ML2111 Datasheet, PDF (13/26 Pages) Micro Linear Corporation – Universal Dual High Frequency Filter

FILTER FUNCTION DEFINITIONS (Continued)
2. Lowpass function: available at the LP output pins,
Figure 13.
G(s) = H_OLP ™
  _{s2 +}
w₀₂
s ™ w₀
Q
+
w
2
0
(2)
where:
H_OLP = DC gain of the LP output
3. Highpass function: available only in mode 3 at
N/AP/HP_A and N/AP/HP_B, Figure 14.
G(s) = H_OHP ™
  _{s2 +}
s²
s ™ w₀
Q
+
w
2
0
(3)
H_OHP = Gain of the HP output for f ® f_CLK/2.
ML2111
BANDPASS OUTPUT
H_OBP
0.707 H_OBP
f_L f₀ f_H
f (LOG SCALE)
Q=
f₀
f_H -
f_L
; f₀
=
f_L ™ f_H
 _{fL = f0 ™}
-1 ₊
2Q

1
2Q

2
+
1
 _{fH = f0 ™}
1₊
2Q

1
2Q

2
+
1
LOWPASS OUTPUT
Figure 12.
H_OP
H_OLP
0.707 H_OLP
f_P
f_C
f (LOG SCALE)
    _{fC = f0 ™}
1-
1
2Q ²
+
2
1-
1
2Q ²
+1
f_P = f₀ ™
1-
1
2Q ²
H_OP = H_OLP ™ _{1 ™}
Q
1
1-
1
4Q ²
Figure 13.
HIGHPASS OUTPUT
H_OP
H_OHP
0.707 H_OHP
f_C
f_P
! _{  } "$### _{fC = f0 ™}
f (LOG SCALE)
1-
1
2Q ²
+
1-
1
2Q ²
-1
2
+1
! "$## _{fP = f0 ™}
-1
1-
1
2Q ²
H_OP = H_OHP ™ _{1 ™}
Q
1
1-
1
4Q ²
Figure 14.
13