• State Resolved
  • Locked Locked
  • Replies 8 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 550 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.

TPS3840-Q1: Voltage divider with TPS3840DLxx-Q1

Lee, Sam
Expert 6225 points
Part Number: TPS3840-Q1
Other Parts Discussed in Thread: TPS3840

Hello team,

 

I’m trying to calculate the divider resistance using the application note (SNVA865). However, my calculation shows there are something wrong when using open drain type of TPS3840-Q1. (TPS3840DL: VPOR=950mV, TPS3840PL: VPOR=300mV). The example in the apps note is calculated with VPOR=300mV, so it seems that the equation between min and max resistance is not matched when using VPOR=950mV. Is it not possible to use TPS3840DL for the following case?

 

Example:

  VBAT_max = 42V,   VBAT_min = 4.2V,   VD = 0.3V

  R1 = 100kohm, R2 = ??

  VDD_max = 10V >= R2 / (R1+R2) * (VBAT_max – VD)

      -->   R2 <= 31.55kohm

  VPOR = 950mV <= R2 / (R1+R2) * (VBAT_min -VD)

      -->   R2 >= 32.20kohm

 

Thanks,

Sam Lee