Hi
I need your input on a detail I am not sure about regarding the TPS23753 Design Guideline (slva305c.pdf). Specifically, section 2.8.4. Where does the 150mV come from? Is that Vce(sat) of the optocoupler transistor? Thanks. /Jim
Vled = Vref + 150mV
Hello Jim,
This value is an assumption that the voltage between the reference and the cathode of the linear regulator is about 150mV.
Please see the circled voltage below and excuse my hand writing:
Please note there are a lot of assumptions throughout this document. Even if every equation and assumption is counted for, the final board will need some tweaking since real components have tolerances and do not always behave ideally.
If this post answers your question, please indicate so by marking this thread as resolved. Thank you.
Regards,
Michael P.
Applications Engineer
Texas Instruments
