Difference between revisions of "Phoenix Schematics"
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Revision as of 20:38, 17 May 2009
Schematics
The root sheet schematic 
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.
