Popular Discussion
- 6 comments
- 1 comment
Legend
TOP223 "Ct" capacitor
Hello
Using TOP223, and we're a little confused about what value to use for Ct, and whether to include a series resistor. I haven't found anything in the datasheet outlining how to calculate the value (unless I missed it). The schematics there indicate in one case to not use a resistor, and in another case to use it, along with a 47uF cap value.
We've tried no resistor with both 47uF and at the extreme other end, 0.1uF. Both seem to work well. The behavior of auto-restart mode is not all that important to us, as a current limited supply is located after this switching supply.
Are there published guidelines on what resistor/capacitor value combination to use, other than the value shown in the datasheet schematics?
I would use 47uF for guarnteed proper start up. Resistor is optional as it can give slight improvement in stability in some cases. If your transient load response looks good then you are OK with no resistor




