Electrostatic discharge protection device

An electrostatic discharge protection device, comprising:

• a P-type semiconductor substrate;
• and
• a first electrostatic discharge protection unit located in the P-type semiconductor substrate and used to protect a first circuit, wherein the first electrostatic discharge protection unit comprises:
• a first N-type well region;
• a first N-type doped region located in the first N-type well region;
• a first P-type doped region located in the first N-type well region, wherein the first P-type doped region and the first N-type doped region are arranged side-by-side and spaced apart from each other;
• a first P-type well region adjacent to the first N-type well region;
• a second N-type doped region located in the first P-type well region;
• a second N-type well region arranged side-by-side with the first N-type well region;
• a second P-type doped region located in the second N-type well region;
• a second P-type well region adjacent to the second N-type well region;
• a third N-type doped region located in the second P-type well region;
• and
• a third P-type doped region located in the second P-type well region, wherein the third P-type doped region and the third N-type doped region are arranged side-by-side and spaced apart from each other,
• wherein the first P-type doped region and the third N-type doped region of the first electrostatic discharge protection unit are electrically connected to a common bus,
• wherein the first N-type doped region and the second P-type doped region of the first electrostatic discharge protection unit are electrically connected to a power supply terminal of the first circuit, and
• wherein the second N-type doped region and the third P-type doped region of the first electrostatic discharge protection unit are electrically connected to a ground terminal of the first circuit.