Altera Cyclone II DSP Development Board - Manual (Page 25)

Altera Corporation Reference Manual 2–17
August 2006 Cyclone II DSP Development Board
Cyclone II DSP Development Board Components
D/A Converter SMA Connector (J31 & J43)
J31 (channel A) and J43 (channel B) are standard through-hole SMA
connectors used to interface the TI DAC904E D/A converter with SMA
cables.
D/A Converter Clock Buffer (U27 & 30)
For channel A, U27 provides the selected D/A clock to U25. For channel
B, U27 provides the selected D/A clock to U30.For more information see
“D/A Converter (U25 & U30)” on page 2–17 .
D/A Converter (U25 & U30)
The D/A converter (U25 for channel A and U30 for channel B) on the
Cyclone II DSP development board provides 14-bit resolution and
produces samples at rates up to 165 MSPS. It is a high-speed TI DAC904E
D/A converter and is set up to drive a differential-to-single output
through a transformer. The output is transformer coupled and can be
found on the SMA connector (J31 for channel A, J43 for channel B). The
output of the TI DAC904E D/A converter is set to the maximum output
current of 20 mA. The signal-to-noise ratio for the system is 70 dB for
output signals from 1 MHz to the Nyquist frequency of the converter.
1
The SLP-50 anti-aliasing filter from Mini-Circuits provides a
55 MHz cutoff frequency. To use the anti-aliasing filter, connect
the filter to one end of the SMA cable. You can perform an
external loopback from the SMA D/A converters to the SMA
A/D converters using the filter and cable assembly. If the cutoff
frequency must be lower than 55 MHz, other filters may be
used. See the Connecting the Cables to the Board & PC section in the
DSP Development Kit, Cyclone II Edition Getting Started User
Guide.
VGA_RED 33
VGA_SYNCN 11 AE2
Note to Table 2–10 :
(1) Blank cells indicate no connection.
Table 2–10. VGA Triple Video D/A Output Converter Pin-Outs (Part 2 of 2) Note (1)
Schematic Signal Name VGA (U21) Pin Number Cyclone II (U12) Pin Number