ltc6416 Linear Technology Corporation, ltc6416 Datasheet - Page 16

• Manufacturer Part Number: ltc6416
• Description: 2 Ghz Low Noise Differential 16-bit Adc Buffer
• Manufacturer: Linear Technology Corporation

LTC6416
APPLICATIONS INFORMATION
Test Circuits
Due to the fully differential design of the LTC6416 and its
usefulness in applications both with and without ADCs,
two test circuits are used to generate the information in
this data sheet. Test circuit A is Demo Board DC1287A,
a two-port demonstration circuit for the LTC6416. The
board layout and the schematic are shown in Figures 6
and 7. This circuit includes input and output 1:1 baluns
for single-ended-to-differential conversion, allowing
direct analysis using a 2-port network analyzer. In this
circuit implementation, there are series resistors at the
16
IN
IN
J1
J2
+
–
0.1μF
C10
OPT
C7
C8
OPT
C12
0.1μF
MABA-007190-000000
5
4
T1
Figure 7. Demo Board DC1287A Schematic (Test Circuit A)
1
3
2
CLLO
CLHI
V
24.9Ω
24.9Ω
CM
R2
R6
Figure 6. Demo Board DC1287A Layout
C1
0.1μF
C4
0.1μF
C15
0.1μF
C13
0.1μF
0Ω
0Ω
R4
R5
1
2
3
4
5
V
CLHI
IN
IN
CLLO
CM
+
–
LTC6416
GND
output to present the LTC6416 with a 382Ω differential
load, thereby optimizing distortion performance. Including
the 1:1 input and output baluns, the –3dB bandwidth is
approximately 2GHz.
Test circuit B is Demo Circuit DC1257B. It consists of an
LTC6416 driving an LTC2208 ADC. It is intended for use in
conjunction with demo circuit DC890B (computer interface
board) and proprietary Linear Technology evaluation soft-
ware to evaluate the performance of both parts together.
Both the DC1257B board layout and the schematic can
be seen in Figures 8 and 9.
11
OUT
OUT
GND
GND
V
+
+
–
10
9
8
7
6
165Ω
165Ω
R1
R3
C2
680pF
MABA-007190-000000
C14
0.1μF
2
3
1
C3
0.1μF
T2
4
5
GND
V
2.7V TO 4V
GND
+
0.1μF
OPT
C11
C6
0.1μF
OPT
C5
C9
6416 TA04
J3
OUT
J4
OUT
+
–
6416f