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SiPM digital control board supporting components (view source)
Revision as of 15:36, 25 June 2008
, 15:36, 25 June 2008Added multipurpose components section, and 20MHz crystal oscillator
While the FPGA, Ethernet controller, DAC, ADC and Temperature sensor are considered the main components of the SiPM digital control board, there are also many other supporting components that will be on the board. This page discusses many of the other minor components on the SiPM digital control board.
While the FPGA, Ethernet controller, DAC, ADC and Temperature sensor are considered the main components of the SiPM digital control board, there are also many other supporting components that will be on the board. This page discusses many of the other minor components on the SiPM digital control board.
== Multipurpose Supporting Components ==
This section discusses components that function to support two or more of the major components on the control board.
=== 20MHz Crystal Oscillator ===
The SiPM digital control board is driven by a 20MHz clock generated from a crystal oscillator. This signal will be divided into a 5MHz signal by the FPGA for some components, but nonetheless, the 20MHz clock is the main timing signal on the board. The component most sensitive to this signal is the CP2201 Ethernet IC, so the oscillator will be selected to meet the requirements of this chip. According to the [http://www.silabs.com/public/documents/tpub_doc/dsheet/Microcontrollers/Interface/en/CP2200.pdf CP2201 data sheet], the CP2201 requires a 20MHz signal with an error of no more than ±50ppm. One crystal oscillator that meets the requirements of the CP2201 is the Epson Toyocom MA-505 20.0000M-C0 ([http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=SE2509CT-ND Digi-Key Part #SE2509CT-ND]). There are also many other similar oscillators available if the Epson Toyocom model proves insufficient.
== FPGA Supporting Components ==
== FPGA Supporting Components ==