ltc1565-31is8-trpbf Linear Technology Corporation, ltc1565-31is8-trpbf Datasheet - Page 8

• Manufacturer Part Number: ltc1565-31is8-trpbf
• Description: 650khz Continuous Time, Linear Phase Lowpass Filter
• Manufacturer: Linear Technology Corporation

APPLICATIONS
Output Drive
Pin 7 and Pin 8 can drive a 1k or 300pF load connected
to AC ground with a 0.5V signal (corresponding to a
2V
connected from Pin 7 to Pin 8) the outputs can produce
a 2V
smaller signal amplitudes the outputs can drive corre-
spondingly larger loads.
Noise
The wideband noise of the filter is the RMS value of the
device’s output noise spectral density. The wideband
noise data is used to determine the operating signal-to-
noise at a given distortion level. Most of the noise is
LTC1565-31
TYPICAL APPLICATIO S
8
P-P
V
IN
P-P
+
–
differential signal). For differential loads (loads
V
CM
differential signal across 2k
4.99k
2.49k
4.99k
10 F
10 F
4.99k
2.49k
4.99k
2.49k
U
2
3
2
3
2
3
INFORMATION
–
+
–
+
–
+
U
LT
LT1809
LT1809
®
A1
A2
A3
1809
5V
5V
5V
7
4
7
4
7
4
4.99k
2.49k
4.99k
U
W
6
6
6
0.1 F
0.1 F
0.1 F
Test Circuit for Single 5V Supply Operation
or 150pF. For
0.1 F
+V
–V
IN
IN
U
/2 + V
/2 + V
AMPLIFIERS A1, A2 AND A3 ALLOW THE USE OF A GROUND-
REFERENCED SINGLE-ENDED AC SOURCE AS THE INPUT
SIGNAL AND A SEPARATE GROUND-REFERENCED DC SOURCE
TO PROVIDE THE INPUT DC COMMON MODE VOLTAGE
AMPLIFIERS A4 AND A5 ALLOW MONITORING/MEASURING
THE DIFFERENTIAL OUTPUT WITH A SINGLE-ENDED, GROUND-
REFERENCED INSTRUMENT
CM
CM
V
1
2
3
4
+
/2
+IN
–IN
GND
V
–
LTC1565-31
concentrated in the filter passband and cannot be removed
with post filtering (Table 1). Table 2 lists the typical change
in wideband noise with supply voltage.
Table 1. Wideband Noise vs Bandwidth, Single 5V Supply
BANDWIDTH
DC to f
DC to 2 • f
Table 2. Wideband Noise vs Supply Voltage, f
POWER SUPPLY
5V
5V
SHDN
–OUT
+OUT
V
+
CUTOFF
8
7
6
5
CUTOFF
1k
0.1 F
0.1 F
4.99k
2.49k
2.49k
5V
2
3
2
3
–
+
–
+
LT1809
LT1812
1k
A4
A5
TOTAL INTEGRATED NOISE
104 V
118 V
TOTAL INTEGRATED NOISE
DC TO 2 • f
118 V
120 V
5V
5V
7
4
7
4
4.99k
RMS
RMS
RMS
RMS
0.01 F
6
6
0.1 F
0.1 F
CUTOFF
CUTOFF
1565-31 TA08
19k
20
V
(SINGLE ENDED)
= 650kHz
OUT
2.2 F