July 1996
Product Highlights
Low Cost Replacement for Discrete Switchers
20 to 50 fewer components - cuts cost, increases reliability
Source-connected tab and Controlled MOSFET turn-on
reduce EMI and EMI filter costs
Allows for a 50% smaller and lighter solution
Cost competitive with linears above 5 W
Up to 90% Efficiency in Flyback Topology
Built-in start-up and current limit reduce DC losses
Low capacitance 700 V MOSFET cuts AC losses
CMOS controller/gate driver consumes only 6 mW
70% maximum duty cycle minimizes conduction losses
Simplifies Design - Reduces Time to Market
Supported by many reference design boards
Integrated PWM Controller and 700 V MOSFET in a
industry standard three pin TO-220 package
Only one external capacitor needed for compensation,
bypass and start-up/auto-restart functions
System Level Fault Protection Features
Auto-restart and cycle by cycle current limiting functions
handle both primary and secondary faults
On-chip latching thermal shutdown protects the entire
system against overload
Highly Versatile
Implements Buck, Boost, Flyback or Forward topology
Easily interfaces with both opto and primary feedback
Supports continuous or discontinuous mode of operation
Description
The TOPSwitch family implements, with only three pins, all
functions necessary for an off-line switched mode control
system: high voltage N-channel power MOSFET with controlled
turn-on gate driver, voltage mode PWM controller with
integrated 100 kHz oscillator, high voltage start-up bias circuit,
bandgap derived reference, bias shunt regulator/error amplifier
for loop compensation and fault protection circuitry. Compared
to discrete MOSFET and controller or self oscillating (RCC)
switching converter solutions, a TOPSwitch integrated circuit
can reduce total cost, component count, size, weight and at the
same time increase efficiency and system reliability. These
®
PI-1703-112995
AC
IN
DRAIN
SOURCE
CONTROL
TOPSwitch
Figure 1. Typical Application.
TOP200-4/14
TOPSwitch
Family
Three-terminal Off-line PWM Switch
devices are intended for 100/110/230 VAC off-line Power
Supply applications in the 0 to 100 W (0 to 50 W universal)
range and 230/277 VAC off-line power factor correction (PFC)
applications in the 0 to 150 W range.
TOP200YAI* 0-25 W 0-12 W 0-25 W
TOP201YAI* 20-45 W 10-22 W 20-50 W
TOP202YAI* 30-60 W 15-30 W 30-75 W
TOP203YAI* 40-70 W 20-35 W 50-100 W
TOP214YAI* 50-85 W 25-42 W 60-125 W
TOP204YAI* 60-100 W 30-50 W 75-150 W
ORDER
PART
NUMBER
230 VAC or
110 VAC
w/Doubler
FLYBACK
85-265
VAC
PFC/
BOOST
230/277
VAC
OUTPUT POWER RANGE
TOPSwitch
SELECTION GUIDE
®
* Package Outline: Y03A
TOP200-4/14
D
7/96
2
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. Trigger input for latching
shutdown. It is also used as the supply bypass and auto-restart/
compensation capacitor connection point.
SOURCE Pin:
Output MOSFET source connection. Primary-side circuit
common, power return, and reference point.
PI-1065A-110194
CONTROL
DRAIN
SOURCE (TAB)
TO-220/3 (YO3A)
Figure 3. Pin Configuration.
PI-1746-011796
SHUTDOWN/
AUTO-RESTART
PWM
COMPARATOR
CLOCK
SAW
OSCILLATOR
CONTROLLED
TURN-ON
GATE
DRIVER
INTERNAL
SUPPLY
5.7 V
4.7 V
SOURCE
S
R
Q
Q
D
MAX
-
+
CONTROL
-
+
5.7 V
I
FB
R
E
Z
C
V
C
MINIMUM
ON-TIME
DELAY
+
-
V
I
LIMIT
LEADING
EDGE
BLANKING
POWER-UP
RESET
R
S
Q
Q
÷ 8
0
1
THERMAL
SHUTDOWN
EXTERNALLY
TRIGGERED
SHUTDOWN
SHUNT REGULATOR/
ERROR AMPLIFIER
+
-
DRAIN
D
7/96
TOP200-4/14
3
TOPSwitch
Family Functional Description
TOPSwitch is a self biased and protected
linear control current-to-duty cycle
converter with an open drain output.
High efficiency is achieved through the
use of CMOS and integration of the
maximum number of functions possible.
CMOS significantly reduces bias
currents as compared to bipolar or
discrete solutions. Integration eliminates
external power resistors used for current
sensing and/or supplying initial start-up
bias current.
During normal operation, the internal
output MOSFET duty cycle linearly
decreases with increasing CONTROL
pin current as shown in Figure 4. To
implement all the required control, bias,
and protection functions, the DRAIN
and CONTROL pins each perform
several functions as described below.
Refer to Figure 2 for a block diagram
and Figure 6 for timing and voltage
waveforms of the TOPSwitch integrated
circuit.
Control Voltage Supply
CONTROL pin voltage V
C
is the supply
or bias voltage for the controller and
driver circuitry. An external bypass
capacitor closely connected between the
CONTROL and SOURCE pins is
required to supply the gate drive current.
The total amount of capacitance
connected to this pin (C
T
) also sets the
auto-restart timing as well as control
loop compensation. V
C
is regulated in
either of two modes of operation.
Hysteretic regulation is used for initial
start-up and overload operation. Shunt
regulation is used to separate the duty
cycle error signal from the control circuit
supply current. During start-up, V
C
current is supplied from a high-voltage
switched current source connected
internally between the DRAIN and
CONTROL pins. The current source
provides sufficient current to supply the
control circuitry as well as charge the
total external capacitance (C
T
).
PI-1691-112895
D
MAX
D
MIN
I
CD1
Duty Cycle (%)
I
C
(mA)
2.5 6.5 45
Slope = PWM Gain
-16%/mA
I
B
Auto-restart
Figure 4. Relationship of Duty Cycle to CONTROL Pin Current.
Figure 5. Start-up Waveforms for (a) Normal Operation and (b) Auto-restart.
DRAIN
0
V
IN
V
C
0
4.7 V
5.7 V
8 Cycles
95%
5%
Off
Switching Switching
Off
I
C
Charging C
T
I
CD1
Discharging C
T
I
CD2
Discharging C
T
I
C
Charging C
T
Off
PI-1124A-060694
DRAIN
0
V
IN
V
C
0
4.7 V
5.7 V
Off
Switching
(b)
(a)
C
T
is the total external capacitance
connected to the CONTROL pin

TOP204YAI

Mfr. #:
Manufacturer:
Power Integrations
Description:
AC/DC Converters 30-50W 85-265 VAC 60-100W100/115/230
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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