SC2446 Semtech Corporation, SC2446 Datasheet - Page 8

• Manufacturer Part Number: SC2446
• Description: Dual-Phase Single or Two Output Synchronous Step-Down Controller
• Manufacturer: Semtech Corporation

POWER MANAGEMENT
Block Diagram
2004 Semtech Corp.
CS1+
CS1-
SYNC
COMP1
COMP2
ROSC
IN1-
REF/IN1+
REF
IN2-
REF
AGND
1
11
12
10
2
6
3
5
4
8
9
7
OUT
IN
/IN2+
+
-
110mV
75mV
ISEN
+
-
+
-
+
+
-
-
EA1
EA2
+
+
-
-
0.5V
ILIM+
ILIM-
Figure 3. SC2446 Block Diagram (Channel 1 PWM Control Only)
OSCILLATOR
+
Figure 4. Soft-Start and Overload Hiccup Control Circuit
+
/ 0.72(V
SLOPE
COMP
0.75(V
SS/EN
UVLO
IN-
OCN
REF
REFOUT
)
0.72 VREF
)
+
-
PWM
-
+
OUT
OCN
CLK2
CLK1
0.75 VREF
0.5V/3.2V
0.9V/1.2V
R
S
Soft-Start And
8
Q
Overload
Control
Hiccup
UVLO
REFERENCE
OL
DSBL
S
R
Q
OL
Non-Overlapping
DSBL
UVLO
Conduction
4.3/4.5V
Control
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SC2446
SS1/EN1
PGND
AVCC
GDH1
PVCC
GDH2
GDL2
BST1
GDL1
VPN1
VPN2
VIN2
16
23
28
20
17
18
26
25
24
27
22
21