Datasheet

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SLUS536C − AUGUST 2002 − REVISED AUGUST 2004
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15
DETAILED DESCRIPTION
+
+
H=CLOSED
+
L=CLOSED
SQ
QR
+
+
+
LCA
+
H=CLOSED
+
SQ
QR
12
13
1.35V
5V
FLT
EN_A
VLIM
4
9
10
6
8
1.4V
5
14
1
3
2
7
100 mV
VLIM
EN_A
11
IRAMP
RAMP
GENERATOR
FAULT
TIMER
OVERLOAD
OVERCURRENT
DRAINSNS
FLTTIME
ISENS
GATE
INSA
UVLO
OVLO
EN
−VIN
INSB
S
R
FT
ON
EN
OC OL
RTN
+
OLC
FLT
UDG−02116
PG
FAULT
10 µA
10 µA
10 µA
10 µA
10 µA
10 µA
Figure 24. Block Diagram of PW Package
Under normal load and input supply conditions, this controlled current charges the module’s input bulk capacitance
up to the input dc voltage level. At this point, the load demand drops off, and the voltage at ISENS decreases. The
LCA now drives the GATE output to its supply rail. The 14-V typical output level ensures sufficient overdrive to fully
enhance the external FET, while not exceeding the typical 20-V V
GS
rating of common N-channel power MOSFETs.