AAT1230/1230-1
18V 100mA Step-Up Converter
From Switching Frequency vs. IOUT curves estimated switching frequency of AAT1230/1230-1 with VOUT = 16V
and IOUT = 100mA, FSW = 800kHz.
IOUT
1 - DMAX
DMAX
·
·
FS L)
VIN(MIN)
·
IPEAK
=
=
+
(2
0.100
1 - 0.840
0.834 (2.7V)
0.8M 2.2µH
+
2
·
·
= 0.625 + 0.640
= 1.265A = 1265mA
IPEAK
1265
3
IRMS
=
=
= 730mA
3
For Coiltronics inductor SD3814-2R2, ISAT = 1.90A, IRMS(MAX) = 1.43A and DCR = 77mΩ.
PLOSS(INDUCTOR) = IRMS2 · DCR
= (0.730)2 (0.077)
= 0.041W
= 41mW
16V Output Capacitor
ΔVOUT = 0.1V
IOUT · DMAX
FS · ΔVOUT
(0.1A) (0.84)
(0.8kHz) (0.1V)
COUT
=
=
= 1.05µF; use 2.2µF/25V MLC
1230.2007.06.1.6
17
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