The EM board provided by TI is designed to give you the best possible performance.  The board you designed might not work as well.   Depending on your schematic, PCB layout and even other wires and parts not related to the radio can affect the performance.   Based on the information you provided I strongly recommend you take a look at the layout of your board and make sure signals are not interfering with the SPI lines and the RF lines. 

If you need some help I would be happy to offer you my services and get you through this issue.

Good Luck

Chris Pinter

http://www.pinterec.ca

twitter: chrispinter_ec

Hi,

Thanks for your reply, but actually i have used the same design given by TI.

062 mil design is there which i am using for my use. I have used all the same parameters and components.

Can you suggest me what could be the reason for poor performance?

And is there any performance difference between old design (By Chipcon) and new 062 mils design by TI.

Regards.

Hi,

Can any TI employee Please look in to this problem, its very urgent.

I will be very much thankful.

Regards.

Hi Steve,

The performance is the same on the two different design. What kind of problem do you have? output power senitivity or something else?

-P

Hi,

Actually i am okay with output power. Actual problem is with my PER(Packet Error Rate).

1. When i am using 062mils design i need to change my smartRF setting, why is so?

2. But then also PER varies with my 062mils design. Actually when i use CC2500EMK(Chipcon EM 1.0) PCB same code works cool with less then 1% PER. But when i use 062 mil design it goes to 10-15% PER. What could be the possible reasons.

3. i have followed all precautions mentioned in pdf and design and components used are as per TI. The only thing is i have mounted them manually. They are not machine mount, so will that affect my PER?

Thanking you for your reply.

Regards,

Steve.

hmm...could you briefly explain your measurement setup. Conducted or wireless? What input power do you have on the chip? Can you measure the RSSI to see if there is a difference?

1. You should not have to change the settings. What settings are you changing?

2. In a perfect world, nothing J. Seems to be some hardware problem..

3. Hand mounting the components shall not affect the performance. However, I know from experience that it can be difficult to get all the soldering good so I do not recommend it. So check all the soldering especially in the the RF part and also the grounding under the chip.

Thank you for your help. I will check with RSSI and then post you again.

1. I am changing the chip version in RF settings.

3. I will check with this suggestion also and will let you know.

Thanking you in anticipation.

Regards,

Steve.

Sorry about the delay, I was out for a day.

There are a couple of things you can try.

1. Add some coupling caps to the power lines....or change the values of the coupling caps up or down a bit.

2. Measure the impedance of the RF balun.  The best way to do this is to transmit a carrier with no modulation at 0 dBm.  If you can measure 0 dB out then the balun is ok.  Sometimes a simple change in the PCB will have a large affect on the impendence.

3. Look for oscillation on an LNA circuit you might have.

4. Can you measure the noise figure of your LNA?   This will also have an effect.

If you are still having problems I can take a look at your circuit a little closer for you,

Chris Pinter

htt://www.pinterec.ca