LNK520
DRAIN
0
1
CONTROL
V
C
INTERNAL
SUPPLY
Z
C
SHUTDOWN/
AUTO-RESTART
CURRENT
LIMIT
ADJUST
SHUNT REGULATOR/
ERROR AMPLIFIER
+
-
÷ 8
-
5.6 V
4.7 V
CURRENT LIMIT
COMPARATOR
5.6 V
+
-
+
I
HYSTERETIC
THERMAL
FB
SHUTDOWN
OSCILLATOR
D
MAX
CLOCK
SAW
S
R
Q
-
+
PW
M
COMPARATOR
I
DCS
LEADING
EDGE
BLANKING
EDGE
LOW
FREQUENCY
OPERATION
R
E
SOURCE
PI-2777-032503
Figure 2. Block Diagram.
Pin Functional Description
LNK520
DRAIN (D) Pin:
S
S
C
S
1
2
8
7
Power MOSFETdrain connection. Provides internal operating
current for start-up. Internal current limit sense point for drain
current.
S
S
3
4
CONTROL (C) Pin:
5
D
Error amplifier and feedback current input pin for duty cycle
and current limit control. Internal shunt regulator connection
to provide internal bias current during normal operation. It is
also used as the connection point for the supply bypass and
auto-restart/compensation capacitor.
P Package (DIP-8B)
G Package (SMD-8B)
PI-3790-121503
Figure 3. Pin Configuration.
SOURCE (S) Pin:
Output MOSFET source connection for high voltage power
return. Primary side control circuit common and reference
point.
E
2/05
2
POWERINT [ Power Integrations ]
