ZHCSJY0B June 2012 – June 2019 LMR12015 , LMR12020
PRODUCTION DATA.
Operating conditions for the LMR12015/20 are:
First the maximum duty cycle is calculated.
Using Figure 27 gives us a recommended ripple ratio = 0.4.
Now the minimum duty cycle is calculated.
The inductance can now be calculated.
This is close to the standard inductance value of 1.8 µH. This leads to a 1% deviation from the recommended ripple ratio, which is now 0.4038.
Finally, we check that the peak current does not reach the minimum current limit of 2.5 A.
The peak current is less than 2.5 A, so the DC load specification can be met with this ripple ratio. To design for the LMR12015 simply replace IOUT = 1.5 A in the equations for ILPK and see that ILPK does not exceed the LMR12015 current limit of 2 A (min).