參數(shù)資料
型號: LM2675M-ADJ
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: SIMPLE SWITCHER Power Converter High Efficiency 1A Step-Down Voltage Regulator
中文描述: 2.2 A SWITCHING REGULATOR, 275 kHz SWITCHING FREQ-MAX, PDSO8
封裝: 0.150 INCH, PLASTIC, SOIC-8
文件頁數(shù): 10/26頁
文件大?。?/td> 912K
代理商: LM2675M-ADJ
LM2675 Series Buck Regulator Design Procedure (Fixed Output)
PROCEDURE (Fixed Output Voltage Version)
To simplify the buck regulator design procedure, National
Semiconductor is making available computer design software to
be used with the
SIMPLE SWITCHER
line of switching
regulators.
LM267X Made Simple
version 6.0 is available on
Windows
3.1, NT, or 95 operating systems.
Given:
V
OUT
= Regulated Output Voltage (3.3V, 5V, or 12V)
V
IN
(max) = Maximum DC Input Voltage
I
LOAD
(max) = Maximum Load Current
1. Inductor Selection (L1)
A.
Select the correct inductor value selection guide from
Figure
4
,
Figure 5
or
Figure 6
(output voltages of 3.3V, 5V, or 12V
respectively). For all other voltages, see the design procedure
for the adjustable version.
B.
From the inductor value selection guide, identify the
inductance 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 manufacturer’s
part numbers listed in
Figure 8
. Each manufacturer makes a
different style of inductor to allow flexibility in meeting various
design requirements. Listed below are some of the
differentiating characteristics of each manufacturer’s inductors:
Schott:
ferrite EP core inductors; these have very low leakage
magnetic fields to reduce electro-magnetic interference (EMI)
and are the lowest power loss inductors
Renco:
ferrite stick core inductors; benefits are typically lowest
cost inductors and can withstand E
T and transient peak
currents above rated value. Be aware that these inductors have
an external magnetic field which may generate more EMI than
other types of inductors.
Pulse:
powered iron toroid core inductors; these can also be low
cost and can withstand larger than normal E
T and transient
peak currents. Toroid inductors have low EMI.
Coilcraft:
ferrite drum core inductors; these are the smallest
physical size inductors, available only as SMT components. Be
aware that these inductors also generate EMI—but less than
stick inductors.
Complete specifications for these inductors are available from
the respective manufacturers. A table listing the manufacturers’
phone numbers is located in
Figure 9
.
2. Output Capacitor Selection (C
OUT
)
A.
Select an output capacitor from the output capacitor table in
Figure 10
. Using the output voltage and the inductance value
found in the inductor selection guide, step 1, locate the
appropriate capacitor value and voltage rating.
EXAMPLE (Fixed Output Voltage Version)
Given:
V
OUT
= 5V
V
IN
(max) = 12V
I
LOAD
(max) = 1A
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 1A vertical line is 33 μH, and the inductor code is L23.
C.
The inductance value required is 33 μH. From the table in
Figure 8
, go to the L23 line and choose an inductor part number
from any of the four manufacturers shown. (In most instances,
both through hole and surface mount inductors are available.)
2. Output Capacitor Selection (C
OUT
)
A.
Use the 5.0V section in the output capacitor table in
Figure
10
. Choose a capacitor value and voltage rating from the line
that contains the inductance value of 33 μH. The capacitance
and voltage rating values corresponding to the 33 μH inductor
are the:
L
www.national.com
10
相關(guān)PDF資料
PDF描述
LM2676S-12 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
LM2676S-3.3 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
LM2676T-12 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
LM2676T-3.3 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
LM2676S-5.0 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM2675M-ADJ 制造商:Texas Instruments 功能描述:SWITCHING REG 0.1A ADJ SMD 2675
LM2675M-ADJ/NOPB 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 HIGH EFF 1A STEP- DOWN VLTG REG 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
LM2675M-ADJ/NOPB 制造商:Texas Instruments 功能描述:DC/DC Converter (DC-DC) / Switching Regu
LM2675MX-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
LM2675MX-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