High voltage amplifier

A high voltage amplifier comprising:

• an input circuit configured to amplify an input signal;
• a positive-electrode-side level shift circuit configured to shift an input amplified signal from the input circuit to a positive side;
• a negative-electrode-side level shift circuit configured to shift the input amplified signal to a negative side;
• a high-voltage output circuit including a positive-electrode-side output circuit configured to amplify a positive-electrode-side level shift signal from the positive-electrode-side level shift circuit and a negative-electrode-side output circuit configured to amplify a negative-electrode-side level shift signal from the negative-electrode-side level shift circuit;
• and
• a feedback circuit configured to feed back a high-voltage output signal from the high-voltage output circuit to the input signal, wherein
• the high voltage amplifier comprises
• a positive-electrode-side current detection circuit configured to detect a current that flows to the positive-electrode-side output circuit,
• a negative-electrode-side current detection circuit configured to detect a current that flows to the negative-electrode-side output circuit,
• a positive-electrode-side offset adjustment circuit configured to perform adjustment to increase an offset amount of the positive-electrode-side level shift circuit to a positive side when a negative-electrode-side detected current of the negative-electrode-side current detection circuit increases, and
• a negative-electrode-side offset adjustment circuit configured to perform adjustment to increase an offset amount of the negative-electrode-side level shift circuit to a negative side when a positive-electrode-side detected current of the positive-electrode-side current detection circuit increases,
• an output terminal to which a load is connected is provided between the positive-electrode-side output circuit and the negative-electrode-side output circuit,
• the positive-electrode-side current detection circuit is disposed upstream or downstream of the positive-electrode-side output circuit,
• the negative-electrode-side current detection circuit is disposed upstream or downstream of the negative-electrode-side output circuit, and
• the positive-electrode-side current detection circuit and the negative-electrode-side current detection circuit are electrically insulated from the positive-electrode-side offset adjustment circuit and the negative-electrode-side offset adjustment circuit.