85
LC-32LE631
LC-40LE631
LC-46LE631
8.12 Diagram
DVBS supply
B08A, TPS54283PWP (IC 7T03)
Figure 8-12 Internal block diagram and pin configuration
18770_305_100217.eps
100217
Block diagram
7
FB1
+
Soft Start
1
C
COMP
+
S
Q
Q
R
R
+
Current
Comparator
BP
f(I
DRAIN1
) + DC(ofst)
2
1
3
Anti-Cross
Conduction
1.2 MHz
Oscilator
Divide
by 2/4
Ramp
Gen 1
Ramp
Gen 2
CLK1
CLK2
BP
CLK1
Weak
Pull-Down
MOSFET
5
EN1
6
EN2
6 A
6 A
VDD2
Internal
Control
10
SEQ
150 k
150 k
Output
Undervoltage
Detect
BP
FB1
FB2
CLK1
4
GND
8
FB2
+
Soft Start
2
C
COMP
+
S
Q
Q
R
R
+
Current
Comparator
BP
13
14
12
Anti-Cross
Conduction
BP
CLK2
Weak
Pull-Down
MOSFET
11
BP
9
ILIM2
150 k
150 k
BP
CLK2
4
GND
Level
Select
5.25-V
Regulator
References
BOOT1
PVDD1
SW1
BOOT2
PVDD2
SW2
f(I
DRAIN2
) + DC(ofst)
0.8 V
REF
I
MAX2
(Set to one of two limits)
f(I
DRAIN1
)
f(I
MAX1
)
Overcurrent Comp
f(I
SLOPE1
)
Level
Shift
Level
Shift
f(I
DRAIN2
)
f(I
MAX2
)
f(I
SLOPE2
)
FET
Switch
TSD
PVDD2
f(I
SLOPE1
)
f(I
SLOPE2
)
SD1
SD2
UVLO
0.8 V
REF
SD2
0.8 V
REF
SD1
UDG-07007
Overcurrent Comp
R
COMP
R
COMP
IC Data Sheets (continued)
