Other Parts Discussed in Thread: LM3481
Hi,
I'm considering LM3481 as controller for my flyback application and my query is with the frequency setting tolerance over temperature.
From datasheet, I see the frequency can vary by +15% over the operating temperature range -40C to 125C.
My desired frequency is 140kHz and the Rfa is chosen as 151 k.Ohm. During tests (on same PCBA, with same test conditions), I measure the switching frequency as 123kHz & 136kHz with two different LM3481 parts, at room temperature which has deviation of about -12% & -3% respectively from the desired value.
Is this normal behaviour from LM3481? In other words, is that the frequency setting tolerance + 15% not distributed (or spread) across the operating temperature range and it can occur at 25C as well?
Awaiting your quick feedback!! Thanks in advance!!
- Chaitanya K