CC2640R2F: The CC2640R2F has too many problems??

Hi,

I would also expect problems if you have tested at -15 kV ESD.

The datasheet specifies a much lower ESD voltage rating:

It's the customers responsibility to add system ESD protection to ensure that the chip is not exposed to higher voltage levels than stated in the datasheet.

Not sure if it's relevant but the watchdog is not running in standby since the clock domain it's using is not on in standby. 

To summarize:

- The JTAG issue, is that with contact ESD only?

- The "crash" happens only for air discharge? 

Our circuit is protected by ESD, but it is still easy for the chip to be damaged. Or it appears that the program died and did not run.

Can you provide some reference design schematics, thank you.

Our circuit is protected by ESD, but it is still easy for the chip to be damaged. Or it appears that the program died and did not run.

Can you provide some reference design schematics, thank you.

The JTAG issue, is that with contact ESD only?

This is mostly the case for ESD testing.

Hi,TER

Our circuit uses ESD protection devices, but the effect is not great. Can you provide some ESD protection devices? 

Thank you.

If I remember correctly you have some ESD protection on the touchpad (code). Since the CC2640R2F is mounted on a board that is placed inside the door I would assume that the doos take some of the ESD charge. TO find out where the board needs more protection, have you tried to disconnect the touchpad to see if the main charge comes into the board this way or done other delta testing to see which part of the design is most sensitive? 

HI，TER，

I have tried to unplug the touchpad for air discharge + -15kv, but it is still prone to chip necrosis and program crashes. None of the other chips on the same board had program crashes and chip necrosis. I think the entire 2640 is the most sensitive.

Added: I checked that those necrotic chips are basically VDDS2 or VDDS3 and GND shorted.

Thank you.

Hi,

Which ESD protection devices do you use ?

The ESD strike can enter the chip in a number of different ways pending your layout and casing. The antenna is a common route for ESD and recommend to protection the antenna port with TPD1E0B04: http://www.ti.com/product/TPD1E0B04.

This has a low capacitance so the antenna will not need to be re-tuned.

Regards,

   Richard

HI，RGW.

The ESD protection device we use is ESD5451.  Our antenna ports are not ESD protected.

Thank you.

HI，RGW.

Can you help us see what's wrong with the PCB design.

Thank you.

Hi,

Air discharge + -15kv, we haven't found any broken antenna ports at present. Those chips that are found to be broken are all VDDS3 pins or VDDS2 pins shorted to the large middle pad.

Regards

Hi,

The antenna is susceptible to ESD since this is normally positioned outside the GND region and in a more free space which makes it more prone for the ESD strike and to carry the energy to the radio pcb.

Recommend to add an ESD protection on the antenna as close as possible to the antenna. 

Look at the part: TPD1E01B04 : http://www.ti.com/lit/ds/symlink/tpd1e01b04.pdf which has low capacitance (antenna does not need to be re-tuned) and meets your ESD levels.

IEC 61000-4-2 Level 4 ESD Protection – ±15-kV Contact Discharge – ±17-kV Air Gap Discharge

Regards,

   Richard

Air discharge + -15kv, we haven't found any broken antenna ports at present. Those chips that are found to be broken are all VDDS3 pins or VDDS2 pins shorted to the large middle pad.

HI，RGW，

The theory of antenna receiving electrostatic interference is clear to me, but what effect does RF_P and RF_N receive high voltage and short circuit with VDDS2 or VDDS3?

Regards