MB39A102 Datasheet, PDF (22/24 Pages) Fujitsu Component Limited. – Evaluation Board

MB39A102
• IL current: Peak value
The peak IL current of this inductor must be within its rated current.
IL current is obtained by the following formula.
IL
≥
VO
VIN (Min)
× IO +
VIN (Min)
2L
× tON
≥
3.3
2.5
×
0.5
+
2.5
2×10×10^−6
×
1
500×10³
× 0.57
≥ 0.802 A
(4) Inductor (L4 : RLF5018T-150MR76, TDK product)
15 µH (tolerance ± 20%) , rated current = 0.76 A
The condition for L to be a continuous current within the operating voltge range is obtained by the following
formula.
L
≥
VIN (Max)
2IO
× tON
≥
6
2×0.5
×
1
500×10³
× 0.355
≥ 4.3µH
The load current satisfying the continuous current condition is obtained by the following formula.
IO ≥
VIN (Max)
2L
× tON
≥
6
2×15×10^−6
×
1
500×10³
× 0.355
≥ 0.142 A
Note : The continuous current condition becomes a large current value compared with the
current value obtained by L3.
• IL current: Peak value
The peak IL current of this inductor must be within its rated current.
IL current is obtained by the following formula.
IL ≥ IO +
VIN (Max)
2L
× tON
≥
0.5
+
6
2×15×10^−6
×
1
500×10³
× 0.355
≥ 0.642 A
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