• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 299 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.

Is it okay to tie SCL, SDO together from multiple bq27520G3 chip (with individual CE control)?

Chuck Hung
Prodigy 10 points

    I have application that requires multiple bq27520G3 chips for multiple sub-system, may I tie all SCL, SDO together with common pull-up? Since there is no address information encoded in bq27520G3 chip, so I will use CE to select the individual bq27520G3 to read/write data from SCL, SDO. Will this cause any contention problem from the un-selected bq27520G3 chip?

    I know that VCC will be dropped to 0V when CE=0, and I assume that VCC is the supply of whole chip, so the SCL, SDO will be in Z-state when CE=0, so it will not cause contention problem to the selected SCL, SDO operation. If this is not right, please advise the solution.

Thanks a lot.

Chuck Hung 10/25/13

  • 0
    Genius 3970 points

    I don't think this is a good idea. Killing off Vcc with the CE pin means that you lose gauging functionality of the disabled chips. Also, there is a ~250 ms delay on startup while the chip boots up from reset.

    Perhaps a better solution would be using a bi-directional multiplexer chip to select each individual gas gauge.