TOP200YAI Power Integrations, TOP200YAI Datasheet - Page 6

• Manufacturer Part Number: TOP200YAI
• Description: IC OFFLINE SWIT PWM OCP HV TO220
• Manufacturer: Power Integrations
• Series: TOPSwitch®r
• Type: Off Line Switcherr

Specifications of TOP200YAI

• Output Isolation: Either
• Frequency Range: 90 ~ 110kHz
• Voltage - Output: 700V
• Power (watts): 12W
• Operating Temperature: -40°C ~ 150°C
• Package / Case: TO-220-3
• Output Voltage: 5.8 V
• Input / Supply Voltage (max): 265 VAC
• Input / Supply Voltage (min): 85 VAC
• Duty Cycle (max): 70 %
• Switching Frequency: 100 KHz
• Supply Current: 1.2 mA
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

General Circuit Operation
Primary Feedback Regulation
The circuit shown in Figure 7 is a simple
5 V, 5 W bias supply using the TOP200.
This universal input flyback power
supply employs primary-side regulation
from a transformer bias winding. This
approach is best for low-cost applications
requiring isolation and operation within
a narrow range of load variation. Line
and load regulation of 5% or better can
be achieved from 10% to 100% of rated
load.
Voltage feedback is obtained from the
transformer (T1) bias winding, which
eliminates the need for optocoupler and
secondary-referenced error amplifier.
High-voltage DC is applied to the
primary winding of T1. The other side
of the transformer primary is driven by
Figure 7. Schematic Diagram of a Minimum Parts Count 5 V, 5 W Bias Supply Utilizing the TOP200.
6
TOP200-4/14
D
7/96
INPUT
DC
CONTROL
SOURCE
DRAIN
TOP200YAI
U1
the integrated high-voltage MOSFET
transistor within the TOP200 (U1). The
circuit operates at a switching frequency
of 100 kHz, set by the internal oscillator
of the TOP200. The clamp circuit
implemented by VR1 and D1 limits the
leading-edge voltage spike caused by
transformer leakage inductance to a safe
value. The 5 V power secondary winding
is rectified and filtered by D2, C2, C3,
and L1 to create the 5 V output voltage.
The output of the T1 bias winding is
rectified and filtered by D3, R1, and C5.
The voltage across C5 is regulated by
U1, and is determined by the 5.7 V
internal shunt regulator at the
CONTROL pin of U1.
rectified bias voltage on C5 begins to
exceed the shunt regulator voltage,
UF4005
1N4764
VR1
47 F
D1
C5
T1
When the
22
R1
1N5822
D2
1N4148
330 F
D3
25 V
C2
current will flow into the control pin.
Increasing control pin current decreases
the duty cycle until a stable operating
point is reached. The output voltage is
proportional to the bias voltage by the
turns ratio of the output to bias windings.
C5 is used to bypass the CONTROL pin.
C5 also provides loop compensation for
the power supply by shunting AC
currents around the CONTROL pin
dynamic impedance, and also determines
the auto-restart frequency during start-
up and auto-restart conditions. See DN-
8 for more information regarding the use
of the TOP200 in bias supplies.
(Bead)
CIRCUIT PERFORMANCE:
L1
Line Regulation - ±1.5%
150 F
Load Regulation - ±4%
Ripple Voltage ±25 mV
25 V
C3
95 to 370 V DC
(10% to 100%)
PI-1749-012296
5 V
RTN