Patent ID: 8570099
Filing Date: 2013-10-29
Classification: H03H

Abstract:
1. A filter for providing single-ended to differential-ended signal conversion, the filter comprising: a first buffer receiving an analog signal; a first resistor; a second resistor; a second buffer, wherein the first buffer, the first resistor, the second resistor, and the second buffer are connected in series; a first capacitor connected between an input of the second buffer and a low voltage source; a third buffer receiving a DC signal; a third resistor; a fourth resistor; a fourth buffer, wherein the third buffer, the third resistor, the fourth resistor, and the fourth buffer are connected in series; a second capacitor connected between an input of the fourth buffer and the low voltage source; and a common mode feedback circuit connected between the first and the second resistors as well as between the third and the fourth resistors, wherein the common mode feedback circuit compares a common mode voltage and a reference voltage and, based on that comparison, modifies voltages on the second and the fourth resistors by application of current, wherein the second buffer outputs a first differential voltage and the fourth buffer outputs a second differential voltage.