Other Parts Discussed in Thread: TINA-TI
Hi everyone,
I am currently using the LM5085 DC/DC converter in order to convert 28V to 3,3V output :
We would like to improve the switching frequency thanks to the Rt resistance (R4002 in the schematic) and in the same time we would like to keep a good stability of the switching frequency.
I tried to change the switching frequency (resp 600kHz and 800kHz) but more it is big more the circuit is not stable ...
In the same time, I calculate the adjustement ripple circuit (R4010 + C4011 + C4016) thanks to this document : Transient response versus ripple - an analysis of ripple injection techniques used in hysteretic controllers, especially for the 600 kHz switching frequency, but the LM5085 seems to be unsteable.( We chose 100 mV output ripple for our application.)
Do you know if this integrated circuit has some metastability criteria above 400 kHz switching ?
Do you know some tips to fix Fsw ?
I would be grateful if you could answer this question as best as possible,
Kind regards,
Olivier D.