wave wrote on Mar 22nd, 2012, 1:45pm:With limited information, this seems fundamental.
Single HPF have settling times and a differential step on a pair may have asymmetry.
Is your input DC same as output CM (0V) ?
Are your waveforms DC balanced?
You might want to plot single ended inputs, with DC content.
How to you plan to amplify this?
Wave
yeah, my input DC is same as output CM(0V)
I plotted single ended transient and the DC contents are same(0V).
One thing is, the fully differential transient response for a sinusoidal input has a constant CM that is zero throughout.