We are designing a battery charger using LT3796 and now we are in need to know how to set the o/p current.
We have two cases,
1.Vctrl is more than 1.2V, by the time the we have a sense resistor of 0.16Ohm so according to calculation 250mv/0.1Ohm=2.5A
But the actual o/p current is less than 0.5A
We didn’t use any current limiter.
And we have one problem
1.The gate frequency is unstable .We want it to be 130Khz and we chosen 58K resistor for that frequency but it is rapidly varying.
My question is whether the current can be programmed only with the sense resistor if Vctrl is >1.2V?
It appears that you are having a problem with the LT3796 which is more complicated than simply using the CTRL voltage for output current control.
Can you please send a schematic to me and give me some more description of your input and output specs (and problem) at Keith.Szolusha@analog.com?
Applications Engineering Manager