Malfunction of a Wearable Device Caused by Potential Drop of a Charged Proximity Object due to Electrostatic Discharge

In the actual situations of wearable devices used, there is a situation where a human body and devices that a human holds are charged to high voltage, and their potential rapidly drops when electrostatic discharge (ESD) from the human body to a surrounding object occurs. In this situation, our previous studies observed that a long-duration induced noise with exponential decay in the order of tens to hundreds of microseconds under the condition that the input circuit of the device had high impedance. The noise could cause wearable devices malfunction due to its long duration. In this study, we examined whether malfunctions occur in a wearable device in the floating state near the charged object when the potential of the charged object drops rapidly due to ESD. We also considered the cause of the malfunctions from the perspective of both the long-duration induced noise and the indirect ESD. From experimental results, we confirmed that malfunctions occur in the wearable device in the floating state near the charged object when the potential of the charged object drops rapidly due to ESD. Additional experimental results showed that the main cause of the malfunctions is the long-duration induced noise.