Hi all,
          Can anyone suggest me how to cope up with the design for Gm-C filters? I was designing the biquad for HP filter. I followed the two integrator loop biquad block diagram and then the general Gm-C block diagram for CT filters given in Johns and Martin  Fig 15.11 Page No 583. I found that for designing HP filter with cut off 1MHz Q=1 and dc gain =0.5; Gm5 and Gm4 turns out to be zero, then where will be the input voltage be feed?

Can anyone suggest me some good reference for two integrator loop biquad concept.

Thanks for your suggestions
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