LTC1068_15 Datasheet, PDF (27/30 Pages) Linear Technology – Clock-Tunable, Quad Second Order, Filter Building Blocks

TYPICAL APPLICATIONS
LTC1068-200 8th Order Highpass, f_CENTER = f_CLK/200,
Attenuation –60dB at (0.6)(f_CENTER).
Maximum f_CUTOFF = 20kHz with ±5V Supplies
R_L1
66.5k
R21 10k
R11 18.2k R31 16.5k
V_IN
R41 11.3k
5V
R63 2.55k
0.1µF
R53
R43 20.5k ^4.99k
R33 36.5k
R23 10k
R_H1 11.8k
1 _{INV B}
2
HPB/NB
28
INV C
27
HPB/NC
3 _BPB
4 _LPB
BPC ²⁶
25
LPC
5 _SB
SC ²⁴
6 _NC ^LTC1068-200 _V– 23
7
AGND
NC ²²
8 _V+
CLK ²¹
9 _NC
10 _SA
NC ²⁰
19
SD
11 _LPA
LPD ¹⁸
12 _BPA
13
HPA/NA
14 _{INV A}
BPD ¹⁷
16
HPD
15
INV D
R_H3 10k
C23 [1/(2π • R23 • C23) = (160)(f_CUTOFF)]
R_L2 249k
R_H2 20.5k
R22 21.5k
R32 10.2k
R42 18.7k
0.1µF
R44 21k
R34 14.3k
R24 20.5k
–5V
200kHz
V_OUT
1068 TA25
LTC1068 Series
10
0
–10
–20
–30
–40
–50
–60
–70
–80
0.2
Gain vs Frequency
1
FREQUENCY (kHz)
10
1068 TA26
FilterCAD Custom Inputs for f_C = 1kHz
2nd ORDER SECTION f₀ (kHz)
Q
f_N (kHz) TYPE MODE
B
0.9407 1.5964 0.4212
HPN
3a
C
1.0723 0.5156 0.2869
HPN
3a
A
0.9088 3.4293 0.5815
HPN
2b
D
0.9880 0.7001 0.0000
HP
3
1068fc
27