- 您现在的位置：买卖IC网 > PDF目录17413 > LM2735YSDEVAL (National Semiconductor)BOARD EVAL LM2735 520KHZ 6LLP PDF资料下载
参数资料
| 型号： | LM2735YSDEVAL |
| 厂商： | National Semiconductor |
| 文件页数： | 20/58页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL LM2735 520KHZ 6LLP |
| 标准包装： | 1 |
| 主要目的： | DC/DC，步升 |
| 输出及类型： | 1，非隔离 |
| 输出电压： | 12V |
| 电流 - 输出： | 500mA |
| 输入电压： | 3 ~ 5.5 V |
| 稳压器拓扑结构： | 升压 |
| 频率 - 开关： | 520kHz |
| 板类型： | 完全填充 |
| 已供物品： | 板 |
| 已用 IC / 零件： | LM2735 |
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页第18页第19页当前第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页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页
SNVS485F – JUNE 2007 – REVISED APRIL 2013
1 ¨
D c ¨ ?
V IN ? 1 ¨
D c 2 R OUT
V OUT
V IN
=
§
1 -
§
¨
?
D c x V D · ¨
¨ 1 +
?
·
?
1 ?
R DCR + ( D x R DSON ) ?
?
1
(19)
One can see that if the loss elements are reduced to zero, the conversion ratio simplifies to:
V OUT
V IN
=
1
D c
(20)
And we know:
V OUT
V IN
=
K
D c
(21)
Therefore:
¨ 1 +
D c x V D ·
R DCR + ( D x R DSON ) ?
?
K = D c
V OUT
V IN
§
¨
¨
= ¨
¨
?
V IN ?
D c 2 R OUT 1
1 - ?
?
(22)
Calculations for determining the most significant power losses are discussed below. Other losses totaling less
than 2% are not discussed.
A simple efficiency calculation that takes into account the conduction losses is shown below:
K| ¨
¨ 1 +
D c x V D ·
R DCR + ( D x R DSON ) ?
?
§
¨
¨
¨
?
V IN ?
D c 2 R OUT 1
1 - ?
?
(23)
The diode, NMOS switch, and inductor DCR losses are included in this calculation. Setting any loss element to
zero will simplify the equation.
V D is the forward voltage drop across the Schottky diode. It can be obtained from the manufacturer’s Electrical
Characteristics section of the data sheet.
The conduction losses in the diode are calculated as follows:
P DIODE = V D x I O
(24)
Depending on the duty cycle, this can be the single most significant power loss in the circuit. Care should be
taken to choose a diode that has a low forward voltage drop. Another concern with diode selection is reverse
leakage current. Depending on the ambient temperature and the reverse voltage across the diode, the current
being drawn from the output to the NMOS switch during time D could be significant, this may increase losses
internal to the LM2735 and reduce the overall efficiency of the application. Refer to Schottky diode
manufacturer’s data sheets for reverse leakage specifications, and typical applications within this data sheet for
diode selections.
Another significant external power loss is the conduction loss in the input inductor. The power loss within the
inductor can be simplified to:
§ I 2 R
P IND = ¨ O
D '
P IND = I IN2 R DCR
·
DCR ?
¨ ?
? 1
The LM2735 conduction loss is mainly associated with the internal NFET:
P COND-NFET = I 2SW-rms x R DSON x D
(25)
(26)
(27)
20
Product Folder Links: LM2735
Copyright ? 2007–2013, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| A9AAT-1606F | FLEX CABLE - AFE16T/AF16/AFE16T |
| A9BAA-0905F | FLEX CABLE - AFF09A/AF09/AFE09T |
| LM2735YMYEVAL | BOARD EVAL LM2735 520KHZ 8MSOP |
| A9AAT-1803F | FLEX CABLE - AFE18T/AF18/AFE18T |
| LM2735YMFEVAL | BOARD EVAL LM2735 520KHZ 6LLP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM2735YSDEVAL | 制造商:Texas Instruments 功能描述:EVAL BOARD, LM2735Y 12V, 500mA SEPIC CON |
| LM2735YSDX | 制造商:NSC 制造商全称:National Semiconductor 功能描述:520kHz/1.6MHz - Space-Efficient Boost and SEPIC DC-DC Regulator |
| LM2735YSDX/NOPB | 功能描述:直流/直流开关调节器 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 |
| LM2736 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Thin SOT23 750mA Load Step-Down DC-DC Regulator |
| LM2736X | 制造商:TI 制造商全称:Texas Instruments 功能描述:LM2736 Thin SOT 750mA Load Step-Down DC-DC Regulator |
发布紧急采购，3分钟左右您将得到回复。