LTC6400IUD-26#TRPBF Linear Technology, LTC6400IUD-26#TRPBF Datasheet - Page 12

• Manufacturer Part Number: LTC6400IUD-26#TRPBF
• Description: IC ADC DRIVER DIFF 16-QFN
• Manufacturer: Linear Technology
• Type: ADC Driverr

Specifications of LTC6400IUD-26#TRPBF

• Applications: Data Acquisition
• Mounting Type: Surface Mount
• Package / Case: 16-WQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
LTC6400-26
converted to a differential signal via a balun and fed to the
input of the LTC6400-26. Figure 8 summarizes the IMD3
performance of the whole system in Figure 7.
Test Circuits
Due to the fully-differential design of the LTC6400 and
its usefulness in applications with differing characteristic
specifi cations, two test circuits are used to generate the
information in this datasheet. Test Circuit A is DC987B,
a two-port demonstration circuit for the LTC6400 family.
The silkscreen is shown in Figure 9. This circuit includes
input and output transformers (baluns) for single-ended-
to-differential conversion and impedance transformation,
allowing direct hook-up to a 2-port network analyzer.
There are also series resistors at the output to present the
LTC6400 with a 375Ω differential load, optimizing distortion
performance. Due to the input and output transformers, the
–3dB bandwidth is reduced from 1.9GHz to 1.67GHz.
12
Figure 7. Single-Ended Input to LTC6400-26 and LTC2208
13
14
15
16
Figure 6. LTC6400-26 with 165MHz Output Bandpass Filter
IF IN
+IN
+IN
–IN
–IN
150Ω
37.4Ω
25Ω
25Ω
IN+
IN–
0.1μF
0.1μF
500Ω
500Ω
+IN
–IN
ENABLE
OUT–
OUT+
LTC6400-26
V
OCM
+OUT
–OUT
12.5Ω
12.5Ω
26dB GAIN
+OUTF
–OUTF
50Ω
50Ω
LTC6400-26
0.1μF
1.7pF
+OUTF
–OUTF
640026 F06
+OUT
–OUT
4.99Ω
4.99Ω
1.25V
8
7
6
5
10Ω
10Ω
16nH
39pF
39pF
AIN
AIN
LTC2208 130Msps
+
–
4.99Ω
4.99Ω
LTC2208
16-Bit ADC
39pF
V
CM
640026 F07
LTC2208
Test Circuit B uses a 4-port network analyzer to measure
S-parameters and gain/phase response. This removes the
effects of the wideband baluns and associated circuitry,
for a true picture of the >1GHz S-parameters and AC
characteristics.
Figure 8. IMD
Figure 9. Top Silkscreen of DC987B, Test Circuit A
3
–100
–110
for the Combination of LTC6400-26 and LTC2208
–40
–50
–60
–70
–80
–90
0
SINGLE-ENDED INPUT
F
DRIVER V
S
= 122.8Msps
50
OUT
100
FREQUENCY (MHz)
= 2V
P-P
150
COMPOSITE
200
250
640026 F08
300
640026fa