Original question:
Hi
We use LM3435 and confuse as same as previous inductance calculation.
So inductance fomula still suit for this part?
For example, as our setting ILED(max) would be set on 1000mA. What inductor in value should I put for our change?
What ILED(min) should be estimated?
Hi,
The formula you gave is used when the inductor current just entered the Critical Conduction Mode operation and the other formula is used in the worst case inductor current.
If you already determined your ILED(MAX), you can first calculate IL(AVG_MAX) in this situation by:
and then replace IL(AVG) by IL(AVG_MAX) and use the value VIN=2.7 to calculate the D and L by:
When you get your L value, use VIN=5.5V to calculate D value and get your VLED(MIN) by:
In this way, you have to now your IL(MAX) and ILED(MAX) at first but the IL(MAX) is not suitable to be set, so I suggest you to follow our datasheet guidance and determine your ILED(MIN) firstly or set the L to common standard value(such as 2.2uH) and check if the parameters are suitable for you.
Hi,
I think if you can determine your ILED(MIN) and ILED(MAX), it will be more convenient 3for you to select your inductor.
So I suggest you follow this flow:
1.Use VIN=5.5V and select your ILED(MIN) to calculate inductance value by:
2.Calculate IL(MAX) based on L value and ILED(MAX):(VIN=2.7V)
3.Choose suitable inductor by inductance value and IL(MAX)
Thanks,
Best Regards!
