- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44530 > LM22671QMR-5.0 (NATIONAL SEMICONDUCTOR CORP) 0.9 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 PDF資料下載
參數(shù)資料
| 型號(hào)： | LM22671QMR-5.0 |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 0.9 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | PLASTIC, PSOP-8 |
| 文件頁(yè)數(shù)： | 5/18頁(yè) |
| 文件大?。?/td> | 419K |
| 代理商： | LM22671QMR-5.0 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)當(dāng)前第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)
Thermal Considerations
The two highest power dissipating components are the re-
circulating diode and the LM22671 regulator IC. The easiest
method to determine the power dissipation within the
LM22671 is to measure the total conversion losses (Pin –
Pout) then subtract the power losses in the Schottky diode
and output inductor. An approximation for the Schottky diode
loss is:
P = (1 - D) x I
OUT x VD
An approximation for the output inductor power is:
P = I
OUT
2
x R x 1.1,
where R is the DC resistance of the inductor and the 1.1 factor
is an approximation for the AC losses. The regulator has an
exposed thermal pad to aid power dissipation. Adding several
vias under the device to the ground plane will greatly reduce
the regulator junction temperature. Selecting a diode with an
exposed pad will aid the power dissipation of the diode. The
most significant variables that affect the power dissipated by
the LM22671 are the output current, input voltage and oper-
ating frequency. The power dissipated while operating near
the maximum output current and maximum input voltage can
be appreciable. The junction-to-ambient thermal resistance of
the LM22671 will vary with the application. The most signifi-
cant variables are the area of copper in the PC board, the
number of vias under the IC exposed pad and the amount of
forced air cooling provided. The integrity of the solder con-
nection from the IC exposed pad to the PC board is critical.
Excessive voids will greatly diminish the thermal dissipation
capacity. The junction-to-ambient thermal resistance of the
LM22671 PSOP-8 package is specified in the electrical char-
acteristics table under the applicable conditions.
13
www.national.com
LM22671/LM22671Q
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM22675QMRX-ADJ | 1.8 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| LM22675QMRE-ADJ | 1.8 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| LM22675QMR-5.0 | 1.8 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| LM22676QMRX-5.0 | 5.5 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| LM22676QMR-5.0 | 5.5 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM22671QMR-ADJ | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:500 mA SIMPLE SWITCHER?, Step-Down Voltage Regulator with Features |
| LM22671QMR-ADJ/NOPB | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| LM22671QMRE-5.0 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:500 mA SIMPLE SWITCHER?, Step-Down Voltage Regulator with Features |
| LM22671QMRE-5.0/NOPB | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| LM22671QMRE-ADJ | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:500 mA SIMPLE SWITCHER?, Step-Down Voltage Regulator with Features |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。