This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Tool/software:
We have a question about the reset function of CC113L.
During ESD testing of our product, a symptom occurred that RF signals could not be received.
After checking the details, we found that immediately after ESD was applied, the VCC voltage dropped (from 3.3V to 1.7V), and as a result, the SO “H” potential also dropped, and the microcontroller could not receive the signal.
Will we know, what was the cause of this VCC voltage drop?
We know that CC113L has low ESD resistance, but is there a possible failure mode where the CC113L power supply overcurrent occurs due to ESD?If so, an overcurrent may have flowed through the protective resistor (R1=10Ω) on the main board, causing a voltage drop.
Also, this phenomenon is not recovered by SRES signal or strobe (CSn Low/High), but by turning VDD of CC113L OFF/ON. Is there any way to recover it by sending some command signal from the microcontroller?
We will send you the circuit diagram of the relevant part and the waveforms during ESD test.
- Waveform when Down by ESD
- Details of noise caused by ESD
- Not recovered by RST command
- It is recovered by VDD OFF/ON
- Sequence from RST to initialization of settings
- Manual RST waveform
- SRES waveform
- Strobe (CSn_low-high) waveform
- Our circuit diagram
In the previous answer(thanks!), we should take adding system level ESD protection if user could touch the antenna, we understand that.
Hi,
Apologies for the delay - we are following this up internally, so this has not been overlooked.
I will update you with an expected timeframe once I have received some initial feedback (it is hard to estimate before that).
Regards,
Zack
the VCC voltage dropped (from 3.3V to 1.7V)
VCC is an externally supplied power supply. A power supply show not drop without an extra current draw. Did you check the system current consumption and the impedance to ground for all pins on CC113L to verify that the chip has not been damaged?