Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Forums Magazine Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Anritsu Alliance Test Equipment Amplifier Solutions Anatech Electronics Axiom Test Equipment Berkeley Nucleonics Bittele Centric RF Conduct RF Copper Mountain Technologies Empower RF everything RF Exodus Advanced Communications Innovative Power Products ISOTEC KR Filters Lotus Systems PCB Directory Rigol RF Superstore San Francisco Circuits Reactel RFCT TotalTemp Technologies Triad RF Systems Windfreak Technologies Withwave LadyBug Technologies Wireless Telecom Group Sponsorship Rates RF Cafe Software Resources Vintage Magazines Thank you for visiting RF Cafe!

PLL interface - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2010 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2010, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. Regardless, there are still lots of great posts in the archive that ware worth looking at. Below are the old forum threads, including responses to the original posts.

NOTICE: The original RF Cafe Forum is available again for reading, and the new RF Cafe Blog is an active board.

-- Amateur Radio

-- Anecdotes, Gripes, & Humor

-- Antennas

-- CAE, CAD, & Software

-- Circuits & Components

-- Employment & Interviews

-- Miscellany

-- Swap Shop

-- Systems

-- Test & Measurement

-- Webmaster

RFguy

Post subject: PLL interface Posted: Wed Dec 28, 2005 9:15 pm

Who can give advice for PLL interface:

if PLL divders and powerdown setting are programmable through a three-wire serial interface, for a fixed frequency operating, can I use a simple three-wire series EEPROM instead of microcontroller for PLL interface.

Your kind help will be greatly appreciated

Top

IR

Post subject: Posted: Thu Dec 29, 2005 2:07 am

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Hello RFguy,

Yes you can use EEPROM for that. The PLL chip doesn´t really care about the way the programming command is being provieded, as long as it provided in the right sequence, timing and logic levels.

_________________

Best regards,

- IR

Top

Guest

Post subject: PLLPosted: Thu Dec 29, 2005 8:12 am

Most if not all EEPROMs are not system controllers. A "system controller" is capable of generating control signals. That means that most if not all EEPROMs cannot be used to generate the control signals needed by the PLL. You'll need a microcontroller or PLD to do that.

EEPROMs merely respond to "read" and "write" commands generated elsewhere.

Good Luck!

Top

RFguy

Post subject: Posted: Thu Dec 29, 2005 5:47 pm

Thanks for guest and IR. Does it mean I should use microcontroller such

as ATMEL ATtiny22, not use a simple three-wire serial EEPROM such AT93C86?

Regards,

Top

RFguy

Post subject: Posted: Thu Dec 29, 2005 6:05 pm

Sorry, another question: if PLL frequency is fixed, does it still need any microcontroller or EEPROM? May it can be programmed outside from PC?

Thanks.

Top

Guest

Post subject: Posted: Thu Dec 29, 2005 6:43 pm

Hello again RFGuy,

The EEPROM is needed to program your PLL to hope from one known fixed frequency to another. In case that your frequency is constant and doesn´t vary at all, you can program your PLL without any EEPROM or any other PLD or µP.

Good luck!

Top

RFguy

Post subject: Posted: Thu Dec 29, 2005 7:20 pm

Thank you. Guest. You are so kind. It means even I don't need to put any EEPROM or uP in the RF board. Right?

Top

IR

Post subject: Posted: Fri Dec 30, 2005 1:14 am

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Hello RFgUy,

That is true. If you use only a single constant frequency then you can deliver your signals directly to the PLL without any additional components.

_________________

Best regards,

- IR

Top

Guest

Post subject: PLLPosted: Fri Dec 30, 2005 1:43 am

IR & RFguy,

It depends on the specific PLL chip. Those that have a 3-wire interface such as I2C (Philips) or SPI (Motorola/Freescale) and including many by National, must have some circuitry to provide serial data and clock. IR is correct, IF and ONLY IF you have a parallel interface PLL chip, or one of the very rare ones with on-board EEPROM. So be careful - just because you need only one frequency does not mean that you don't have to get the correct divisor(s) into the chip.

Good Luck!

Top

RFguy

Post subject: Posted: Fri Dec 30, 2005 2:11 pm

Guest and IR,

Thank your help. How about Silicon Lab Si3133 or Si4136? it has 3 -wire serial interface. No need extra components?

Happy New Year

Top

Guest

Post subject: PLLPosted: Sat Dec 31, 2005 8:01 pm

I think you require external parts with the SiLabs Si4136. According to the data sheet:

The Si4136 is programmed serially with 22-bit words

comprised of 18-bit data fields and 4-bit address fields.

When the serial interface is enabled (i.e., when SEN is

low) data and address bits on the SDATA pin are

clocked into an internal shift register on the rising edge

of SCLK. Data in the shift register is then transferred on

the rising edge of SEN into the internal data register

addressed in the address field. The serial interface is

disabled when SEN is high.

Which sounds to me like there are no dependable default values loaded in.

IR, do you read it the same way?

Good Luck!

Top

RFguy

Post subject: Posted: Sat Dec 31, 2005 10:03 pm

Thank guest. You helped me many times. Before that, I did PLL design only for loop filter and VCO, the frequency is not fixed, so always used microcontroller , but no direct design with control function. so I am not good at PLL interface. if frequency is fixed, Si4136 need microcontroller or not? welcome more advices from PLL expert

Top

Guest

Post subject: Need to pay attention to sink/source currentsPosted: Sun Jan 01, 2006 9:24 am

Regardless of what you use for a controller, you will need to check the sink/source current requirements for the PLL control lines. I found out about this minor, but important, detail the hard way in one of my former designs.

Top

IR

Post subject: Posted: Sun Jan 01, 2006 10:14 am

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Hello RFguy and guest,

Indeed you will need control over the timing of writing to the Si4136.

In the designs I have been involved with, it was done through a CPLD.

The function of the CPLD is to assure the right timing of the writing sequence to the PLL device.

Also using CPLD makes it easier for you to debug the circuit in case of problems. Most often it happens that bits are sent in a wrong order because of misunderstanding the sequence mentioned in the data sheet.

Then while getting a strange output frequency or none at all, one can´t really understand if the problem is programming-related or RF-related. By using a CPLD or similar programmable device it is easier to eliminate and tackle problems.

_________________

Best regards,

- IR

Top

RFguy

Post subject: Posted: Sun Jan 01, 2006 11:47 am

Thank IR and guest again. Have a wonderful new year!

Posted  11/12/2012

Exodus Advanced Communications Best in Class RF Amplifier SSPAs
Amplifier Solutions Corporation (ASC) - RF Cafe
RF Electronics Shapes, Stencils for Office, Visio by RF Cafe
Lotus Communication Systems Modular RF Component Building Blocks - RF Cafe
KR Electronics (RF Filters) - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free

 

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024

Webmaster:

    Kirt Blattenberger,

    BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:

AirplanesAndRockets.com