May I know what is the function of the below highlighted discrete components in the Switch circuit? enter image description here

Regards, Chitharanjan M

  • 2
    \$\begingroup\$ DNP means Do Not Populate, so these components are not fitted and hence don't do anything. \$\endgroup\$
    – Finbarr
    Jul 26 at 8:53
  • 1
    \$\begingroup\$ Does this answer your question? Symbol identification (DNP & 0R) \$\endgroup\$
    – Finbarr
    Jul 26 at 9:05
  • \$\begingroup\$ @Finbarr Yes in the Design its DNP, but what is the function of that discrete, why these are been used as optional (DNP) \$\endgroup\$ Jul 26 at 9:51

1 Answer 1


The combination of C199, R243 & R233 seems to be for the purpose of inrush current limit. R243-R233 combination also reduces the VGS of the PMOS when it is ON. See this for more explanation: https://www.powerctc.com/en/node/4564

C6-R1 combination appears to be a feedback from switch output to the gate. So, serves the purpose of ensuring that the output does not rise faster than a desired slew rate and hence also helps in reducing the inrush current.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.