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三、多路电流源电路 |
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用一个参考电流去获得多个电流,而且各个电流的数值可以不相同。如图所示,其中,T1构成参考电流源。 |
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UBE1
+ IE1R1
= UBE2
+ IE2R2
= UBE3
+ IE3R3
= UBE4
+ IE4R4
由于这几个管子的UBE大致相同,因此有
IE1R1
≈ IE2R2≈
IE3R3≈
IE4R4
当IE1R1确定后,各支路可以通过选择合适的电阻来获得不同数值的电流。
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四、有源负载电路 |
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(一)有源负载共射放大电路 |
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若负载RL很大: |
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T1管集电极动态电流几乎全部流向负载,负载使放大倍数大大提高。 |
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(二)有源负载差分放大电路 |
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输出信号电流和放大倍数比单端输出时大了一倍,这种电路称为单端化电路。 |
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