LT6604-5
Dual Very Low Noise,
Differential Amplifier and
5MHz Lowpass Filter
DESCRIPTION
FEATURES
The LT®6604-5 consists of two matched, fully differential
amplifiers, each with a 4th order, 5MHz lowpass filter. 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 82dB. 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 5MHz Lowpass Filters
4th Order Filters
Approximates Chebyshev Response
Guaranteed Phase and Gain Matching
Resistor-Programmable Differential Gain
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>82dB Signal-to-Noise (3V Supply, 2V Output)
P-P
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Low Distortion (1MHz, 2V Output, 800Ω Load)
P-P
HD2: 93dBc
HD3: 96dBc
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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
Gain and phase are well matched between the two chan-
nels. Gain for each channel is independently programmed
using two external resistors. The LT6604-5 enables level
shifting by providing an adjustable output common mode
voltage, making it ideal for directly interfacing to ADCs.
The LT6604-5 is fully specified for 3V operation. The dif-
ferential design enables outstanding performance at a
APPLICATIONS
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Dual Differential ADC Driver and Filter
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Single-Ended to Differential Converter
2V signal level for a single 3V supply.
P-P
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Matched, Dual, Differential Gain or Filter Stage
See the back page of this datasheet for a complete list of
relatedsingleanddualdifferentialamplifierswithintegrated
2.5MHz to 20MHz lowpass filters.
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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
3V
Channel to Channel Gain Matching
25
50 TYPICAL UNITS
= 25°C
LT6604-5
+INA
LTC22xx
DUAL ADC
+
V A
3V
3V
T
806Ω
A
50Ω
50Ω
GAIN = 1
–
+
–OUTA
+OUTA
20
15
10
5
V
+
AIN
–
f
= 5MHz
–
+
MIDA
IN
18pF
18pF
V
DOUT
OCMA
0.01μF
–INA
+
–
–
+
806Ω
806Ω
+
V B
+INB
V
50Ω
–OUTB
+OUTB
+
AIN
–
–
MIDB
V
DOUT
OCMB
50Ω
0.01μF
+
–INB
+
–
–
806Ω
0
V
–0.20
–0.10
0
0.10
0.20
66045 TA01
GAIN MATCH (dB)
66045 TA01b
66045fa
1