LMR23625 - Vin=12V, Vout=-16V, Iout=1.0A

Hirotaka Matsumoto

Other Parts Discussed in Thread: LMR23625, LM22670

Hi all

Would you mind if we ask LMR23625(LMR2625CF)?

We'd like to realize the following spec using LMR23625(LMR2625CF).
-Vin=12V, Vout=-16V, Iout=1.0A, L=4.7uH, F=2.1MHz
-D=|Vout|/Vin+|Vout|

-IOUT(MAX) = (ICLMIN – (VIN x D)/(2 x F x L)) x (1 - D)

Iout(MAX)=1.03A

We guess that it is possible.
Is our recognition correct?

Kind regards,

Hirotaka Matsumoto

over 8 years ago

0 Luke Pan over 8 years ago

TI__Intellectual 2790 points

Hi,

The formuIa should be IOUT(MAX) = (ICLMIN + (VIN x D)/(2 x F x L)) x (1 - D)= 1.35A.

Luke

0 Hirotaka Matsumoto over 8 years ago in reply to Luke Pan

Guru 27585 points

Luke san

Thank you for your reply.

We'd like to confirm one point.

FormuIa shows as following URL P8 (8).
-IOUT(MAX) = (ICLMIN - (VIN x D)/(2 x F x L)) x (1 - D)
http://80.93.56.75/pdf/0/2/0/3/4/02034084.pdf

Which is correct?(Your saying (ICLMIN + (VIN x D)/(2 x F x L)) x (1 - D) or document showing (ICLMIN - (VIN x D)/(2 x F x L)) x (1 - D))

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 8 years ago in reply to Hirotaka Matsumoto

Guru 27585 points

Luke san

We guess that you are so busy, however could you give us the reply?

Kind regards,

Hirotaka Matsumoto

0 Luke Pan over 8 years ago in reply to Hirotaka Matsumoto

TI__Intellectual 2790 points

Hirotaka san,

The fomula in the LM22670 is also correct. This difference is caused by the different OCP circuit. The LM22670 OCP is achieved with cycle by cycle peak current limit, so the max load current equals to peak current minus half of the current ripple.While LMR23625 hiccup mode is detected by valley current limit, so the max load current equals to the valley current plus half of the current ripple. Reminder, the ICLMIN means ILS_LIMIT_MIN for LMR23625.

0 Hirotaka Matsumoto over 8 years ago in reply to Luke Pan

Guru 27585 points

Luke san

Thank you very much for your very kind reply.

Kind regards,

Hirotaka Matsumoto

Power management

Power management forum

LMR23625 - Vin=12V, Vout=-16V, Iout=1.0A