sc4525c Semtech Corporation, sc4525c Datasheet - Page 6

• Manufacturer Part Number: sc4525c
• Description: 28v 3a Step-down Switching Regulator
• Manufacturer: Semtech Corporation

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