LT6600-10_15 Datasheet, PDF (1/16 Pages) Linear Technology – Very Low Noise, Differential Amplifi er and 10MHz Lowpass Filter

LT6600-10
Very Low Noise, Differential
Amplifier and 10MHz 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 10MHz}
Cutoff
n _{82dB S/N with 3V Supply and 2VP-P Output}
n _{Low Distortion, 2VP-P, 800Ω Load}
1MHz: 88dBc 2nd, 97dBc 3rd
5MHz: 74dBc 2nd, 77dBc 3rd
n _{Fully Differential Inputs and Outputs}
n _{Compatible with Popular Differential Amplifier Pinouts}
n _{SO-8 and DFN-12 Packages}
APPLICATIONS
n _{High Speed ADC Antialiasing 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, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
The LT^®6600-10 combines a fully differential amplifier with a
4th order 10MHz lowpass filter approximating a Chebyshev
frequency response. Most differential amplifiers require
many precision external components to tailor gain and
bandwidth. In contrast, with the LT6600-10, two external
resistors program differential gain, and the filter’s 10MHz
cutoff frequency and passband ripple are internally set.
The LT6600-10 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 LT6600-10
integrates an antialiasing filter and a differential ampli-
fier/driver without compromising distortion or low noise
performance. At unity gain the measured in band signal-
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 LT6600-10 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, LT6600-15, LT6600-5 and LT6600-2.5.
TYPICAL APPLICATION (S8 pin numbers shown)
LT6600-10
5V
0.1μF
R_IN
402Ω
1
7
3
–
V_MID
+
4
0.01μF
V_IN
2
8
V_OCM
+
–
5
R_IN
6
402Ω
49.9Ω
49.9Ω
GAIN = 402Ω/R_IN
5V
18pF
V⁺
+
A_IN
LTC1748
–
V_CM
D_OUT
V^–
1μF
6600 TA01a
An 8192 Point FFT Spectrum
0
INPUT IS A 4.7MHz SINEWAVE
–10
2V_P-P
–20
f_SAMPLE = 66MHz
–30
–40
–50
–60
–70
–80
–90
–100
–110
0 4 8 12 16 20 24 28 32
FREQUENCY (MHz)
6600 TA01b
66001fe
1