LT6604-15
Dual Very Low Noise,
Differential Amplifier and
15MHz Lowpass Filter
DESCRIPTION
FEATURES
TheLT®6604-15consistsoftwomatched,fullydifferential
amplifiers,eachwitha4thorder,15MHzlowpassfilter.The
fixed frequency lowpass filter approximates a Chebyshev
response. By integrating a filter and a differential ampli-
fier, distortion and noise are made exceptionally low. At
unity gain, the measured in band signal-to-noise ratio is
an impressive 76dB. At higher gains, the input referred
noise decreases, allowing the part to process smaller
input differential signals without significantly degrading
the signal-to-noise ratio.
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Dual Differential Amplifier with 15MHz Lowpass
Filters
4th Order Filters
Approximates Chebyshev Response
Guaranteed Phase and Gain Matching
Resistor-Programmable Differential Gain
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76dB Signal-to-Noise (3V Supply, 2V Output)
P-P
S
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Low Distortion, 2V , 800Ω Load, V = 3V
P-P
1MHz: 86dBc 2nd, 90dBc 3rd
10MHz: 63dBc 2nd, 69dBc 3rd
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Specified for Operation with 3V, 5V and 5V Supplies
Fully Differential Inputs and Outputs
Adjustable Output Common Mode Voltage
Small 4mm × 7mm × 0.75mm QFN Package
Gainandphasearehighlymatchedbetweenthetwochan-
nels. Gain for each channel is independently programmed
using two external resistors. The LT6604-15 enables level
shifting by providing an adjustable output common mode
voltage, making it ideal for directly interfacing to ADCs.
APPLICATIONS
The LT6604-15 is fully specified for 3V operation. The
differential design enables outstanding performance at
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Dual Differential ADC Driver Plus Filter
a 2V signal level for a single 3V supply. See the back
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P-P
Single-Ended to Differential Converter
page of this datasheet for a complete list of related single
and dual differential amplifiers with integrated 2.5MHz to
20MHz lowpass filters.
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Matched, Dual, Differential Filter Stage
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Common Mode Translation of Differential Signals
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High Speed ADC Antialiasing and DAC Smoothing in
Wireless Infrastructure or Networking Applications
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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High Speed Test and Measurement Equipment
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Medical Imaging
TYPICAL APPLICATION
Channel to Channel Gain Matching
3V
16
50 TYPICAL UNITS
LT6604-15
+INA
LTC22xx
DUAL ADC
+
V A
3V
T
= 25°C
A
14
12
10
8
536Ω
GAIN = 1
= 15MHz
50Ω
50Ω
0.01μF
+
+
–OUTA
+OUTA
f
IN
V
V
+
AIN
–
–
+
MIDA
18pF
18pF
DOUT
OCMA
536Ω
536Ω
–INA
–
+
–
+
+
V B
3V
6
4
+INB
V
50Ω
50Ω
0.01μF
–OUTB
+OUTB
+
AIN
–
–
MIDB
V
DOUT
OCMB
–INB
2
0
536Ω
+
–
–
–
V
–0.25–0.2–0.15–0.1–0.05 0 0.05 0.1 0.15 0.2 0.25
660415 TA01
GAIN MATCH (dB)
660415 TA01b
660415fa
1