Difference between revisions of "Phoenix Schematics"
(link back, remove blank lines, remove redundant heading) |
(+cat) |
||
Line 20: | Line 20: | ||
Note there is no DDS clock circuit at this point. This is still under development, though a simple crystal oscillator module will be used for prototypes. | Note there is no DDS clock circuit at this point. This is still under development, though a simple crystal oscillator module will be used for prototypes. | ||
+ | |||
+ | [[Category:Phoenix]] |
Latest revision as of 10:53, 25 January 2010
The root sheet schematic for the Phoenix board gives an idea of the overall layout.
Interface Circuit
The interface Circuit uses a small CPLD as in the other HPSDR modules to map to the bus in a programmable way. It will also allow experimentation with various clock schemes.
DDS circuit The DDS circuit uses the latest device from Analog Devices - the AD9912. This has better SFDR and output freq range than previous devices. I have elected to use a PECL driver for the CPLD and a packaged LPF for convenience.
The DDS requires several regulators for best performance.
Mixer/QSD The Mixer/QSD is based on various comments and sources.It uses the devices proposed originally. The CPLD will be used to generate quadrature signals from the DDS. No preamp/filters have been included at this stage.
QSE The QSE circuit is basically the reverse of the receiver with a low level power amp
Note there is no DDS clock circuit at this point. This is still under development, though a simple crystal oscillator module will be used for prototypes.