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CC113L: RF core stuck in EFT test

Part Number: CC113L

Hi Team,

A customer uses CC113L in their RF solution. The CC113L was laid on a small plug-in board[which was powered with a non-isolated power board through LDO] together with the microcontroller.

They tested multiple prototypes, CC113L had two issues in EFT test:

1.Software crashed: EFT high voltage 4000V test, during the initial test or when the voltage was reversed, the software would stuck into an infinite loop, all the keys and the RF TX were fail. The chip could be restored to normal via reset, the RF tx distance was not significantly shorten.

2.RF chip destruction: Started the EFT test from a low voltage to 4000V, it could pass it. However they found the RF TX distance was significantly shortened. Replace a new CC113L could make the range back to normal.  As to the destroyed ones, the distance could not restore in subsequent test.

For hardware: They already have someone checked the schematic and the PCB layout, no problem was found. They tried add ESD protection but was still no efficient.

For software: Most of the prototypes got stuck in EFT test, it was caused by fail RF calibration in EFT, which led the chip enter dead loop and could not open normally.

Please check their hardware and software information:

Power bottom plate:电源底板.pdf

RF module:射频模块.PDF

RF module PCB:

射频模块PCB.pdf

Software setting:

  • The RF_P/ RF_N pins on CC113L has limited ESD protection and if using an antenna that is exposed it's recommended that an ESD diaode is included as close as possible to the antenna to ground to protect the RF inputs. It's not clear from the above how tests with ESD protection has been done.

    From the description I would assume a ESD damage. If they measure the impedance from each pin to ground on a "good" unit and a "bad" unit I would expect lower impedance to ground for the RF_P/ RF_N pins on a "bad" unit compared to a "good" unit.