top221 Power Integrations, Inc., top221 Datasheet - Page 2

• Manufacturer Part Number: top221
• Description: Three-terminal Off-line Pwm Switch
• Manufacturer: Power Integrations, Inc.

Figure 2. Functional Block Diagram.
Pin Functional Description
DRAIN Pin:
Output MOSFET drain connection. Provides internal bias
current during start-up operation via an internal switched high-
voltage current source. Internal current sense point.
CONTROL Pin:
Error amplifier and feedback current input pin for duty cycle
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 Pin:
Y package – Output MOSFET source connection for high
P and G package – Primary side control circuit common and
SOURCE (HV RTN) Pin: (P and G package only)
Output MOSFET source connection for high voltage power return.
2
CONTROL
TOP221-227
D
7/01
voltage power return. Primary side circuit
common and reference point.
reference point.
R E
Z C
I FB
SHUNT REGULATOR/
ERROR AMPLIFIER
OSCILLATOR
V C
CLOCK
D MAX
SAW
+
-
5.7 V
SHUTDOWN
COMPARATOR
5.7 V
4.7 V
THERMAL
PWM
-
+
AUTO-RESTART
SHUTDOWN/
+
-
POWER-UP
RESET
0
1
INTERNAL
SUPPLY
S
R
Figure 3. Pin Configuration.
8
Q
Q
S
R
Connected to SOURCE Pin
CONTROL
Q
Q
SOURCE
SOURCE
SOURCE
Tab Internally
Y Package (TO-220/3)
G Package (SMD-8)
P Package (DIP-8)
2
1
3
4
BLANKING
LEADING
EDGE
CONTROLLED
TURN-ON
DRIVER
GATE
8
6
5
7
+
-
SOURCE (HV RTN)
SOURCE (HV RTN)
SOURCE (HV RTN)
DRAIN
MINIMUM
ON-TIME
DELAY
V I
LIMIT
DRAIN
SOURCE
CONTROL
PI-2084-040401
PI-1935-091696
DRAIN
SOURCE