ESD diode, also known as (ESD protection diode), is a special diode, which is mainly used for anti-static protection. When electrostatic charges accumulate in the circuit, ESD diodes can protect the circuit from damage by directing these charges to ground.
How ESD diodes work
ESD electrostatic diode capacitance value is very low, when the device is connected in parallel in the circuit, when the circuit works normally, it is in the cut-off state (high-impedance state), for normal electrical appliances will not have any impact, when the circuit has abnormal overvoltage and reaches its breakdown voltage, it quickly changes from a high-impedance state to a low-impedance state, providing a low-impedance conduction path for the instantaneous current, while clamping the abnormal high voltage within a safe level, thereby protecting the protected IC or line; When the abnormal overvoltage disappears, it returns to a high-impedance state and the circuit works normally.
1. When a high-frequency spike interference signal enters the circuit, the "bleed resistor" is first induced to produce a high-voltage pulse waveform orthogonal to the outside world; The larger the amplitude of this spike interference signal and the shorter the pulse width, the higher and closer the pulse waveform produced by the "bleed resistor" is to the shape of the square wave.
2. At this time, if a suitable negative feedback value is added to this high-amplitude spike interference signal, the "bleed resistor" will quickly convert the added DC bias into an AC component to eliminate this harmful spike interference.
3. When there is no input of the high-frequency spike interference signal outside, the "bleed resistor" remains in the cut-off state until the next low-frequency sine wave appears.
4. In this way, the continuous work of the cycle can achieve the suppression of various high-frequency spurious signals from the outside world.
Application: Due to the above characteristics and advantages of ESD diodes, it is very suitable for use as lightning protection components in various electronic devices. For example, there are many such devices on computer motherboards. In addition, this lightning protection device is also often applied to communication equipment.
