Can we disable LM25085 soft star function?

Chen Bogey8

Mastermind 9990 points

Other Parts Discussed in Thread: LM25085, LM5085

Dear Sir

May we check if LM25085 can disable soft star function? and if LM25085 have by pass mode?

our competitor part is LTC3864. LTC3864 include these 2 functions and more wide input voltage.

Or we have more powerful part can replace it?

Best regards,

Bogey

over 9 years ago

0 Vijay86929 over 9 years ago

TI__Genius 11490 points

The soft-start function in LM5085 or LM25085 cannot be disabled.

LM5085/LM25085 can operate at 100% duty cycle. The FET will remain 'on' if at the end of the on-time the FB comparator is still below the reference.

Hope that helps.

0 Chen Bogey8 over 9 years ago in reply to Vijay86929

Mastermind 9990 points

Dear Sir
Sorry for i am not clear, may i double check with you. it is mean Vin voltage will pass to Vout. just only Vin > Vfb(1.25V)?
From my case My Vin set 12V~32V and Vout set to 6V/3A, and when i down Vin voltage under 6V, then Vout voltage will the same with Vin till Vin <1.25V?
Best regards,
Bogey

0 Vijay86929 over 9 years ago in reply to Chen Bogey8

TI__Genius 11490 points

The chip operating range is 4.5VIN(min). So the converter will turn off when VIN falls below that.
VIN and Vfb are not directly related.Hope that helps.

0 Chen Bogey8 over 9 years ago in reply to Vijay86929

Mastermind 9990 points

Dear Sir

Thanks for your reply

Best regards,

Bogey

Power management

Power management forum

Can we disable LM25085 soft star function?