MB39A106 Datasheet, PDF (32/46 Pages) Fujitsu Component Limited. – 2-Channel DC/DC Converter IC with Overcurrent Protection Symmetrical-Phase Type

MB39A106
CH2 (Main side)
Input voltage VIN (Max) = 15 V, output voltage VO = 5 V, drain current ID = 3 A, Oscillation frequency fOSC = 300
kHz, L = 22 µH, drain-source on resistance RDS (ON) =: 33 mΩ, tr = 13.8 ns, tf = 8 ns.
Drain current (Max) : ID (Max)
ID (Max) = IO +
VIN (Max) −VO
2L
ton
=3
+
15−5
2 × 22 × 10^−6
×
1
300 × 10³
× 0.33
=: 3.25 (A)
Drain current (Min) : ID (Min)
ID (Min) =
IO
+
VIN (Max) −VO
2L
ton
= 3−
15−5
2 × 22 × 10^−6
×
1
300 × 10³
× 0.33
=: 2.75 (A)
PC1 = ID2 × RDS (ON) × Duty (ON)
= 3² × 0.033 × 0.33
=: 0.098 W
PS1 (ON)
=
VD (Max)
× ID × tr × fOSC
6
=
15 × 3 × 13.8 × 10^−9 × 300 × 10³
6
=: 0.031 W
PS1 (OFF)
=
VD (Max) × ID (Max) × tf × fOSC
6
=
15 × 3.25 × 8 × 10^−9 × 300 × 10³
6
=: 0.020 W
PT1 = PC1 + PS1 (ON) + PS1 (OFF)
=: 0.098 + 0.031 + 0.020
=: 0.149 W
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