Patent ID: 8410847
Filing Date: 2013-04-02
Classification: H03F,H03K

Abstract:
1. A voltage level shifter for a direct coupling of a voltage source to an amplifier including a common mode at a common-mode level, comprising: an amplifier including a first input, a second input, and an output, the first input being coupled to the common mode and the output indicating a voltage difference between the first and second inputs; a voltage-controlled current source having a control input coupled to the output of the amplifier and an output for supplying an output current as a function of a voltage at the control input; a first resistor being coupled between the external voltage source and the output of the voltage-controlled current source; and a second resistor being coupled between the output of the voltage-controlled current source and the second input of the amplifier, wherein the output current from the voltage-controlled current source supplies to the second resistor so as to minimize the voltage difference between the first and second inputs of the amplifier.