Device and operation method for electrostatic discharge protection

An operation method of an electrostatic discharge (ESD) protection device, comprising:

• providing a first ESD current rail;
• providing a first ESD protection element string, a first end and a second end of the first ESD protection element string being electrically connected to the first ESD current rail and a signal pad, respectively, wherein the first ESD protection element string comprises a first ESD protection element and a second ESD protection element serially connected to each other, and the first ESD protection element is electrically connected to the signal pad;
• and
• providing, by a first bias circuit, a first bias voltage to a first common connection node between the first ESD protection element and the second ESD protection element, wherein the first bias circuit provides the first bias voltage to increase a voltage drop of the first ESD protection element in the first ESD protection element string in order to reduce a parasitic capacitance of the first ESD protection element string,
• wherein the first bias voltage is in the range between an original division voltage and a voltage of the first ESD current rail in normal operation, and the original division voltage is a voltage of the first common connection node when the first bias voltage is zero.

An electrostatic discharge (ESD) protection device comprising:

• a first ESD current rail;
• a first ESD protection element string, a first end and a second end of the first ESD protection element string being electrically connected to the first ESD current rail and a signal pad, respectively, wherein the first ESD protection element string comprises a first silicon controlled rectifier and a second silicon controlled rectifier serially connected to each other, and the first silicon controlled rectifier is electrically connected to the signal pad;
• and
• a first bias circuit electrically connected to a gate of only one of the first silicon controlled rectifier and further connected to the second silicon controlled rectifier to provide a first bias voltage, wherein the first bias circuit provides the first bias voltage to increase a voltage drop of the first silicon controlled rectifier in the first ESD protection element string in order to reduce a parasitic capacitance of the first ESD protection element string.

An operation method of an electrostatic discharge (ESD) protection device, comprising:

• providing a first ESD current rail;
• providing a first ESD protection element string, a first end and a second end of the first ESD protection element string being electrically connected to the first ESD current rail and a signal pad, respectively, wherein the first ESD protection element string comprises a first silicon controlled rectifier and a second silicon controlled rectifier serially connected to each other, and the first silicon controlled rectifier is electrically connected to the signal pad;
• and
• providing, by a first bias circuit, a first bias voltage to a gate of only one of the first silicon controlled rectifier and further connected to the second silicon controlled rectifier, wherein the first bias circuit provides the first bias voltage to increase a voltage drop of the first silicon controlled rectifier in the first ESD protection element string in order to reduce a parasitic capacitance of the first ESD protection element string.