參數(shù)資料
型號(hào): TOP246F-TL
廠商: POWER INTEGRATIONS INC
元件分類: 穩(wěn)壓器
英文描述: 4.32 A SWITCHING REGULATOR, 140 kHz SWITCHING FREQ-MAX, PZIP6
封裝: PLASTIC, TO-262, 7/6 PIN
文件頁數(shù): 24/52頁
文件大?。?/td> 2175K
代理商: TOP246F-TL
TOP242-250
N
4/05
30
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 efciency.
Also, in applications where transformer size is not a concern,
use of the 66 kHz option will provide lower EMI and higher
efciency. Note that the second harmonic of 66 kHz is still
below 150 kHz, above which the conducted EMI specications
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 ux density of 3000 Gauss and a peak ux
densityof4200Gaussatmaximumcurrentlimit. Theturnsratio
should be chosen for a reected voltage (V
OR) no greater than
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 signicantly lower than
the default current limit, it is recommended to use an externally
setcurrentlimitclosetotheoperatingpeakcurrenttoreducepeak
ux density and peak power (see Figures 20 and 34). In most
applications,thetightercurrentlimittolerance,higherswitching
frequency and soft-start features of TOPSwitch-GX contribute
to a smaller transformer when compared to TOPSwitch-II.
Standby Consumption
Frequency reduction can signicantly 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
signicantly 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 higherpowerlevels 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 lter 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 lter capacitor.
The CONTROL pin bypass capacitor should be located as
close as possible to the SOURCE and CONTROL pins and its
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 F 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, sufcient 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 rectier and output lter capacitor. This trace acts
as a thermal relief between the rectier and lter capacitor to
prevent excessive heating of the capacitor.
相關(guān)PDF資料
PDF描述
TOP248F-TL 7.2 A SWITCHING REGULATOR, 140 kHz SWITCHING FREQ-MAX, PZIP6
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相關(guān)代理商/技術(shù)參數(shù)
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TOP246G- 制造商:POWERINT 制造商全稱:Power Integrations, Inc. 功能描述:TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
TOP246GN 功能描述:交流/直流開關(guān)轉(zhuǎn)換器 22W 85-265 VAC 30 W 230 VAC RoHS:否 制造商:STMicroelectronics 輸出電壓:800 V 輸入/電源電壓(最大值):23.5 V 輸入/電源電壓(最小值):11.5 V 開關(guān)頻率:115 kHz 電源電流:1.6 mA 工作溫度范圍:- 40 C to + 150 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SSO-10 封裝:Reel
TOP246GN- 制造商:POWERINT 制造商全稱:Power Integrations, Inc. 功能描述:TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
TOP246GN-TL 功能描述:交流/直流開關(guān)轉(zhuǎn)換器 22 W 85-265 VAC 30 W 230 VAC RoHS:否 制造商:STMicroelectronics 輸出電壓:800 V 輸入/電源電壓(最大值):23.5 V 輸入/電源電壓(最小值):11.5 V 開關(guān)頻率:115 kHz 電源電流:1.6 mA 工作溫度范圍:- 40 C to + 150 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SSO-10 封裝:Reel
TOP246G-TL 制造商:POWERINT 制造商全稱:Power Integrations, Inc. 功能描述:TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher