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LM5170-Q1: Relation among Ripk, Rramp, duty

Part Number: LM5170-Q1

Could you please give me advice for LM5170-Q1? 

As attached file, the system shows IPK may affect by the RAMP and duty. But calculator doesn't change Boost/ Buck mode duty cycle when %. RAMP selection is updated.
1. Let me know the relation between RAMP selection and Boot/Buck Mode duty cycle?
2. If user update IPK Resistor (Ripk) to double, the system could support 400W output but there is no information between Ripk and (RAMP, Duty). could you please let me know the relation?

LM5170DESIGN-CALC(with questions).xlsx

Regards,
Nagata.

  • Hi Nagata,

    You should always satisfy eq.14 in the datasheet by selecting Rramp.

    If you satisfy eq.14, peak current limit will not change with duty cycle.

    We will update the calculator to satisfy eq.14.

    Best Regards,

    Feng Ji