• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 338 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

BQ79656EVM-021: BMS is not awake

hamzeh ahangari
Prodigy 111 points
Part Number: BQ79656EVM-021
Other Parts Discussed in Thread: USB2ANY

Hello,

I got 2 dev.kit, BQ79656EVM and BQ79616EVM. I don't have USB2ANY device.My problem is that just at the first try, it seems in both kits, the BMS is not awake after I connect the supply.

I did these:

- to use internal resistor ladder: short all S1 and S2, short J14 and J16. Later, I can see voltage steps on Cell-x (white test points near to J15 connector) as expected.

- connect external power supply (i tested both 33V and 50V) to PWR and GND.

using test points, I observe:

- BAT pin is same as PWR, then BMS gets the power.

- NPNB (of Q1) is 5.0V, but I expected > 6.5V.

- Then the LDOIN is also 4.5V, but I expected 6.0V, as written in datasheet.

- Both CVDD and NFAULT pins are also 4.5V.

I have also some samples from both BMS chips. Then if it seems the chip is damaged, I can replace them.

Best regards.

  • 0
    TI__Intellectual 1845 points

    Hello,

    If you are not using the USB2ANY are you using a different MCU? To wake the BQ79656EVM and BQ79616EVM you need to send a wake tone from the microcontroller to the device on the RX pin. Details about the wake tone's pulse width can be found in the datasheets.