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BQ25672: BQ25672EVM input power not selected

Part Number: BQ25672
Other Parts Discussed in Thread: , USB2ANY, EV2400, BQSTUDIO

I  have a BQ25672EVM  connected to one PSU on VIN1, nothing on VIN2 et USB connector, one  5W 100ohm resistor between SYS pin and GND, one cell LiFePO4 battery on Battery port.

I checked VAC1 is 5V.

I have no connection to PC to configure chip.

VBUS is floating except if I bypass VAC1 to VBUS with JP3.

Why?

Same thing if my PSU is connected to VIN2.

Does BQ25672 need anything else to activate ACDRVx when 

I  have a BQ25672EVM  connected to one PSU on VIN1, nothing on VIN2 et USB connector, one  5W 100phm resistor between SYS pin and GND, one cell LiFePO4 battery on Battery port.

JP30 and JP33 are shunted to provide 3.3V to USBANT. I checked PULLUP is at 3.3V.

I have one USBANY card connected to my PC.

I first downloaded Browser extension, then TI Cloud Vinx is the only available power source?

  • Hi Pascal,

    Unlike some of our other chargers (and the pre-prod PQ25672 that we shipped earlier this year), this charger's poor source detection does not lock out the channel if poor source detected.  Is it possible that your input source is failing poor source detection?

    Regards,

    Jeff

  • Hi Jeff,

    PSU has 20V 5A capability. I use it connected to charger of competitors without any problem. I checked voltage on the EVB. For my point of view no fail. What do you mean by failing poor source detection?

    I connected via USB connector one PC, same behaviour. This PC is OK without competitor's charger.

    Regards,

  • Hi Pascal,

    Were you able to get the USB2ANY and charger GUI working?  The USB2ANY has its own pull up so you don't need to install the shunt on jumper JP33 but it shouldn't cause a problem if installed.  Can you also confirm that either JP13 or JP14 are installed to set default input current limit?   

    If working, what does GUI show for the status and fault registers?  What do the VAC_OVP register bits in REG0x10 report?

    Regarding poor source, the charger attempts to pull a small current (12mA typical) from the input source at power up.  If the voltage sensed at VACx drops to to 3.4V typical, that source is assumed to be poor (bad) and the IC is placed in HiZ mode.  The device waits 7 minutes to retry.

    Regards,

    Jeff 

  • Hi Jeff,

    Unfortunately USB2ANY and GUI are still not working.

    I tested with and without JP13 installed, same problem.

    JP13 is installed, not JP14.

    My input source is 5V doublechecked so no risk to be detected as faulty.

    Regards,

  • Hi Pascal,

    Have you tried the GUI with only a battery attached at BAT?  If you short VBUS to VACx using JP3 and JP4, does the GUI work?  Are there switching pulses at SWx nodes?  If not, then the EVM is damaged.

    Do you by chance have one of our EV2400 boxes?  If so, there is a different GUI that you can try.

    Regards,
    Jeff  

  • Hi Jeff,

    yes I did with only battery connected, same thing GUI not working.

    Same thing with Vac1 or Vac2 shorted to VBUS with JP3 and JP4.

    Unfortunately I have no EV2400 for test.

    best Regards,

  • Hi Pascal,

    So, it appears there is a problem with the online GUI server.   I have a version downloaded on my PC so that I is why I didn't see it initially.  We are investigating.  I will keep you posted.

    When you short the input FETS so that VAC1 connects to VBUS=5V-20V, does REGN voltage ~=5V?  If so, then is there a pulsing waveform at SWx?  If no to either, the IC on the EVM is damaged.  

    Regards,

    Jeff

  • Hi Jeff,

    For GUI please keep in touch.

    For Hardware input problem, I shorted FET with Jumper VBUS=VAC1, no output voltage on REGN. Either on VAC1 or VAC2.

    Regards,

  • Jeff,

    For GUI problem, may EV2400 be an alternate solution for short term?

    Regards,

  • Hi Pascal,

    If REGN voltage come up when a voltage is applied at VBUS (and the charger is not in HiZ from JP21 being installed or JP13 or JP14 not being installed), then the IC is damaged.

    Yes, EV2400 uses different downloadable software (BQSTUDIO) to read and write to the charger's I2C registers.

    Regards,
    Jeff 

  • Hi Jeff,

    I received a second EVB. With 5V at VAC1 input, VBUS=VREG=5V, SYSTEM Load is active and battery is being charging.

    You were right, EVB was damaged or faulty.

    Regards