LTC1062
TYPICAL APPLICATIO S
AC Coupling an External CMOS Clock Powered
from a Single Positive Supply, V
+
V
IN
C
1
2
FB
AGND
V
–
B
OUT
OUT
V
+
8
7
V
OUT
Adding an External (R1, C1) to Eliminate the Clock Feedthrough and
to Improve the High Frequency Attenuation Floor
V
IN
C
1
2
FB
AGND
V
–
B
OUT
OUT
V
+
8
7
C1
0.01C
Filtering AC Signals from High DC Voltages
R
25.8k
V
IN
1
HIGH DC INPUT = 100V
2
C
0.01µF
FB
AGND
V
–
B
OUT
OUT
V
+
8
7
C
0.01µF
12R
309.6k
DC OUTPUT
PASSBAND GAIN (dB)
LTC1062
V
–
= –5V
3
4
6
5
CLK IN = f
C
• 100
DIVIDER C
OSC
RATIO
V
+
= 5V
EXAMPLE:
f
CLK
= 100KHz, f
C
= 1kHz. THE FILTER ACCURATELY PASSES
THE HIGH DC INPUT AND ACTS AS 5TH ORDER LP FILTER
FOR THE AC SIGNALS RIDING ON THE DC
8
U
R
LTC1062
V
–
3
4
6
5
V
+
0.01µF
V
+
0
DIVIDER C
OSC
RATIO
100k
1062 TA03
–
R1
10R
EXTERNAL
BUFFER
V
OUT
+
LTC1062
V
–
3
4
6
5
V
+
f
CLK
1062 TA04
DIVIDER C
OSC
RATIO
Passband Amplitude Response for the
High DC Accurate 5th Order Filter
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2 V
S
=
±5V
f
CLK
= 100kHz
–1.4
0.01
1062 TA05
0.1
f
IN
/f
C
1
1062 TA06
1062fd
LINER [ LINEAR TECHNOLOGY ]
