Description:
(1) input signals for 100 KHZ square wave signals, which first 50 times larger, 20 times second-level amplification
(2) the op-amp with AD797 ultra low noise amplifier, 100 KHZ, only 1 nv/hz noise, gain bandwidth product for 110 MHZ
(3) the first level of the C44 and R16 high-pass filter, the design of the high-pass filter passband cutoff frequency of 1 KHz, secondary constitute a second-order butterworth low-pass filter, cutoff frequency is 3 MHZ
(4) C41 is advised to increase the output of the flat in the manual, will be the capacitor has a problem?

Phenomenon:
(1) at the first stage amplifier of the test, the input signal amplitude is 25 MVPP,
the following distortion of
(2) the input signal amplitude is the 7 MVPP, the first-level op-amp are similar triangle wave distortion waveform

(3) the input signal amplitude is the 5 MVPP, secondary output for the class triangle wave


Please help analysis, seeks the solution ~ ~ ~ ~

CodePudding user response:

Seems to be the phase distortion, first remove the capacitance, see how the performance of the dc amplifier;

CodePudding user response:

You is to point to remove the high-pass filter in front of you, C71 and R31

CodePudding user response:

Is that high and low on capacitance are first removed, should be mainly affected by the cut-off frequency of the low-pass of

CodePudding user response:

Resistance design unusual: all 10-100 times smaller resistance,
Because the input resistance is too small, so capacity is relatively small (10 times),

Circuit design problems such as input impedance no precise!!!!!!

CodePudding user response:

1000 times magnification, why don't put in front of the low-pass, high-pass, behind this system harmonic minimum,