usb charger, mobile terminal and charging control method

Abstract

The invention provides a USB charger, a mobile terminal using the USB charger and a charging control method thereof. The USB charger is adapted to charge the mobile terminal, including a first logic control unit, and the USB charger is adapted to realize two-way synchronous communication with the mobile terminal through the first logic control unit, wherein the USB The charger sends the maximum output capability signal of the USB charger to the mobile terminal through the first logic control unit; receives the charging voltage request signal sent by the mobile terminal; and adjusts the USB charger according to the charging voltage request. The output voltage. The USB charger and the mobile terminal provided by the embodiment of the present invention use two signal lines between them to realize two-way synchronous communication through the pulse encoding and decoding protocol, so as to achieve fast and safe charging with a large current, and the implementation method is simple.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to a USB charger, a mobile terminal using the USB charger and a charging control method thereof. Background technique [0002] The characteristics of the step-down switching power supply conversion circuit: the output voltage is lower than the input voltage, the output current is higher than the input current, and the output power is slightly lower than the input power, so the efficiency of the entire conversion circuit is relatively high, and the heat dissipation power on the conversion circuit is relatively small . If the output voltage is not much different from the input voltage, then the input current is not much different from the output current. [0003] Please refer to figure 1 , figure 1 is the circuit schematic of a standard USB charger. The USB charger has four pins, which are respectively connected to two data signal lines (D+ and D-), a power line (VBUS) and a gr...

AI Technical Summary

Problems solved by technology

[0005] The existing mature scheme of switching charging circuit can generally support a maximum charging current of 1.5A. Large current charging has very high requirements for the wire of the charger. This is because: when the output current increases, the input current also increases. The voltage drop caused by the impedance of the USB cable will also increase significantly, and the voltage reaching the charging circuit end of the mobile terminal will decrease significantly

For the above-mentioned switching charging circuit, if the input voltage is reduced, the output capability will be weakened, and the output power that can be provided will be reduced, so the output current increase will soon reach a bottleneck

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