--- In [email protected], "David Brainerd" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], "drmail377" <drmail377@> wrote: > > > > Hi All... > > > > I've been thinking about using a Cypress Semiconductor > > (www.cypress.com) serial Programmable Clock Generator (PCG) as a VFO. > > I think the PLL-based design would have much cleaner output compared > > to a DDS. But I have some questions: > > > > Do any of the decent PC programs for SDR control either the Blueberry > > or Peppermint PGC eval boards via USB? > > > > Are the Cypress parts the best solution out there in terms of > > PLL-based PCGs? > > > > It seems Cypress has discontinued the Blueberry evaluation board for > > the CY27EE16 PCG (P/N CY30703). > > > > There is a $20 USD Peppermint eval board available though (P/N > > CY30701). Peppermint is USB capable. Peppermint is based on the > > CY22393 part, which seems fine, SPI programmable, three PLL's, up to > > 200MHz 4X4 crosspoint switch. > > > > Has anyone used the Peppermint board? Are there any disadvantages to > > using the CY22393 instead of the older CY27EE16 that was on the now > > discontinued Blueberry board? The only down-side I can see is minor: > > The older part supported both SPI and I2C serial protocols, the latter > > part does SPI only. > > > > Thanks, David > Take a look at the Si570. It is programmable over the I2C bus and goes > as high as 1.4 GHz > with very good noise specs. There is a group buy going on at > <http://www.softrockradio.org/si570> > > I sell a little board that will hold the Si570 and has a voltage > regulator and a level shifter for > the I2C bus. Look on my "For_Sale" page. I have sold over 400 at this > point. Many of the > people on the SoftRock40 group are using them with the softrocks in place > of the crystal. > There is also software to control it over the PC parallel port. The > dds_controller group is > working on a program to control it using the Universal Bit Wacker board. > > Dave - WB6DHW > <http://wb6dhw.com> >
Dave (WB6DHW), Whew - we've got three Dave's on this thread... Thanks for the heads up on your Si570 breakout boards, nice. However, the SI570 has an internal oscillator. Ultimately I want to use a GPS stabilized reference to lock the VFO. The Si570 has a VCXO input and will probably work with your Si570 breakout board, but then I have to add another lock loop externally. I have been looking at the Si5326 clock generator though. I think I'll pick up some of your Si570 boards and parts. Are the Si570's you quote 20ppm or 50ppm? But; my first choice was the $20 Cypress CY27EE16 based Blueberry board because it seems existing programs like G8JCF's application may be able to drive it out of the box. But as I said before, the Blueberry is discontinued. After further investigation I kind of doubt the newer Cypress CY22393 based Peppermint board will work with the likes of G8JCF software as it is today though. The reason is because it seems the the Elektor May-2007 SDR, which works with the G8JCF software intefaces with the CY27EE16 via I2C, and the CY22393 has only SPI. I've posed the CY22393 compatibility question on the G8JCFSDR Yahoo Group. Let's see what rolls in. Thanks, David WB4ONA
