Re: [time-nuts] Si570 question
I just picked up the si5351a and the thing that jumps out at mee is the 228 registers to program. Granted it lets you create just about any frequency and there is a good program that tells you what to set the registers to. But 228 registers is a lot. The traditional I2C is indeed simple. Make sure you watch the LSB order and setup times. I see there are various ebay class boards to connect to usb for a few $ and also boards that let you program in Windows studio as an example. Or as you want to do straight out of a micro. Regards Paul On Tue, Nov 18, 2014 at 10:59 AM, Jim Lux jim...@earthlink.net wrote: I'm sure someone here has fooled with the Si570. I just got a few of them (CMOS output), and am about to deadbug one of them to fool with it (unless there's some convenient protoboard out there available.. I didn't look too long and hard, but some casual googling didn't find one). Looking at AN334 from SiLabs: It looks like you just need a 10nF bypass on the Vcc, a pull down on the OE (1k), 1k pullups to 3.3V on SDA/SCL (which is going to be driven by a 3.3V teensy 3.0/3.1 microcontroller) 150 ohm loads to ground, followed by a 0.1 uF DC block? I'm going to be running it at less than 50 MHz (although the parts I got are preset to 100 MHz) Any traps for the unwary? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
On 11/18/14, 8:04 AM, paul swed wrote: I just picked up the si5351a and the thing that jumps out at mee is the 228 registers to program. Granted it lets you create just about any frequency and there is a good program that tells you what to set the registers to. But 228 registers is a lot. The traditional I2C is indeed simple. Make sure you watch the LSB order and setup times. I see there are various ebay class boards to connect to usb for a few $ and also boards that let you program in Windows studio as an example. Or as you want to do straight out of a micro. yes, there are a lot of registers, but there is some code out there to manage them, which I haven't actually looked at. The micro I'm using does I2C quite nicely, and I've used it for a variety of devices. I was wondering more about RF aspects.. How much Power supply rejection do these things have (yeah, the ap note shows a single bypass cap, but that may be good enough to demonstrate function)... and how much harmonic output content is there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
Clue-less. As to the good code I have only found maybe 1 site. I thought there would be more. I think it was hackaday. Regards On Tue, Nov 18, 2014 at 12:58 PM, Jim Lux jim...@earthlink.net wrote: On 11/18/14, 8:04 AM, paul swed wrote: I just picked up the si5351a and the thing that jumps out at mee is the 228 registers to program. Granted it lets you create just about any frequency and there is a good program that tells you what to set the registers to. But 228 registers is a lot. The traditional I2C is indeed simple. Make sure you watch the LSB order and setup times. I see there are various ebay class boards to connect to usb for a few $ and also boards that let you program in Windows studio as an example. Or as you want to do straight out of a micro. yes, there are a lot of registers, but there is some code out there to manage them, which I haven't actually looked at. The micro I'm using does I2C quite nicely, and I've used it for a variety of devices. I was wondering more about RF aspects.. How much Power supply rejection do these things have (yeah, the ap note shows a single bypass cap, but that may be good enough to demonstrate function)... and how much harmonic output content is there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
Jim, thre is some info at: http://www.box73.de/product_info.php?products_id=1869 it's all in German. If you can read that, goto Zusaztinformationen (additional informations) where you will find a comprehensive articel (pdf-document) also in German language (no I have not played with it). enjoy Götz Am 18.11.2014 16:59, : I'm sure someone here has fooled with the Si570. I just got a few of them (CMOS output), and am about to deadbug one of them to fool with it (unless there's some convenient protoboard out there available.. I didn't look too long and hard, but some casual googling didn't find one). Looking at AN334 from SiLabs: It looks like you just need a 10nF bypass on the Vcc, a pull down on the OE (1k), 1k pullups to 3.3V on SDA/SCL (which is going to be driven by a 3.3V teensy 3.0/3.1 microcontroller) 150 ohm loads to ground, followed by a 0.1 uF DC block? I'm going to be running it at less than 50 MHz (although the parts I got are preset to 100 MHz) Any traps for the unwary? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
I have one of these: http://sdr-kits.net/PA0KLT_Description.html built with the CML output Si570 that goes to 1417 MHz (!) There is a schematic in the assembly manual that's linked to from that page. They use 100n and 1n capacitors in parallel on Vdd and 4K7 pullups on SCL/SDA. They have 100n DC blocks directly on the output pins. Into a 50 ohm load, the CML outputs produce about 4dBm as I recall. Obviously, the CMOS output will be different. There is a review of a different Si570 kit on the Clifton Labs site: http://www.cliftonlaboratories.com/si570_kit_from_k5bcq.htm I got similar results comparing my kit against an HP 8640B. The Si570 beats the 8640B close in just as shown on the Clifton Labs site. Some Softrock SDR radios also use the Si570. They use a single 10n capacitor on Vdd and 2K2 pullups...: http://www.wb5rvz.org/ensemble_rxtx/03_lo I have the Softrock Ensemble RXTX. It works fine on RX, but unfortunately I have not been able to get satisfactory image rejection on TX. I suspect the FST3253. So, it looks like decoupling isn't that critical - 10n or 100n||1n in these examples. 1K pullups on SDA/SCL seem to be overkill and anything reasonable = 4K7 should work. Orin. On Tue, Nov 18, 2014 at 7:59 AM, Jim Lux jim...@earthlink.net wrote: I'm sure someone here has fooled with the Si570. I just got a few of them (CMOS output), and am about to deadbug one of them to fool with it (unless there's some convenient protoboard out there available.. I didn't look too long and hard, but some casual googling didn't find one). Looking at AN334 from SiLabs: It looks like you just need a 10nF bypass on the Vcc, a pull down on the OE (1k), 1k pullups to 3.3V on SDA/SCL (which is going to be driven by a 3.3V teensy 3.0/3.1 microcontroller) 150 ohm loads to ground, followed by a 0.1 uF DC block? I'm going to be running it at less than 50 MHz (although the parts I got are preset to 100 MHz) Any traps for the unwary? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
On 11/18/14, 10:24 AM, Götz Romahn wrote: Jim, thre is some info at: http://www.box73.de/product_info.php?products_id=1869 it's all in German. If you can read that, goto Zusaztinformationen (additional informations) where you will find a comprehensive articel (pdf-document) also in German language (no I have not played with it). enjoy Götz that was quite informative (and not totally beyond my limited German vocabulary) Looks like they just send the output out through a couple of DC blocks, with no load resistors. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
On 11/18/14, 11:19 AM, Orin Eman wrote: I have one of these: http://sdr-kits.net/PA0KLT_Description.html built with the CML output Si570 that goes to 1417 MHz (!) There is a schematic in the assembly manual that's linked to from that page. They use 100n and 1n capacitors in parallel on Vdd and 4K7 pullups on SCL/SDA. They have 100n DC blocks directly on the output pins. Into a 50 ohm load, the CML outputs produce about 4dBm as I recall. Obviously, the CMOS output will be different. There is a review of a different Si570 kit on the Clifton Labs site: http://www.cliftonlaboratories.com/si570_kit_from_k5bcq.htm I got similar results comparing my kit against an HP 8640B. The Si570 beats the 8640B close in just as shown on the Clifton Labs site. Some Softrock SDR radios also use the Si570. They use a single 10n capacitor on Vdd and 2K2 pullups...: http://www.wb5rvz.org/ensemble_rxtx/03_lo I have the Softrock Ensemble RXTX. It works fine on RX, but unfortunately I have not been able to get satisfactory image rejection on TX. I suspect the FST3253. So, it looks like decoupling isn't that critical - 10n or 100n||1n in these examples. 1K pullups on SDA/SCL seem to be overkill and anything reasonable = 4K7 should work. Orin. thanks... looks like it's time to stop analyzing and go find a piece of copper clad to stick this thing down on. I see a lunchtime project coming up, ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
Hi Jim: A number of hams have built VFOs using this chip, for example here's some data: http://www.cliftonlaboratories.com/si570_kit_from_k5bcq.htm#Frequency_Spectrum Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Jim Lux wrote: I'm sure someone here has fooled with the Si570. I just got a few of them (CMOS output), and am about to deadbug one of them to fool with it (unless there's some convenient protoboard out there available.. I didn't look too long and hard, but some casual googling didn't find one). Looking at AN334 from SiLabs: It looks like you just need a 10nF bypass on the Vcc, a pull down on the OE (1k), 1k pullups to 3.3V on SDA/SCL (which is going to be driven by a 3.3V teensy 3.0/3.1 microcontroller) 150 ohm loads to ground, followed by a 0.1 uF DC block? I'm going to be running it at less than 50 MHz (although the parts I got are preset to 100 MHz) Any traps for the unwary? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Si570 question
Jim- Do you need to tune it? The 571 is the VCXO - but if you're feeling adventuresome you could drive the 570 as an NCO (numerical) via its i2c interface. NS On Tuesday, November 18, 2014, Jim Lux jim...@earthlink.net wrote: On 11/18/14, 11:19 AM, Orin Eman wrote: I have one of these: http://sdr-kits.net/PA0KLT_Description.html built with the CML output Si570 that goes to 1417 MHz (!) There is a schematic in the assembly manual that's linked to from that page. They use 100n and 1n capacitors in parallel on Vdd and 4K7 pullups on SCL/SDA. They have 100n DC blocks directly on the output pins. Into a 50 ohm load, the CML outputs produce about 4dBm as I recall. Obviously, the CMOS output will be different. There is a review of a different Si570 kit on the Clifton Labs site: http://www.cliftonlaboratories.com/si570_kit_from_k5bcq.htm I got similar results comparing my kit against an HP 8640B. The Si570 beats the 8640B close in just as shown on the Clifton Labs site. Some Softrock SDR radios also use the Si570. They use a single 10n capacitor on Vdd and 2K2 pullups...: http://www.wb5rvz.org/ensemble_rxtx/03_lo I have the Softrock Ensemble RXTX. It works fine on RX, but unfortunately I have not been able to get satisfactory image rejection on TX. I suspect the FST3253. So, it looks like decoupling isn't that critical - 10n or 100n||1n in these examples. 1K pullups on SDA/SCL seem to be overkill and anything reasonable = 4K7 should work. Orin. thanks... looks like it's time to stop analyzing and go find a piece of copper clad to stick this thing down on. I see a lunchtime project coming up, ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
