- 您现在的位置：买卖IC网 > PDF目录13332 > LM2575D2T-015 (ON Semiconductor)IC REG BUCK 15V 1A D2PAK PDF资料下载
参数资料
| 型号： | LM2575D2T-015 |
| 厂商： | ON Semiconductor |
| 文件页数： | 18/28页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK 15V 1A D2PAK |
| 产品变化通告： | LTB Notification 03/Jan/2008 |
| 标准包装： | 50 |
| 类型： | 降压（降压） |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 15V |
| 输入电压： | 4.75 V ~ 40 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： | 表面贴装 |
| 封装/外壳： | TO-263-6，D²Pak（5 引线+接片），TO-263BA |
| 包装： | 管件 |
| 供应商设备封装： | D2PAK |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页当前第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LM2575, NCV2575
GENERAL RECOMMENDATIONS
Output Voltage Ripple and Transients
Source of the Output Ripple
Since the LM2575 is a switch mode power supply
regulator, its output voltage, if left unfiltered, will contain a
sawtooth ripple voltage at the switching frequency. The
output ripple voltage value ranges from 0.5% to 3% of the
output voltage. It is caused mainly by the inductor sawtooth
ripple current multiplied by the ESR of the output capacitor.
Short Voltage Spikes and How to Reduce Them
The regulator output voltage may also contain short
voltage spikes at the peaks of the sawtooth waveform (see
Figure 24). These voltage spikes are present because of the
fast switching action of the output switch, and the parasitic
inductance of the output filter capacitor. There are some
other important factors such as wiring inductance, stray
capacitance, as well as the scope probe used to evaluate these
transients, all these contribute to the amplitude of these
spikes. To minimize these voltage spikes, low inductance
capacitors should be used, and their lead lengths must be
kept short. The importance of quality printed circuit board
layout design should also be highlighted.
Voltage spikes caused by switching action of the output
switch and the parasitic inductance of the output capacitor
UNFILTERED
OUTPUT
VOLTAGE
VERTICAL
Heatsinking and Thermal Considerations
The Through ? Hole Package TO ? 220
The LM2575 is available in two packages, a 5 ? pin
TO ? 220(T, TV) and a 5 ? pin surface mount D 2 PAK(D2T).
There are many applications that require no heatsink to keep
the LM2575 junction temperature within the allowed
operating range. The TO ? 220 package can be used without
a heatsink for ambient temperatures up to approximately
50 ° C (depending on the output voltage and load current).
Higher ambient temperatures require some heatsinking,
either to the printed circuit (PC) board or an external
heatsink.
The Surface Mount Package D 2 PAK and its
Heatsinking
The other type of package, the surface mount D 2 PAK, is
designed to be soldered to the copper on the PC board. The
copper and the board are the heatsink for this package and
the other heat producing components, such as the catch
diode and inductor. The PC board copper area that the
package is soldered to should be at least 0.4 in 2 (or 100 mm 2 )
and ideally should have 2 or more square inches (1300 mm 2 )
of 0.0028 inch copper. Additional increasing of copper area
beyond approximately 3.0 in 2 (2000 mm 2 ) will not improve
heat dissipation significantly. If further thermal
improvements are needed, double sided or multilayer PC
boards with large copper areas should be considered.
Thermal Analysis and Design
The following procedure must be performed to determine
whether or not a heatsink will be required. First determine:
RESOLUTION:
20 mV/DIV
1. P D(max)
maximum regulator power dissipation in
the application.
FILTERED
OUTPUT
VOLTAGE
HORIZONTAL TIME BASE: 10 m s/DIV
Figure 24. Output Ripple Voltage Waveforms
Minimizing the Output Ripple
In order to minimize the output ripple voltage it is possible
to enlarge the inductance value of the inductor L1 and/or to
use a larger value output capacitor. There is also another way
to smooth the output by means of an additional LC filter
(20 m H, 100 m F), that can be added to the output (see
Figure 33) to further reduce the amount of output ripple and
transients. With such a filter it is possible to reduce the
output ripple voltage transients 10 times or more. Figure 24
shows the difference between filtered and unfiltered output
waveforms of the regulator shown in Figure 33.
The upper waveform is from the normal unfiltered output
of the converter, while the lower waveform shows the output
2. T A(max ) maximum ambient temperature in the
application.
3. T J(max) maximum allowed junction temperature
(125 ° C for the LM2575). For a conservative
design, the maximum junction temperature
should not exceed 110 ° C to assure safe
operation. For every additional 10 ° C
temperature rise that the junction must
withstand, the estimated operating lifetime
of the component is halved.
4. R q JC package thermal resistance junction ? case.
5. R q JA package thermal resistance junction ? ambient.
(Refer to Absolute Maximum Ratings in this data sheet or
R q JC and R q JA values).
The following formula is to calculate the total power
dissipated by the LM2575:
P D = (V in x I Q ) + d x I Load x V sat
where d is the duty cycle and for buck converter
ripple voltage filtered by an additional LC filter.
http://onsemi.com
18
相关PDF资料 |
PDF描述 |
|---|---|
| VI-2V1-EX-F2 | CONVERTER MOD DC/DC 12V 75W |
| BU31TA2WNVX-TR | IC REG LDO 3.1V .2A 4-SSON |
| LM2575D2T-012G | IC REG BUCK 12V 1A D2PAK |
| VI-2V1-EX-F1 | CONVERTER MOD DC/DC 12V 75W |
| VI-2TY-EV-F3 | CONVERTER MOD DC/DC 3.3V 99W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM2575D2T-015G | 功能描述:直流/直流开关调节器 15V 1A Buck PWM RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| LM2575D2T-12 | 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:EASY SWITCHERE⑩ 1.0 A STEP-DOWN VOLTAGE REGULATOR |
| LM2575D2T-12R4 | 功能描述:直流/直流开关调节器 12V 1A Buck PWM RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| LM2575D2T-12R4G | 功能描述:直流/直流开关调节器 12V 1A Buck PWM RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| LM2575D2T-15 | 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:EASY SWITCHERE⑩ 1.0 A STEP-DOWN VOLTAGE REGULATOR |
发布紧急采购，3分钟左右您将得到回复。