Tracker circuit, communication device, and voltage supply method

A tracker circuit comprising:

• a first switched-capacitor circuit including:
• a first input terminal configured to receive a first input voltage, and
• a first output terminal and a second output terminal that are configured to output a first output voltage and a second output voltage, respectively, that are generated from the first input voltage, the second output voltage being lower than the first output voltage;
• a second switched-capacitor circuit including:
• a second input terminal and a third input terminal respectively connected to the first output terminal and the second output terminal, and
• a third output terminal configured to output a third output voltage generated from the first output voltage and the second output voltage, the third output voltage being lower than the first output voltage and higher than the second output voltage;
• and
• a supply modulator including:
• a fourth input terminal, a fifth input terminal, and a sixth input terminal connected to the first output terminal, the second output terminal, and the third output terminal, respectively, and
• a fourth output terminal connected to a power amplifier.

A voltage supply method comprising:

• generating, by a first switched-capacitor circuit, a first output voltage and a second output voltage from an input voltage;
• generating, by a second switched-capacitor circuit, a third output voltage from the first output voltage and the second output voltage, the third output voltage being lower than the first output voltage and higher than the second output voltage;
• and
• selectively supplying, to a power amplifier, at least one discrete voltage of a plurality of discrete voltages that includes the first output voltage, the second output voltage, and the third output voltage.