- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄358823 > LM2595T-ADJ (NATIONAL SEMICONDUCTOR CORP) SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator PDF資料下載
參數(shù)資料
| 型號： | LM2595T-ADJ |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator |
| 中文描述： | 2.6 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, PZFM5 |
| 封裝： | BENT STAGGERED, TO-220, 5 PIN |
| 文件頁數(shù)： | 12/29頁 |
| 文件大?。?/td> | 935K |
| 代理商： | LM2595T-ADJ |
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頁第11頁當前第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
LM2595 Series Buck Regulator Design Procedure (Adjustable Output)
(Continued)
PROCEDURE (Adjustable Output Voltage Version)
EXAMPLE (Adjustable Output Voltage Version)
2. Inductor Selection (L1)
A.
Calculate the inductor Volt
microsecond constant E
T
(V
μs), from the following formula:
where V
SAT
= internal switch saturation voltage = 1V
and V
D
= diode forward voltage drop = 0.5V
B.
Use the E
T value from the previous formula and match
it with the E
T number on the vertical axis of the Inductor
Value Selection Guide shown in Figure 7
C.
on the horizontal axis, select the maximum load current.
D.
Identify the inductance region intersected by the E
T
value and the Maximum Load Current value. Each region is
identified by an inductance value and an inductor code
(LXX).
E.
Select an appropriate inductor from the four manufactur-
er’s part numbers listed in Figure 8
2. Inductor Selection (L1)
A.
Calculate the inductor Volt
microsecond constant
(E
T),
B.
E
T = 34.8 (V
μs)
C.
I
LOAD
(max) = 1A
D.
From the inductor value selection guide shown in Figure 7
the inductance region intersected by the 35 (V
μs) horizon-
tal line and the 1A vertical line is 100 μH, and the inductor
code is L29.
E.
From the table in Figure 8 locate line L29, and select an
inductor part number from the list of manufacturers part num-
bers.
3. Output Capacitor Selection (C
OUT
)
A.
In the majority of applications, low ESR electrolytic or solid
tantalum capacitors between 47 μF and 330 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 330 μF.
For additional informa-
tion, see section on output capacitors in application in-
formation section.
B.
To simplify the capacitor selection procedure, refer to the
quick design table shown in Figure 3 This table contains dif-
ferent output voltages, and lists various output capacitors
that will provide the best design solutions.
C.
The capacitor voltage rating should be at least 1.5 times
greater than the output voltage, and often much higher volt-
age ratings are needed to satisfy the low ESR requirements
needed for low output ripple voltage.
3. Output Capacitor SeIection (C
OUT
)
A.
See section on C
OUT
in Application Information section.
B.
From the quick design table shown in Figure 3 locate the
output voltage column. From that column, locate the output
voltage closest to the output voltage in your application. In
this example, select the 24V line. Under the output capacitor
section, select a capacitor from the list of through hole elec-
trolytic or surface mount tantalum types from four different
capacitor manufacturers. It is recommended that both the
manufacturers and the manufacturers series that are listed in
the table be used.
In this example, through hole aluminum electrolytic capaci-
tors from several different manufacturers are available.
82 μF, 35V
Panasonic HFQ Series
82 μF, 35V
Nichicon PL Series
C.
For a 20V output, a capacitor rating of at least 30V or
more is needed. In this example, either a 35V or 50V capaci-
tor would work.A35V rating was chosen, although a 50V rat-
ing could also be used if a lower output ripple voltage is
needed.
Other manufacturers or other types of capacitors may also
be used, provided the capacitor specifications (especially the
100 kHz ESR) closely match the types listed in the table. Re-
fer to the capacitor manufacturers data sheet for this informa-
tion.
4. Feedforward Capacitor (C
FF
) (See
Figure 1
)
For output voltages greater than approximately 10V, an ad-
ditional capacitor is required. The compensation capacitor is
typically between 50 pF and 10 nF, and is wired in parallel
with the output voltage setting resistor, R
. It provides addi-
tional stability for high output voltages, low input-output volt-
ages, and/or very low ESR output capacitors, such as solid
tantalum capacitors.
This capacitor type can be ceramic, plastic, silver mica, etc.
(Because of the unstable characteristics of ceramic capaci-
tors made with Z5U material, they are not recommended.)
4. Feedforward Capacitor (C
FF
)
The table shown in Figure 3 contains feed forward capacitor
values for various output voltages. In this example, a 1 nF
capacitor is needed.
www.national.com
12
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM2595S-12 | Octal Buffers/Drivers With 3-State Outputs 20-SOIC -40 to 85 |
| LM2595S-3.3 | Octal Buffers/Drivers With 3-State Outputs 20-PDIP -40 to 85 |
| LM2595S-ADJ | Octal Buffers/Drivers With 3-State Outputs 20-PDIP -40 to 85 |
| LM2595S-5.0 | SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator |
| LM2595J-ADJ-QML(5962-9650 | Circular Connector; No. of Contacts:18; Series:LJT06R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:15; Circular Contact Gender:Pin; Circular Shell Style:Straight Plug; Insert Arrangement:15-18 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM2595T-ADJ 0135 | 制造商:Texas Instruments 功能描述:Conv DC-DC Single Inv/Step Down 4.5V to 40V 5-Pin(5+Tab) TO-220 Rail |
| LM2595T-ADJ | 制造商:Texas Instruments 功能描述:SWITCHING REG 1A ADJ 2595 TO2205 |
| LM2595T-ADJ/LB02 | 制造商:Texas Instruments 功能描述:Conv DC-DC Single Inv/Step Down 4.5V to 40V 5-Pin(5+Tab) TO-220 Rail |
| LM2595T-ADJ/LB05 | 制造商:Texas Instruments 功能描述:Conv DC-DC Single Inv/Step Down 4.5V to 40V 5-Pin(5+Tab) TO-220 Rail |
| LM2595T-ADJ/LF02 | 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 安裝風格:SMD/SMT |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。