- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄39399 > LT3757MPMSE#TRPBF (LINEAR TECHNOLOGY CORP) SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO10 PDF資料下載
參數(shù)資料
| 型號： | LT3757MPMSE#TRPBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| 封裝： | 3 X 3 MM, LEAD FREE, PLASTIC, MSOP-10 |
| 文件頁數(shù)： | 11/36頁 |
| 文件大小： | 436K |
| 代理商： | LT3757MPMSE#TRPBF |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁當(dāng)前第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁
LT3757
19
3757fc
applicaTions inForMaTion
Flyback Converter: Transformer Design for
Discontinuous Mode Operation
The transformer design for discontinuous mode of opera-
tion is chosen as presented here. According to Figure 8,
the minimum D3 (D3MIN) occurs when the converter
has the minimum VIN and the maximum output power
(POUT). Choose D3MIN to be equal to or higher than 10%
to guarantee the converter is always in discontinuous
mode operation (choosing higher D3 allows the use of low
inductances, but results in a higher switch peak current).
The user can choose a DMAX as the start point. Then, the
maximum average primary currents can be calculated by
the following equation:
ILP(MAX) =ISW(MAX) =
POUT(MAX)
DMAX VIN(MIN) η
where
h is the converter efficiency.
If the flyback converter has multiple outputs, POUT(MAX)
is the sum of all the output power.
The maximum average secondary current is:
ILS(MAX) =ID(MAX) =
IOUT(MAX)
D2
where:
D2 = 1 – DMAX – D3
the primary and secondary RMS currents are:
ILP(RMS) = 2ILP(MAX)
DMAX
3
ILS(RMS) = 2ILS(MAX)
D2
3
According to Figure 8, the primary and secondary peak
currents are:
ILP(PEAK) = ISW(PEAK) = 2 ILP(MAX)
ILS(PEAK) = ID(PEAK) = 2 ILS(MAX)
The primary and second inductor values of the flyback
converter transformer can be determined using the fol-
lowing equations:
LP =
D2MAX V
2
IN(MIN) η
2 POUT(MAX) f
LS =
D22 (VOUT + VD)
2 IOUT(MAX) f
The primary to second turns ratio is:
NP
NS
=
LP
LS
Flyback Converter: Snubber Design
Transformer leakage inductance (on either the primary
or secondary) causes a voltage spike to occur after the
MOSFET turn-off. This is increasingly prominent at higher
load currents, where more stored energy must be dis-
sipated. In some cases a snubber circuit will be required
to avoid overvoltage breakdown at the MOSFET’s drain
node. There are different snubber circuits, and Application
Note 19 is a good reference on snubber design. An RCD
snubber is shown in Figure 7.
The snubber resistor value (RSN) can be calculated by the
following equation:
RSN = 2
V2SN VSN VOUT
NP
NS
I2SW(PEAK) LLK f
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3757HMSE#TRPBF | SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LT574AKNW | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDIP28 |
| LT574ALNW | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDIP28 |
| LT574AJNW | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDIP28 |
| LT6350CDD#TRPBF | 1-CH 16-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDSO8 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3758 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller |
| LT3758A | 制造商:LINER 制造商全稱:Linear Technology 功能描述:60V Low IQ Inverting DC/DC Controller Wide Operating VIN Range: 3.5V to 60V |
| LT3758AEDD#PBF | 制造商:Linear Technology 功能描述:IC REG CTRLR BST FLYBK INV 10DFN |
| LT3758AEDD#TRPBF | 制造商:Linear Technology 功能描述:IC REG CTRLR BST FLYBK INV 10DFN 制造商:Linear Technology 功能描述:SP-SWREG/Controller, High Input Voltage, Boost, Flyback, SEPIC and Inverting Con |
| LT3758AEMSE#PBF | 制造商:Linear Technology 功能描述:IC REG CTRL BST FLYBK INV 10MSOP 制造商:Linear Technology 功能描述:SP-SWREG/Controller, High Input Voltage, Boost, Flyback, SEPIC and Inverting Con |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。