Component Power Dissipation
Operating in discontinuous mode, power loss in
the winding resistance of inductor can be ap-
proximate equal to
PDL
=
2 TON * (RD) * VOUT + VF * (POUT)
3 L
VOUT
where POUT=VOUT * IOUT; RS=Inductor DC R;
AIC1642
VD = Diode drop.
The power dissipated in a switch loss is
PDSW = 2 TON * (RON) * VOUT + VD − VIN * (POUT)
3 L
VOUT
The power dissipated in rectifier diode is
PDd = VD * (POUT)
VOUT
■ PHYSICAL DIMENSIONS
l SOT-89 (unit: mm)
D
D1
H
L
e
e1
E
B
l SOT-89 MARKING
Part No.
AIC1642-27
AIC1642-30
AIC1642-33
AIC1642-50
Marking
AM27
AM30
AM33
AM50
A
SYMBOL
MIN
MAX
C
A
1.40
1.60
B
0.36
0.48
C
0.35
0.44
D
4.40
4.60
D1
1.62
1.83
E
2.29
2.60
e
1.50 (TYP.)
e1
3.00 (TYP.)
H
3.94
4.25
L
0.89
1.20
13