Replacement part for Skyworks CC1120 design?

Not sure why SKYWORKS is not recommending their module for new designs, as the CC1120 is certainly active.  Please refer to TI's CC1120-CC1190 CC1120-CC1190EM915RD Reference Design as an alternative:  http://www.ti.com/tool/cc1120-cc1190em915rd  .

-Leonard

Hi,

The CC1120 Skyworks ref design is still valid.

Information from Skyworks:

SKY65313-21 is the same part as SKY65613-11 but mainly with improved Sleep Icc and some other minor parameters.  No changes needed to the reference design other than calling the -21 part number.

Regards,

   Richard

Hi All,

By TI support, we succeed to make a radio system (0.5W) with CC1125 & CC1190. Now we are designing 1W radio system with CC1125 & SKY65313-21.

By using this link http://www.ti.com/tool/CC112XSKY65313EM-RD a new board designed. But, we are facing a problem in Tx. i.e. After transmission of 4000 to 5000 packets, it gets stopped then, it won't transmit even if power restart of radio system.

We need your valuable support again.

Thanks & Regards,

Chaitanya

Are you able to check where the transmission stops?

Eq, after when the transmission stops, are you able to read/ write to the CC1125? Do you have a signal out on the CC1125? What power setting do you use on CC1125?

Hi Everyone,

Yes, I able to read and write to the CC1125, when transmission is stops. And by using Spectrum Analyzer, I checked out the O/p of CC1125 signal power. And I interfaced the 1-Watt SKY65313 FEM with CC1125 and verified the Output power of PA with different i/p power levels by using Spectrum Analyzer. Observed the packet transmission between two radios, some times I receiving the packets and sometime I getting CRC error. After 5000 packet transmission, I getting grounding problem with CC1125.

Q1: Why I am not receiving the packets?

Q2: Why I am CC1125 grounding problems are rising?

Q3: Why I am getting -25dBm RSSI, when I am transmitting the packets with +5dBm I/p power?

Please clarify my doubts & replay to me.

Thanks & Regards,

Tarakeswara Rao

Hi Everyone,

Yes, I able to read and write to the CC1125, when transmission is stops. And by using Spectrum Analyzer, I checked out the O/p of CC1125 signal power. And I interfaced the 1-Watt SKY65313 FEM with CC1125 and verified the Output power of PA with different i/p power levels by using Spectrum Analyzer. Observed the packet transmission between two radios, some times I receiving the packets and sometime I getting CRC error. After 5000 packet transmission, I getting grounding problem with CC1125.

Please clarify and support me.

Q1: Why I am not receiving the packets?

Q2: Why I am facing the grounding problems with CC1125?

Q3: Why I am getting -25dBm RSSI, when I am transmitting the packets with +5dBm I/p power?

Thanks & regards,

Tarakeswara Rao

Q2: What do you mean by grounding problems? Please elaborate what you mean.

Q3: +5 dBm, is this the output power of CC1125 or the SKY65313?

Hi TER,

Q3-Answer: Yes, +5dBm is the O/p power of CC1125.

Q2-Answer: While I transmitting with PA, Current consumption of our board is from 560mA to 265mA (Varying). After some time transmission gets stops.

I observed the RSSI graph with TI-Smart RF Studio7.

Been to the lab and tested communication between 2 x CC1200-SKY65313. SmartRF Studio were used to configure the boards and to log the received data. Even after 10000 packets the the communication link worked without any issues.

You should note that CC1200 RSSI reading saturates at approx -10 dBm. The SKY65313 has a gain of approx 16 dB, so the RSSI reading of the CC1200-SKY65313 saturates at approx -26 dBm. The maximum input power level to the CC1200 is +10 dBm (saturation level); for SKY65313 the maximum input is +5 dBm. Thus, if you transmit at +27 dBm (0.5W), make sure you keep some distance between RX and TX units - otherwise you will be violating the CC1200 and/or SKY65313 maximum operation.

It is not clear from your post if it is the TX or the RX units that stops working after 4000 - 5000 packets. Please let us know which unit fails (RX or TX) and how you came to this conclusion.

Did you test using your own SW or SmartRF Studio? What are the system parameters and register settings in your test setup?

Have you tested the conducted performance before you set up an RF link? That is, have you measured output power using a spectrum analyzer? Any issues if you keep the TX unit continuously on for a long period of time (degradation in output power, drift in frequency,....)? Have you measured sensitivity using a signal generator?

If you provide the gerber files and schematic we can do a review to check for obvious mistakes.   

Hi All,

Q3-Answer: Yes, +5dBm is the O/p power of CC1125.

Q2-Answer: While I transmitting with PA, Current consumption of our board is from 560mA to 265mA (Varying). After some time transmission gets stops.

I observed the RSSI graph with TI-Smart RF Studio-7.

Please clarify my questions and support me.

Thanks & Regards,

Tarakesh

If you want us to support you, please read my previous posting carefully and provide answer to the questions. The information you have provided so far is not sufficient for us to be of help.

Dear All,

Thanks for replay.

My Observation in Radio Testing:

1. Kept the 0.5W radio's at 3mt  distance, one module is in TX mode and another module is RX mode. We Transmitting the data from TX module, I'm receiving the data with RX Module. Here both TX and RX is working. No SW issues. Both TX & RX are tested 48 Hours continuously. This 0.5W radio project is designed with CC1125 and CC1190 FEM as per TI Evaluation schematics.

2. And I tested my SW, O/p power (with PA and without PA) with 0.5W radio boards in both TX & RX mode after 48 Hours, both are working.

3. Now we designed the 1W radio with CC1125 and SKY65313-21 FEM (869 MHz). And Updated the SW as per FEM instructions. I kept my 1W radio as in TX mode and 0.5W radio as in RX mode and separated by distance with 3mt. And I kept the TX unit continuously for 36 Hours.

4. After then, I'm facing the problem in TX mode and observed the power o/p PA (without CC1125) by using Signal generator & Spectrum analyzer, It is OK.

5. Tested the matching networks between IC's (Filter has IL=0.5dB and RL=-18dB) by using NK Analyzer, those are OK.

6. Tested the CC1125 without PA by using Spectrum Analyzer, Observed that, signal power is slowly degrading, no drift in frequency. 

7. SKY65313-21 FEM has Maximum CW I/p: +15dBm and In Receiving mode Maximum I/p: +5dBm.

8. Smart RF Studio-7 is using for Receiving purpose only.

We need to see a schematic for the CC1125 + SKY65313 solution.

3) Which PA_CFG2 setting did you use for CC1125?

4) How do you measure this? Have you removed the CC1125? Please show on the schematic where you inserted the signal. What input power did you use from the SG and what did you measure as output power? Table with output power vs input power would be nice.

6) Slowly degrading when you do the measurement? How did you disconnect the FEM? Again a table with output power vs input power would be nice.

What I would suspect if I understand your description correctly is that you have reduced the lifetime of the CC1125 somehow but that is not possible if you followed the ref design.

Dear All,

We find-out & rectified the problem in module. Now the module in TX mode and another module is in RX mode. But I didn't get any receiving packets in RX Module. Please guide me for next step. 

Test Setup:

Distance between Antennas: 1.2 mt

Transmitting power: +5 dBm (without PA) . Antenna is directly connected to CC1125 O/p.

Sorry for all the questions but your problem description is missing quite a few details.

- I assume +5 dBm is the setting you are using on the CC1120. What is the conducted output power?

- What is the conducted sensitivity?

- What do you mean "connected to CC1125 O/p" ? I assume that you have connected the antenna to a 50 ohm point after the balun/ match? Again a schematic would be helpful.

4530.RADIO GERBER 02-08-2014.rar

8400.PAGE04_CC1125.pdf

3603.PAGE05_SKY65313.pdf

1.4744.CC1125 CKT Design.pdf

Hi Team,

Please find attached Gerber file of our project. 2nd & 3rd pages are CC1125 and SKY65313-21_1W_FEM Module. We are fallowed as per your schematics only. Please verify and support me for our project completion ASAP. Here SKY_FEM is fallowed by CC1125 and both are on one side of PCB and other side is Micro controller part.

As per schematics we did small modifications:

1. A.     In CC1125 Page:
   1. 1.     We didn’t place the some components and is called as DNI.
   2. 2.     Compare the component vales in Band Pass Filter (Matching NK) at Pin_17_TX in our schematic with your Schematic.
   3. 3.     Compare the component vales in Balanced NK at Pin_19 & 20_RX in our schematic with your Schematic.
   4. 4.     In our Schematic, Pin_18 is not connected to anywhere. It is opened.
2. B.    In SKY65313 Page:
   1. After SAW filter’s we removed the components and directly connected to FEM with 0Ω as per our schematic and remaining components are same as.

Thanks & Regards,

TARAKESWARA RAO.

I have to look at the gerber files tomorrow but I would recommend following our ref design (http://www.ti.com/tool/cc112xsky65313em-rd). L21, C82, C77 have wrong values, the Tx network is wrong, L20 should not be there, L15, C96, C91 have wrong values, R48/ C66 is not needed in this design. Is Both R50 and R49 mounted? If so you are applying 3.3 V to the digital part that has a maximum rating of 2 V. R66 should be mounted if U10 is not used.

Hi TER,

I verified our schematic and your schematic. You point out the components numbers (L21, C82, C77, L15, C96, C91, R48, C66, R50 and R49) are not in both schematics. Please suggest the correct component values and numbers as per our schematics in TX and RX part. 

Thanks in-advance,

Regards,

Tarakeswara Rao

The component numbers I'm referring to are used in your schematic.

As previously stated, follow the ref design I linked to in my previous post. As you have not followed the same topology in your design as in ours it is not possible to map your component numbering to ours.