Fast charging is to shorten the charging time by increasing the charging power P. There are three ways to increase the power, namely, increasing the voltage, increasing the current and increasing both the voltage and the current.
There are three elements to realize the fast charging function on mobile phones, which are indispensable. Charger, battery, charging integrated circuit. The charger needs to meet enough output current and output voltage, because the wiring of the charger has great parasitic resistance, and the on-load output voltage of the charger needs to be high to realize large charging current.
Extended data:
Battery charging is controlled by mobile phone charging program and power management chip MT6305N(U400).
1. When the charger is plugged into the charging I/O port, the VCHG signal is sent to the power management IC MT6305, triggering the generation of the charging interrupt signal CHRDET;
2. The 2.CPU accepts the interrupt request, executes the charging program instead, displays the charging icon, and outputs the charging control signal CHRCNTL to MT6305.
3.MT6305 outputs the control signal GATEDRY to turn on U405 to charge the battery;
4.MT6305 detects the charging current through the current detection signal ISENSE, and detects the battery voltage through the voltage detection signal VBATSENSE to control the charging state;
5. When it is detected that the battery is fully charged, MT6305 outputs a charging off signal through GATEDRY to terminate the charging process and end the charging.
References:
Baidu encyclopedia-fast charging of mobile phone
References:
Baidu encyclopedia-mobile phone charger