Driving voltage generation device and method for controlling driving voltage generation device

A driving voltage generation device, comprising:

• a first selector section for receiving a plurality of first supply voltages and selecting one of the first supply voltages;
• a supply current generation section for generating a supply current having a current value according to an amplitude signal indicating a predetermined potential difference;
• first to fourth switches connected in series between the first selector section and the supply current generation section;
• a first line connecting the first selector section and the first switch with each other;
• a second line connecting the supply current generation section and the fourth switch with each other;
• a second resistor connected between a first node along the first line and a second node along the second line;
• a clamp circuit connected to the first line for restricting a potential at the first line within a predetermined range;
• a first specified voltage supply section for outputting a first specified voltage to a first interconnection node between the first switch and the second switch;
• and
• a second specified voltage supply section for outputting a second specified voltage to a second interconnection node between the third switch and the fourth switch, wherein:
• the first switch is connected between the first selector section and the second switch;
• the second switch is connected between the first switch and the third switch;
• the third switch is connected between the second switch and the fourth switch;
• the fourth switch is connected between the third switch and the supply current generation section;
• the first specified voltage supply section does not output the first specified voltage when the first switch is on;
• the second specified voltage supply section does not output the second specified voltage when the fourth switch is on;
• an impedance of an output of the first specified voltage supply section is lower than that of an output of the supply current generation section;
• and
• an impedance of an output of the second specified voltage supply section is lower than that of an output of the first selector section.

A method for controlling a driving voltage generation device, the driving voltage generation device comprising:

• a first selector section for receiving a plurality of first supply voltages and outputting one of the first supply voltages;
• a second selector section for receiving a plurality of second supply voltages and outputting one of the second supply voltages;
• first to fourth switches connected in series between the first selector section and the second selector section;
• a fifth switch connected between a first interconnection node and a first input node receiving a first specified voltage, the first interconnection node being present between the first switch and the second switch;
• and
• a sixth switch connected between a second interconnection node and a second input node receiving a second specified voltage, the second interconnection node being present between the third switch and the fourth switch, wherein:
• an impedance of the first specified voltage supplied via the fifth switch is lower than that of an output of the second selector section;
• and
• an impedance of the second specified voltage supplied via the sixth switch is lower than an output of the first selector section, the control method comprising:
• a step (A) of turning off the first, second and sixth switches and turning on the third, fourth and fifth switches;
• a step (B) of turning on the first, second and sixth switches and turning off the third, fourth and fifth switches;
• a step (C) of turning off the third switch and turning on the second switch, and then turning on the first and sixth switches and turning off the fourth and fifth switches, the step (C) being performed when an operation is switched from the step (A) to the step (B);
• and
• a step (D) of turning off the second switch and turning on the third switch, and then turning on the fourth and fifth switches and turning off the first and sixth switches, the step (D) being performed when an operation is switched from the step (B) to the step (A).