a third terminal connected to a second node; a first resistor connected between the first and second nodes; a plurality of second resistors, each comprising one end connected to the first node; and a plurality of switches, each coupled between the other end of the corresponding second resistor and a fixed voltage and controlled by a corresponding control signal; wherein the voltage at the second node is output as the output voltage which is selectable according to the control signals.