LTC1068 Linear Technology, LTC1068 Datasheet - Page 19

• Manufacturer Part Number: LTC1068
• Description: Clock-Tunable/ Quad Second Order/ Filter Building Blocks
• Manufacturer: Linear Technology

TYPICAL APPLICATIONS
1 F
3.3V
V
IN
LTC1068-50 8th Order Linear Phase Lowpass, f
for Single Supply Low Power Applictions. Maximum f
22.6k
R11
20kHz with a 3.3V Supply and 40kHz with a 5V Supply
R43 48.7k
R33 12.7k
R23 10.7k
R21 20.5k
R41 22.6k
26.7k
R31 10k
R
L3
0.1 F
FilterCAD Custom Inputs for f
10
11
12
13
14
2nd ORDER SECTION
1
2
3
4
5
6
7
8
9
INV B
HPB/NB
BPB
LPB
SB
NC
AGND
V
NC
SA
LPA
BPA
HPA/NA
INV A
+
LTC1068-50
R
56.2k
13.3k
B3
B
C
A
D
R
R
A1
B1
24.9k
U
HPD/ND
HPC/NC
INV D
INV C
BPC
LPD
BPD
LPC
CLK
NC
NC
SD
SC
V
–
28
27
26
25
24
23
22
21
20
19
18
17
16
15
11.0472
11.0441
f
9.5241
6.9687
O
(kHz)
C
R44 34.8k
R34 14.3k
R24 16.9k
= 10kHz
CUTOFF
R22 43.2k
R32 43.2k
R42 196k
9.09k
R
R
34k
0.5248
1.1258
1.3392
0.6082
L2
H2
CUTOFF
= f
Q
CLK
1068 TA12a
/50
is
21.7724
f
N
500kHz
V
(kHz)
OUT
0.5248
1.5781
Q
N
– 80
–10
–20
–30
– 40
– 50
– 60
–70
10
0
1
TYPE
LPBP
LPN
AP
LP
GROUP
DELAY
GAIN
Gain and Group Delay
LTC1068 Series
MODE
vs Frequency
FREQUENCY (kHz)
4a3
2n
2s
3
10
1068 TA12b
19
100
150
140
130
120
110
100
90
80
70
60