CC1125: CC1125 Link Budgetting

Sean McGarvey

Prodigy 10 points

Part Number: CC1125

Looking for some help here to understand why we do not achieve the -123dbm sensitivity (for 1.2kHz data rate)

We have a UHF front end chain NF with the below parameters:

Freq Range = 400-450MHz

NF = 3.2dB (including CC1125)

Modulation = 2-GFSK

SNR Requirement = 12dB

Channel Filter = 10kHz

Using the above we should be in the region of -121dBm sensitivity from calculations. In reality (testing our hardware) we are getting -115dBm. Is there anything else I should consider before I look at possible inference in the system?

over 2 years ago

0 TER over 2 years ago

TI__Guru**** 317180 points

How do you measure sensitivity? Note that the datasheet numbers are measured sending packets with 3 byte packet length and a PER limit set to give 1 % BER as the sensitivity limit.

Has your HW been review by TI (https://www.ti.com/tool/SIMPLELINK-SUB1GHZ-DESIGN-REVIEWS) to ensure that your HW is in accordance with our EM and reference design?

0 Sean McGarvey over 2 years ago in reply to TER

Prodigy 10 points

Thanks for the reply. Where can I view the test parameters for this measurement? We are using much larger packets so maybe this could be a factor. Would be good to have all test parameters to ensure we are meeting the performance expectations

0 TER over 2 years ago in reply to Sean McGarvey

TI__Guru**** 317180 points

The sensitivity goes poorer with number of bytes in the packet. Try testing with 3 byte payload, fixed packet length and a PER limit of 47%. Also see https://en.wikipedia.org/wiki/Bit_error_rate on how to go from PER to BER or the other way around

Sub-1 GHz

Sub-1 GHz forum

CC1125: CC1125 Link Budgetting