EVAL-ADF411xEBZ1 problem

Is the board powered up? If you are using a power supply, what current is being drawn by the board?

If you are using a spectrum analyzer to monitor RFout, increase the span to cover the full output range of the VCO. For example, if your VCO outputs 5.7 GHz to 5.9 GHz, then, if the VCO is working, there will be a signal visible somewhere between 5.6 GHz and 6 GHz.

Next, you need to test if the ADF4157 is being programmed.

1. Toggle the powerdown bit, R3, DB5. If the current drawn drops, then the part is powering down, so you are correctly communicating with the part.
2. Alternatively, toggle the phase detector polarity bit, R3, DB6. If the signal on the spectrum analyzer moves, then you are correctly communicating with the part.

If you have verified you are communicating with the part, you can use the MUXOUT (R0) signals to debug the system. If you program MUXOUT for R Counter Output, then the signal coming out of the R counter should be visible on the MUXOUT pin. You can do the same with the N counter.

Let me know how this goes.

Thanks for your quick answer!

Yes, the board is powered up by the 9VDC battery provided with the eval kit. That makes it inconvenient to monitor the current as you suggested but I can work something out! I will also try to solder a SMA connector on the MUXout.

However when I searched for EVAL-ADF411xEBZ1 on your website, I only found references to the EVAL-ADF411xEB1 with ADF4107 part (instead of ADF4157). What does 'Z' stand for? Is it possible something has been mixed up? That would also explain why the software provided on the CD was incorrect...

Regards

If you have access to a power supply, remove the battery and connect the power supply outputs to the battery connectors.

You don't need an SMA connector to monitor MUXOUT. You can use an oscilloscope. Or even a voltmeter if you are testing the DVdd and DGND outputs.

Lots of our parts use the same EVAL-ADF411xEBZ1 evaluation board because they are all pin compatible. These parts include the ADF4107 and ADF4157.

The Z means the boards is ROHS compliant.

What software provided on the CD?

The software on the CD is ADF4xx rev5 and there was no available option for ADF4157 to select.

I think I made some progress :

- the MUXout is changing correctly between DVDD and DGND so the communication is well established

- the Reference Frequency (test point T1) is correct (I see a 10 MHz sine wave with the scope)

- test point T2 shows the same wave with a DC-offset (offset is approximately 1.5VDC)

- test point T7 (connected to the Vtune of the VCO) shows no sign of life

- output of the VCO (capacitor C18) stays at 0 too

- VCO is powered correctly (5V)

I will now look at the current consumption

EDIT : that's done :

- current @ 28 mA in power-down

- 56 mA in operation

Is there a loop filter on your board? Are R1, R2, C1, C2 and C3 populated?

ADF4153, ADF4154, ADF4156, ADF4157 software can be downloaded here:

http://ez.analog.com/message/38414#38414

Yes! The loop filter is mounted (except R1A).

The link you mentioned for the software is actually the one I used...

What register settings are you using? Can you attach a screenshot of the evaluation software?

Of course,

here you go

Did you put your own VCO on the board?

The standard VCO is not capable of producing 580 MHz. I think the VCO's output range is 5725 - 5875 MHz.

If you want to output 580 MHz, you will need to replace the VCO.

Sorry, it was just a try. I have the original VCO on the board. I switched back to the dafault value of 5800 MHz. But if I want 580 MHz on RFout, how can i do? Because the textboxes to tune FRAC, MOD and INT are grayed (disabled)?