| 摘要 |
PROBLEM TO BE SOLVED: To efficiently save power and to attain a long life in a built-in battery by forming a shunt resistance which interferes serially in the operation current supply path by means of a MOS transistor and on/off-controlling it. SOLUTION: A logic control unit 2 outputs a power control signal Dx, consisting of a binary logical signal based on the operation state of a portable telephone terminal. When the power saving control signal Dx is set to a low inactive level, the MOS transistor M3 is controlled in an off state, and the operation current path to the transistor T1 of LNA1 is interrupted. Thus, its operation current Id is surely interrupted and a non-power consumption power saving state is set. Furthermore, the MOS transistor M3 for detecting the operation current in order to feedback-control the bias voltage Vb of the transistor T1 is commonly used as the function of a switch circuit for interrupting the bias operation current Id of the transistor T1 at saving of power. |
