Datasheet
C1
0.1uF
R1
100k
C4
2.2uF
C3
0.1uF
Q1
4
5
1 - 3
4
5
1 - 3
FDMS8680
Q2
FDMS8670AS
4
5
1 - 3
Q3
FDMS8670AS
L1
0.45uH
C7
5x330uF
C8
12x22uF
C5
C6
4x10uF
/25V
0.1uF
/50V
R4
0
R3
0
R2
1k
C2
0.01uF
VSNS
GSNS
REFIN
V5
DL
DH
2
3
4
12
9
10
1
VREF SW
11U1
TPS51219
PGND
GN D
TR IP
COMP
EN
MODE
PGOOD
PwPd
17
16
15
14
13
5
6
7
8
BST
R5
36k
VIN
Vout
EN
V5IN
8V to 20V
1.05V/20A
4.5V to 5.5V
Vout_GND
3.3V
R6
10
C9
1nF
TPS51219
SLUSAG1B – MARCH 2011– REVISED OCTOBER 2011
www.ti.com
•
Connections from gate drivers to the respective gate of the high-side or the low-side MOSFET should be as
short as possible to reduce stray inductance. Use 0.65 mm (25 mils) or wider trace and via(s) of at least 0.5
mm (20 mils) diameter along this trace.
• The PCB trace defined as SW node, which connects to the source of the switching MOSFET, the drain of the
rectifying MOSFET and the high-voltage side of the inductor, should be as short and wide as possible.
• In order to effectively remove heat from the package, prepare the thermal land and solder to the package
thermal pad. Wide trace of the component-side copper, connected to this thermal land, helps to dissipate
heat. Numerous vias with a 0.3-mm diameter connected from the thermal land to the internal/solder-side
ground plane(s) should be used to help dissipation.
TPS51219 1.05-V/20-A, D-CAP2™ 500-kHz, R
DS(on)
Sensing Application Circuit
Figure 33. 1.05-V/20-A, D-CAP2™ 500-kHz, R
DS(on)
Sensing
Table 3. 1.05-V/20-A, D-CAP2™ 500-kHz, R
DS(on)
Sensing, List of Materials
REFERENCE
QTY SPECIFICATION MANUFACTURE PART NUMBER
DESIGNATOR
C6 4 10 µF, 25 V Taiyo Yuden TMK325BJ106MM
C7 5 330 µF, 2 V, 6 mΩ Panasonic EEFSX0D331XE
C8 12 22 µF, 6.3 V Murata GRM21BB30J226ME38
L1 1 0.45 µH, 17 A, 1.1 mΩ Panasonic ETQP4LR45XFC
Q1 1 30 V, 35 A, 8.5 mΩ Fairchild FDMS8680
Q2, Q3 2 30 V, 42 A, 3.5 mΩ Fairchild FDMS8670AS
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