Datasheet
40 mV
Cr = 3300 pF
(V
IN(MIN)
± V
OUT
)T
ON
C
ac
= 100 nF
Rr x Cr <
ûI
L
40 mV
C8
5
R2
>
g
SW
(R
1
|| R
6
)
>
V
REF
40 mV
R2 >
ûI
L
(MIN)
V
OUT
x
GND
R
r
C
ac
To FB
L1
C
OUT
R
FB2
R
FB1
V
OUT
C
r
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
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Ripple Configuration
Table 1. Bill of Materials
Item Description Mfg., Part Number Package Value
C5 Ceramic Capacitor Kemet, C0805C104K1RACTU 0805 0.1uF, 100V, X7R
C7 Ceramic Capacitor TDK, C2012X7R1C105K 0805 1uF, 16V, X7R
C8 Ceramic Capacitor Murata, GRM188R71E104KA01D 0603 0.1uF, 25V, X7R,
0603
C9 Ceramic Capacitor Murata, GRM21BR61E475KA12L 0805 4.7uF, 25V, X5R
D2 Diode Diodes, Inc., SDM10U45–7–F SOD-523 Schottky, 45V,
0.1A
Inductor Bourns, SRR0603–221kL 6.5mm x 6.5mm 220uH, 0.310A
L1 Alternate Inductor Wurth, 744053221 5.8mm x 5.8mm 220uH, 0.290A
Alternate Inductor Coilcraft, LPS5030–224 5mm x 5mm 220uH, 0.245A
R1 Resistor Vishay-Dale, CRCW08056K98FKEA 0805 220uH, 0.6A
R2 Resistor Vishay-Dale, CRCW08051R50FKEA 0805 1.50 ohm, 1%,
0.125W
R3 Resistor Vishay-Dale, CRCW0805237KFKEA 0805 237k ohm, 1%,
0.125W
R5 Resistor Vishay-Dale, CRCW0805127KFKEA 0805 127k ohm, 1%,
0.125W
R6 Resistor Vishay-Dale, CRCW08051K00FKEA 0805 1.00k ohm, 1%,
0.125W
R7 Resistor Vishay-Dale, CRCW080514K0FKEA 0805 14.0k ohm, 1%,
0.125W
U1 Sync Switching Texas Instruments, LM5019 SO PowerPAD-8 100V, 100 mA
Regulator
5 Ripple Configuration
The LM5019 is a constant-on-time (COT) buck, and requires adequate ripple at feedback (FB) node.
Three commonly used ripple generation methods are shown in Table 2.
The LM5019 evaluation board has been supplied with reduced ripple configuration (Type 2). For more
information on ripple configuration, refer to LM5019 datasheet.
Table 2. Ripple Configuration
Type 1 Type 2 Type 3
Lowest Cost Configuration Reduced Ripple Configuration Minimum Ripple Configuration
C8 open. Select R2: Select R2 and C8: (Not on Board)
(4)
(5)
(6)
3
SNVA647A–May 2012–Revised April 2013 AN-2238 LM5019 Buck Evaluation Board
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