POWER CONTROL CIRCUIT OF MOBILE TERMINAL

摘要

PURPOSE: A power control circuit of a mobile terminal is provided to effectively use a battery, extend a time of using the battery by switching a power supply path and applying a converted DC power to a constant voltage part. CONSTITUTION: A battery(6) is a Li-Ion cell battery. An output voltage of the battery is 2.8V to 4.2V. An A/D converter(7) converts an analogue voltage value into a digital voltage value. The output of the battery is connected to the A/D converter(7). An output of the A/D converter(7) is connected to a microprocessor(8) that outputs a switching control signal. The microprocessor compares the battery output voltage value that is converted into the digital voltage signal by the A/D converter with a preset reference voltage value, and outputs a high or low switching control signal according to the comparison result. The switching control signal is inputted to the first switching part(9) and the second switching part(11) as a switching control signal. The microprocessor has a memory in which the reference voltage value is stored in a digital signal. The first contact point of the first switching part is connected to the output of the battery and the second contact point(9b) is connected to the second contact point of the second switching part(11). The third contact point is connected to an input terminal of a DC/DC converter(10).