TPD4E1B06 is an ESD protection diode array which is typically used to provide a path to ground for dissipating ESD events on hi-speed signal lines between a human interface connector and a system. As the current from ESD passes through the diode, only a small voltage drop is present across the diode. This is the voltage presented to the protected IC. The low R_DYN of the triggered diode holds this voltage, V_CLAMP, to a safe level to the protected IC.