• State TI Thinks Resolved
  • +1 person also asked this people also asked this
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 210 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.

Original question:

BQ40Z50: Deactivation of Safety PTC Thermistor (PTC to VSS)

BQ40Z50: Deactivate the Safety PTC Thermistor function Issue

joy zhou1
Intellectual 530 points
Part Number: BQ40Z50

Tool/software:

Dear TI expert,

We followed the TI E2E TI expert's answers to generate our schematic. I copied the links below:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1320333/bq40z50-deactivation-of-safety-ptc-thermistor-ptc-to-vss?tisearch=e2e-sitesearch&keymatch=bq40z50%2525252520ptc#

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1319260/bq40z50-about-bq40z50-ptc-thermistor?tisearch=e2e-sitesearch&keymatch=bq40z50%252520ptc#

We generated our circuit, to deactivate the Safety PTC Thermistor function as the below a copy of our schematic, but something is wrong. We did exactly what we were supposed to do, but nobody noticed that the Iq went up! Could you please help to explain why the extra Iq (around 230uA) from the PTC pin connection below? And I want to know if we can leave it open. I mean just remove R11, leave the PTC (pin23) floating? 

Please clarify and advise.

Thanks,

Joy