DAC121C08XEB/NOPB National Semiconductor, DAC121C08XEB/NOPB Datasheet - Page 7

• Manufacturer Part Number: DAC121C08XEB/NOPB
• Description: BOARD EVAL FOR DAC121C081/5
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of DAC121C08XEB/NOPB

• Number Of Dac's: 1
• Number Of Bits: 12
• Outputs And Type: 1, Single Ended
• Data Interface: Serial
• Settling Time: 6µs
• Dac Type: Voltage
• Voltage Supply Source: Single
• Operating Temperature: -40°C ~ 125°C
• Utilized Ic / Part: DAC121C081/5
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: DAC121C08XEB

4.4 Analog Output
The analog output of this Eval board is available in
two places. For a DC coupled output, pin 1 of J5
provides V
coupled output is provided by the SMA connector
(J4). See Figure 5 below for details.
If using a spectrum analyzer to look at the output
of the DAC, the AC coupled output (J4) is
recommended.
For very low frequency (i.e. less than 1kHz), use
J5 to see the output signal DC coupled. For an
AC coupled output at low frequencies, simply
replace the AC coupling capacitor at C9 with a
larger capacitor. Use the J4 SMA to look at the
AC coupled output.
4.5 Power Supply Connections
In Computer mode, the board can be powered by
either an external supply or the local WaveVision4
board
Evaluation Board must be powered by an external
supply.
If you wish to use the local supply from the
WaveVision4 Board, place a jumper across pins 1
and 2 of JP9. This connection will supply +5V to
V
short pins 2 & 3 of JP7. For WaveVision to
recognize the board, the 3P3V supply must be
enabled as well.
across pins 1 and 2 of JP10. The board comes
configured to use the local supply. The default
jumper settings are shown in Figure 1.
A
V
on the DAC board. To set V
OUT
supply.
AC Coupled
OUT
Figure 5: Analog Output
V
and pin 2 provides AGND. An AC
OUT
In
Do this by placing a jumper
Stand-alone mode, the
REF
=V
A
, simply
7
If you wish to supply V
voltage supply to connector J2. Connect GND to
the center terminal and V
Place a jumper across pins 2 and 3 of JP9 to
select V
anywhere from +2.7V to +5.5V. The source of
V
V
V
Refer to Figure 6 for a diagram of the power
supply connections.
Typical supply currents when applying an external
supply to V
Note: These values are specified for a
continuously operating DAC in High Speed Mode,
driving a full-scale sinewave output. The majority
of this current is for powering devices external to
the DAC121C085 such as the pull-up resistors
and the LED.
REF
REF
REF
=V
from the top terminal of J2, short pins 1 & 2.
is controlled by the JP7 jumper.
• For V
• For V
A
Figure 6: Power Supply Connections
A
, short pins 2 & 3. To use an external
_REMOTE. This voltage (V
A
and V
A
A
= +3.3V, I = 7mA
= +5.0V, I = 12mA
REF
http://www.national.com
are as follows:
A
externally, connect a DC
A
to the bottom terminal.
A
) can be set
To set
V
AGND
V
REF
A
Remote