Datasheet

ADP1610
Rev. A | Page 12 of 20
For very low ESR capacitors, such as ceramic capacitors, the ripple
current due to the capacitance is calculated using the following
equation. Because the capacitor discharges during the on-time
(t
ON
), the charge removed from the capacitor (Q
C
) is the load
current multiplied by the on-time. The output voltage ripple
(V
OUT
) is
OUT
ON
L
OUT
C
OUT
C
t
I
C
Q
V
×
==Δ (8)
where:
C
OUT
is the output capacitance.
I
L
is the average inductor current.
SW
ON
F
D
t
= (9)
and
OUT
IN
OUT
V
VV
D
−
=
(10)
Choose the output capacitor based on the following equation:
OUTOUT
SW
IN
OUT
L
OUT
VVF
VVI
C
Δ××
−
×
≥
)(
(11)
The following are recommended capacitor manufacturers:
• AVX
• Kyocera
• Murata
• Sanyo
• Taiyo –Yude n
• TDK