参数资料
型号: LM2575MX-3.3/NOPB
厂商: NATIONAL SEMICONDUCTOR CORP
元件分类: 稳压器
英文描述: 3.2 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, PDSO24
封装: SO-24
文件页数: 6/40页
文件大小: 917K
代理商: LM2575MX-3.3/NOPB
INDUCTOR VALUE SELECTION GUIDES (For Continuous Mode Operation) (Continued)
PROCEDURE (Adjustable Output Voltage Versions)
EXAMPLE (Adjustable Output Voltage Versions)
3. Output Capacitor Selection (C
OUT)
A. The value of the output capacitor together with the inductor
defines the dominate pole-pair of the switching regulator loop.
For stable operation, the capacitor must satisfy the following
requirement:
The above formula yields capacitor values between 10 F and
2000 F that will satisfy the loop requirements for stable
operation. But to achieve an acceptable output ripple voltage,
(approximately 1% of the output voltage) and transient re-
sponse, the output capacitor may need to be several times
larger than the above formula yields.
B. The capacitor’s voltage rating should be at last 1.5 times
greater than the output voltage. For a 10V regulator, a rating
of at least 15V or more is recommended.
Higher voltage electrolytic capacitors generally have lower
ESR numbers, and for this reasion it may be necessary to
select a capacitor rate for a higher voltage than would nor-
mally be needed.
3. Output Capacitor Selection (C
OUT)
A.
However, for acceptable output ripple voltage select
C
OUT ≥ 220 F
C
OUT = 220 F electrolytic capacitor
4. Catch Diode Selection (D1)
A. The catch-diode current rating must be at least 1.2 times
greater than the maximum load current. Also, if the power
supply design must withstand a continuous output short, the
diode should have a current rating equal to the maximum
current limit of the LM2575. The most stressful condition for
this diode is an overload or shorted output. See diode selec-
tion guide in
B. The reverse voltage rating of the diode should be at least
1.25 times the maximum input voltage.
4. Catch Diode Selection (D1)
A. For this example, a 3A current rating is adequate.
B. Use a 40V MBR340 or 31DQ04 Schottky diode, or any of
the suggested fast-recovery diodes in
5. Input Capacitor (C
IN)
An aluminum or tantalum electrolytic bypass capacitor located
close to the regulator is needed for stable operation.
5. Input Capacitor (C
IN)
A 100 F aluminum electrolytic capacitor located near the
input and ground pins provides sufficient bypassing.
To further 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. Switchers Made Simple (version 3.3) is available on a (312")
diskette for IBM compatible computers from a National Semiconductor sales office in your area.
LM1575/LM2575/LM2575HV
www.national.com
14
相关PDF资料
PDF描述
LM3420AM5-16.8/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LH2320-2D4 2-OUTPUT AC-DC UNREG PWR SUPPLY MODULE
LS4001-7ERD5T 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE
LS4001-7ERD5TB1 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE
LS2660-9ERD8TB1 2-OUTPUT 100 W AC-DC REG PWR SUPPLY MODULE
相关代理商/技术参数
参数描述
LM2575MX-5.0 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2575MX-5.0 NOPB 制造商:National Semiconductor 功能描述:Conv DC-DC Single Step Down 4V to 40V 24-Pin SOIC W T/R 制造商:National Semiconductor 功能描述:Conv DC-DC Single Step Down 4V to 40V 24-Pin SOIC T/R
LM2575MX-5.0/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2575MX-ADJ 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2575MX-ADJ/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT