| 摘要 |
<p>A power circuit is provided which is capable of lengthening use time of a battery (59) in a portable communication terminal of a TDMA (Time Division Multiple Access) or TDD (Time Division Duplex) type portable communication devices, and of making them compact and lightweight. Since, by using a control circuit (63), an output current having been limited to become a pre-set current value is supplied from the battery (59) to a transmission power amplifier (57) and an electrical double layer capacitor (64) is charged so that power is accumulated therein and since power is applied from the electrical double layer capacitor (64) to both the control circuit (63) and the transmission power amplifier (57), even if power consumption of the transmission power amplifier (57) increases during a burst period, a drop of the output voltage from the battery (59) is small. Therefore, time required for the output voltage to reach a terminating voltage in the battery (59) is made longer and a life of the battery (59) can be lengthened. Also, even if the battery (59) is put under a low-temperature circumstance and its internal resistance increases, shortening of the life of the battery (59) can be avoided. <IMAGE></p> |
