cupoftea
Advanced Member level 5
Hi,
We need to know core loss in IHLP8787 inductor 6.8uH (pushpull output L)
https://www.vishay.com/docs/34350/ihlp8787mz5a.pdf
Irms = 9.5A, therefore conduction loss is 0.27W
When we try to calculate core loss in the calculator, it asks for voltage drop in the switch and voltage drop in the diode ("VSW" and "VD").....but surely that has nothing to do with it?
(our topology is pushpull, but in the calculator i had to "pretend" it was a buck, 48vin, 32vout, 300wout, 225khz (each fet at half that)
[its actually a synchronous pushpull with 2:1 txformer and 24 vin]
Vishay IHLP core loss calculator
www.vishay.com
[6.8uH is too low value, but its on the cust PCB that they want tested, so thats that for us]
EDIT...my apologies, i get it now......they want to know these voltages so they can calculate the actual voltages across the inductor.....i thought they would let me do that....my apologies...problem solved.
New problem.....it says its 3.5W of total loss and 2.7W of core loss....do you think its too much?......there is no fan air...its in enclosed metal (Al) box....the footprint is as attached...it 4 layer PCB......no thermal vias, and ridiculously than thermal reliefs as shown.........surely that footprint and 3.5W is asking for trouble?
Max external ambient 50degc
We need to know core loss in IHLP8787 inductor 6.8uH (pushpull output L)
https://www.vishay.com/docs/34350/ihlp8787mz5a.pdf
Irms = 9.5A, therefore conduction loss is 0.27W
When we try to calculate core loss in the calculator, it asks for voltage drop in the switch and voltage drop in the diode ("VSW" and "VD").....but surely that has nothing to do with it?
(our topology is pushpull, but in the calculator i had to "pretend" it was a buck, 48vin, 32vout, 300wout, 225khz (each fet at half that)
[its actually a synchronous pushpull with 2:1 txformer and 24 vin]
Vishay IHLP core loss calculator
Products - Inductors - IHLP® Inductor Loss Calculator Tool Landing Page - IHLP® inductor loss calculator tool | Vishay
Vishay’s IHLP Core Loss Calculator is a free tool that assists designers in selecting the proper IHLP inductor based on the operating conditions of their circuit.
www.vishay.com
[6.8uH is too low value, but its on the cust PCB that they want tested, so thats that for us]
EDIT...my apologies, i get it now......they want to know these voltages so they can calculate the actual voltages across the inductor.....i thought they would let me do that....my apologies...problem solved.
New problem.....it says its 3.5W of total loss and 2.7W of core loss....do you think its too much?......there is no fan air...its in enclosed metal (Al) box....the footprint is as attached...it 4 layer PCB......no thermal vias, and ridiculously than thermal reliefs as shown.........surely that footprint and 3.5W is asking for trouble?
Max external ambient 50degc
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