Table of Contents
Advertisement
When using the ADC121S101 Evaluation Board with the
WaveVision Capture Board, the 5V logic power supply for
that Capture board is passed to the ADC121S101
evaluation board through pins A1, B1, A2 and B2 of J10.
However, that voltage is not connected to the power
header J6. If it is desired to use the +5V from the
WaveVision
Capture
board
evaluation board, it is necessary to add a wire from A1,
B1, A2 or B2 of J5 to pin 1 of J6.
4.7 Power Requirements
Voltage and current requirements for the ADC121S101
Evaluation Board is
•
Pin 1 of J6: +2.7V to 5.7V at 5 mA
•
Pin 2 of J6: Ground
4.8 Analog Inputs
The ADC121S101 evaluation board input channel is
composed of termination components and a user choice
of a.c. or d.c. signal coupling to the ADC121S101. Short
together pins 2 and 3 of J4 to a.c. couple the input signal.
Short pins 1 and 2 on J4 to present your input signal
directly to the ADC121S101.
Caution: Be sure that the input signals to the
ADC121S101 do not go more negative than -0.3V or
more than 0.3V above the ADC121S101 power
supply.
5.0 Installing and Using the ADC121S101
Evaluation Board
The evaluation board requires a power supply as
described in Section 4.7. An appropriate signal generator
(such as the HP3325B, HP8662A or the Tektronix
AWG2000 series) with 50 Ohm source impedance should
be connected to the Analog Input BNC J3. A bandpass
filter should be inserted between the generator output
and the input to the ADC121S101 evaluatoin board when
evaluating sinusoidal signals to be sure there are no
unwanted frequencies (harmonics and noise) presented
to the ADC. A USB cable must be connected between
the WaveVision Capture Board and the host computer.
See the WaveVision Capture Board User' s Guide for
details.
5.1 Software Installation
The WaveVision software provided requires about 6
Megabytes of hard drive space, include the Java files,
and will run under Windows. See the WaveVision
Capture
Board
Manual
installation instructions.
5.2 Setting up the ADC121S101 Evaluation Board
This evaluation package was designed to be easy and
simple to use, and to provide a quick and simple way to
for
the
ADC121S101
for
WaveVision
software
evaluate the ADC121S101. The procedures given here
will help you to properly set up the board.
5.2.1 Board Set-up
Refer to Figure 1 for locations of the major components
on the board.
1.
Connect The ADC121S101 evaluation board to
WaveVision Capture Board, WAVEVSN BRD 4.0.
2.
Connect the desired jumper to J4. See Section 4.8.
3.
Connect power to the board per requirements of
paragraph 4.7.
4.
Connect an USB cable between the Capture Board
and a USB port on your computer.
5.
Apply power to both the WaveVision Capture Board
and the ADC121S101 evaluation board.
6.
Connect an appropriate test signal source to BNC
connector J3 of the ADC121S101 evaluation board
through an appropriate filter.
5.2.2 Quick Check of Analog Functions
Refer to Figure 1 for locations of major components on
the board. If at any time the expected response is not
obtained, see section 5.2.5 on Troubleshooting.
1.
Perform steps 1 through 6 of Section 5.2.1.
2.
Adjust VR1 for the desired ADC121S101 supply
voltage (and reference voltage) at TP6.
3.
Scope TP8 to be sure the input signal is present.
This completes the testing of the analog portion of the
evaluation board.
5.2.3 Quick Check of Software and Computer
Interface Operation
1.
Perform steps 1 through 3 of Paragraph 5.2.2,
above.
2.
Adjust the signal source at Analog Input J3 for a
peak-to-peak signal amplitude at TP8 very slightly
below the value of the d.c. voltage at TP6.
3.
Be sure there is an interconnecting cable between
the Capture Board and your computer USB port.
4.
R
the WaveVision4 program.
UN
5.
Acquire data by pressing the F1 key. Data transfer
can take a few seconds.
6.
When transfer is complete, the data window should
show many sine waves. The display may show a
nearly solid area of red, which is O.K.
7.
With the mouse, you may click on the magnifying
glass, then and drag (top left to bottom right) to
select a small portion of the displayed waveform for
better examination.
8.
Click on the FFT tab to compute the FFT and
display a frequency domain plot.
The FFT data will provide a measurement of SINAD,
SNR, THD SFDR and ENOB, easing the performance
verification of the ADC121S101.
6
http://www.national.com
Advertisement
Table of Contents
