Knowledge about electrostatic protection

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Knowledge about electrostatic protection [Copy link]

I. Discharge type

1) Contact discharge (static guns are generally pointed)

2) Air discharge (static guns are generally round)

II. Electrostatic discharge path: "Proximity principle", generally the nearest path and the path with the smallest impedance will be found for discharge.

Common methods for releasing static electricity: 1) Stick a piece of copper on the metal plate to lead the energy to a less sensitive position

2) If a bidirectional TVS is used, it is recommended to change to a unidirectional one

III. The difference between static electricity and surge

1) Waveform: Surge is short and fat, static electricity is tall and thin

2) Duration: Surge generally follows the 8/20us principle, and the duration of static electricity will reach the ns level

3) Energy: Surge is high, static electricity is low

IV. Common solutions 1. Structural design: 1) Maintain the integrity of the ground 2) Increase the area of the "ground" 2. PCB layout: 1) Discharge at the tip of the pad 2) Devices that are easily affected by static electricity should not be placed near static electricity sources 3) Keep the traces as short and wide as possible to reduce the parasitic inductance of the traces and avoid secondary impact 4) Place high-frequency bypass capacitors between the power supply and the ground 3. Choose ICs with high voltage resistance 4. Use ESD protection devices

shakencity

Electrostatic discharge path: "Proximity principle", generally the nearest path and the path with the smallest impedance will be found for discharge. Common methods for discharging static electricity: 1) Stick a copper sheet on the metal plate to lead the energy to a less sensitive position 2) If a bidirectional TVS is used, it is recommended to change to a unidirectional

langtuodianzi

With the advancement of semiconductor technology, the operating voltage of IC is getting lower and lower, which greatly increases the probability of suffering from overvoltage and ESD damage. According to statistics, about 30% of all field failures of electronic devices are caused by ESD. In addition to ESD, circuit designers also need to consider other factors such as overvoltage, overcurrent, and lightning protection.

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Electrostatic discharge path: "Proximity principle", generally the nearest path and the path with the smallest impedance will be found for discharge.
Common methods for discharging static electricity: 1) Stick a copper sheet on the metal plate to lead the energy to a less sensitive position
2) If a bidirectional TVS is used, it is recommended to change to a unidirectional