High Performance RF Modulators, PLL and VCO products Forum - Recent Threads

TRF372017EVM

Mingran Guo — Tue, 29 Jan 2013 00:14:56 GMT

Hi there,

We are working on a project about a communication test set. We want to use the IQ modulator TRF372017 but here are some questions, hope someone can give us answers soon.

1. Can it injects a signal directly into the IQ pins?

2. The TRF372017 seems to have an oscillator built into it. Correct?

3. There is a reference clock input. Do we need to connect a reference oscillation signal directly for the TRF372017 to produce the quadrature RF signal? What value do we need for the reference clock? Where is it coming from, and what is it in reference to?

4. Is the board (TRF372017EVM) recommended for the quad-modulator populated and functional?

5. What kind of co-axial cable recommended for IQ connection (TRF372017EVM)?

Thank you.

Fractional/Integer-N PLL Basics Technical Brief SWRA029

Michael Choi — Mon, 06 May 2013 05:32:21 GMT

Dear Sir:

I have a question about the TI Technical Brief (SWRA029), entitled,"Fractional/Integer-N PLL Basics."

I have enclosed a link to this technical brief for your convenience:

http://www.ti.com/lit/an/swra029/swra029.pdf

Please go to page 17, the section entitled: Loop Transfer Function:

Can you please set forth the calculation method that is used to justify this statement:

"For N=1000, the output noise at this offset due to crystal noise calculates to: -105 dBC/Hz."

I look forward to reading your reply.

LMX2485E boundary spurs

Zheng Li3 — Fri, 22 Mar 2013 04:24:35 GMT

Hi,

I am using LMX2485E in our PLL, the comparison frequency is 2MHz. The boundary spurs occurs at +/- 5kHz offset when the VCO operates at 396.005MHz. The spurs varied with temperature. At room temperature it is about -64dBc. At 0 degree C it increased to -54dBc. Do someone know what cause this? Thanks. Zheng

LMX2485E Eval Board to CST Studio Suite

Daniel Pulito — Wed, 24 Apr 2013 18:47:30 GMT

Hello All,

I am interested in doing some EMI/EMC testing on PLL circuits. I currently own an LMX2485E Evaluation Board and was wondering if it would be possible to obtain a file type of that board compatible with CST Studio Suite for use in CST Microwave Studio/PCB Studio. The software is compatible with Cadence Alegro (.brd/.mcm/.sip), Mentor Graphics (.hkp/.hyp/.asc) ODB++ (.zip) and Zuken CR-5000 (.pcf) files.

If you are opposed to giving out EDA files, maybe it could be possible for one of the engineers to import the board for me and just send me the .cst file. CST is capable of importing EDA but I do not believe it is capable of exporting EDA. I’ve talked with some of reps at CST of America before and I was told that T.I. was one of its customers.

I have tried using gerber files in the past, but the conversion process from 2D to 3D over complicates the process. Furthermore, the software recognizes the text data in the files as part of the layer or substrate and there is no convenient way to remedy this.

Additionally, if this isn’t something available to the LMX2485E, I am not opposed to purchasing a different evaluation board for this application as long as it is in the PLL family.

There are several other file types CST is capable of importing such as CAD models too. Let me know if something like this is possible. It would be much appreciated!

Thanks in Advance,

Dan

TRF372017EVM - 2

Mingran Guo — Tue, 16 Apr 2013 21:23:25 GMT

What is the harmonic spec of 3720117EVM? My test results of the RF output signal is shown in graph. We want harmonic to be less than -35dbc/Hz. Is that possible to be done by TI board? Thank you.

DC component at the output of TRF372017EVM

Stefano Straullu — Fri, 19 Apr 2013 14:52:20 GMT

Good afternoon,

I am using the TRF372017EVM with I and Q inputs in order to obtain a 16QAM output signal around a LO central frequency.

I set the GUI according to the datasheet rules, in order to exploit the internal VCO to have a 3GHz LO, as reported in the following figure:

(Please visit the site to view this file)

Could you please clarify me why does the spectrum of the signal at the output of the modulator have an important component around the DC and other replica at multiple frequency of 3GHz?

If you need, I can attach the spectrum plot of this signal.

Thanks in advance for your help.

Best regards.

Stefano Straullu

TRF 1112/1212 and TRF 1222/1122 where i can buy these?

Giorgos Fovakis — Sun, 24 Mar 2013 00:06:08 GMT

Hi!I am working in a Wireless Communications Lab in Athens, Greece. We bought before some years ( i don't know, how many) TRF1115 Evaluation Module which perform the first down conversion of a RF signal. So about the second down conversion WE NEED the TRF 1112/1212 to down convert the signal at 20-50MHz. We want to buy the 1112/1212 module but i cannot find it,to make an order.Can you help me about this? Also we have a problem with the transmitter. We have in the LAB TRF1222/1122 but WE NEED TO BUY the first up-conversion the TRF1221/1121 but also we cannot find it to buy.

Thanks

George

TRF371125, what is minimum base-band output frequency?

Paul Spisar — Tue, 16 Apr 2013 22:31:12 GMT

Is this part suitable for ZIF applications?

TRF371135 query

Sai Jagini — Wed, 27 Feb 2013 06:31:32 GMT

HI,

The data sheet is missing on the following information: (1) The typical values of IQ imbalance (phase and amplitude) of this chip over the entire frequency range. (2) The LPF is adjustable with values between 0 to 255. We need to know the LPF type (I guess it is analog. Is it chebyshev?). and the taps of the filter for the widest LPF (Cutoff approx 15MHz by setting a value of 0). We see that there is a peaking in the response and we need to equalize this, hence we need the impulse response of the filter. (3) The SPI is not very stable. Our Logic Analyser has dumped the three pins and it meets the timing diagram very accurately. Is there anything missing in the timing diagram? We get is to work 80% of the times, some times it will not configure. We have used the clock below 20MHz (tired at 5MHz and 10MHz).

Please help us to get the following information.

NEED INFORMATION- TRF371109IRGZR

Jayakumara krishnasetty — Fri, 11 Jan 2013 09:51:52 GMT

Hi Can you please provide the following information for the TRF371109IRGZR Part ?

1. Junction Temperature Max (Tj Max)

2. Typical Power dissipation (Pd typ)

3. Maximum Power dissipation (Pd max)

4. Weight

Regards,

Jayakumara K

jayakumara.krishnasetty@honeywell.com

NEED INFORMATION- TRF371109IRGZR

Jayakumara krishnasetty — Wed, 05 Dec 2012 07:00:22 GMT

Hi Can you please provide the following information for the TRF371109IRGZR Part ?

1. Junction Temperature Max (Tj Max)

2. Typical Power dissipation (Pd typ)

3. Maximum Power dissipation (Pd max)

4. Weight

Regards,

Jayakumara K

jayakumara.krishnasetty@honeywell.com

GERBER files

hussen basha — Fri, 26 Oct 2012 05:33:33 GMT

Hi,

We are interested in TRF 1115 EVM, so can we have gerber file of TRF 1115 EVM

TRF 3711X EVM not responding...

vamsee krishna — Thu, 21 Feb 2013 07:11:48 GMT

Sir,

Have bought TRF 3711X EVM board (trf 371135) IQ demodulator ..... performed initial DC setup which you have mentioned in the datasheet,it failed to draw current of 350mA as specified was able to draw only a current of 150mA. I also tried to do other RF test couldn't get any signal at output...

My DC power source is completely fine..

Please suggest me any possible solution for it.

TRF371109 BBoutn and BBoutp pins

Daniel Barany — Tue, 24 Jul 2012 14:40:34 GMT

Hello,

I am examining the documentation of TRF371109 (http://www.ti.com/lit/ds/symlink/trf371109.pdf).

BBIoutn and BBIoutp pin positions are not well defined:

page 1: 33 BBIoutn, 34 BBIoutp

page 2: 33 BBIoutp, 34 BBIoutn

page 6: 33 BBIoutn, 34 BBIoutp

page 7: 33 BBIOUTN Baseband I (in-phase) output: positive terminal (???)

34 BBIOUTP Baseband I (in-phase) output: negative terminal (???)

page 38: 33 BBIoutn, 34 BBIoutp

TRF3711xxEVM documentation (http://www.ti.com/lit/ug/slwu069b/slwu069b.pdf):

page 11: 33 BBIoutp, 34 BBIoutn

What are the correct positions of BBIout signals?

Thanks in advance.

Daniel

TRF3765 and TRF371109 on the same bus

Eric Barkhouse — Thu, 04 Apr 2013 15:37:29 GMT

Is it possible to have the TRF3765 and the TRF371109 on the same SPI bus? From the datasheets it doesn't seem to be possible, but is there something I'm missing?

TRF372017EVM stuck on "downloading firmware, please wait"

Alexander Scheuermann — Thu, 11 Apr 2013 15:59:00 GMT

I am currently working with some TI eval boards, namely the TSW1400 pattern generator and the DAC5668EVM dac eval board.

I received an eval board for the IQ modulator with VCO (TRF372017EVM), and got that all connected and the GUI software installed. Now when I start everything up I get to where the FPGA on the TSW1400 pattern generator gets loaded and the software hangs up. It looks like the FPGA gets loaded because all the correct LEDs come on, but the software never recovers from the “Downloading Firmware, please wait” message. To recover I have to kill the process and re-boot the computer.

So far I have removed and re-installed the TSW1400 software, removed the TRF372017EVM software, and re-booted several times. Still hangs up after loading the FPGA on the pattern generator board. I can’t even get back to where it was working. Can you help me get the TRF372017 to work?

TRF3702 on wired application

Viktor Michel — Wed, 10 Apr 2013 07:32:15 GMT

Hi,

i have a customer enquiry, which could be solved by using the TRF3702 (I/Q modulator) and TRF3710 as demodulator. Can I tie the output on a STP cabel (wired instead of wireless)?

Could i reach a distance of about 300 feet?

Beginners questions: Using a TRF370417 (or one of the other IQ Modulators as phase modulator for 2.8GHz Freq input)

John Hadden — Mon, 15 Apr 2013 05:11:59 GMT

Hi,

Apologies in advance... I'm very definitely a beginner to the rf world - so I am probably asking obvious (or impossible) questions. I'd be really grateful if you will bear with me.

Basically I have a microwave generator with frequency ~2.88GHz, which I am outputing ~0-10dBm. It has a pulse modulator which is able to pulse arbitrary length pulses. Typically i pulse ~5ns-100ns. It is finally amplified by 20dBm. I would like to be able to phase modulate the signal between pulses - eg so that I can have a 10ns pulse at 0 phase, then after some variable delay another pulse with pi/2 phase (The actual pulse sequence will be many more pulses than 2 - but the key is to be able to switch phases in between.). So it is important to be able to switch phases within a few ns (or 10s of ns).

Initially being able to switch digitally between phases is what i would want - but in the future it may be useful to do more complicated IQ control.

I was looking at the TRF370417 and the others in the family, (with a special look at the testing board) and as a optimist this looks to me like it will be able to do everything I want (and more). However I guess I'm not 100% clear on the specifications (or exactly how to work it).

Questions\Thoughts

How fast can the IQ modulator follow an input signal? (I read the input bandwidth to be 1GHz - does that mean it would be able to switch phase on the order of ns?)

will the IQ modulator work if I send an already modulated signal through it - and try to switch the phase of it - or would it be a case of feeding a constant signal into it and using the modulator as a amplitude modulator as well as a phase modulator?

If so - how fast is it? (presumably as fast as it would be in phase modulation mode?)

What sort of signals would i have to feed into the IQ controls to control it. Can I get away with sending ttl signals to I and Q ports - (naively the 0 phase signal would be a I=1.5V, Q=0, and pi/2 would be I=0V, Q=1.5V Presumably to do arbitrary more complicated things I'm figuring I'm probably going to need to get some sort of arbitrary waveform generator.

Please let me know if I'm asking silly questions - I'll do my best to improve them.

TSW3065 Local Oscillator accuracy

Robert P��hlmann — Fri, 05 Apr 2013 14:20:11 GMT

Hello,

when verifying the performance of the TSW3065 Local Oscillator I noticed that it has an offset of about 14kHz at a frequency of 2.42Ghz. When using fractional mode for the PLL i could compensate that offset.

Is there a better way to get an accurate frequency, maybe by calibrating the device?

Best regards and thanks for your help,

Robert

Setting LMX2531 internal loop filter components in Clock Design Tool software

PJB — Wed, 03 Apr 2013 20:35:16 GMT

Does anyone know how to select the advanced loop filter component selection in Clock Design Tool?

I'm trying to set the internal C and R loop filter values by choosing one of the`drop down box settings in the advance section of the loop filter menu. Looking at the phase noise results they don't seem to have any effect, which strikes me as wrong / odd.

Any ideas on why this doesn't appear to be working, or what I've done wrong, would be gratefully received.

PJB

LMX2541 RFoutEN

serguei khoudiakov — Tue, 12 Mar 2013 17:40:52 GMT

Hi,

I'm looking for some timing diagrams for LMX2541 power on/off using RFoutEN pin. What are the raise/fall times (lag) of the output RF carrier with relation to RFoutEN signal.

I wanted to generate 400ns RF pulses at 2.4GHz with 50% duty cycle, would I be able to do this using RFoutEN pin?

thanks,

serguei

Improve TRF370417 Performance

Brian May — Thu, 07 Mar 2013 15:03:44 GMT

Currently using the TRF370317 as a quadrature modulator with an advertised operating RF output from 400 to 4000 MHz. A customer requested RF output at 200 MHz. The TRF370417 has an advertised RF output from 50 to 6000 MHz, however, sideband supression is degraded down to 70 MHz according to the datasheet. IC swap from '317 to '417 shows that '317 has better amplitude imbalance and phase error at 200 MHz. That was a surprise! What steps are required to tune the circuit for use with a '417? What are the equivelent circuit models for '417 LO/IF/RF pins?

thanks,

B.May

Discrete solution for FM modulation

venkat narayana — Mon, 04 Feb 2013 10:23:16 GMT

I want to design a FM modulation ciruit with discrete components

Carrier frequency of 100KHz, Message signal frequency in the range of 2.8KHz to 7.6KHz.

I got some circuits from net which uses the varactor diodes, resistors , capacitors, and inductors. But the selection (design) of these components for my frequencies are not there.

Can any one please suggest me a solution for this.

Regards

Venkat

TRF372017 at Extreme Temperatures

George Vogel — Tue, 12 Feb 2013 14:25:20 GMT

Hello, I'm using the TRF372017 to modulate 10Msps onto a carrier at 2GHz, but I'd like to operate it beyond its specified temperature range (-40C to +85C) to -45C to 100C. Has anyone done this before, and know what to expect for performance? I'm not looking for a guarantee of operation, but it would be helpful to know what parameters I should watch out for to fall out of specification.

Thank you.

TRF3765/TSW3065 GUI for Windows 7

Dave Weinzierl — Tue, 22 Jan 2013 19:59:06 GMT

Is the GUI for TSW3065 supposed to be compatible with Windows 7 (32 and 64 bit).

I have seen it work, but it seems a little finicky - needing to double click on settings , loss of USB connections etc.