Low second harmonic single ended class AB amplifier

A circuit, comprising:

• a high side output transistor having a control terminal coupled to a first capacitor;
• a low side output transistor having a control terminal coupled to a second capacitor and to a balancing capacitor;
• a first differential input stage configured to receive a differential input and provide a first output current to the control terminal of the high side output transistor;
• a second differential input stage configured to receive the differential input and provide a second output current to the control terminal of the low side output transistor;
• a floating battery coupled to the control terminal of the high side output transistor and the control terminal of the low side output transistor;
• and
• wherein the balancing capacitor is configured to balance a gate-to-source capacitance of the low side output transistor with a gate-to-source capacitance of the high side output transistor.

A system, comprising:

• a transducer;
• a transconductance amplifier having an input coupled to an output of the transducer;
• an operational amplifier having an input coupled to an output of the transconductance amplifier, the operational amplifier including:
• a first differential input stage;
• a second differential input stage having a balancing capacitor;
• a floating battery coupled to the first differential input stage and the second differential input stage;
• an output stage including:
• a high side output transistor having a control terminal coupled to the first differential input stage and the floating battery;
• a low side output transistor having a control terminal coupled to the second differential input stage and the floating battery;
• a first compensation capacitor coupled to the floating battery;
• and
• a second compensation capacitor coupled to the floating battery.