Datasheet

25 mV
C4 = 3300 pF
R5 x C4
(V
IN(MIN)
± V
OUT
)T
ON
C7 = 100 nF
<
ûI
L
25 mV
C7
5
R4
>
g
SW
(R
3
|| R
6
)
>
V
REF
25 mV
R4 >
ûI
L
(MIN)
V
OUT
x
GND
To FB
L1
C
OUT
R
FB2
R
FB1
V
OUT
R
C
GND
To FB
L1
C
OUT
R
FB2
R
FB1
V
OUT
R
C
C
ac
GND
R
r
C
ac
To FB
L1
C
OUT
R
FB2
R
FB1
V
OUT
C
r
Ripple Configuration www.ti.com
6 Ripple Configuration
The LM25019 is a COT buck and requires adequate ripple at feedback (FB) node. Three commonly used
ripple generation methods are shown in Table 1.
LM25019 evaluation board has been supplied with minimum ripple configuration (Type 3), but can be
configured to Type 1 or Type 2 with modifications as suggested in Table 1.
Table 1. Ripple Configuration
Type 1 Type 2 Type 3
Lowest Cost Configuration Reduced Ripple Configuration Minimum Ripple Configuration
R5, C4, C7 open. Select R4: R5 open, C4 = 0 Ω. Select R4 and C7: R4 = 0 Ω. Select R5, C4, and C7:
(4)
(5)
(6)
4
LM25019 Evaluation Board SNVU225–April 2013
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