BQ76PL455A-Q1: cannot receive data after running for sometimes

Hi Yuan,

Please provide more details to be able to help you on this:

• What is the sequence you followed (all steps)?
• Was the polling function enabled ("poll start")? 
• How much time elapsed before you got the timeout error?
• Are you using the TI BQ76455 EVM or your own hardware?

You can double check the setting of the CTO (communication timeout) register (address 40 or 0x28). If the device doesn't receive any valid communication frames during the communication timeout specified in this register, the device will flag a timeout and eventually shutdown. See details in the datasheet section "7.6.3.19 CTO 0x28 (40) Communication Timeout".  You can disable these timeouts by writing 0x00 to this register.

Best regards,

Leslie

Hi,deal all

1.press the  command of poll start, Interface receive cell volt about one minute,then data no change.

2.test on my own hardware.

hi,deal all

thanks  Leslie, the problem has already been solved,but another question consult you.

at  pl455 init, clear fualt then  read register 0x82-0x83, the bit of CHIP_FAULT_SUM is set ,i can't  start  balance.

Best regards,

tanms

Hi,

thank you, the problem has already been solved according to your advice, but i have another  problem.

let  PL455 go to sleep, write command:

 WriteReg(0, 12, 0x40, 1, FRMWRT_ALL_NR); // send out broadcast pwrdown command

but now  i can not  wake up PL455 with  the pin  wake up (250 us keep on high ). i don’t know how to wake up PL455.

Best regard, 

tanms

Hi,

I'm glad your other issue was solved. I don't see anything wrong with your procedure to wake up the device. How did you determine that the device is not waking up?

I recommend to capture the wake up signal to make sure you are sending >100us high with the correct VIH/VIL levels on WAKEUP pin. The best way to get your software working is to use the device GUI. This way you can make sure that your hardware is working correctly and then you can capture the signals sent by the GUI and then compare to the signals sent by your software. 

Best regards,

Leslie

hi,

i test the voltage of C2  and R2, normal C2 is ~5.3V, R2 is ~0.62V , i find that PL455 don't go to sheep when  i  send out broadcast pwrdown command . some condition stop PL455 going to  sleep.

Best regards,

tanms

Hello,

Were you trying to upload an image / diagram? I only see an icon but the image is not attached. The best way to get your software working is to use the device GUI. This way you can make sure that your hardware is working correctly and then you can capture the signals sent by the GUI and then compare to the signals sent by your software. 

Regards,

Leslie

HI,

I use  Interface ,press the  command of power down,  pl455 can't go to sleep (PV :5.3V).i don't know how to solve the problem.

Best regards,

tanms

Hello,

I'm sorry, I'm not able to follow what you explained on the last post. Could you please clarify:

• When you say "I use interface" do you mean that you used the device GUI provided by TI?
• What is "PV:5.3V"? on which pin of the device are you measuring this value?

A reason why BQ76PL455 might not stay in shutdown is if the WAKEUP pin is held high. If WAKEUP pin is high when the PL455 device is sent to shutdown mode, the device will immediately wake up again. In order to stay in shutdown, the WAKEUP pin must be low.

Best regards,

Leslie

hi,

Interface   is  GUI .

PV is VP ,it write wrong.

the problem has already been solved. I clear the fault flag ,before PL455 go to sleep.

why fault flag stop going to  sleep?   datasheet can'find such information.

Best regards,

tanms

hi,

the problem of going to sleep  still  exist ,because  test  is wrong.. I clear the fault flag,PL455 can't go to sleep

Best regards,

tanms

Hi,

thank you, the problem has already been solved ,but I don't know that 

i send SHUTDOWN command or set Communications time-out (CTO),PL455 can't go to sleep (keep on) ,

,but  the register of FAULT_SYS is 0x80.

now I control power of the PL455's VIO (PIN 41), it can go to sleep.

Best regards,

tanms