System and method to directly couple to analog to digital converter having lower voltage reference

A device comprising:

• a first terminal to receive a first common-mode reference voltage;
• a second terminal to receive a second common-mode reference voltage;
• a variable gain amplifier comprising an input terminal to receive an input signal, an output terminal to provide a first output signal that is biased based on the first common-mode voltage reference, and a supply voltage terminal to receive a first supply voltage;
• a voltage shifter circuit comprising a first input terminal coupled to the output terminal of the variable gain amplifier, a second input terminal, and an output terminal to provide a third output signal that is biased based on the second common-mode voltage reference;
• a variable gain amplifier half replica module comprising an output terminal coupled to the second input terminal of the voltage shifter circuit, the variable gain amplifier half replica module to control the third output signal of the voltage shifter circuit based on the first common-mode voltage reference and the second common-mode voltage reference;
• and
• an analog to digital converter comprising an input terminal coupled to the output terminal of the voltage shifter, the analog to digital converter to provide a digital output signal based on the third output signal.