Dear Respected eetech00,Try inserting a non-inverting opamp buffer between part-a and part-b. Isolate the opamp +input from the triangle stage with a 0.1u cap then bias the +input to reduce the dc offset to move the waveform lower peak closer to zero. The buffer should be a rail-rail opamp.
Thank you very much for your kind reply and suggestions. I am working on it, if i found some problems i will ask again.
Thank you very much for your kind help.
With Humble Regards