LM5161: FB comparator dropout hysteresis

Marsh Cai

Part Number: LM5161
Other Parts Discussed in Thread: LM5166, LM5164

Hi experts,

what's the FB comparator dropout hysteresis of the LM5161?

I can't find it in the LM5161 datasheet.

FOR EXAMPLE: ( to lm5166) page 5.

thanks and best regards,

Marsh

0 Daniel Li14 over 2 years ago

LM5161 don't have low Iq feature, so it don't have the hysteresis value. if you want to have this feature, you can use LM5164.

0 Marsh Cai over 2 years ago in reply to Daniel Li14

Hi, thanks for your reply.

can you explain more about this? why hysteresis is related to Low Iq feature? In my understanding, each comparator has its own hysteresis.

if lm5161 doesn't have hysteresis, can i understand like this, that the Vfb needn't meet the requirement of 20mv?

thanks.

0 Daniel Li14 over 2 years ago in reply to Marsh Cai

Hi Marsh:

the hysteresis of LM5166 is for achieve dropout (COT mode) or PFM mode, it is not used for stable statues.

Another requirement is the ripple injection value for COT control need higher than 25mV, it is more for duty cycle stable.

Thanks

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