SC220
Pin Descriptions
Pin # Pin Name Pin Function
1
SW
Switching output node — connect to the output LC filter.
2
PVIN Power input supply voltage (2.7V to 5.5V).
3
VOUT Input for sensing the output of LC filter.
Input for regulation of output LC filter — Using R and R to set the output voltage, V = V x (1+ R /R ). (Please refer
4
FB
1
2
OUT FB
12
to the typical application circuit diagram on page 1).
Enable Input — when low, circuit draws <1μA. Apply a square wave clock at EN to synchronize the switching frequency
5
EN
with an external clock. It is recommended that the externally applied clock frequency should not be above 20MHz.
6
AVIN Input supply voltage.
7
AGND Analog ground.
8
PGND Power ground.
Block Diagram
EN 8
REF
1.0V
OSC
Therm al
S hutdow n
E xternal Freq .
S ynchronization
20 M H z
F re q u e n c y
C ontrol
AVIN
7
S oft-S tart
C LIM
1 .0 V
+
E rror
FB 1
Amp
-
+
C om p
-
C ontrol Logic
D river
ZCD
PVIN
3
4 SW
6
AGND
C om pensator
5
PGND
2 VOUT
5