TP5100 is a step-down switching double 8.4V / 4.2V single lithium battery charge management chip. QFN16 ultra small package with its simple external circuit, so that the large current charging management application TP5100 ideal is for portable devices. Meanwhile, TP5100 has a built-in input overcurrent, undervoltage protection, over temperature protection, short circuit protection, battery temperature monitoring, and reverse battery protection. The Unicersal LiPo charger has a wide input voltage 5V-18V, provides pre-charge from battery trickle charging, provides constant current, and constant-voltage three phase. The pre-charge current trickle charge is adjusted through an external resistor. It has a maximum charging current of 2A. TP5100 uses a frequency of 400kHz for switching modes which makes it possible to use smaller peripheral devices, and still maintain a smaller amount of heat with the large current charging. TP5100 has a built-in power PMOSFET, anti-intrusion circuit, so there is no need peripheral anti-intrusion protection Schottky diode.