TOP250Y Power Integrations, TOP250Y Datasheet - Page 30
![IC OFFLINE SWIT UVLO HV TO220](/photos/7/32/73245/596-to-220-7c_sml.jpg)
TOP250Y
Manufacturer Part Number
TOP250Y
Description
IC OFFLINE SWIT UVLO HV TO220
Manufacturer
Power Integrations
Series
TOPSwitch®-GXr
Type
Off Line Switcherr
Datasheet
1.TOP242GN-TL.pdf
(52 pages)
Specifications of TOP250Y
Output Isolation
Isolated
Frequency Range
66 ~ 132kHz
Voltage - Output
700V
Power (watts)
290W
Operating Temperature
-40°C ~ 150°C
Package / Case
TO-220-7 (Formed Leads), 5 Leads
Output Voltage
12 V
Input / Supply Voltage (max)
265 VAC
Input / Supply Voltage (min)
85 VAC
Duty Cycle (max)
83 %
Switching Frequency
132 KHz
Supply Current
2.4 mA
Operating Temperature Range
- 40 C to + 150 C
Mounting Style
Through Hole
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
TOP250Y
Manufacturer:
POWER
Quantity:
3 585
Company:
Part Number:
TOP250Y
Manufacturer:
POWER
Quantity:
990
Company:
Part Number:
TOP250YN
Manufacturer:
PowerInt
Quantity:
2 750
Part Number:
TOP250YN
Manufacturer:
POWER
Quantity:
20 000
frequency radiated noise (for example, video noise sensitive
applications such as VCR, DVD, monitor, TV, etc.), operating
at 66 kHz will reduce snubber loss resulting in better efficiency.
Also, in applications where transformer size is not a concern,
use of the 66 kHz option will provide lower EMI and higher
efficiency. Note that the second harmonic of 66 kHz is still
below 150 kHz, above which the conducted EMI specifications
get much tighter.
For 10 W or below, it is possible to use a simple inductor in
place of a more costly AC input common mode choke to meet
worldwide conducted EMI limits.
Transformer Design
It is recommended that the transformer be designed for
maximum operating flux density of 3000 Gauss and a peak flux
density of 4200 Gauss at maximum current limit. The turns ratio
should be chosen for a reflected voltage (V
135 V when using a Zener clamp, or 150 V (max) when using
an RCD clamp with current limit reduction with line voltage
(overload protection).
For designs where operating current is significantly lower than
the default current limit, it is recommended to use an externally
set current limit close to the operating peak current to reduce peak
flux density and peak power (see Figures 20 and 34). In most
applications, the tighter current limit tolerance, higher switching
frequency and soft-start features of TOPSwitch-GX contribute
to a smaller transformer when compared to TOPSwitch-II.
Standby Consumption
Frequency reduction can significantly reduce power loss at
light or no load, especially when a Zener clamp is used. For
very low secondary power consumption, use a TL431 regulator
for feedback control. Alternately, switching losses can be
significantly reduced by changing from 132 kHz in normal
operation to 66 kHz under light load conditions.
TOPSwitch-GX Layout Considerations
As TOPSwitch-GX has additional pins and operates at
much higher power levels compared to previous TOPSwitch
families, the following guidelines should be carefully
followed.
Primary Side Connections
Use a single point (Kelvin) connection at the negative terminal
of the input filter capacitor for the TOPSwitch-GX SOURCE
pin and bias winding return. This improves surge capabilities
by returning surge currents from the bias winding directly to
the input filter capacitor.
The CONTROL pin bypass capacitor should be located as
close as possible to the SOURCE and CONTROL pins and its
30
TOP242-250
O
11/05
OR
) no greater than
SOURCE connection trace should not be shared by the main
MOSFET switching currents. All SOURCE pin referenced
components connected to the MULTI-FUNCTION, LINE-
SENSE or EXTERNAL CURRENT LIMIT pins should
also be located closely between their respective pin and
SOURCE. Once again, the SOURCE connection trace of these
components should not be shared by the main MOSFET
switching currents. It is very critical that SOURCE pin
switching currents are returned to the input capacitor negative
terminal through a seperate trace that is not shared by the
components connected to CONTROL, MULTI-FUNCTION,
LINE-SENSE or EXTERNAL CURRENT LIMIT pins. This
is because the SOURCE pin is also the controller ground
reference pin.
Any traces to the M, L or X pins should be kept as short as
possible and away from the DRAIN trace to prevent noise
coupling. LINE-SENSE resistor (R1 in Figures 47-49) should
be located close to the M or L pin to minimize the trace length
on the M or L pin side.
In addition to the 47 µF CONTROL pin capacitor, a high
frequency bypass capacitor in parallel may be used for better
noise immunity. The feedback optocoupler output should
also be located close to the CONTROL and SOURCE pins of
TOPSwitch-GX.
Y-Capacitor
The Y-capacitor should be connected close to the secondary
output return pin(s) and the positive primary DC input pin of
the transformer.
Heat Sinking
The tab of the Y package (TO-220) or F package (TO-262)
is internally electrically tied to the SOURCE pin. To avoid
circulating currents, a heat sink attached to the tab should not
be electrically tied to any primary ground/source nodes on the
PC board.
When using a P (DIP-8), G (SMD-8) or R (TO-263) package,
a copper area underneath the package connected to the
SOURCE pins will act as an effective heat sink. On double
sided boards (Figure 49), top side and bottom side areas
connected with vias can be used to increase the effective heat
sinking area.
In addition, sufficient copper area should be provided at
the anode and cathode leads of the output diode(s) for heat
sinking.
In Figures 47, 48 and 49, a narrow trace is shown between
the output rectifier and output filter capacitor. This trace acts
as a thermal relief between the rectifier and filter capacitor to
prevent excessive heating of the capacitor.