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Figure 1 Component and Test Point Locations
3.0 Quick Start
The ADC121S625B evaluation board may be
used in the Stand-Alone mode to capture data
with a logic analyzer or third party equipment, or it
may be used in the Computer Mode with a
WaveVision4 Data Capture (WV4) Board. In both
cases, the data may be analyzed with the
WaveVision4 software.
3.1 Stand Alone Mode
Refer to
Figure 1
for locations of test points and
major components.
1. Install an appropriate crystal oscillator into
socket Y2 and short pins 1 & 2 of JP5 (See
Table 1
). Alternatively, connect a signal
generator with TTL logic levels to BNC
connector J6 and short pins 2 & 3 of JP5. In
either case, short pins 4 & 10 of J4 to provide
the clock signal to the ADC121S625. If using
an external source, remove the oscillator from
Y2. If using an oscillator at Y2, remove the
signal source from J6. The presence of a
second clock source could add noise to the
conversion process.
2. Connect a clean analog (non-switching) +5V
power source to Power Connector J5.
3. Short pins 1 & 2 of JP3 and turn on the power
supply.
4. Dynamic differential signal sources centered
around ground should be connected across
pins 1 & 3 of J2. Pin 2 of J2 is ground. If the
source has a 50
Ω
output impedance, install a
51 ohm resistor at R4. Otherwise, the signal
level will be twice as large as expected. To
accurately evaluate the performance of the
ADC121S625, the source must be better than
90dB THD.
5. Short pins 1 & 2 and pins 3 & 4 of JP2 to
provide the bias voltage of VREF for the input
to the ADC when driving the ADC from J2.
6. Differential DC sources or dynamic differential
signal sources centered at a DC bias point
should be connected across pins 1 & 3 of J3.
Pin 2 of J3 is ground.
7. Remove the shorts across pins 1 & 2 and pins
3 & 4 of JP2 when driving the ADC input from
J3.
8. Select the 2.5V shunt voltage reference as
VREF by shorting pins 2 & 3 of JP1 or select
VA as VREF by shorting pins 1 & 2 of JP1. If it
is desirable to provide an external reference
voltage, the jumper must be removed from
JP1 and pin 2 may be driven directly.
9. The digital inputs and outputs are available for
probing at J4.
3.2 Computer Mode
Refer to
Figure 1
for locations of test points and
major components.
1. Run the WaveVision4 program. Version 4.2
or higher is required to interface the WV4
board with the ADC121S625B evaluation
board. While the program is loading, continue
below.
2. Install an appropriate crystal oscillator into
socket Y2 and short pins 1 & 2 of JP5 (See
Table 1
). Alternatively, connect a signal
generator with TTL logic levels to BNC
connector J6 and short pins 2 & 3 of JP5.
3. Connect a USB cable between the
WaveVision4 Data Capture Board and the PC
running the WaveVision4 program.
4. Connect a ribbon cable (order number
WV4ADCIFCABLE) between J4 of the
ADC121S625B evaluation board and J3 of the
WV4 board.
5. Connect a clean analog (non-switching) +5V
power source to Power Connector J5.
6. Short pins 1 & 2 of JP3 and turn on the power
supply.
See Section 4.5 for detailed Power
Supply Information
7. Connect a separate 5V power source
to power connector J1 on the WV4 board and
turn on the power.
8. Connect a jumper cable between TP10
(+3.3V) of the WV4 board and TP5 (3P3V) of
the ADC121S625B board.
9. Perform steps 4 & 5 or 6 & 7 of section 3.1 to
drive the analog inputs.
10. Perform step 8 of section 3.1 to select the
reference voltage.
11. Refer to section 5.0 on Software Operation
and Settings.
