lt6600cs8-5-trpbf Linear Technology Corporation, lt6600cs8-5-trpbf Datasheet - Page 9

• Manufacturer Part Number: lt6600cs8-5-trpbf
• Description: Very Low Noise, Differential Amplifier And 10mhz Lowpass Filter
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
Interfacing to the LT6600-10
Note: The referenced pin numbers correspond to the S8
package. See the Pin Functions for the equivalent DFN-12
package pin numbers.
The LT6600-10 requires 2 equal external resistors, R
set the differential gain to 402Ω/R
filter are the voltages V
external components, Figure 1. The difference between
V
of V
Similarly, the voltages V
4 and 5 of the LT6600-10 are the filter outputs. The
difference between V
output voltage. The average of V
common mode output voltage.
Figure 1 illustrates the LT6600-10 operating with a single
3.3V supply and unity passband gain; the input signal is
DC coupled. The common mode input voltage is 0.5V and
IN
+
IN
and V
+
and V
IN
–
is the differential input voltage. The average
IN
–
is the common mode input voltage.
U
OUT
–1
OUT
IN
2
1
0
3
2
1
0
3
2
1
0
+
U
+
V
V
V
+
and V
and V
500mV
and V
V
V
IN
IN
+
–
P-P
(DIFF)
OUT
IN
V
OUT
V
V
OUT
IN
W
IN
IN
+
–
IN
+
–
–
presented to these
. The inputs to the
+
–
is the differential
appearing at pins
and V
t
t
t
V
V
IN
IN
V
V
V
IN
IN
–
+
IN
OUT
–
+
+
U
Figure 1. (S8 Pin Numbers)
Figure 2. (S8 Pin Numbers)
Figure 3. (S8 Pin Numbers)
0.1μF
0.1μF
402Ω
402Ω
–
62pF
100Ω
100Ω
62pF
is the
0.01μF
402Ω
402Ω
0.01μF
IN
, to
0.01μF
+
–
1
7
2
8
2V
LT6600-10
–
+
3
3.3V
6
1
7
2
8
the differential input voltage is 2V
output voltage is 1.65V and the differential output voltage
is 2V
output voltage is determined by the voltage at V
V
mid-supply voltage. In addition, the common mode input
voltage can be equal to the mid-supply voltage of V
(refer to the Distortion vs Input Common Mode Level
graphs in the Typical Performance Characteristics).
Figure 2 shows how to AC couple signals into the
LT6600-10. In this instance, the input is a single-ended
signal. AC coupling allows the processing of single-ended
or differential signals with arbitrary common mode levels.
The 0.1μF coupling capacitor and the 402Ω gain setting
resistor form a high pass filter, attenuating signals below
4kHz. Larger values of coupling capacitors will propor-
tionally reduce this highpass 3dB frequency.
In Figure 3 the LT6600-10 is providing 12dB of gain. The
gain resistor has an optional 62pF in parallel to improve
+
0.01μF
0.1μF
–
1
7
2
8
LT6600-10
–
+
OCM
4
5
3.3V
3
6
LT6600-10
+
–
3
6
+
–
5V
0.1μF
P-P
+
4
–
5
0.1μF
is shorted to V
4
5
for frequencies below 10MHz. The common mode
V
V
OUT
OUT
V
V
+
–
OUT
OUT
V
V
OUT
OUT
+
–
+
–
3
2
1
0
3
2
1
0
V
3
2
1
0
V
V
MID
V
V
the output common mode is the
V
V
OUT
OUT
OUT
OUT
V
+
–
V
+
OUT
OUT
–
6600 F01
6600 F03
+
–
6600 F02
t
t
P-P
. The common mode
LT6600-10
OCM
. Since
6600fa
9
MID