LTC1062
TYPICAL APPLICATIO S
7th Order 100Hz Lowpass Filter with Continuous Output Filtering, Output Buffering and Gain Adjustment
R3
5V
2
R4
2.6k
V
IN
1µF
1
2
FB
AGND
V
–
–5V
5V
THE LTC1052 IS CONNECTED AS A 2ND ORDER SALLEN AND KEY LOWPASS FILTER WITH A CUTOFF
FREQUENCY EQUAL TO THE CUTOFF FREQUENCY OF THE LTC1062. THE ADDITIONAL FILTERING
ELIMINATES ANY 10kHz CLOCK FEEDTHROUGH PLUS DECREASES THE WIDEBAND NOISE OF THE FILTER
DC OUTPUT OFFSET (REFERRED TO A DC GAIN OF UNITY) = 5µV MAX
WIDEBAND NOISE (REFERRED TO A DC GAIN OF UNITY) = 60µV
RMS
OUTPUT FILTER COMPONENT VALUES
DC GAIN R3
R4
R1
R2
C1
C2
1
∞
0
14.3k 53.6k 0.1µF 0.033µF
10
3.57k 32.4k 46k 274k 0.01µF 0.02µF
10µF
SOLID
TANTALUM
U
3
4
–
+
1
7
LTC1052
6
8
4
0.1µF
V
OUT
R1
R2
C1
C2
3
B
OUT
OUT
V
+
8
7
0.1µF
–5V
LTC1062
6
5
5V
10kHz
CLK IN
1062 TA13
DIVIDER C
OSC
RATIO
Single 5V Supply 5th Order LP Filter
R
5V
V
IN
C
25k
1
2
25k
5V
FB
AGND
V
–
B
OUT
OUT
V
+
8
7
BUFFERED
OUTPUT
C
DC ACCURATE
OUTPUT
+
LTC1062
3
4
6
5
5V
CLK
DIVIDER C
OSC
RATIO
12R
1062 TA14
FOR A 10Hz FILTER: R = 29.4k, C = 1µF, f
CLK
= 1kHz
1 = f
C
THE FILTER IS MAXIMALLY FLAT FOR
2πRC 1.84
1062fd
11
LINER [ LINEAR TECHNOLOGY ]
