Digital current sensing circuit and related apparatus

An apparatus comprising:

• a first voltage circuit coupled to at least one amplifier circuit and comprising:
• a first tracker circuit configured to generate a first modulated voltage at a first output node based on a first supply voltage;
• a first charge pump circuit configured to generate a first current at the first output node;
• and
• a first digital current sensing circuit comprising:
• a voltage input configured to receive a voltage corresponding to a battery current in the first charge pump circuit;
• an analog current sensing circuit configured to generate an analog sense current proportional to the battery current based on the voltage;
• and
• a sense current processing circuit configured to:
• estimate the battery current in the first charge pump circuit based on the analog sense current;
• generate a binary word representing the estimated battery current in the first charge pump circuit;
• and
• generate a battery current indication signal indicative of an estimation of the battery current in the first charge pump circuit based on the binary word;
• a second voltage circuit coupled to the at least one amplifier circuit and comprising:
• a second tracker circuit configured to generate a second modulated voltage at a second output node based on a second supply voltage;
• and
• a second charge pump circuit configured to generate a second current at the second output node;
• and
• a third charge pump circuit configured to provide the first supply voltage and the second supply voltage to the first tracker circuit and the second tracker circuit, respectively.