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dc2078af
DEMO MANUAL DC2078A
L3, L4, C19 and C20 are optional parts. They are for ad-
ditional matching components when further optimization to
a lower or wider frequency range applications is required.
Table 2 shows the function of each input and output on
the board.
Additional Information
As with any RF device, minimizing ground inductance is
critical. Care should be taken with the board layout because
of the exposed pad packages. The maximum number of
minimum diameter vias holes should be placed underneath
the exposed pad. This will ensure 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 the exposed
pad interface.
The T_DIODE Pin (Turret E3) can be forward biased to
ground with 1mA of current. The measured voltage will
be an indicator of the chip junction temperature (TJ).
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
DC2090A
50 to 1200
Power Doubler
50Ω
Dual LTC6430-15
Differential 50Ω
DC2076A-A
50 to 350
Low Frequency
50Ω
LTC6430-20
Differential 100Ω
DC2076A-B
350 to 1000
Mid Frequency
50Ω
LTC6430-20
Differential 100Ω
DC2078A
50 to 1000
Cable Infrastructure
75Ω
LTC6430-20
Differential 100Ω
OPERATION
Please note that a number of DNC pins are connected on
the demo board. These connections are not necessary for
normal operation, however, failure to float these pins may
impair the operation of the device.
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 LTC6430-20 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 LTC6430-20
requires certain precautions to be observed in the test
setup as well as in the testing procedure.
