lnk623 Power Integrations, Inc., lnk623 Datasheet - Page 2

• Manufacturer Part Number: lnk623
• Description: Energy-efficient, Off-line Switcher With Accurate Primary-side Constant-voltage Cv Control
• Manufacturer: Power Integrations, Inc.

Rev. C 12/08
Figure 2
Pin Functional Description
DRAIN (D) Pin:
This pin is the power MOSFET drain connection. It provides
internal operating current for both start-up and steady-state
operation.
BYPASS (BP) Pin:
This pin is the connection point for an external bypass capacitor
for the internally generated 6 V supply.
FEEDBACK (FB) Pin:
During normal operation, switching of the power MOSFET is
controlled by this pin. This pin senses the AC voltage on the
bias winding. This control input regulates the output voltage
based on the fl yback voltage of the bias winding.
SOURCE (S) Pin:
This pin is internally connected to the output MOSFET source
for high voltage power and control circuit common returns.
2
FEEDBACK
SOURCE
BYPASS
Functional Block Diagram.
(BP)
(FB)
(S)
LNK623-626
6.5 V
V
TH
+
FB
-
t
SAMPLE-OUT
DC
MAX
I
LIM
OSCILLATOR
Auto-Restart
Open-Loop
FAULT
D
Q
OUT
FB
I
LIM
DC
MACHINE
MAX
STATE
Drive
Reset
Figure 3.
V
SHUTDOWN
ILIMIT
BP
THERMAL
FB
P Package (DIP-8C)
D
Current Limit
Comparator
t
1
2
4
Pin Confi guration.
SAMPLE-OUT
6 V
5 V
+
-
3a
V
+
-
ILIMIT
SAMPLE
BLANKING
DELAY
LEADING
8
7
6
5
EDGE
S
S
S
S
REGULATOR
6 V
D Package (SO-8C)
FB
BP
D
1
2
4
www.powerint.com
3b
SOURCE
DRAIN
PI-5198-071608
(D)
(S)
8
PI-5197-110408
7
6
5
S
S
S
S