STWLC68 PROBLEMS

[ALeon.11]

Hi all,

We're on a project which involves WPT, so we selected the STWLC68 component. We bought the evaluation board STEVAL-ISB68WA and we tested it with the steval-isb045v1 base, as indicated.

Once verified the functionality and the tuning procedure, we designed our custom board with the STWLC68JRH chip, and by exactly following the design reference for the STEVAL-ISB68WA, with the same coil from Wurth Elektronik.

Once produced, the chip doesn't seem to work. The output Voltage at Vout pin reaches 0.3V. I also changed the frequency of the charge base station to see if the resonant frequency was shifted but nothing changed. I verified the layout and the lumped elements values and everything seems ok. We produced two prototypes and the same issue occurred in both, so I exclude a defective chip.

Could you please help me debug this issue? Thanks a lot

[PZaya.1]

Had exactly the same problem.... after studying the very limited documentation @st i figured out the chips doesnt have any configuration. Thus i hotwired the i2c interface from the STEVAL-ISB68WA to my design and voila i was able to program the chip with my slight altered settings and now it boots as it should.

WIth the hotwire i2c you have to connect VBUS (From STEVAL) to VOUT(Or vrect) on the chip. Make no sense cuz with a catch 22 you cant OTP program without powering the chip. And you cant power the chip without OTP config. Be careful... its OTP... :)

[MPend.3]

I am having the same problem. Would really like to know what your settings were / are. Or perhaps someone else can help with settings.

In my case the chip starts to power up but apparently the transmitter (several different models tried) does not like something and shuts down the AC signal. This happens at about 1.7Hz rate. The signal is applied for about 85mS on each cycle.

Apparently a configuration value is not what it needs to be. These are chips directly from the factory.

Interestingly, I have the eval board and that will not power up either so I can't copy settings from there.

Again with several transmitters have been tried.

I can do the back power trick and talk to the chip -- I just don't know what to send it. And with only one try I need to be careful.