Si570 Group Buy

 Last Update 07/08/2008

SI570 group buy by KM5H Tom Hoflich


PayPal the appropriate U.S. funds to KM5H at  

 Start-up frequency 56.32 MHz

Si570BBC000141DG LVDS 20ppm Si570CAC000141DG CMOS 50ppm

1                                      $22                                                   $20
2                                      $41                                                   $37
3                                      $60                                                   $53
4                                      $79                                                   $70
5                                      $98                                                   $87
6                                    $117                                                $105
10                                  $193                                                $170

Add one dollar per order for DX addresses
Lead time is up to 6 weeks


For US and Canada addresses only.  See the rest of the world.

 USB-Controlled Synthesizer for Softrock RXTX and Local Oscillator Applications Kit

CMOS $37,  $23 without Si570

LVDS $40,  $24 without Si570

Add one dollar per order for Canada addresses

You can also order from the KM5H webpage.






(June 4, 2009)

All orders have been shipped.

I still have stock on everything.

73, Tom KM5H

(April 19, 2009)

All outstanding orders have been shipped.

As of now, I have everything in stock.

Thanks and 73

Tom KM5H


(Dec. 23, 2008)

This afternoon, I shipped all orders on hand after finally getting all of the shipments that I have been waiting for. I now have everything stock so if you have been waiting, now is a good time to order.

Thanks and 73, Tom KM5H


(Nov. 18, 2008)

All CMOS parts and kits with CMOS parts have been shipped.

I am still waiting on the LVDS parts. I don't know when they are 

coming until I get the notice from FedEX. But I expect them before the 

end of the month. I have everything set up to ship very quickly when 

they arrive.

I have some CMOS parts and version 2.03 kits for immediate shipment.

Thanks for you patience and 73. Tom KM5H


(July 17, 2008)

The price of the LVDS kit (w/o Si570) is $24 instead of $25.

 (July 13, 2008)

Pricing available for USB-Contorlled Synthesizer kits.

 (July 12, 2008)

 All Si570's have been shipped.  More are on order.

I will be shipping the SDR-kits in the US and Canada.

Watch for details soon


(July 2, 2008)

 All Si570 orders have been shipped (or will be in the next couple of hours).

I have 4 CMOS left that can be shipped quickly.

New orders will "collect" until I have close to 25 for a new order.

Thanks and 73, Tom KM5H

 (June 24, 2008)

I have received my latest shipment of both CMOS and LVDS versions of the SI570.

All of the domestic orders are packaged and will go in the mail tomorrow.  I am working on the DX orders now and they will go in the mail soon.

I ordered some extra again this time so now is a good time to order and get them quickly.

73, Tom KM5H

 (June 1, 2008)

All of the May orders have been shipped and the June list has started. I will post that soon. Thanks for the DX reports of when you receive your parts.  I am surprised at how quickly some arrive.

Thanks to all

73, Tom KM5H

(May 10, 2008)

First, I want to thank you for all of the "thank you" notes and the DXers letting me know that you received your parts.
Yesterday afternoon, the CMOS parts came in. Avnet sent them overnight since the messed up the order.  So I was able to get them out this week rather than next week.
All of the paypal domestic orders are going into today's mail.
DX and non paypal orders will go in the mail Monday morning since I need an open post office.

Thanks to all
73, Tom KM5H

(May 8, 2008)

I just got notice that the CMOS parts which are shown in the current list on will arrive next week and will be in the mail by next Thrusday or Friday at the latest.

73, Tom KM5H

(APR 27, 2008)

Good news. By Tuesday, I should receive enough LVDS parts to fill all orders that I have thru today.  I will  be getting those in the mail as fast as possible.
Unfortunately Avnet messed up again and it will be a little longer for the CMOS parts.  I will let you know when I have some information. I only publish information when I get the FedEx tracking information.

Thanks for your patience.

73, Tom KM5H


 (APR 12, 2008)

Yesterday I received 70 CMOS parts. They are all packed. Those that don't require a trip to the post office will go in the mail today.  Those that have to go to the PO will be mailed Monday morning.
I have 50 CMOS on order and 57 orders and 40 LVDS on order and 44 orders so it looks like I will be planning another order when the orders get to 25.

Thanks, Tom KM5H

 (MAR 30, 2008)

 I am preparing another order to go in tomorrow so if you are lurking in the shadows, now is the time. Lead time is still 4 to 6 weeks.
All 25 LVDS on order came in last Monday. But only 10 of the CMOS came in. They have all been mailed to you. I expect balance of 70 CMOS to come in the next two weeks.
Thanks for you patience.

Tom KM5H

(MAR 13, 2008)

This week, the last order came in and most have been shipped out.
The few left will go out no later than tomorrow.
I am preparing the next order for both versions.
It will go in later this afternoon. Any orders that come after this afternoon will be in the next order.

Thanks to all.
Tom KM5H

(MAR 8, 2008)  

I had paid orders for 85 CMOS parts so I ordered 90. The 90 will be in on Tuesday and I will get them out as quickly as possible.
I already have enough for another CMOS order which I will do on Monday.
If you want to be included and have not yet paid, please do you paypal before Monday afternoon (CDT).  We got lucky this time because lead time is usually about 4 weeks.
Tom KM5H

(FEB 27, 2008)

The order has been submitted.

Anything coming in now will be in a future order.

Tom KM5H

 (FEB 25, 2008)

I have shipped all of the chips on hand.

Tomorrow, I will place an order for both versions of the chip.

73, Tom KM5H

  ( FEB 23, 2008)

I have shipped the backlog of 400 Si570's.
I really appreciate all of the "thank yous" and kind words from all of you who have received your parts in the last few days.
I am working on the last shipment of 25 and will have those out soon.
Most of the orders for the last few days have been for the CMOS version I believe mainly because of the announcement of the very neat XTALL.  But, there has been a lot of progress on ways to interface the LVDS version.
It is time to send an order for more LVDS chips. If you are interested, get your payment in soon so you don't have to until the next order.

Thanks to all
73, Tom KM5H

(FEB 17, 2008)

 290 are in the mail.  Some of you have already received them.  I have about 40 more packaged and ready to go to the post office (which is closed Monday). Another way of putting it is that orders thru Jan 2, 2008 are on the way to you.

73, Tom KM5H

  (FEB 14, 2008)

The 300 Si570's finally arrived. it turns out that they were marked leaving the factory 12/13/2007 so they were the origial order. Wonder where they were for the last two months. Anyway all of the order one are at the post office as of this morning (some yestersay).
I will start working on order 2 today.
73, Tom KM5H


(FEB 10, 2008)      

 Good News!!           FedEx tells me that they will deliver the illusive 300 Si570s on Tuesday afternoon. So, I will get a bunch of them in the mail on Wednesday. I will get all of them out as soon as possible. I figured at 3 minutes per shipment, it will take 8 hours so I ask a little more patience from you.  Thanks
Tom KM5H

(FEB 3, 2008) 

The latest buy is up to 22 so I am going to send the order for 25 today.
I am still expecting 100 in to arrive in about two weeks.
Thanks for your patience.

73, Tom KM5H


(JAN 27, 2008)

I received 25 Si570's and packaged them to be shipped tomorrow.
So look for an S in the ship column at
Next shipment in 3 week.

73 Tom KM5H

(JAN 22, 2008) later

  I finally got a commitment from Avnet.  300 parts will arrive in Phoenix on Feb. 20 and then on to me in a couple of days.  Then on to you in a few days.  This is where it gets wierd.  The seem to have found 25 and I should get them in a few days. I will get those out as soon as I get them.  Where did they get 25????? I am guessing that someone messed up really bad and they don't want to admit it.  More news when I actually get them.
The current order is now full and there are 2 into the next order of 25.

Thanks for all of your patience. 73, Tom, KM5H


 (JAN 22, 2008)

The current group of 25 has only 3 openings. I already ordered it.
The demand has slowed. I will take orders for another 25 with the understanding that I will refund those if we do not get to 25. But, I am guessing that when we get the lost 300 into your hands, the demand will increase.
About the lost 300, I was on the phone yesterday about that.  I will be on the phone every day until I get some clear information to report to you.

(JAN 14, 2008)

First, I would like to thank you for the "thank you"s and kind words for my efforts. I really appreciate it.
Second, the orders just keep coming even though I closed Buy 4. So, I am extending that buy to include as many as possible.
Again, you can check to see what is happening with your order. It is always up to date within 24 hours.
Third, for the last three weeks I have been getting the run-around from the order clerk at Avnet about the order for 300 that just does not show up.  So I escalated the issue to management. I apologize for not doing it sooner. Anyway they say that the order for 300 was lost and they are looking around the warehouse for it. They say that it should have been delivered in December. If they find it, we should get it soon.  I will let you know as soon as I find out anything.
Thanks for you patience.
73, Tom


(JAN 4, 2008)

Buy 4 is now Closed.
Since then, I have gotten email expressing interest in 12 more which is almost half of a new buy of 25. So I will just keep doing the for a while.
I am thinking that there will be more excellent work like that of Mike KF4BQ and Guido PE1NNZ and others which will generate even more orders. Way to go guys.

73 Tom, KM5H

 (JAN 3, 2008)

I just submitted an order for 50 more Si570's even though I have 44 paid.  If history means anything, the other 6 will be gone before the order arrives.
Also they say that 300 are in transit from the factory so I expect to receive those and start shipping them in a week or so.
Keep checking for details.

73, Tom

(DEC 31st, 2007)

I had to go to two post offices today (first one closed at noon), but all of the LVDS parts that came in this week are in the mail. The 6 week lead time if nearly up so I hope to receive more soon.
The buy 4 is already up to 23 paid so any payments more than two will roll into buy 5.
There have been some requests for the CMOS version and I assume less accuracy and therefore less cost(otherwise CMOS & LVDS cost the same).  I am not against doing a buy of 25 of those if there is enough interest.  Email me directly.

(DEC 30th 2007)

First, I received 50 of the LDVS version and will getting them in the mail tomorrow. It seems like I should have gotten more. I will check on that tomorrow. I ship out in the order that payment was received.

Second, for a group buy 4, I have 5 paid.  All I need is 20 more to order so if you are interested, now is the time.
I will update the status on later today so you will know to watch your mailbox (an S will be added to the ship column).

(DEC 21, 2007)

All 100 of the CMOS versions have been shipped. Waiting for more to arrive.

Thanks, Tom  


(DEC 19, 2007)

The FedEx guy showed up with 100 of the CMOS version at 5:30 yesterday afternoon. I just mailed about 25 and have another 25 packaged to be mailed later this afternoon. I plan to have the others ready to mail later today. It took over 6 hours to get those 50 packaged but I am getting better at it. I have several cross checks to make sure I don't make any mistakes. I appreciate Tony more and more. 73, Tom KM5H

(DEC 13, 2007)

Good news! My credit card was charged for 100 of the A option chips which means that they should be on the way to me. I will let you know when they arrive and will quickly get them on the way to you. I have enough paid orders to order 25 more of the B option chips. I will do that tomorrow. You can send money for the next 25 if you want, but I can't guarantee that there will be enough. I will of course refund if there is not enough for another order. Tom KM5H

(DEC 6, 2007)

Somehow I did not communicate very well. If one payment is sent the 30 cents is included. If you have to send two payments because the first one was wrong then add the 30 cents to the second. Sorry.

(DEC 6, 2007)

OK, OK I am opening up the next buy of the Si570. Because the demand has slowed, I have to switch to the 25 price from the 100 price. Those of you who sent money already will have to send more or I will refund if that is what you want. For PayPal you will have to add 30 cents for the additional fee. The new prices are:

PayPal to my email address

(DEC 4, 2007)

I got several comments about how fast the buys have been moving and that some were not able to order in time. I agree with you. In fact, if you think it is moving fast, you should be in my shoes. The other complaint is that it was not clear when the second "open" period began. I agree that while it was stated, it was not totally clear unless my status was read completely. Sorry, I should have made it more clear. The problem is that the minimum order is 50 parts at a time. I have no control over that. When, I warned that the 50 point was getting close, I was flooded with orders and had to shut it off before it went past 50. So, now what do I do? I have eliminated the A option and the only part that I will work with is the LVDS part since it is the most popular. One possibility is that we now move to groups of 25. The price for one goes from $18 to $22 and 2 goes from $33 to $41 and so on. So, those who missed the previous orders, are you still interested? Please email directly to me rather than the whole group.

Tom KM5H

(NOV 26, 2007 a little later)

The second order group buy is now closed. We have reached 50. Send no more money now. If the demand continues, I would be willing to go for another 50. There are still over a hundred people who have expressed interest but have not paid, so we will see.

Tom, KM5H

(NOV 26, 2007)

Since the interest in the A part has only generated 7 payments, no new orders will be accepted for the A part. I know that one person has requested to switch to a B which will leave 5. If anyone else is willing to switch, let me know. For one A to B switch the additional funds will be $2.30 and for two $4.30. Let me know. On the B or LVDS part we are really close to the 50 limit. The demand is pretty slow and very soon, I will have to stop accepting payments for them.\

Thanks, Tom KM5H

(NOV 20, 2007)

I received some disappointing news today. Avnet is now are giving me 6 to 8 week delivery rather than the 4 to 6 weeks (before the order) with a date of Jan 10. I have ask them to expidite this as much as possible even if it means getting a partial order. They have promised an answer by Monday. I know you guys are all ready to get to work. I sure am. Also, on the second buy we have 6 A and 22 B paid. Since we need to get to 50, we have a way to go (but sadly plenty of time). I know that some of you with A's on the first order want to switch to B. Maybe we can work something out with these 6 A's on the second order and increase the B orders.

(NOV 15, 2007)

The order for 100 option A and 300 B has been finalized. I hope to have a ship date soon. My credit card company shut off my card thinking that this large charge must be fraud. It was quickly fixed since it really was me. The spreadsheet that goes with this order will be available below soon. Check it out and make sure your part is right. Those of you who made requests but did not bet around to paying will be in another sheet for the next order. Some payments arrived after this buy was closed. Those will be on this second sheet. I need to get up to 50 paid to do another order. It looks like that won't be a problem. I am thinking about just going with the B option in the future. So, if you are willing to switch to B let me know.

Thanks to all. Tom, KM5H

(NOV 14, 2007)

For now, the group buy is closed. Do not send any more money. If the interest continues, and we get at least 25 more requests, I am willing to do another. Please check and make sure that your status is corrent on the spreadsheet below. Later today, I will move the requests that did not send money to another spreadsheet. Thanks to all. Tom KM5H

(NOV 12, 2007)

Orders for Option A are now


You can still request them, but don't send any money for Option A. Contact me directly if this is a problem for you. Option B is still strong.

(NOV 11, 2007)

The orders for option A are slowing down. Paid orders are at 91 at the moment. I have decided to stop taking orders for A at 100. If there is still demand, I will consider taking more orders at a little over $2 per part more because the cost will be the Quantity 25 price. Demand for option B is still strong.

(NOV 9, 2007)

I just sent the order for the first 150 570BBC000141DG's I don't quite have enough paid orders for the 570CAC000141DG order. The spreadsheet will be updated in a couple of hours. Good News!! I finally have all of the information. I was not able to get out of sales tax, but because I live out in the boonies it will only be 5.4%. Unfortunately, the lead time is 4 to 6 weeks. I am told that once the order is in they may be able to expedite it some.



PayPal the appropriate U.S. funds to KM5H at foreign addresses add $1 per order Fine Print I will order as soon as I get 100 paid orders. The next order will be when I get 50 more and so on. I just found out that to get the good price, I have to order in multiples of 50 each part number. This means that if I get 201 orders, I have a problem to solve. I am confident that I can work it out. One possibility is for some to upgrade to option B or downgrade to option A. Some have already expressed willingness to do that. If you ordered option A and option B you will probably receive them separately. Tom KM5H

To place an order or make changes send an email to Tom Hoflich the address is above, do not post on this website.
Information on the SI-570 and it's possible uses

The CMOS part is easier to interface to CMOS circuits but it's much noisier (jitter). The LVDS version is way more quiet

but it does not interface to CMOS logic directly, in the SoftRock it can connect to where the crystal connects, the built in transistor brings it up to where it will work with the CMOS logic so nothing extra is needed. Make sure you email Tom with which parts you desire.

What is the SI570? It's a programmable Oscillator with fairly low noise compared to similar chips using the I2C serial bus to control it's frequency. It can be used in place of multiple crystals to allow a SoftRock to cover multiple frequency sections. For example a SoftRock 80M/40M could with this chip be able to receive signals in the range of 3.5MHz to 7.5Mhz and everything in-between. You would not only get full band coverage but also get International Flights, Shortwave and government stations in that range. Another possible use is a poor man's signal generator, this chip is capable of working at very high frequencies, the lowest frequency quality chip can go as high as 215MHz. Two persons have already mentioned that they will be laying out PCB boards to allow the use of the chip. The noise specifications are as follows;

Noise figures for the SI570 chip, specially notice the figures for LVDS outputs;

See the links below for

additional information.