sc4524d Semtech Corporation, sc4524d Datasheet - Page 6

• Manufacturer Part Number: sc4524d
• Description: 18v 2a Step-down Switching Regulator
• Manufacturer: Semtech Corporation

Block Diagram
ROSC
COMP
SS/EN
FAULT
SS/EN
FB
3
3 3
6
6 6
7
7 7
5
5 5
V1
V1
2.4 A
FREQUENCY
+
+
-
-
+
+
FOLDBACK
I C
I
Figure 3. Soft-start and Overload Hiccup Control Circuit
EA
REFERENCE
SHUTDOWN
1V
& THERMAL
R
R
1.9V
A1
A1
OSCILLATOR
+
+
-
-
1.9V
COMP
SLOPE
I D
I
3.9 A
R
R
1.2V
+
+
Figure 2. SC4524D Block Diagram
1V/2.15V
FAULT
+
+
-
-
B4
+
+
B1
+
+
+
PWM
-
-
-
SOFT - START
OVERLOAD
CONTROL
HICCUP
AND
-
OC
S
S
R
R
CLK
Q
ILIM
+
+
-
-
S
R
Q
Q
_
_
18mV
B2
B3
ISEN
Q
S
R
+
+
-
-
BST
8
8
GND
SW
SW
OC
PWM
IN
2
2
OVERLOAD
4
4
1
1 1
TRANSISTOR
5.5m
POWER
SC4524D
6