![](http://datasheet.mmic.net.cn/Linear-Technology/LTC1066-1CSW-TRPBF_datasheet_97958/LTC1066-1CSW-TRPBF_18.png)
LTC1066-1
18
10661fa
–
+
–
+
–
+
–
+
13
12
11
10
RF
–
+
–
+
VIN
CP
50pF
CA
0.047
F
0.1
F
7
9
5
12
5
7
8
10
9
15
16
2
6
11
14
3
1
4
3
2
8
15
16
17
18
413
19
LTC1045
14
RA
PULSE
OUTPUT
6
RP
2k
12.1k
1k
500
500
0.1
F
0.1
F
CLOCK INPUT
(TTL OR CMOS)
PULSE
AVERAGE
CLOCK FREQUENCY DETECTOR
20
LTC1045
1
F
5V
0.1
F
0.1
F
0.1
F
LTC202
–5V
5V
C3
C2
R1
1k
RIN*
200
20
20
CLOCK-TUNABLE,
8TH ORDER LOWPASS FILTER
FIRST ORDER RC
LOWPASS ANTI-ALIASING FILTER
1
CF
18
0.1
F
C1
CIN*
0.1
F
0.1
F
0.1
F
VOUT
0.1
F0.1F
–5V
C4
C5
217
316
415
514
613
712
811
910
V +
OUT B
+IN B
GND
LTC1066-1
FIN
COMP 2
CON 2
COMP 1
V –
OUT A
–IN A
+IN A
V –
V +
CON 1
F OUT
50/100
CLK
COMPONENT CALCULATIONS FOR A CLOCK-TUNABLE RANGE OF FIVE OCTAVES:
DEFINITIONS: 1. THE CUTOFF FREQUENCY OF LTC1066-1 IS ABBREVIATED AS fC
2. fC(LOW) IS THE LOWEST CUTOFF FREQUENCY OF INTEREST
3. A RANGE OF FIVE OCTAVES IS FROM fC(LOW) TO 32fC(LOW)
COMPONENT CALCULATIONS:
EXAMPLE:
1
2
πRFCF
fC(LOW)
125
1
fC(LOW)
=
; RIN* = RF (IF RF CAN BE CHOSEN TO BE 20k, RIN AND CIN ARE OMITTED.
fC(LOW)/125 ALLOWS FOR 0.2dB GAIN PEAK IN THE PASSBAND)
C1 =
F (fC(LOW) IN Hz) ; R1 = 1k
105
50fC(LOW)
5
×105
50fC(LOW)
CP = 50pF; RP =
k
CA = 0.047F; RA =
k
C2 = C1, C3 = 2C1, C4 = 4C1, C5 = 8C1
LET’S CHOOSE A FIVE OCTAVE RANGE FROM 1kHz TO 32kHz. fC(LOW) = 1kHz (1000Hz).
LET CF = 1F, THEN RF CALCULATES TO BE 20k. RIN AND CIN OMITTED;
R1 = 1k, C1 = 0.001
F, C2 = 0.001F, C3 = 0.0022F, C4 = 0.0039F,
C5 = 0.0082
F. CP = 50pF, RP = 2k, CA = 0.047F, RA = 10k
1066-1 TA07
DC Accurate Clock-Tunable Lowpass Filter with Tunable Input Anti-Aliasing Filter
(Circuit provides at least – 20dB attenuation to input frequencies at 2fCLK.
The clock-tunable range is 5 octaves.)
TYPICAL APPLICATIO
U