Hello E2E community,
I am currently debugging a design based on the BQ500110-EVM and the BQ51013-EVM.
I apply power to the BQ500110 and probe the COIL_PWM pin I do see the
three 100kHz pulses except they occur every 0.4 sec instead of 0.5 sec
(EVM user guide states it should be 0.5 sec). I also notice that sometimes (around
10 - 20% of the time) the BQ500110 will output a 175kHz square wave for
about 50 ms instead of the three 100kHz pulses.
Should this be
happening? or should I just be seeing the 100kHz pulses until I place my
reciever on the transmiting coil? (I dont have an EVM kit to do these
Any feedback or comments would be much appreciated
All your observations are correct.
The 0.4s repetition rate you observing is the right number. The WPC spec requires detection of the receiving devise in no more than 0.5s. Considering some processing time needed, the 0.4s ping repetiton rate has been implimented in BQ500110.
The 175kHz, 50ms square wave is the digital ping sequence. The digital ping can be issued at any time the analog ping detects something being placed on the charging pad. Independently of that the digital ping is sent every 5s as a back up to the analog ping.
Wireless Power, Tx
Hello Vladimir and thank you very much for your informative response.
Now that i know the BQ500110 seems to be switching the coil correctly, I have moved onto debugging the reviever side/communication channels.
When I first place my reciever on the transmit coil (there is about 5mm spacer between the coils) I get zero volts at the output of the receiver. when probing the V-RECT pin the voltage is varying about 500mV to 1V during the transmitter analog pings and rises to around 8 - 10V during the digital pings.
I probe the COMM1 and COMM2 pins on the 51013 receiver and they
show a digital signal with 'spaces' as zero volts and 'marks' as a 175
kHz AC voltage (10 Vp-p). when I look at the COMM pins on the receiver I see some pre-amble followed by a header byte, then the message then the checksum as expected.This is shown in the following screen shot where the yellow trace is the COMM1 pin and the purple trace is the VRECT pin.
Probing the COMM1 and COMM2 pins on the 500110
shows about a 100 mVp-p with a DC offset of around 3.25 volts. Obviously my demodulation circuit is not working correctly. I have based this demodulaiton circuit off the BQ500110-EVM, what kind of signal should I expect to see at the COMM pins of the 500110 using this circuit?
One other thing I notice is that if I move the coils a tiny bit closer together (using a slightly thinner spacer) the status LED on the BQ500110 tranmitter starts blinking at a 200ms rate indicating a fault. After this the transmitter stops driving the TX coil until I reset the BQ500110.
If the communication demodulation circuit is not working correctly then why am I getting fault conditions on the transmitter only when I place the receiver on the transmitting coil? (almost seems as if the transmitter is getting a fault communication from the receiver). I've got PMOD disabled and the fault light doesn't blink if i place just an unconnected receiver coil on the TX coil.
Is there a way to determine the type of fault that is occurring (PLD, SYS, DEV or NVM)?
there any detailed information on the faults that are indicated by the
BQ500110 LED status indicators (what exactly are the PLD, SYS, DEV and
Sorry about the length of this question, once again any help would be greatly appreciated.
Just a follow up on the last post I made:
I fixed the errors I had with my demodulator circuit and the receiver is now communicating with the transmitter. The 500110 is no longer indicating faults when i place the receiver coil closer than about 5mm to the transmit coil.
The last problem with my BQ500110 circuit is that when I power it up, it doesn't initialize properly and an external reset must be performed to get the BQ500110 to enter standby mode. Is there any particular conditions that must be met while the IC is doing its initial POR/initialization (such as holding the external reset pin low until the initialization is complete)?
I glad you reselve most of the issues.
Per WPC maximum guranteed distances between coils is 5mm. The distance should be measured from coil to coil. It means that plastic covers in TI bqTesla kit should be included into this 5mm.
Can you provide the details how you power bq500110 up. Are you using TI EVM, or this is the board built by you? What power supply are you using and what is over current set point on it?
You may like responding me directly.
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