Current sense amplifier with enhanced common mode input range

A method, comprising:

• receiving, through a first signal path, a signal for measuring a current through a device, wherein the signal comprises a small signal with a large common mode;
• shifting, through a second signal path, a level of the signal without changing other characteristics of the signal such that the common mode of the signal is reduced;
• and
• sensing the current through the device,
• wherein the steps of receiving the signal and shifting the level of the signal are performed in a first analog-to-digital conversion (ADC) path comprising an analog-to-digital converter.

A mobile device, comprising:

• a transducer;
• and
• a controller integrated circuit (IC) coupled to the transducer, wherein the controller IC is configured to measure a current through the transducer, the controller IC comprising:
• a first analog-to-digital conversion (ADC) path comprising:
• an amplifier coupled to the transducer;
• a first input terminal;
• a first signal path coupled to the amplifier and the first input terminal, wherein the first signal path is configured to measure the current through the transducer by generating a voltage proportional to the measured current, wherein the generated voltage comprises a small signal voltage with a large common mode voltage;
• a second signal path coupled to the amplifier and the first input terminal, wherein the second signal path is configured to reduce the common mode of the generated voltage by level shifting the generated voltage to reduce the common mode voltage;
• and
• an analog-to-digital converter coupled to an output of the amplifier.