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参数资料
| 型号： | LM2576-3.3MDC |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 7.5 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, UUC |
| 封装： | DIE |
| 文件页数： | 2/27页 |
| 文件大小： | 741K |
| 代理商： | LM2576-3.3MDC |
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LM2576 Series Buck Regulator Design Procedure
PROCEDURE (Fixed Output Voltage Versions)
EXAMPLE (Fixed Output Voltage Versions)
Given:
V
OUT = Regulated Output Voltage
(3.3V, 5V, 12V, or 15V)
V
IN(Max) = Maximum Input Voltage
I
LOAD(Max) = Maximum Load Current
Given:
V
OUT = 5V
V
IN(Max) = 15V
I
LOAD(Max) = 3A
1. Inductor Selection (L1)
A. Select the correct Inductor value selection guide from
Figures 3, 4, 5 or Figure 6. (Output voltages of 3.3V, 5V,
12V or 15V respectively). For other output voltages, see
the design procedure for the adjustable version.
B. From the inductor value selection guide, identify the in-
ductance region intersected by V
IN(Max) and ILOAD(Max),
and note the inductor code for that region.
C. Identify the inductor value from the inductor code, and
select an appropriate inductor from the table shown in
Figure 3. Part numbers are listed for three inductor manu-
facturers. The inductor chosen must be rated for opera-
tion at the LM2576 switching frequency (52 kHz) and for a
current rating of 1.15 x I
LOAD. For additional inductor in-
formation, see the inductor section in the Application
Hints section of this data sheet.
1. Inductor Selection (L1)
A. Use the selection guide shown in
Figure 4.
B. From the selection guide, the inductance area inter-
sected by the 15V line and 3A line is L100.
C. Inductor value required is 100 H. From the table in
Figure 3. Choose AIE 415-0930, Pulse Engineering
PE92108, or Renco RL2444.
2. Output Capacitor Selection (C
OUT)
A. The value of the output capacitor together with the in-
ductor defines the dominate pole-pair of the switching
regulator loop. For stable operation and an acceptable
output ripple voltage, (approximately 1% of the output
voltage) a value between 100 F and 470 F is recom-
mended.
B. The capacitor’s voltage rating should be at least 1.5
times greater than the output voltage. For a 5V regulator,
a rating of at least 8V is appropriate, and a 10V or 15V
rating is recommended.
Higher voltage electrolytic capacitors generally have
lower ESR numbers, and for this reason it may be neces-
sary to select a capacitor rated for a higher voltage than
would normally be needed.
2. Output Capacitor Selection (C
OUT)
A. C
OUT = 680 F to 2000 F standard aluminum electro-
lytic.
B.Capacitor voltage rating = 20V.
3. 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 LM2576. The most stressful
condition for this diode is an overload or shorted output
condition.
B. The reverse voltage rating of the diode should be at
least 1.25 times the maximum input voltage.
3. Catch Diode Selection (D1)
A.For this example, a 3A current rating is adequate.
B. Use a 20V 1N5823 or SR302 Schottky diode, or any of
the suggested fast-recovery diodes shown in
Figure 8.
4. Input Capacitor (C
IN)
An aluminum or tantalum electrolytic bypass capacitor lo-
cated close to the regulator is needed for stable opera-
tion.
4. Input Capacitor (C
IN)
A 100 F, 25V aluminum electrolytic capacitor located
near the input and ground pins provides sufficient
bypassing.
www.national.com
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相关代理商/技术参数 |
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|---|---|
| LM2576-5 | 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:Easy Switcher 3.0A Step-Down Voltage Regulator |
| LM2576-5.0 | 制造商:FCI 制造商全称:First Components International 功能描述:SMIPLE SWITCHER 3.0A Step-Down Voltage Regulator |
| LM2576-5.0BT | 功能描述:IC REG BUCK 5V 3A TO220-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:20 系列:SIMPLE SWITCHER® 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP（0.300"，7.62mm） 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12 |
| LM2576-5.0BT⒂ | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:52kHz Simple 3A Buck Voltage Regulator |
| LM2576-5.0BU | 功能描述:IC REG BUCK 5V 3A TO263-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:20 系列:SIMPLE SWITCHER® 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP（0.300"，7.62mm） 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12 |
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