TPS54350-EP_15 Datasheet, PDF (25/37 Pages) Texas Instruments – 4.5-V TO 20-V INPUT, 3-A OUTPUT SYNCHRONOUS PWM SWITCHER WITH INTEGRATED FET (SWIFT™)

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TPS54350-EP
SGLS308 – OCTOBER 2005
U1
TPS54350PWP
6 V − 18 V
1 _VIN
BOOT ¹⁶
+
C1
47 µF
2
C9
10 µF
3
Power Good 3.3 V 4
5
VIN
UVLO
PWRGD
RT
PH ¹⁵
14
PH
13
LSG
VBIAS ¹²
6
SYNC
7
ENA
8
COMP
11
PGND
AGND ¹⁰
VSENSE ⁹
PWRPAD
17
C6
82 nF
R3
768 Ω
Pull up to 3.3 V or 5 V
C7
1800 pF
C3
0.1 µF
12367
Q1
4
85
C4
1 µF
C10
3300 pF
R1
1k Ω
L1
10 µH
1
2
R10
4.7 Ω
+
C2
100 µF
R4
10 k Ω
R2
374 Ω
Power Good 1.8 V
C18
47 µF
C15
10 µF
R13
110 k Ω
Easy 1805 Out of Phase
Synchronization
U2
TPS54350PWP
1 _VIN
BOOT ¹⁶
2
VIN
PH ¹⁵
3 _UVLO
14
PH
4
PWRGD
13
LSG
5 _RT
VBIAS ¹²
6 _SYNC
7
ENA
11
PGND
AGND ¹⁰
8
COMP
VSENSE ⁹
PWRPAD
17
C13
82 nF
R6
768 Ω
C5
0.1 µF
C17
1800 pF
R5
137 Ω
C8
33 nF
12367
Q2
4
85
C16
1 µF
C14
3300 pF
R12
1k Ω
L2
10 µH
1
2
R9
4.7 Ω
+
C11
100 µF
Q1, Q2: Fairchild Semiconductor FDR6674A
L1, L2: Vishay IHLP-5050CE
C2, C11: Sanyo 6TPC100M
R7
976 Ω
R11
137 Ω
C12
33 nF
Figure 26. 3.3-V/1.8-V Power Supply With Sequencing
VOUT 3.3 V @ 3 A
VOUT 1.8 V @ 3 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.
25