Ic in mobile power boost can be referred to as mobile power ic, is the current mainstream charging mode is the more common single-cell lithium battery voltage of 2.9V to 4.2V between the boost to 5V. Throughout the process of charging, mobile power boost ic equivalent of a load stabilizer, when the voltage is below 3V can automatically determine and start booster circuit for charging; will determine when the battery is low is lower than 2.9V, stopping boost very stable control of charging. Typically, mobile power ic with load boost function, is a high-end technology products, at the low end of technology, boost ic role and not so extensive. We can be understood by four high-end mobile power boost ic: 1. boost with a boost limiting function when, ic is detected by CS and CSN load current, if the load current is gradually increased, reaching the current limit output voltage will drop, until no boost (PMOS synchronous rectifier normally open). The current limit value is calculated as shown: Intuitively, the boost charging current and the current are related, if the charging current is set to 1A, a voltage step-up at the lowest battery case, the boosting can output up to about 1A, . If you want to increase the boost output current, the charging current is also increased accordingly. 2 has a discharge overcurrent and short circuit protection load current exceeds the current limit continues to increase, when the pressure at both ends of the CS and CSN than 60mV, and maintained for longer than 1S, the system will start the load over-current protection, chip off USB The output path into standby mode. 3 chip boost soft-start function, boost at startup, the current will gradually increase to the maximum, to ensure the stability of the system work. 4.-load detection function when the pressure is lower than CS ends with CSN 2mV and sustained 16s, the chip determine the external load disappears into standby.