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參數(shù)資料
| 型號(hào)： | LM2598-ADJ |
| 英文描述： | SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator with Features(572.00 k) |
| 中文描述： | SIMPLE SWITCHER系列電源轉(zhuǎn)換器150千赫1A步降穩(wěn)壓器的功能（572.00十一） |
| 文件頁數(shù)： | 9/28頁 |
| 文件大?。?/td> | 739K |
| 代理商： | LM2598-ADJ |
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LM2594/LM2594HV Series Buck Regulator Design Procedure (Fixed
Output)
PROCEDURE (Fixed Output Voltage Version)
EXAMPLE (Fixed Output Voltage Version)
Given:
V
OUT
= Regulated Output Voltage (3.3V, 5V or 12V)
V
IN
(max) = Maximum DC Input Voltage
I
LOAD
(max) = Maximum Load Current
Given:
V
OUT
= 5V
V
IN
(max) = 12V
I
LOAD
(max) = 0.4A
1. Inductor Selection (L1)
A.
Select the correct inductor value selection guide from Fig-
ures 4, 5or Figure 6 (Output voltages of 3.3V, 5V, or 12V re-
spectively.) For all other voltages, see the design procedure
for the adjustable version.
B.
From the inductor value selection guide, identify the induc-
tance region intersected by the Maximum Input Voltage line
and the Maximum Load Current line. Each region is identified
by an inductance value and an inductor code (LXX).
C.
Select an appropriate inductor from the four manufactur-
er’s part numbers listed in Figure 8
1. Inductor Selection (L1)
A.
Use the inductor selection guide for the 5V version shown
in Figure 5
B.
From the inductor value selection guide shown in Figure 5
the inductance region intersected by the 12V horizontal line
and the 0.4A vertical line is 100 μH, and the inductor code is
L20.
C.
The inductance value required is 100 μH. From the table
in Figure 8 go to the L20 line and choose an inductor part
number from any of the four manufacturers shown. (In most
instance, both through hole and surface mount inductors are
available.)
2. Output Capacitor Selection (C
OUT
)
A.
In the majority of applications, low ESR (Equivalent Series
Resistance) electrolytic capacitors between 82 μF and
220 μF and low ESR solid tantalum capacitors between 15
μF and 100 μF provide the best results. This capacitor should
be located close to the IC using short capacitor leads and
short copper traces. Do not use capacitors larger than
220 μF.
For additional information, see section on output capaci-
tors in application information section.
B.
To simplify the capacitor selection procedure, refer to the
quick design component selection table shown in Figure 2
This table contains different input voltages, output voltages,
and load currents, and lists various inductors and output ca-
pacitors that will provide the best design solutions.
C.
The capacitor voltage rating for electrolytic capacitors
should be at least 1.5 times greater than the output voltage,
and often much higher voltage ratings are needed to satisfy
the low ESR requirements for low output ripple voltage.
D.
For computer aided design software, see Switchers Made
Simple version 4.1 or later.
2. Output Capacitor Selection (C
OUT
)
A. See section on output capacitors in application infor-
mation section.
B.
From the quick design component selection table shown
in Figure 2 locate the 5V output voltage section. In the load
current column, choose the load current line that is closest to
the current needed in your application, for this example, use
the 0.5A line. In the maximum input voltage column, select
the line that covers the input voltage needed in your applica-
tion, in this example, use the 15V line. Continuing on this line
are recommended inductors and capacitors that will provide
the best overall performance.
The capacitor list contains both through hole electrolytic and
surface mount tantalum capacitors from four different capaci-
tor manufacturers. It is recommended that both the manufac-
turers and the manufacturer’s series that are listed in the
table be used.
In this example aluminum electrolytic capacitors from several
different manufacturers are available with the range of ESR
numbers needed.
120 μF
25V
Panasonic HFQ Series
120 μF
25V
Nichicon PL Series
C.
For a 5V output, a capacitor voltage rating at least 7.5V or
more is needed. But, in this example, even a low ESR,
switching grade, 120 μF 10V aluminum electrolytic capacitor
would exhibit approximately 400 m
of ESR (see the curve
in Figure 14 for the ESR vs voltage rating). This amount of
ESR would result in relatively high output ripple voltage. To
reduce the ripple to 1% of the output voltage, or less, a ca-
pacitor with a higher voltage rating (lower ESR) should be se-
lected. A 16V or 25V capacitor will reduce the ripple voltage
by approximately half.
L
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相關(guān)代理商/技術(shù)參數(shù) |
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| LM2598S-12 | 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 |
| LM2598S-12/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 |
| LM2598S12P+ | 制造商:Texas Instruments 功能描述: |
| LM2598S-12P+ | 制造商:Texas Instruments 功能描述:2.6 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, PSSO7 |
| LM2598S-3.3 | 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 |
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