LT6600-2.5
1
660025i
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Programmable Differential Gain via Two External
Resistors
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Adjustable Output Common Mode Voltage
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Operates and Specified with 3V, 5V, – 5V Supplies
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0.5dB Ripple 4th Order Lowpass Filter with 2.5MHz
Cutoff
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86dB S/N with 3V Supply and 1V
RMS
Output
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Low Distortion, 1V
RMS
, 800W Load
1MHz: 95dBc 2nd, 88dBc 3rd
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Fully Differential Inputs and Outputs
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Compatible with Popular Differential Amplifier
Pinouts
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SO-8 Package
Very Low Noise, Differential
Amplifier and 2.5MHz Lowpass Filter
June 2003
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High Speed ADC Antialiasing and DAC Smoothing in
Networking or Cellular Base Station Applications
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High Speed Test and Measurement Equipment
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Medical Imaging
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Drop-in Replacement for Differential Amplifiers
The LT
®
6600-2.5 combines a fully differential amplifier
with a 4th order 2.5MHz lowpass filter approximating a
Chebyshev frequency response. Most differential amplifi-
ers require many precision external components to tailor
gain and bandwidth. In contrast, with the LT6600-2.5, two
external resistors program differential gain, and the filter’s
2.5MHz cutoff frequency and passband ripple are inter-
nally set. The LT6600-2.5 also provides the necessary level
shifting to set its output common mode voltage to accom-
modate the reference voltage requirements of A/Ds.
Using a proprietary internal architecture, the LT6600-2.5
integrates an antialiasing filter and a differential amplifier/
driver without compromising distortion or low noise
performance. At unity gain the measured in band
signal-to-noise ratio is an impressive 86dB. At higher
gains the input referred noise decreases so the part can
process smaller input differential signals without signifi-
cantly degrading the output signal-to-noise ratio.
The LT6600-2.5 also features low voltage operation. The
differential design provides outstanding performance for
a 4V
P-P
signal level while the part operates with a single 3V
supply. The LT6600-2.5 is available in an SO-8 package.
For similar devices with higher cutoff frequency, refer to
the LT6600-10 and LT6600-20 data sheets.
Amplitude Response
DESCRIPTIO
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FEATURES
APPLICATIO S
U
TYPICAL APPLICATIO
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Final Electrical Specifications
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
1580Ω
1580Ω
0.01µF
0.1µF
LT6600-2.5
5V
–
+V
IN
+
V
IN
–
V
OUT
–
660025 TA01a
V
OUT
+
3
4
1
7
2
8
5
6
FREQUENCY (Hz)
100k
–36
GAIN (dB)
–24
–12
0
12
1M 10M 50M
660025 TA01b
–48
–60
–84
–96
–72
V
S
= – 2.5V