Linear Technology DC1525A Demo Manual page 4

DEMO MANUAL DC1525A
QUICK START PROCEDURE
using a sinusoidal signal generator a squaring circuit can
be used. Linear Technology also provides demo board
DC1075A that divides a high frequency sine wave by four,
producing a low jitter square wave for best results with
the LTC2175.
Using bandpass filters on the clock and the analog input
will improve the noise performance by reducing the
wideband noise power of the signals. In the case of the
DC1525A a bandpass filter used for the clock should be
used prior to the DC1075A. Data sheet FFT plots are taken
with 10 pole LC filters made by TTE (Los Angeles, CA) to
suppress signal generator harmonics, non-harmonically
related spurs and broadband noise. Low phase noise Agi-
lent 8644B generators are used for both the Clock input
and the Analog input.
Digital Outputs
Data outputs, data clock, and frame clock signals are avail-
able on J1 of the DC1525A. This connector follows the
VITA-57/FMC standard, but all signals should be verified
when using an FMC carrier card other than the DC1371.
Software
The DC1371 is controlled by the PScope™ System Soft-
ware provided or downloaded from the Linear Technology
website at http://www.linear.com/software/.
To start the data collection software if PScope.exe is in-
stalled (by default) in \Program Files\LTC\PScope\, double
click the PScope Icon or bring up the run window under
the start menu and browse to the PScope directory and
select PScope.
If the DC1525A demonstration circuit is properly connected
to the DC1371, PScope should automatically detect the
DC1525A, and configure itself accordingly.
If everything is hooked up properly, powered and a suit-
able convert clock is present, clicking the Collect button
should result in time and frequency plots displayed in
the PScope window. Additional information and help for
4
PScope is available in the DC1371 Quick Start Guide and in
the online help available within the PScope program itself.
Serial Programming
PScope has the ability to program the DC1525A board
serially through the DC1371. There are several options
available in the LTC2175 family that are only available
through serially programming. PScope allows all of these
features to be tested.
These options are available by first clicking on the Set
Demo Bd Options icon on the PScope toolbar (Figure 3).
This will bring up the menu shown in Figure 4.
Figure 3. PScope Toolbar
Figure 4. Demobd Configuration Options
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