SC2441 Datasheet, PDF (8/35 Pages) Semtech Corporation – Very Low Input Voltage 2-Phase Synchronous Step-down Controllers with Step-up Converter

SC2441
POWER MANAGEMENT
Block Diagram
SYNC/SHDN
6
ROSC
10
OSCILL ATO R
CLK
COMP1
12
FB1
11
0.5V
SHDN
-
EA1
+
SLOPE1
CLK2
FREQUENCY
DIVIDER CLK1
SLOPE COMP
SLOPE2
-
PWM1
+
1.25V
REFERENCE
0.5V 0.36V
R
Q
S
SHDN
VIN UVLO
1.60/1.74V
UVLO
4.45/4.65V
Non-Overlapping
Condu ction
Control
CS1+
4
CS1-
5
+
ISEN1
-
++
Σ
50mV
+
ILIIM1
-
1.25V -
+
COMP2
13
FB2
14
0.5V
-
EA2
+
SEL
ANALOG SWITCH
SLOPE2
-
PWM2
+
FAULT
Soft-Start
And
Overload
Hiccup
Control 1
OL
DSBL
CLK2
R
Q
S
BA
SEL
Y
Non-Overlapping
Condu ction
Control
VCC
CS2+
16
CS2-
15
GND
9
+
ISEN2
-
+
+
Σ
50mV
+
ILIIM2
-
FAULT
Soft-Start
And
Overload
Hiccup
Control 2
OL
DSBL
Step-down Controllers Functional Diagram
IN
1
PVIN
28
VCC
21
BST1
25
GDH1
23
VPN1
26
GDL 1
22
PGND
24
SS1/EN1
3
BST2
18
PVIN
GDH2
19
VPN2
2
GDL 2
20
SS2/EN2
17
Figure 2
 2005 Semtech Corp.
8
www.semtech.com