LMR33630AP-Q1: Delta Iout Calculation

Hi Frank,

Thanks for response and I understand its an example. I have some additional questions about capacitance calculation below and could you also take a look?

1. In 9.2.2.6 Input Capacitor Selection, it says,

"A minimum of 10 µF of ceramic capacitance is required on the input of the LMR33630."

Does this mean that 10µF must never be less than 10µF, taking into account all variations such as DC bias, temperature characteristics, and capacitance tolerance?

Or does it mean that the typical capacitance value should be selected to be 10µF or more?

Also, in Table 9-4, CIN is 2×4.7µF, and even when combined, a capacitance of 10µF or less is selected. Why is this selected?

One more point, if the input ripple voltage is allowed up to 0.3V, an actual capacitance of 1µF would be acceptable. If the input ripple voltage is within the specification range, is an actual capacitance of 1µF acceptable?

Are there any other points to consider? Please also tell me the reason why 10µF is recommended as the lower limit.

2. In 9.2.2.7 CBOOT, it says,

"A high-quality ceramic capacitor of 100 nF and at least 10 V is required."

As with 1, does this mean 100nF or more, taking into account all variations? Or is 100nF typically enough?

Also, what is the maximum voltage that could be applied to CBOOT?

3. In 9.2.2.8 VCC, it says,

"This output requires a 1-µF, 16-V ceramic capacitor connected from VCC to GND for proper operation."

As with 1 and 2, does this mean 1µF or more, taking into account all variations? Or is 1µF typically enough?

4. Could you provide LTspice model of LMR33630?

Thank you,

Muwei Zheng