LT6600-5_15 Datasheet, PDF (1/12 Pages) Linear Technology – Very Low Noise, Differential Amplifi er and 5MHz Lowpass Filter

LT6600-5
Very Low Noise, Differential
Amplifier and 5MHz Lowpass Filter
FEATURES
DESCRIPTION
n _{Programmable Differential Gain via Two External}
Resistors
n _{Adjustable Output Common Mode Voltage}
n _{Operates and Specified with 3V, 5V, ±5V Supplies}
n _{0.5dB Ripple 4th Order Lowpass Filter with 5MHz}
Cutoff
n _{82dB S/N with 3V Supply and 2VP-P Output}
n _{Low Distortion, 2VP-P, 800Ω Load}
1MHz: 93dBc 2nd, 96dBc 3rd
n _{Fully Differential Inputs and Outputs}
n _{Compatible with Popular Differential Amplifier}
Pinouts
n _{Available in an SO-8 Package}
APPLICATIONS
n _{High Speed ADC Anti-Aliasing and DAC Smoothing in}
Networking or Cellular Base Station Applications
n _{High Speed Test and Measurement Equipment}
n _{Medical Imaging}
n _{Drop-in Replacement for Differential Amplifiers}
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
The LT^®6600-5 combines a fully differential amplifier with a
4th order 5MHz lowpass filter approximating a Chebyshev
frequency response. Most differential amplifiers require
many precision external components to tailor gain and
bandwidth. In contrast, with the LT6600-5, two external
resistors program differential gain, and the filter’s 5MHz
cutoff frequency and passband ripple are internally set.
The LT6600-5 also provides the necessary level shifting
to set its output common mode voltage to accommodate
the reference voltage requirements of A/Ds.
Using a proprietary internal architecture, the LT6600-5
integrates an anti-aliasing filter and a differential ampli-
fier/driver without compromising distortion or low noise
performance. At unity gain the measured in band sig-
nal-to-noise ratio is an impressive 82dB. At higher gains
the input referred noise decreases so the part can process
smaller input differential signals without significantly
degrading the output signal-to-noise ratio.
The LT6600-5 also features low voltage operation. The
differential design provides outstanding performance for
a 2V_P-P signal level while the part operates with a single
3V supply.
For similar devices with other cutoff frequencies, refer to
the LT6600-20, LT6600-10 and LT6600-2.5.
TYPICAL APPLICATION
Dual, Matched, 5MHz Lowpass Filter
3V 0.1μF
R_IN
0.01μF
I_IN
R_IN
V_OCM
(1V-1.5V)
R_IN
0.01μF
Q_IN
R_IN
1
7
–
3
+
4
2 ^LT6600-5
8₊ –₅
6
3V 0.1μF
1
7
–
3
+
4
2 ^LT6600-5
8₊ –₅
6
Q_OUT
GAIN = ^806Ω
R_IN
I_OUT
5MHz Phase Distribution
(50 Units)
30
25
20
15
10
5
0
–135 –134.5 –134–133.5–133 –132.5–132 –131.5
5MHz PHASE (DEG)
66005 TA01
66005fb
1