LMF100_15 Datasheet, PDF (21/40 Pages) Texas Instruments – LMF100 Dual High-Performance Switched Capacitor Filters

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Device Functional Modes (continued)
R3
Q = 1+ R2 / R4 ´
R2
R3
Q_z = 1- R1/ R4 ´ _R1
H_0z1
=
gain
at
C.Z.
output
(as
f
®
0
Hz)
-R2(R4 - R1)
R1(R2 + R4)
H2
=
gain
at
C.Z.
output
æ
ç ^as
f
®
f_CLK
ö
÷
-R2
è
2 _ø R1
H_OBP
=
-
æ
çè
R2
R1
+
ö
1_÷ø
´
R3
R2
H_OLP
=
-
æ
çè
R2 + R1
R2 + R4
ö
÷ø
´
R4
R1
LMF100
SNOSBG9B – JULY 1999 – REVISED JUNE 2015
(61)
(62)
(63)
(64)
(65)
(66)
Figure 46. MODE 4
Figure 47. MODE 5
8.4.1.9 MODE 6a: Single-Pole, HP, LP Filter (See Figure 48)
f₀
= cutoff
frequency
of
LP or HP output
=
R2
R3
f_CLK
100
or
R2
R3
f_CLK
50
(67)
R3
H_OLP = - _R1
(68)
R2
H_OHP = - _R1
(69)
Figure 48. MODE 6a
8.4.1.10 MODE 6b: Single-Pole LP Filter (Inverting and Noninverting) (See Figure 49)
f_c
=
cutoff
frequency
of
LP outputs
=
R2
R3
f_CLK
100
or ^R2
R3
f_CLK
50
(70)
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