losing data with a TNY264 power supplier

[alba800]

hello,
I recently made a project with an ATmega64 microcontroller powered by an off-line switching power supply (230V) made with a Power Integration's TNY264 chip (as per application examples, there a PI filter at the input.

what happens is that sometimes the ATmega goes to reset or LOSES EEPROM DATA!
The microcontroller has the brown out reset enabled
This happens sometimes also when testing the circuit with a burst generator at less than 1KV.

anyone has used the Power Integration chips?
any idea on how to filter out these problems?

Thank You in advance

 

[MADURAN]

The TNY series has a fast response for an overload condition.
Try to use a TNY268 or put for the beginning a 1uF (or 10uF) capacitor at pin BP (pin 1).
This capacitor create an useful delay in the response to overload.
Try to use a 2.7V BODLEVEL (bit BODLEVEL unprogrammed).
I think that you have a low EMC in your project.

 

[satya_vijayawada]

hi

try this also
increase the output capacitor value
use UFR diode in output ((Trr is <50nS)
decrease/remove the Y1 series safty capacitor value(primary to secondary)

good luck

satya

 

[veioloko]

Hello!
It seems that you need to use anoter TNY26x. Because TNY resets when it needs more current.
Sorry for my english