lnk501 Power Integrations, Inc., lnk501 Datasheet - Page 2

• Manufacturer Part Number: lnk501
• Description: Energy Ef?cient, Cv/cc Switcher For Very Low Cost Chargers And Adapters
• Manufacturer: Power Integrations, Inc.

Pin Functional Description
DRAIN (D) Pin:
Power MOSFET drain connection. Provides internal operating
current for start-up. Internal current limit sense point for drain
current.
CONTROL (C) Pin:
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.
SOURCE (S) Pin:
Output MOSFET source connection for high voltage power
return. Primary side control circuit common and reference
point.
Figure 2. Block Diagram.
2
CONTROL
LNK501
I
2/05
I DCS
R E
Z C
SHUNT REGULATOR/
I
FB
ERROR AMPLIFIER
OSCILLATOR
CLOCK
V C
D MAX
SAW
+
-
5.6 V
COMPARATOR
5.6 V
4.7 V
PW M
+
-
AUTO-RESTART
SHUTDOWN/
+
-
FREQUENCY
OPERATION
LOW
HYSTERETIC
SHUTDOWN
THERMAL
0
1
Figure 3. Pin Configuration.
INTERNAL
SUPPLY
÷ 8
S
R
Q
G Package (SMD-8B)
S
S
S
S
P Package (DIP-8B)
2
3
1
4
LNK501
CURRENT
CURRENT LIMIT
ADJUST
COMPARATOR
BLANKING
LIMIT
LEADING
EDGE
EDGE
8
5
7
+
-
C
D
S
SOURCE
PI-2777-032503
PI-2711-073107
DRAIN