3
dc2077af
DEMO MANUAL DC2077A
OPERATION
Please note that a number of DNC pins are connected on
the demo board. These connections are not necessary for
normal operation. Failure to float these pins may impair
the operation of the device. Table 2 shows the function of
each input and output on the board.
Table 2. DC2077A Board I/O Descriptons
CONNECTOR
FUNCTION
J1 (IN)
Single-ended input. Impedance matched to 50Ω. Drive
from a 50Ω network analyzer or signal source.
J2 (OUT)
Single-ended output. Impedance matched to 50Ω.
Drives a 50Ω network analyzer or spectrum analyzer.
E1 (T_DIODE)
The measured voltage will be an indicator of the chip
junction temperature.
E2 (VCC)
Positive supply voltage source.
E3 (GND)
Supply ground.
Additional Information
As with any RF device, minimizing ground inductance is
critical. Care should be taken during the board layout when
using these exposed pad packages. The maximum number
of small-diameter vias should be placed underneath the
exposed pad. This will ensure a good RF ground and low
thermal impedance. Maximizing the copper ground plane
will also improve heat spreading and lower the inductance
to ground. It is a good idea to cover the via holes with
solder mask on the back side of the PCB to prevent solder
from wicking away from the critical PCB to exposed pad
interface.
The DC2077A is a wide bandwidth demo board, but it is not
intended for operation down to DC. The lower frequency
cutoff is limited by on-chip matching elements.
FREQUENCY (MHz)
0
|S21| (dB)
|S11|, |S12|, |S22| (dB)
16
20
24
NOMINAL WORKING
FREQUENCY RANGE
1600
12
8
14
18
22
10
6
4
–12
–4
4
–20
–28
–16
–8
0
–24
–32
–36
400
800
1200
2000
|S21|
|S22|
|S11|
|S12|
Figure 2. Demo Board S-Parameters
Table 3 shows the LTC643X-YY amplifier series and its
associated demo boards. Each demo board lists the typical
working frequency range and the input and output imped-
ance of the amplifiers.
Setup Signal Sources and Spectrum Analyzer
The LTC6431-20 is an amplifier with high linearity perfor-
mance. Therefore, the output intermodulation products are
very low. Even using high dynamic range test equipment,
third-order intercept (IP3) measurements can drive test
setups to their limits. Consequently, accurate measure-
ment of IP3 for a low distortion IC such as the LTC6431-20
requires certain precautions to be observed in the test
setup as well as the testing procedure.
Table 3. The LTC643X-YY Amplifier Family and Corresponding Application Demo Boards
DEMO BOARD NUMBER
FREQUENCY RANGE
(MHz)
NOTES/APPLICATIONS
BOARD’S IN/OUT
IMPEDANCE
AMPLIFIER
AMPLIFIER’S
IMPEDANCE
DC1774A-A
50 to 350
Low Frequency
50Ω
LTC6430-15
Differential 100Ω
DC1774A-B
400 to 1000
Mid Frequency
50Ω
LTC6430-15
Differential 100Ω
DC1774A-C
100 to 1200
Wide Frequency
50Ω
LTC6431-15
Single-Ended 50Ω
DC2032A
50 to 1000
Cable Infrastructure
75Ω
LTC6430-15
Differential 100Ω
DC2077A
100 to 1200
Wide Frequency
50Ω
LTC6431-20
Single-Ended 50Ω
DC2153A
700 to 1700
High Frequency
50Ω
LTC6430-15
Differential 100Ω
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