Hello：
1、We use cc1125 transceiver in the front end of UHF applications (430-470mhz applications). In our previous six chip prototype, the output consistency of cc1125 is good. Under the same configuration, the power stray is within ± 1dB.
Now we have produced 300 UHF boards in a small batch for the first time. At present, 100 UHF boards have been tested. It is found that 20 of them are quite different from our previous prototype. Under the same configuration, the overall output power of cc1125 is more than 3-6db lower.
Of course, the first thing we suspect is the hardware matching or welding problems on the board, but these problems have been eliminated. Through cross verification (the OK board and the defective board exchange cc1125), it is determined that the consistency difference of cc1125 is the cause of this problem.
I directly disconnect the circuit connecting the rear PA, weld the coaxial cable from the cc1125 output port (retaining the cc1125 output pin power supply bias matching circuit), and test its output power through conduction. The data of 6 samples measured in the following table (3 OK, 3 bad)
Under the same configuration conditions of sn115 and sn067 (l-gear), the power difference is 6dB, which I think is abnormal.
|
SN |
Power gear |
CC1125 Output power/dBm |
|
087（defective board） |
H |
0.56 |
|
M |
-6.45 |
|
|
L |
-9.42 |
|
|
091（OK board） |
H |
4 |
|
M |
-2.46 |
|
|
L |
-5.06 |
|
|
116（OK board） |
H |
4.16 |
|
M |
-2.32 |
|
|
L |
-4.9 |
|
|
057（defective board） |
H |
0.64 |
|
M |
-6.42 |
|
|
L |
-9.43 |
|
|
115（OK board） |
H |
4.82 |
|
M |
-1.57 |
|
|
L |
-4.15 |
|
|
067（defective board） |
H |
-0.03 |
|
M |
-7.22 |
|
|
L |
-10.18 |
Ti's description of cc1125 output power error is not found in the data manual. There is only a typical value typ (page 17 of the data manual), and there is no description of the error range of min/max.
What is the output error range of cc1125 chip port under the same configuration?
2、The following figure shows the schematic diagram of cc1125 and the description of conduction test points.Please help check
