| 摘要 |
PURPOSE: A two-path amplifier circuit is provided to minimize current consumption by bypassing an input signal without operating the amplifier when the input signal has a higher level than a reference level. CONSTITUTION: An amplifier(Tr_3) has a gate terminal connected to an input matching unit(211), a drain terminal connected to a power supply voltage(VDD) and an output matching unit(213), and a source terminal connected to a ground terminal through a switching transistor(Tr_5). The input matching unit(211) matches an input signal with the amplifier(Tr_3), and the output matching unit(213) matches a signal from the amplifier(Tr_3) with an output side. The first switch transistor(Tr_1) is connected between input and output terminals of a receiving amplifier, and its control terminal is connected to a switching control voltage(Vp). The second switch transistor(Tr_2) is connected between an input signal and the input matching unit and has its control terminal connected to a ground terminal and a drain terminal connected to the switching control voltage(Vp) via a resistor(108). The third switch transistor(Tr_4) is connected between the output matching unit(213) and an output terminal, and has a control terminal connected to the ground terminal and a drain terminal connected to the voltage(Vp) via a resistor(111). A current controlled transistor(Tr_5) is connected between the source terminal of the amplifier(Tr_3) and the ground terminal, and its control terminal is connected to a current control voltage(V_cont).
|
