Driving a LMX1601 with Bascom-AVR

bzijlstra

For a transceiver project we have used a LMX1601 1.1 Ghz/500 Mhz low cost dual frequency synthesizer. It drives the VCO of a MC3362, a single chip narrow band FM receiver. Very stable. It has taken some time to get things up and running. The input frequency is taken from the 11.059.200 hertz crystal from the driving Atmega128. Coupled with a 100 pf to the F-aux-in of the LMX1601. With a Shiftout the Atmega128 is configering the LMX1601 at the startup of the program. Four 18 bits codes are shiftout. The last two bits of the code (LSB) are to define to which register this code has to be written. The four registers are AUX_R, AUX_N, MAIN_R and MAIN_N. With the four bits (MSB) of the AUX_R the type of output is selected. With these four bits you can choose the output of the input freq. divided by the AUX_R, by the AUX_N register, lock detect etc. etc.

A nice webpage with some extra info:
http://www.cappels.org/dproj/Home.htm

Some pictures:
The Bascom-AVR code:

The calculator from National Semiconductor, a big help:

You will have to check the datasheet of the LMX1601 to get the full details. It is a very nice programmable prescaler.

Have fun
Ben Zijlstra

plusboy · Joined: 17 Aug 2008 Posts: 21

hello.
very nice project..
I have a project about FM receiver with saa1057 and mc3362 .. I dont know how to drive saa1057 or any kind of pll in the range of 130 to 144 MHZ .
what kind of data should send to the saa1057 and how?

please help me to program an avr chip to drive saa1057.!
do u offer me another PLL SYNTHESIZER?

thanks alot

bzijlstra · Posted: Wed Jan 04, 2012 12:02 am Post subject: LMX2306

Here the code for a LMX2306

Instead of the 18 bit of the LMX1601 it is 21 bit

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

Thanks for sharing Ben.
What a difference compared to the PLL i made decades ago using TTL/CMOS chips. And that was just 100 Mhz.

Stefanus · Joined: 14 Aug 2012 Posts: 8

Hello
Please post links LMX2306 calculator.
Thank you

bzijlstra

http://www.ti.com/tool/codeloader

have fun
Ben Zijlstra

Stefanus · Joined: 14 Aug 2012 Posts: 8

Hello sir,
i have install codeloader4, but when i select device LMX2306 allways runtime error "13" type mismatch

please help me

Thank you

bzijlstra · Posted: Tue Nov 13, 2012 8:46 am Post subject: Error 13

Installed this new codeloader4 and get also the error 13.
Got the older one that is working somewhere so will put that online.

Have fun
Ben Zijlstra

Nothing to do with Bascom-AVR, (but still nice) SDR with a funcube DVB-T USB-stick to get a radio from 24 mHz - 1700 Mhz. AM/FM/LS/US/CW. Stick must contain either the E4000 or the RTL2832U chip. Including NOAA weathermaps. Check youtube.

Stefanus · Joined: 14 Aug 2012 Posts: 8

Dear sir,

Do you have older version for codeloader LMX2306? or give me link

Thank you

Stefanus · Joined: 14 Aug 2012 Posts: 8

Dear, sir
actualy iwant to make RF oscilator 136.000 to 150.000mhz using MAX2606 pll LMX2306, step 100hz, 12,8mhz crystal for LMX2306.

can you give calculation for LMX2306?

Thank you very much

bzijlstra

Here the older Codeloader 4 software. It is freeware.

This one is from the National Semiconductor site, the new one is from the TI.com site and gives an error 13 message.

Have fun
Ben Zijlstra

Stefanus · Joined: 14 Aug 2012 Posts: 8

Dear, Sir
Thank you very much for codeloder4

warm regards
Stefanus