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ESD protection circuit. Circuit 1. DM model. 1.) the circuit shows that the SRV05-4 is short to shut down,when the surge is DM model , so the circuit can protect the IC away from DM model surge(EFT ,lightning). CM model.
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DM model 1.) the circuit shows that the SRV05-4 is short to shut down,when the surge is DM model , so the circuit can protect the IC away from DM model surge(EFT ,lightning).
CM model 1.) the ESD and CDE are the CM model , so the SRV05-4 will do not work because it is not connect to GND thinking of HI-POT. 2. the protection for CM model relies on the transformer . But the isolation of transformer is 1500V , so it is not enough for ESD AND CDE
DM model 1.) the circuit shows that the SRV05-4 is short to GND , when the surge is DM model , so the circuit can protect the IC away from DM model surge.
CM model 1.) the ESD and CDE are the CM model , so the SRV05-4 will do work because it is connected to GND . 2. The transformer also supply the 1500V isolation
RJ45 ICM IC Discrete design When ESD occurs , the blue wire will bring out inductance and it will result VB=LB * di/dt. 2.) the red wire will bring out inductance and it also result VR=LR* di/dt caused by ESD and VB higher than ESD only 3.) the VIC= VC + VR may be is higher than the IC ESD degree.
RJ45 with ESD device ICM IC Integrated design When ESD occur , the VIC= VC is less than the IC ESD degree.
conclusion 1.Thinking of HI-POT , DM model and CM model, the ESD device is best between the transformer and PHY side in our RJ45 ICM product . 2.the integrated design is better than the discrete design 3.the design method is same to 1000base type .