GX to HX "upgrade"

Posted by: natb1 on 01/23/2013

We have an existing Flyback OL SMPS using an TOP249YN which has served us well for years.

We will soon be performing significant changes to the product design (including layout).

Provided no other components are changed, is there an HX equiv part we can replace TOP249YN?

It is understood that the pin-out are different, but we will be re-laying out the PCB anyway.

If so...please recommend. Thanks

Comments

TOP259YN should do. You can determine this by simply looking at output power table on the Web pages for the two product series

Thanks for the Reply.

My GX based (TOP249YN) supply was designed to operate at 133KHz (particularly the x-fmr). I noticed the HX data sheet stipulates, "TOP259-261 YN packages are fixed to operate at 66KHz".

Is this correct? Would this preclude its usage as a replacement for my TOP249YN?

Thanks!

You are right, TOP259yn has no 132Khz option. SInce you will start a new layout, why not using TOP-JX. TOP269 E package should be a good choice for you.

Regards

You are right, TOP259yn has no 132Khz option. SInce you will start a new layout, why not using TOP-JX. TOP269 E package should be a good choice for you.

Regards

Thanks,

Would compensation components need to be recalculated?

We are stuck with a heatsink solution that accommodates TO-220. It utilizes a belt type retainer across the face of the component (not the tab). I the jx part feature a thinner body?

You have to scan the bode plot again to optimize the loop. I believe the converter should be stable with the old loop compeanstion, but the phase margin and gain margin should be less with TOP-JX.

Regards