Protection circuit

A semiconductor device, comprising:

• a first well, a second well and a third well arranged in order;
• a first region disposed in the first well and coupled to a first reference voltage terminal;
• a second region disposed in the first well and coupled to the first reference voltage terminal;
• a third region disposed in the third well and coupled to the first reference voltage terminal;
• a fourth region disposed in the third well;
• a fifth region disposed in the first well and coupled to the fourth region;
• and
• an insulator disposed between the fourth region and the fifth region,
• wherein each of the first well, the third well, the second region, and the third region corresponds to a first conductive type, and
• each of the second well, the first region, the fourth region, and the fifth region corresponds to a second conductive type different from the first conductive type.

A method, comprising:

• discharging charges from a first reference voltage terminal to a second reference voltage terminal through a first well, a first region disposed in the first well and a second region disposed in the first well;
• and
• discharging charges from the first reference voltage terminal to the second reference voltage terminal through the first well, a third region disposed in the first well and separated from the second region, a fourth region disposed in a second well and the second well in order,
• wherein each of the first well, the first region and the second well corresponds to a first conductive type,
• each of the second region, the third region and the fourth region corresponds to a second conductive type different from the first conductive type,
• the third region is separated from the second region, and
• the first well is separated from the second well.