Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Offline Flyback...single stage, 55W, fully dimmable, no electrolytic capacitors

Status
Not open for further replies.
T

treez

Guest
Hello,

We are doing an offline 55W PFC’d Flyback SMPS LED driver. (fully dimmable)
It is a single stage converter, with a constant off time flyback, and uses no electrolytic capacitors.

The schematic and LTspice simulation are as attached. One of the issues which is of concern is that the inverting opamp U11 in the pdf schematic (MCP6001U) , may for a short instant get a voltage on its inverting input that is more negative than minus 300mV. The datasheet doesn’t hint towards problems, but do you believe that this could cause reliability issues?

MCP6001U datasheet:-
https://www.mouser.com/ds/2/268/21733h-26779.pdf
 

Attachments

  • Flyback PFC 55W.pdf
    200.3 KB · Views: 92
  • PFC flyback 55W ConstantOffTime.txt
    22.8 KB · Views: 41

Hi,

a voltage on its inverting input that is more negative than minus 300mV
Click to expand...
This is not informative.
Is it 301mV? This is within the abs. max. specification.
Or is it 3000mV? This is beyond specification.

Don't expect problems as long as you keep within specifications.

Klaus
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top