LT6600-20
Very Low Noise, Differential
Ampli er and 20MHz Lowpass Filter
FEATURES DESCRIPTION
n
Programmable Differential Gain via Two External
The LT 6600-20 combines a fully differential ampli er with a
Resistors
4th order 20MHz lowpass lter approximating a Chebyshev
n
Adjustable Output Common Mode Voltage
frequency response. Most differential ampli ers require
n
Operates and Speci ed with 3V, 5V, 5V Supplies
many precision external components to tailor gain and
n
0.5dB Ripple 4th Order Lowpass Filter with 20MHz
bandwidth. In contrast, with the LT6600-20, two external
Cutoff
resistors program differential gain, and the lters 20MHz
n
76dB S/N with 3V Supply and 2V Output
cutoff frequency and passband ripple are internally set.
P-P
n
Low Distortion, 2V , 800 Load
The LT6600-20 also provides the necessary level shifting
P-P
2.5MHz: 83dBc 2nd, 88dBc 3rd
to set its output common mode voltage to accommodate
20MHz: 63dBc 2nd, 64dBc 3rd
the reference voltage requirements of A/Ds.
n
Fully Differential Inputs and Outputs
Using a proprietary internal architecture, the LT6600-20
n
SO-8 Package
integrates an antialiasing lter and a differential ampli-
n
Compatible with Popular Differential Ampli er
er/driver without compromising distortion or low noise
Pinouts
performance. At unity gain the measured in band signal-
to-noise ratio is an impressive 76dB. At higher gains the
APPLICATIONS input referred noise decreases so the part can process
smaller input differential signals without signi cantly
n
High Speed ADC Antialiasing and DAC Smoothing in
degrading the output signal-to-noise ratio.
Networking or Cellular Base Station Applications
n The LT6600-20 also features low voltage operation. The
High Speed Test and Measurement Equipment
n differential design provides outstanding performance for
Medical Imaging
n a 2V signal level while the part operates with a single
Drop-in Replacement for Differential Ampli ers
P-P
3V supply.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
The LT6600-20 is packaged in an SO-8 and is pin compat-
ible with stand alone differential ampli ers.
TYPICAL APPLICATION
An 8192 Point FFT Spectrum
0
INPUT 5.9MHz
10
2V
LT6600-20 A/D
P-P
20 f = 80MHz
LTC1748
SAMPLE
5V
30
0.1F
5V
40
R
IN
50
3
402
+
1
49.9 V
60
4
+
7 +
V 70
MID
D
18pF A
IN OUT
2
49.9 80
V
0.01F
OCM
8
90
5
V +
IN
V
V
CM
R
6 100
IN
402
110
1F
120
GAIN = 402/R
IN 0 20 40
10 30
66002 TA01a
FREQUENCY (MHz)
66002 TA01b
66002fb
1
AMPLITUDE (dB)LT6600-20
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Note 1)
TOP VIEW
Total Supply Voltage .................................................11V
+
IN 1 8 IN
Input Current (Note 8) ..........................................10mA
V 2 7 V
OCM MID
Operating Temperature Range (Note 6).... 40C to 85C
+
V V
3 6
Speci ed Temperature Range (Note 7) .... 40C to 85C
+
OUT OUT
4 5
Junction Temperature ........................................... 150C
S8 PACKAGE
Storage Temperature Range ................... 65C to 150C
8-LEAD PLASTIC SO
Lead Temperature (Soldering, 10 sec) .................. 300C
T = 150C, = 100C/W
JMAX JA
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT6600CS8-20#PBF LT6600CS8-20#TRPBF 660020 8-Lead Plastic SO 40C to 85C
LT6600IS8-20#PBF LT6600IS8-20#TRPBF 600I20 8-Lead Plastic SO 40C to 85C
LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT6600CS8-20 LT6600CS8-20#TR 660020 8-Lead Plastic SO 40C to 85C
LT6600IS8-20 LT6600IS8-20#TR 600I20 8-Lead Plastic SO 40C to 85C
Consult LTC Marketing for parts speci ed with wider operating temperature ranges.
For more information on lead free part marking, go to: