How di/dt is decided by the controller of tny289
Posted by: AbdallahTalaat
on
I want to ask about how the Integrated circuit decides the proper (di/dt) for next cycle , the voltage across an inductor/transformer is L*(di/dt) the Integrated circuit TNY289 as I understand it ramps up current so that (di/dt) is constant and consequently the voltage across an inductor/transformer is constant during ramp up (on time) , my question does the decision about (di/dt) for next cycle is to maintain constant Voltage on drain constant (Vsupply - L(di/dt)) ? On what criteria this decision is taken ? to maintain what constant at what value ?
I understand also that the slope should be (di/dt)= Ilimit/Ton , to change (di/dt) does Ilimit only change or Ton also ?
Hi AbdallahTalaat,
We cannot disclose detail logic or scheme on current slope of the transformer.
On the top level and as disclosed in the datasheet, the IC controls the ILIM.
ILIM varies with respect to the load of the power supply.
The higher the load the higher the ILIM
The lower the load the lower the ILIM
Thanks
Regards
PI-Chloe