LNK562P POWERINT [Power Integrations, Inc.], LNK562P Datasheet - Page 2

• Manufacturer Part Number: LNK562P
• Description: Energy Effi cient Off-Line Switcher IC for Linear Transformer Replacement
• Manufacturer: POWERINT [Power Integrations, Inc.]

Pin Functional Description
DRAIN (D) Pin:
The power MOSFET drain connection provides internal
operating current for both start-up and steady-state operation.
BYPASS (BP) Pin:
A 0.1 µF external bypass capacitor for the internally generated
5.8 V supply is connected to this pin.
FEEDBACK (FB) Pin:
During normal operation, switching of the power MOSFET is
controlled by this pin. MOSFET switching is disabled when a
current greater than 70 µA fl ows into this pin.
SOURCE (S) Pin:
This pin is the power MOSFET source connection. It is also the
ground reference for the BYPASS and FEEDBACK pins.
LinkSwitch-LP Functional
Description
LinkSwitch-LP comprises a 700 V power MOSFET switch with
a power supply controller on the same die. Unlike conventional
PWM (pulse width modulation) controllers, it uses a simple
ON/OFF control to regulate the output voltage. The controller
consists of an oscillator, feedback (sense and logic) circuit, 5.8 V
regulator, BYPASS pin under-voltage circuit, over-temperature
Figure 2. Functional Block Diagram.
2
LNK562-564
OPEN LOOP
F
10/05
PULLDOWN
FEEDBACK
BYPASS
(FB)
(BP)
0.8 V
1.69 V -V
+
TH
6.3 V
OSCILLATOR
ADJ
JITTER
AUTO-RESTART
RESET
CLOCK
DC
COUNTER
MAX
FAULT
PRESENT
Figure 3. Pin Confi guration.
protection, frequency jittering, current limit circuit, and leading
edge blanking.
Oscillator
The typical oscillator frequency is internally set to an average
of 66/83/100 kHz for the LNK562, 563 & 564 respectively.
Two signals are generated from the oscillator: the maximum
duty cycle signal (DC
the beginning of each switching cycle.
4.85 V
5.8 V
SHUTDOWN
THERMAL
+
R
-
S
Q
Q
BYPASS PIN
UNDER-VOLTAGE
BP
FB
G Package (SMD-8B)
P Package (DIP-8B)
S
S
REGULATOR
MAX
1
2
3
4
5.8 V
) and the clock signal that indicates
CURRENT LIMIT
COMPARATOR
PI-3958-092905
BLANKING
LEADING
EDGE
+
-
8
7
5
S
D
S
V I
LIMIT
SOURCE
DRAIN
PI-3491-111903
(D)
(S)