MB39A112 Datasheet, PDF (26/35 Pages) Fujitsu Component Limited. – 3-ch DC/DC Converter IC

MB39A112
Example : Using the A916CY-100M
10.0 µH (allowable tolerance ± 20 %) , rated current = 1.49 A
• CH3
Vo3
Io ≥
tOFF
2L
5
≥
2 × 10 × 10^−6
≥ 62.0 mA
1
×
× (1 − 0.417)
2350 × 10³
To determine whether the current through the inductor is within rated values, it is necessary to determine the
peak value of the ripple current as well as the peak-to-peak values of the ripple current that affect the output
ripple voltage. The peak value and peak-to-peak value of the ripple current can be determined by the following
formulas.
Peak value : IL
VIN − Vo
IL ≥ Io +
tON
2L
Peak-to-peak value : ∆IL
VIN − Vo
∆IL =
tON
L
Example : Using the A916CY-2R0M
2.0 µH (allowable tolerance ± 20 %) , rated current = 3.0 A
• CH1
Peak value
VIN − Vo1
IL ≥ Io +
tON
2L
12 − 1.2
≥ 1.5 +
2 × 2.0 × 10^−6
≥ 1.61 A
1
×
× 0.1
2350 × 10³
Peak-to-peak value
VIN − Vo1
∆IL =
tON
L
12 − 1.2
=
2.0 × 10^−6
1
×
× 0.1
2350 × 10³
=: 0.23 A
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