sc2441a Semtech Corporation, sc2441a Datasheet - Page 10

• Manufacturer Part Number: sc2441a
• Description: Sc2441a 1.8v To 20v Input 2-phase Synchronous Step-down Controllers With Step-up Converter
• Manufacturer: Semtech Corporation

POWER MANAGEMENT
Block Diagram
2006 Semtech Corp.
CKOUT
SYNC/SHDN
28
6
Figure 5. Phase-Locked Loop (a) and Its Timing Diagram in Locked Condition (R
EXT CLOCK
BUFFER
XCLK
FREQUENCY
DETECTOR
PHASE /
QT
CLK
XCLK
QT
CKOUT
CLK1
CLK2
GDH1
GDH2
QU
QD
QT
QT
I
I
S1
S2
PLLF
PLLF
1.5V
COMPENSATION
EXTERNAL PLL
(a)
(b)
10
1K
R1
C1
CLK1
FLIP-FLOP
INTERNAL
TOGGLE
CLAMP
C2
CLK2
PLLF
2
R2
SETTING PHASE
RESISTOR FOR
OPTIONAL
0.4V
SHIFT
+
+
-
CLK
V/I
CONTROLLED
OSCILLATOR
CURRENT-
2
not Used) (b).
FREQUENCY
SETS FREE -
ROSC
RUNNNG
ROSC
10
SC2441A
www.semtech.com