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dc1620afb
DEMO MANUAL DC1620A
QUICK START PROCEDURE
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
DC1620A a bandpass filter used for the clock should be
used prior to the DC1075. 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 Agilent
8644B generators are used with TTE bandpass filters for
both the clock input and the analog input.
Apply the analog input signal of interest to the SMA con-
nectors on the DC1620A demonstration circuit board
marked J5 AIN+. These inputs are capacitive coupled to
Balun transformers ETC1-1-13 (lead free part number:
MABA007159-000000).
An internally generated conversion clock output is available
on J1 which could be collected via a logic analyzer, or other
data collection system if populated with a SAMTEC MEC8-
150 type connector or collected by the DC890 QuikEval™-II
data acquisition board using PScope™ software.
Software
The DC890 is controlled by the PScope system software
provided or downloaded from the Linear Technology
website at http://www.linear.com/software/. If a DC890
was provided, follow the DC890 Quick Start Guide and
the instructions below.
To start the data collection software if “PScope.exe” is
installed (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 DC1620A demonstration circuit is properly connected
to the DC890, PScope should automatically detect the
DC1620A, and configure itself accordingly. If necessary
the procedure below explains how to manually configure
PScope.
Under the Configure menu, go to ADC Configuration. Check
the Config Manually box and use the following configura-
tion options, see Figure 2:
Manual configuration settings:
Bits:
16
Alignment:
16
FPGA Ld: DDR LVDS
Channs:
2
Bipolar:
Unchecked
Positive-Edge Clk: Checked
If everything is hooked up properly, powered, and a suitable
convert clock is present, clicking the Collect button will
result in time and frequency plots displayed in the PScope
window. Additional information and help for PScope is
available in the DC890 Quick Start Guide and in the online
help available within the PScope program itself.
Serial Programming
PScope has the ability to program the DC1620A board
serially through the DC890. There are several options
available in the LTC2185 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).
Figure 2: ADC Configuration
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