Datasheet
SLVS485 − AUGUST 2003
www.ti.com
18
DI +
ǒ
V
O
) V
(SCHOTTKY)
) R
RL
I
O
Ǔ
t
off
,min
L
+ 110 mA
(24)
The current rating for the inductor must be:
(25)
I, inductor u I
O
)
DI
2
+ 555 mA
6. Select the input and output capacitor
The output capacitor is selected for an output voltage ripple of less than 20 mVpp.
With
ESR, max [
DV
pp
1.1 DI
+
0.02 V
1.1 0.11 A
+ 165 mW
(26)
A 47-µF PosCap with an ESR of 100 mΩ was selected to meet the ripple requirements.
The input capacitor was selected to its minimum value of 10 µF.
SW
CDRH4D18-100
Si2301DS
MBR0530T1
EN
GND
FB
VIN
ISENSE
1 Li-lon Cell
10 µF
TPS64202
R1
620 kΩ
R2
360 kΩ
47 µF PosCap
6TPA47M
3.3 V / 0.5 A
R
(ISENSE)
= 120 mΩ
1
2
3
6
5
4
10 µH
Figure 21. Application Circuit