SC4525C Datasheet, PDF (6/21 Pages) Semtech Corporation – 28V 3A Step-Down Switching Regulator Thermal Shutdown

SC4525C
Block Diagram
COMP
6
FB
7
ROSC
3
SS/EN
5
-
+ EA
+
SLOPE
COMP ₊
S
+
V1
FREQUENCY
FOLDBACK
+
PWM
-
OSCILLATOR
+
ISEN
-
OC
+
ILIM
18mV
-
BST
8
S
Q
R
CLK
+
A1
-
R
1.2V
R
1V
1.9V
REFERENCE
& THERMAL
SHUTDOWN
FAULT
SOFT- START
AND
OVERLOAD
HICCUP
CONTROL
IN
2
3.53m W
POWER
TRANSISTOR
1
SW
GND
4
Figure 2. SC4525C Block Diagram
SS/EN
1.9V
IC
2.4mA
-
+B4
B1
1V/2.15V
S
Q
R
B2
OVERLOAD
FAULT
ID
3.9mA
_S
Q
R
B3
OC
PWM
Figure 3. Soft-start and Overload Hiccup Control Circuit