Damith
We do NOT recommend that you change any of the equations in the excel design calculator. Many of the values from equations are used in subsequent calculations, so any change can cause errors. We recommend that you use the unlocked tool to just…
Hi support team,
I would like simulate my flyback design with LT-Spice, all my circuits are simulatet with LT-Spice. But I need therefore a unencryptet version of UCC28700x.lib. It is possible to get it?
Many thanks
Oliver
Part Number: PMP10344 Hi everyone.
I made a power supply based on PMP10344 with voltage and current adjustments and a new transformer. Now i'm having issues starting up the power supply, it's suposedly to start at around 90V, but in reality it only…
Hello Winston,
The QVFF is supposed to have hystersis and should not be behaiving as you describe. If there is exesive noise on the VINAC pin it could cause the QVFF circuitry to misbehaive. A noisy ground poor layout could also cause the QVFF circuit…
Hello David,
Most likely this is due to your layout and OVP ringing.
Please probe your aux winding voltage, CS, DRV and VDD during this behavior with your oscilloscope it will show what is going on.
Regards,
Mike
Part Number: UCC28740 Tool/software:
Dear Experts,
At present, we are designing a flyback power supply using UCC28740. The design requirement is to input 300VDC can start, but during actual testing, we found that it cannot start at this voltage. The…
Guifre,
I would suggest maybe reviewing this video about debug of UCC287xx designs:
training.ti.com/getting-started-ucc287xx-family
There is also this debug document that would be useful:
e2e.ti.com/.../Trouble-shooting-startup-for-TI-PSR-controllers…
Other Parts Discussed in Thread: UCC28722 Having startup issues with UCC2877 flyback
Perhaps this question is best directed at the authors of the application not for the circuit tidu789c 230-V, 400-W, 92% High Efficiency Battery Charger With PFC and…
Hi Len,
The UCCx8C4x is an enhanced BiCMOS version with pin-for-pin compatibility to the industry standard UCx84xA family. There is a offline flyback design example in Section 9.2 in datasheet.
https://www.ti.com/lit/ds/symlink/ucc38c42.pdf
Below…
