LT6604-5
1
66045fa
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
Dual Very Low Noise,
Differential Amplifi er and
5MHz Lowpass Filter
The LT
®
6604-5 consists of two matched, fully differential
amplifi ers, each with a 4th order, 5MHz lowpass fi lter. The
fi xed frequency lowpass fi lter approximates a Chebyshev
response. By integrating a fi lter and a differential ampli-
fi er, 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 signifi cantly degrading
the signal-to-noise ratio.
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 specifi ed for 3V operation. The dif-
ferential design enables outstanding performance at a
2V
P-P
signal level for a single 3V supply.
See the back page of this datasheet for a complete list of
related single and dual differential amplifi ers with integrated
2.5MHz to 20MHz lowpass fi lters.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
n
Dual Differential Amplifi er with 5MHz Lowpass Filters
4th Order Filters
Approximates Chebyshev Response
Guaranteed Phase and Gain Matching
Resistor-Programmable Differential Gain
n
>82dB Signal-to-Noise (3V Supply, 2V
P-P
Output)
n
Low Distortion (1MHz, 2V
P-P
Output, 800Ω Load)
HD2: 93dBc
HD3: 96dBc
n
Specifi ed for Operation with 3V, 5V and ±5V Supplies
n
Fully Differential Inputs and Outputs
n
Adjustable Output Common Mode Voltage
n
Small 4mm × 7mm × 0.75mm QFN Package
n
Dual Differential ADC Driver and Filter
n
Single-Ended to Differential Converter
n
Matched, Dual, Differential Gain or Filter Stage
n
Common Mode Translation of Differential Signals
n
High Speed ADC Antialiasing and DAC Smoothing in
Wireless Infrastructure or Networking Applications
n
High Speed Test and Measurement Equipment
n
Medical Imaging
Channel to Channel Gain Matching
GAIN MATCH (dB)
NUMBER OF UNITS
25
20
15
10
5
66045 TA01b
0
50 TYPICAL UNITS
T
A
= 25°C
GAIN = 1
f
IN
= 5MHz
–0.20 0.10–0.10 0.200
806Ω
806Ω
3V
3V
+
–
+
–
66045 TA01
+
–
DOUTAIN
LT6604-5 LTC22xx
–
+
806Ω
806Ω
3V
–OUTA
+OUTA
–OUTB
+OUTB
+INA
+INB
V
MIDA
V
MIDB
V
OCMA
V
OCMB
–INA
–INB
V
–
+
–
+
–
+
–
DOUTAIN
–
+
50Ω
50Ω
DUAL ADC
V
+
A
V
+
BV
+
B
50Ω
50Ω
18pF
18pF
0.01μF
0.01μF