電路能力測試：運算放大器音頻電路

Circuit Knowledge Test-5: Audio Operation Amplifier

??? 2.???What will be the amplifier gain for this whole circuit?(without frequency response consideration)

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試題解答

Circuit Knowledge Test-5: Audio Operation Amplifier

ANS-1:

Band pass filter for DVD output.

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ANS-2:

Amplifier Gain: Av = RD16/RD17 = 1

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ANS-3:

RD18 and RD20 set up the center bias for maximum undistorted output of ICA3.

CD30: the ripple filter for ICA3.

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ANS-4:

CD26 and RD17 set up the low frequency cut-off point for band pass filter.

CD28 and RD17 set up the high frequency cut-off point for band pass filter.

CD26 also acts as dc-isolation capacitor.

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ANS-5:

CD27 and RD19 act as a second low pass filter and set for cut-off point 40 KHz or more to improve S/N. To set at 40 KHz means there will be 3 db cut-off for 20 KHz. (while RD19 in series with RD17)

RD16 sets up the gain for band pass filter. (Av = RD16/RD17)