參數(shù)資料
型號(hào)： TOP242
廠商： Power Integrations, Inc.
英文描述： Family Extended Power, Design Flexible,Integrated Off-line Switcher
中文描述： 家庭擴(kuò)展的電源，設(shè)計(jì)靈活，集成的離線切換
文件頁(yè)數(shù)： 6/48頁(yè)
文件大小： 771K
代理商： TOP242
TOP242-249
6
E
7/01
August 8, 2000
PI-2545-082299
S1
S2
~
S6
S7
S1
S2
~
S6
S7
S0
S1
S7
S0
S0
5.8 V
4.8 V
S7
0 V
0 V
0 V
V
LINE
V
C
V
DRAIN
V
OUT
0 V
Note: S0 through S7 are the output states of the auto-restart counter
2
1
2
3
4
~
~
~
~
S6
S7
~
~
~
~
V
UV
~
~
~
S2
~
CONTROL (C) Pin Operation
The CONTROL pin is a low impedance node that is capable of
receiving a combined supply and feedback current. During
normal operation, a shunt regulator is used to separate the
feedback signal from the supply current. CONTROL pin
voltage V
is the supply voltage for the control circuitry
including the MOSFET gate driver. An external bypass capacitor
closely connected between the CONTROL and SOURCE pins
is required to supply the instantaneous gate drive current. The
total amount of capacitance connected to this pin also sets the
auto-restart timing as well as control loop compensation.
When rectified DC high voltage is applied to the DRAIN pin
during start-up, the MOSFET is initially off, and the CONTROL
pin capacitor is charged through a switched high voltage current
source connected internally between the DRAIN and CONTROL
pins. When the CONTROL pin voltage V
reaches
approximately 5.8 V, the control circuitry is activated and the
soft-start begins. The soft-start circuit gradually increases the
duty cycle of the MOSFET from zero to the maximum value
over approximately 10 ms. If no external feedback/supply
current is fed into the CONTROL pin by the end of the soft-start,
the high voltage current source is turned off and the CONTROL
pin will start discharging in response to the supply current
drawn by the control circuitry. If the power supply is designed
properly, and no fault condition such as open loop or shorted
output exists, the feedback loop will close, providing external
CONTROL pin current, before the CONTROL pin voltage has
had a chance to discharge to the lower threshold voltage of
approximately 4.8 V (internal supply under-voltage lockout
threshold). When the externally fed current charges the
CONTROL pin to the shunt regulator voltage of 5.8 V, current
in excess of the consumption of the chip is shunted to SOURCE
through resistor R
as shown in Figure 2. This current flowing
through R
controls the duty cycle of the power MOSFET to
provide closed loop regulation. The shunt regulator has a finite
low output impedance Z
that sets the gain of the error amplifier
when used in a primary feedback configuration. The dynamic
impedance Z
of the CONTROL pin together with the external
CONTROL pin capacitance sets the dominant pole for the
control loop.
When a fault condition such as an open loop or shorted output
prevents the flow of an external current into the CONTROL pin,
the capacitor on the CONTROL pin discharges towards 4.8 V.
At 4.8 V, auto-restart is activated which turns the output
MOSFET off and puts the control circuitry in a low current
standby mode. The high-voltage current source turns on and
charges the external capacitance again. A hysteretic internal
supply under-voltage comparator keeps V
within a window of
typically 4.8 to 5.8 V by turning the high-voltage current source
on and off as shown in Figure 8. The auto-restart circuit has a
divide-by-8 counter which prevents the output MOSFET from
turning on again until eight discharge/charge cycles have elapsed.
This is accomplished by enabling the output MOSFET only
when the divide-by-8 counter reaches full count (S7). The
counter effectively limits
TOPSwitch-GX
power dissipation by
reducing the auto-restart duty cycle to typically 4%. Auto-
restart mode continues until output voltage regulation is again
achieved through closure of the feedback loop.
Oscillator and Switching Frequency
The internal oscillator linearly charges and discharges an internal
capacitance between two voltage levels to create a sawtooth
Figure 8. Typical Waveforms for (1) Power Up (2) Normal Operation (3) Auto-restart (4) Power Down.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TOP242-249 制造商:POWERINT 制造商全稱(chēng):Power Integrations, Inc. 功能描述:Family Extended Power, Design Flexible,Integrated Off-line Switcher
TOP242-250 制造商:POWERINT 制造商全稱(chēng):Power Integrations, Inc. 功能描述:TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
TOP242F 功能描述:IC OFFLINE SWIT UVLO HV TO262 RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - AC-DC 轉(zhuǎn)換器，離線開(kāi)關(guān) 系列:TOPSwitch®-GX 標(biāo)準(zhǔn)包裝:1 系列:FPS™ 輸出隔離:隔離 頻率范圍:61kHz ~ 73kHz 輸入電壓:8 V ~ 26 V 輸出電壓:650V 功率（瓦特）:12W 工作溫度:-40°C ~ 115°C 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-MDIP 包裝:Digi-Reel® 其它名稱(chēng):FSL206MRBNFSDKR
TOP242F- 制造商:POWERINT 制造商全稱(chēng):Power Integrations, Inc. 功能描述:TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
TOP242FN 功能描述:交流/直流開(kāi)關(guān)轉(zhuǎn)換器 10W 85-265 VAC 15 W230 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(kāi)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
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