1, Linear charge PO: The use of a pure resistor limited flow step-down or charging management chip step-down, the input 5V voltage directly to the battery required voltage, in the middle through the transistor amplification or chip inside the comparator amplification to limit flow. With open
The advantages of short time cycle success rate are quite high.
2, Pulse charging PO: The use of the CMOS electronic switch, through the control of the switch time and frequency of step-down, constant current charge is also called PWM control charge. The middle control process needs to be controlled by the CPU port to check the data to adjust the PWM width or frequency to complete the charging process, the disadvantage is that this line technology is quite complex. Pulse charging PO usually has a slow charge constant current-fast charge constant current-fast charge constant pressure-trickle repair four process.