- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄30769 > LTC1871EMS-1 (LINEAR TECHNOLOGY CORP) SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 PDF資料下載
參數(shù)資料
| 型號： | LTC1871EMS-1 |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| 封裝： | PLASTIC, MSOP-10 |
| 文件頁數(shù)： | 8/36頁 |
| 文件大?。?/td> | 523K |
| 代理商： | LTC1871EMS-1 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁當前第8頁第9頁第10頁第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
LTC1871-1
16
18711fb
APPLICATIONS INFORMATION
for VSENSE(MAX) and the RDS(ON) of the MOSFET listed in
the manufacturer’s data sheet.
The power dissipated by the MOSFET in a boost converter
is:
PFET =
IO(MAX)
1– DMAX
2
RDS(ON) DMAX T
+k VO1.85
IO(MAX)
1– DMAX
(
)
CRSS f
The rst term in the equation above represents the I2R
losses in the device, and the second term, the switching
losses. The constant, k = 1.7, is an empirical factor inversely
related to the gate drive current and has the dimension
of 1/current.
From a known power dissipated in the power MOSFET, its
junction temperature can be obtained using the following
formula:
TJ = TA + PFET RTH(JA)
The RTH(JA) to be used in this equation normally includes
the RTH(JC) for the device plus the thermal resistance from
the case to the ambient temperature (RTH(CA)). This value
of TJ can then be compared to the original, assumed value
used in the iterative calculation process.
Boost Converter: Output Diode Selection
To maximize efciency, a fast switching diode with low
forward drop and low reverse leakage is desired. The output
diode in a boost converter conducts current during the
switch off-time. The peak reverse voltage that the diode
must withstand is equal to the regulator output voltage.
The average forward current in normal operation is equal
to the output current, and the peak current is equal to the
peak inductor current.
ID(PEAK) =IL(PEAK) = 1+
2
IO(MAX)
1– DMAX
The power dissipated by the diode is:
PD = IO(MAX) VD
and the diode junction temperature is:
TJ = TA + PD RTH(JA)
The RTH(JA) to be used in this equation normally includes
the RTH(JC) for the device plus the thermal resistance from
the board to the ambient temperature in the enclosure.
Remember to keep the diode lead lengths short and to
observe proper switch-node layout (see Board Layout
Checklist) to avoid excessive ringing and increased
dissipation.
Boost Converter: Output Capacitor Selection
Contributions of ESR (equivalent series resistance), ESL
(equivalent series inductance) and the bulk capacitance
must be considered when choosing the correct component
for a given output ripple voltage. The effects of these three
parameters (ESR, ESL and bulk C) on the output voltage
ripple waveform are illustrated in Figure 12e for a typical
boost converter.
The choice of component(s) begins with the maximum
acceptable ripple voltage (expressed as a percentage of
the output voltage), and how this ripple should be divided
between the ESR step and the charging/discharging ΔV.
For the purpose of simplicity we will choose 2% for the
maximum output ripple, to be divided equally between the
ESR step and the charging/discharging ΔV. This percent-
age ripple will change, depending on the requirements
of the application, and the equations provided below can
easily be modied.
For a 1% contribution to the total ripple voltage, the ESR
of the output capacitor can be determined using the fol-
lowing equation:
ESRCOUT
0.01 VO
IIN(PEAK)
where:
IIN(PEAK)= 1+
2
IO(MAX)
1– DMAX
For the bulk C component, which also contributes 1% to
the total ripple:
COUT
IO(MAX)
0.01 VO f
相關PDF資料 |
PDF描述 |
|---|---|
| LTC1871IMS-1#TR | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LTC1871EMS-1#TR | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LTC2908IDDB8-B1 | 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC2908CDDB8-B1#PBF | 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC2908CDDB8-A1#PBF | 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1871EMS-1#PBF | 功能描述:IC REG CTRLR BST FLYBK CM 10MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC1871EMS-1#TRPBF | 功能描述:IC REG CTRLR BST FLYBK CM 10MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC1871EMS7 | 制造商:Linear Technology 功能描述: |
| LTC1871EMS-7 | 功能描述:IC REG CTRLR BST FLYBK CM 10MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC1871EMS-7#PBF | 功能描述:IC REG CTRLR BST FLYBK CM 10MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 特色產(chǎn)品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標準包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR |
發(fā)布緊急采購，3分鐘左右您將得到回復。