SC2620 Datasheet, PDF (5/26 Pages) Semtech Corporation – Dual 2A, 30V Step-down Regulator with Programmable Frequency up to 1.4MHz

SC2620
POWER MANAGEMENT
Block Diagrams
PGOOD1
15
COMP1
16
FB1
1
SS1
14
CHANNEL 1 ONLY
-
+
POWER
GOOD
100m V
-
EA
+
+
PWM
-
+
Σ
+
SLOPE
COMP 1
+
ISEN
-
+
ILIM
-
20mV
BOOST1
2
4 PVIN1
6.3mΩ
S
Q
R
POWER
TRANSISTOR
FB1
3 SW1
Soft-Start
1V
0.7V
And
Overload
OVLD
SS2
REFERE NCE
& THERMAL
FAULT
Hiccup
Control 1
10
SHUTDOWN
12 VIN
SLOPE SLOPE
COMP 1 COMP 2
ROSC
13
OSCILLATOR
SLOPE COMP
CLK1
FREQUENC Y
DIVIDER CLK2
Figure 2. SC2620 Block Diagram (Channel 1)
11 GND
FB
0.7V
SS
+
-
1.8µA
1V/2V
S
Q
R
OVLD
FAULT
2.6µA
Figure 3. Details of the Soft-Start and Overload Hiccup Control Circuit
 2006 Semtech Corp.
5
www.semtech.com