- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄44548 > LM2586-5.0MWC (NATIONAL SEMICONDUCTOR CORP) 7 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, UUC PDF資料下載
參數(shù)資料
| 型號(hào)： | LM2586-5.0MWC |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類(lèi)： | 穩(wěn)壓器 |
| 英文描述： | 7 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, UUC |
| 封裝： | WAFER |
| 文件頁(yè)數(shù)： | 18/32頁(yè) |
| 文件大?。?/td> | 858K |
| 代理商： | LM2586-5.0MWC |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)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)當(dāng)前第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)
Application Hints (Continued)
CIRCUIT LAYOUT GUIDELINES
As in any switching regulator, layout is very important. Rap-
idly switching currents associated with wiring inductance
generate voltage transients which can cause problems. For
minimal inductance and ground loops, keep the length of the
leads and traces as short as possible. Use single point
grounding or ground plane construction for best results.
Separate the signal grounds from the power grounds (as in-
dicated in
Figure 45). When using the Adjustable version,
physically locate the programming resistors as near the
regulator IC as possible, to keep the sensitive feedback wir-
ing short.
HEAT SINK/THERMAL CONSIDERATIONS
In many cases, a heat sink is not required to keep the
LM2586 junction temperature within the allowed operating
temperature range. For each application, to determine
whether or not a heat sink will be required, the following must
be identified:
1) Maximum ambient temperature (in the application).
2) Maximum regulator power dissipation (in the application).
3) Maximum allowed junction temperature (125C for the
LM2586). For a safe, conservative design, a temperature ap-
proximately 15C cooler than the maximum junction tem-
perature should be selected (110C).
4) LM2586 package thermal resistances
θ
JA and θJC (given
in the Electrical Characteristics).
Total power dissipated (P
D) by the LM2586 can be estimated
as follows:
V
IN is the minimum input voltage, VOUT is the output voltage,
N is the transformer turns ratio, D is the duty cycle, and I
LOAD
is the maximum load current (and
∑I
LOAD is the sum of the
maximum load currents for multiple-output flyback regula-
tors). The duty cycle is given by:
where V
F is the forward biased voltage of the diode and is
typically 0.5V for Schottky diodes and 0.8V for fast recovery
diodes. V
SAT is the switch saturation voltage and can be
found in the Characteristic Curves.
When no heat sink is used, the junction temperature rise is:
T
J = PD θJA.
Adding the junction temperature rise to the maximum ambi-
ent temperature gives the actual operating junction tempera-
ture:
T
J = TJ +TA.
If the operating junction temperature exceeds the maximum
junction temperatue in item 3 above, then a heat sink is re-
quired. When using a heat sink, the junction temperature rise
can be determined by the following:
T
J = PD (θJC + θInterface + θHeat Sink)
Again, the operating junction temperature will be:
T
J = TJ +TA
As before, if the maximum junction temperature is exceeded,
a larger heat sink is required (one that has a lower thermal
resistance).
Included in the
Switchers Made Simple design software is
a more precise (non-linear) thermal model that can be used
to determine junction temperature with different input-output
parameters or different component values. It can also calcu-
late the heat sink thermal resistance required to maintain the
regulator junction temperature below the maximum operat-
ing temperature.
To further simplify the flyback regulator design procedure,
National Semiconductor is making available computer de-
sign software to be used with the Simple Switcher line of
switching regulators. Switchers Made Simple is available
ona312" diskette for IBM compatible computers from a Na-
tional Semiconductor sales office in your area or the National
Semiconductor
Customer
Response
Center
(1-800-272-9959).
www.national.com
25
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM2586-ADJMDC | 7 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, UUC |
| LM2586SX-12/NOPB | 3 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, PSSO7 |
| LM2587SX-3.3/NOPB | 5 A SWITCHING REGULATOR, 100 kHz SWITCHING FREQ-MAX, PSSO5 |
| LM2588-12MWC | 9.5 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, UUC |
| LM2588-12MDC | 9.5 A SWITCHING REGULATOR, 200 kHz SWITCHING FREQ-MAX, UUC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM2586S-12 | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)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 |
| LM2586S-12/NOPB | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)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 |
| LM2586S-3.3 | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)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 |
| LM2586S-3.3/NOPB | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)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 |
| LM2586S-5.0 | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)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 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。