Tool/software:
Dears,
The customer used the TPS562201DDCR as the primary power supply and TLV62569DBVR as the secondary power supply to power the subsequent radar, and the customer found that the BUCK power supply caused the radar to have an SPUR condition.
1. The schematic diagram and PCB traces are shown in the attachment below, please help to check whether the schematic is correct?
1-TI power schematic.pdfTI power cables.pdf
Specifically, the inference for determining that BUCK causes the presence of SPUR on radar is as follows:
a. As attached to the original design, there is SPUR, as shown below.
b. Remove the primary power supply, and directly supply the power from the secondary 5V, with SPUR
c.The primary power supply is changed to TPS562208DDCR+4.7uH power inductor, the second stage is changed to LDO3.3V and then to LDO1.5V, and the 1.15V inductor is changed to 1uH.
Others remain unchanged, there is no SPUR (This scenario is only used to verify that the spur is caused by BUCK)
Please help analyze the cause, many thanks!
