Datasheet


SLVS456C − OCTOBER 2003 − REVISED OCTOBER 2004
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21
BOOT
2
PWRPAD
17
1
VIN
VIN
UVLO
PWRGD
RT
SYNC
ENA
COMP
VSENSE
AGND
PGND
VBIAS
LSG
PH
PH
3
4
5
6
7
8
16
15
14
13
12
11
10
9
U1
TPS54350PWP
C3
10 µF
C2
220 µF
+
C5
1 µF
4
Q1
1
L1
22 µH
+
C4
220 µF
C6
22 µF
C9
2200 pF
R9
130 kΩ
C8
470 pF
R4
3.09 kΩ
R8
100 kΩ
C10
470 pF
5 V
GND
D-Case Alum
R2
100 k
R3
43.2 kΩ
123
C1
0.1 µF
C7
10 µF
D-Case Alum
VOUT
–5 V @ 1.5 A
R1
21.5 kΩ
C4: Panasonic EEVFK1A221XP
L1: Coilcraft DO3340P-223
Q1: International Rectifier IRF7402
7865
2
Ω
(1)
Do not connect to system ground plane.
(1)
(1)
(1)
Figure 27. Inverting Power Supply, 5 V to −5 V at 1.5 A
In Figure 27 the TPS54350 is configured as an inverting
supply. The −5-V output is at the pins which would normally
be connected to ground. The output junction of the LC
output filter, which is normally the output in a buck
converter, is tied to ground. An additional 10-µF capacitor,
C7, is required from the output to VIN.
1
VIN
VIN
UVLO
PWRGD
RT
SYNC
ENA
COMP
PWRPAD
17
VSENSE
AGND
PGND
VBIAS
LSG
PH
PH
BOOT
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
U1
TPS54350PWP
C5
1 µF
L1
10 µH
220 µF
6.3 V
C4
10
µF
6.3 V
C7
0.01
µF
R2
5.90 k
Ω
C9
10 pF
R4
7.50 k
Ω
R3
4.64 k
Ω
C8
4700 pF
R1
80.6 kW
C1
0.1
µF
R5
1 k
Ω
C2
10 µF
16 V
D1: On Semiconductor MBRS340T3
C3: Panasonic EEVFK0J221P
L1: Coilcraft DO3316P-103
+12 V
VOUT 5 V @ 3
A
D1
C3
+
Figure 28. 12-V to 5-V Using Aluminum Electrolytic for LCD TV
Figure 28 is an example of a 12-V to 5-V converter using economical output filter components.