參數(shù)資料
型號(hào): TOP245Y
廠商: POWER INTEGRATIONS INC
元件分類: 穩(wěn)壓器
英文描述: Family Extended Power, Design Flexible,Integrated Off-line Switcher
中文描述: 2.88 A SWITCHING REGULATOR, 140 kHz SWITCHING FREQ-MAX, PZFM6
封裝: PLASTIC, TO-220, 7/6 PIN
文件頁(yè)數(shù): 21/48頁(yè)
文件大?。?/td> 771K
代理商: TOP245Y
TOP242-249
21
August 8, 2000
E
7/01
Figure 41. 30 W Power Supply using External Current Limit Programming and Line Sensing for UV and OV.
Application Examples
A High Efficiency, 30 W, Universal Input Power Supply
The circuit shown in Figure 41 takes advantage of several of the
TOPSwitch-GX
features to reduce system cost and power
supply size and to improve efficiency. This design delivers
30 W at 12 V, from an 85 to 265 VAC input, at an ambient of
50
°
C, in an open frame configuration. A nominal efficiency of
80% at full load is achieved using TOP244Y.
The current limit is externally set by resistors R1 and R2 to a
value just above the low line operating peak DRAIN current of
approximately 70% of the default current limit. This allows use
of a smaller transformer core size and/or higher transformer
primary inductance for a given output power, reducing
TOPSwitch-GX
power dissipation, while at the same time
avoiding transformer core saturation during startup and output
transient conditions. The resistors R1 & R2 provide a signal
that reduces the current limit with increasing line voltage,
which in turn limits the maximum overload power at high input
line voltage. This function in combination with the built-in
soft-start feature of
TOPSwitch-GX
, allows the use of a low cost
RCD clamp (R3, C3 and D1) with a higher reflected voltage, by
safely limiting the
TOPSwitch-GX
drain voltage, with adequate
margin under worst case conditions. Resistor R4 provides line
sensing, setting UV at 100 VDC and OV at 450 VDC. The
extended maximum duty cycle feature of
TOPSwitch-GX
(guaranteed minimum value of 75% vs. 64% for
TOPSwitch-II
)
allows the use of a smaller input capacitor (C1). The extended
maximum duty cycle and the higher reflected voltage possible
with the RCD clamp also permit the use of a higher primary to
secondary turns ratio for T1 which reduces the peak reverse
voltage experienced by the secondary rectifier D8. As a result
a 60 V Schottky rectifier can be used for up to 15 V outputs,
which greatly improves power supply efficiency. The frequency
reduction feature of the
TOPSwitch-GX
eliminates the need for
any dummy loading for regulation at no load and reduces the no
load/standby consumption of the power supply. Frequency
jitter provides improved margin for conducted EMI meeting the
CISPR 22 (FCC B) specification.
Output regulation is achieved by using a simple Zener sense
circuit for low cost. The output voltage is determined by the
Zener diode (VR2) voltage and the voltage drops across the
optocoupler (U2) LED and resistor R6. Resistor R8 provides
bias current to Zener VR2 for typical regulation of
±
5% at the
12 V output level, over line and load and component variations.
12 V
@ 2.5 A
D2
1N4148
T1
C5
47
μ
F
10 V
U2
LTV817A
VR2
1N5240C
10 V, 2%
R6
150
R15
150
C14
1 nF
D1
UF4005
R3
68 k
2 W
C3
4.7 nF
1 kV
CY1
2.2 nF
U1
TOP244Y
D
L
S
X
F
C
R8
150
C1
68
μ
F
400 V
C6
0.1
μ
F
D8
MBR1060
C10
560
μ
F
35 V
C12
220
μ
F
35 V
C11
560
μ
F
35 V
RTN
R5
6.8
R1
4.7 M
1/2 W
R4
2 M
1/2 W
R2
9.09 k
PI-2657-040501
L3
3.3
μ
H
BR1
600 V
2A
F1
3.15 A
J1
L1
20 mH
L
N
CX1
100 nF
250 VAC
CONTROL
TOPSwitch-GX
PERFORMANCE SUMMARY
Output Power:
Regulation:
Efficiency:
Ripple:
30 W
±
4%
79%
50 mV pk-pk
相關(guān)PDF資料
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TOP245Y- 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
TOP245Y/F 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Up to 290 W Extended power. design flexible.
TOP245YN 功能描述:交流/直流開(kāi)關(guān)轉(zhuǎn)換器 60W 85-265 VAC 85 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(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
TOP245YN- 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
TOP245YN-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