• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 413 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

ua78l05 output cap

Sal LaRussa
Genius 9530 points
Other Parts Discussed in Thread: LM317

there is no mention of the output cap requirement in the uA78L05A data sheet.  My guess is that it requires some ESR on the output for stability and a ceramic cap may not be appropriate.  Is that correct?  Can you tell me the minimum ESR that is required for stability?

Thanks.

  • 0
    TI__Expert 8890 points

    Good Morning Sal,

    It would be a good idea to use a 1uF capacitor at the output.  However, the first generation of old linear regulators did not require output capacitors: LM317, ua7805, TL1117.  These had high dropout voltages but were very stable.

    Believe it or not, but a linear regulator that employs either a NPN bipolar transistor or an N-channel MOSFET does not theoretically require an output capacitor.  But it is always a good idea to provide one because it invariably helps - and these days the LDOs are so complicated that they actually do need some output capacitance.

    Regards

    Bill