SC2447 Semtech Corporation, SC2447 Datasheet - Page 13

• Manufacturer Part Number: SC2447
• Description: Dual-Phase Single or Two Output Synchronous Step-Down Controller
• Manufacturer: Semtech Corporation

POWER MANAGEMENT
Timing Chart
0
0
0
0
2006 Semtech Corp.
GDH in high impedance state
t0
4.5V
0.5V (V
t1
(a) Normal Start Up
REF
A
VCC
1.25V
)
GDH
GDH
GDL
GDL
1.5V
V
V
t2 t4
REFSS
REFSS
V
V
IN-
IN-
V
V
V
V
SS/EN
SS/EN
A
A
COMP
COMP
VCC
VCC
Figure 6. SC2447 UVLO Shutdown Timing Diagram
Figure 5. SC2447 Start-up Timing Diagram
t16
t16
3.2V
t5 t6 t7
Enable Hiccup
V
t17
t17
SS/EN
4.3V
4.3V
GDH in high impedance state
0.5V (V
0.5V (V
V
V
V
GDL
REFSS
GDH
IN-
COMP
REF
REF
13
)
)
0
0
0
0
t0
4.5V
0.5V (V
GDH in high impedance state
t1
REF
A
(b) Pre-Biased Start Up
1.25V
VCC
)
t2
t3 t4
1.5V
www.DataSheet4U.com
3.2V
t5 t6 t7
www.semtech.com
V
SC2447
Enable Hiccup
SS/EN
V
V
V
REFSS
GDH
GDL
IN-
COMP