
16
Analog Circuits Cookbook
through. Without these, the usable dynamic range of an jV-path filter may
be limited to as little as 40 dB or less; with them the breakthrough was
reduced to -90 dBV Figure
1.12(b)
was recorded after the adjustment of the
said measures.) The slope across the passband, is shown in greater detail in
Figure
1.12(c)
(lower trace) - this was recorded before the adjustment, the
centre frequency breakthrough providing a convenient 'birdie marker'
indicating the exact centre of the passband. The upper trace shows the
result of connecting -39 pF to ground from point C of Figure
1.12(b),
correcting the slope. Figure
1.12(d ...