Nowadays, most touch screen mobile phones are capacitive touch screens, which rely on detecting small changes in capacitance at a certain point or points on the screen to determine the touch point. The mobile phone charger has two legs, which means that there is no real ground wire, which is not in common with the earth! This causes the common mode noise of the charger (the noise is positive and negative in the same direction, and the difference is equal), which affects the detection of the capacitance value. The control chip of the touch screen cannot distinguish whether it is noise or human operation. . So your question:
1. Although there is no common ground with the earth, the work of the electrical appliances only needs to ensure that the differential mode voltage is normal. The common mode voltage will not affect even if the common mode voltage drifts to several thousand volts (in fact, it may drift so much!), except Some circuits that require small errors and poor common-mode noise suppression, such as capacitive touch, will have an impact, and resistive ones will be much better.
2. Use a good charger, in addition to the improvement of the anti-noise ability of the capacitive touch screen. At present, some companies are also working to solve these problems.
3. The grounds of all chips in the phone are together
