1.0 Introduction
3.0 Quick Start
The ADC08100EVAL Design Kit (consisting of the
ADC08100 Evaluation Board, National's WaveVision
software and this manual) is designed to ease evaluation
and design-in of Nationals ADC08100 8-bit Analog-to-
Digital Converter, which operate at sample rates up to
130 Msps.
Refer to
Figure 1
for locations of test points and major
components.
1.
Connect the evaluation board to the Digital Interface
Board (order number WAVEVSN BRD 3.0). See the
Digital Interface Board Manual for operation of that
board.
The WaveVision software operates under Microsoft
Windows. The signal at the Analog Input is digitized and
can be captured and displayed on the computer monitor
as dynamic waveforms. The digitized output is also
available at Euro connector J3.
1.
Install a 100 MHz (or lower) crystal into socket Y1.
While the oscillator may be soldered to the board,
using a socket will allow you to easily change clock
frequencies.
2.
Connect a clean power supply to the terminals of
connector P1. Adjust power supply to voltages of
+4.75V to +5.25V and -5.2V to -5.3V before
connecting it to the board. Turn on the power and
confirm that there is 3 Volts at the pins of inductor
L1.
The software can perform an FFT on the captured data
upon command. This FFT display also shows dynamic
performance in the form of SNR, SINAD, THD and
SFDR.
Evaluation with this system is simplified by connecting
the board to the WaveVision Digital Interface Board
(order number WAVEVSN BRD 3.0), which is connected
to a personal computer through a serial communication
port and running WaveVision software, operating under
Microsoft Windows. Use program WAVEVSN2.EXE
3.
Use VR1 to set the top reference voltage (VRT) for
the ADC to 1.9V at TP2. Use VR2 to set the bottom
reference voltage (VRB) for the ADC to 0.3V at TP4.
4.
Connect the jumper at J4 to pins 1 and 2 (those
farthest from oscillator Y1).
5.
Connect a signal of 1.6VP-P amplitude from a 50-
Ohm source to Analog Input BNC J2. The ADC
input signal can be observed at TP7. Because of
isolation resistor R17 and the scope probe
capacitance, the input signal at TP7 will not have
the same frequency response as the ADC input
signal.
The signal at the Analog Input to the board is digitized
and is available at pins B16 through B19 and C16
through C19 of J3. Pins A16 through A21 of J3 are
ground pins.
Provision is made for adjustment of the Reference
Voltages, VRT and VRB with potentiometers VR1 and
VR2, respectively. These voltages are not regulated and
will vary with the input potential at pin 1 of Power
Connector P1.
6.
The Digital Interface Board should be set up for
40MHz operation with an 80MHz crystal installed.
See the Digital Interface Board manual.
7.
See the Digital Interface Board Manual for data
gathering instructions.
2.0 Board Assembly
The ADC08100 Evaluation Board may come pre-
assembled or as a bare board that must be assembled.
Refer to the Bill of Materials for a description of
components, to
Figure 1
for major component placement
and to
Figure 2
for the Evaluation Board schematic.
NOTE:
The FFT will not indicate the correct frequencies
because this information is derived from the clock
frequency selected on the Digital Interface Board. To
show the correct frequency information on the FFT,
double click on the FFT window to open the FFT Dialog
Box, then click on "Frequency", then click on "OK".
Alternatively, you may double click on the data capture
window before performing the FFT and change the
frequency at "Sampling Rate of This Data (MHz)" to 100
to indicate a 100MHz rate.
5
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