• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 1383 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.

bq34z100-g1 Full Sleep Mode Configuration

Sebastian M
Intellectual 720 points
Other Parts Discussed in Thread: BQ34Z100-G1

Hi,

some details about the Full Sleep Mode in the bq34z100-G1 datasheet are not clear to me:

"FULL SLEEP mode is entered automatically when the device is in SLEEP mode and the timer counts down to 0
(Full Sleep Wait Time > 0). FULL SLEEP mode is disabled when Full Sleep Wait Time is set to 0."

1. In 8.3.1.2.12 SET_FULLSLEEP: 0x0010 it says "This allows the gauge to enter the FULL SLEEP power mode ...". So i have to send this command to set the FULLSLEEP flag first, otherwise it doesn't enter automatically the Full Sleep mode. Is this correct?

2. "Full Sleep Wait Time" must be greater than 0 to allow the gas gauge to enter Full Sleep mode. I guess that "FS Wait" (Subclass ID 68, Offset 11) is meant, is this correct?

3. There are two different specifications regarding the time until the gas gauge is ready after Full Sleep for serial communication:

"While in FULL SLEEP mode, the fuel gauge can suspend serial communications as much as 4 ms by holding the communication line(s) low."

"For I2C communications, the first I2C message will incur a 6-ms–8-ms clock stretch while the oscillator is started and stabilized."

Which one is correct or what is the absolutely longest time the gas gauge needs for answering an I2C request after Full Sleep (ACK the address)?

Best Regards

Sebastian

  • 0
    TI__Mastermind 34775 points

    Hello Sebastian,

    Let me review your questions/concerns and myself or my colleague will respond to you.

  • 0
    TI__Mastermind 34775 points

    Hello Sabastian,

    Here's my response to your questions:

    1. In 8.3.1.2.12 SET_FULLSLEEP: 0x0010 it says "This allows the gauge to enter the FULL SLEEP power mode ...". So i have to send this command to set the FULLSLEEP flag first, otherwise it doesn't enter automatically the Full Sleep mode. Is this correct?

    Damian: Yes you have to set FULLSLEEP  bit in control register to 1 first, so the gauge knows that you want it to enter in to FULLSLEEP after entering SLEEP mode. 

    2. "Full Sleep Wait Time" must be greater than 0 to allow the gas gauge to enter Full Sleep mode. I guess that "FS Wait" (Subclass ID 68, Offset 11) is meant, is this correct?

    Damian: Yes FS Wait is where you enter the "Full Sleep Wait Time. 

    3. There are two different specifications regarding the time until the gas gauge is ready after Full Sleep for serial communication:

    "While in FULL SLEEP mode, the fuel gauge can suspend serial communications as much as 4 ms by holding the communication line(s) low."

    "For I2C communications, the first I2C message will incur a 6-ms–8-ms clock stretch while the oscillator is started and stabilized."

    Which one is correct or what is the absolutely longest time the gas gauge needs for answering an I2C request after Full Sleep (ACK the address)?

    Damian: BQ34Z100-G1 supports Two-Wire I 2C and HDQ Single-Wire Communication Interfaces with Host System, hence the two conditions. For HDQ communication it's 4ms where the first one of the host message will be dropped. For I2C it's a 6ms to 8ms clock stretch, so worst case 8ms + 8 / ( SCL FREQUENCY).