power protection
3.1 3.7 V lithium battery static surge protection scheme
(The purpose of adding a sampling resistor to the TVS back-end circuit is to resist current and make TVS more conducive to releasing surges, thus protecting the back-end power）
The circuit board layout can restrain electrostatic discharge and electrical fast transient（EFT) and surge transients. The following guidelines are recommended:
1 Keep TVS ESD as close to the input terminal or connector as possible.
2 The path length between TVS ESD and the protected line shall be minimized.
3 Minimize parallel signal paths.
4 Avoid parallel operation of protective conductor and unprotected conductor.
5 Minimize all printed circuit boards（PCB) conductive circuit, including power supply and grounding circuit.
6 Minimize the length of the transient return path to ground.
7 Avoid using a shared transient return path to a common ground point.
8 Use ground plane as much as possible. For multilayer PCB, use the grounding through-hole.
The battery of the mobile phone is generally 4.2 － 4.5V, which may be more than the battery of the mobile phone. Precise protection for battery terminal, Lei
4.5V TVS is recommended for Mao Electronics.
