- 您现在的位置：买卖IC网 > PDF目录4961 > LT3758EDD#PBF (Linear Technology)IC REG CTRLR BST FLYBK INV 10DFN PDF资料下载
参数资料
| 型号： | LT3758EDD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 21/36页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BST FLYBK INV 10DFN |
| 标准包装： | 121 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 电源电压： | 5.5 V ~ 100 V |
| 降压： | 无 |
| 升压： | 是 |
| 回扫： | 是 |
| 反相： | 是 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 10-WFDFN 裸露焊盘 |
| 包装： | 管件 |
| 产品目录页面： | 1340 (CN2011-ZH PDF) |
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页第20页当前第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
LT3758/LT3758A
APPLICATIONS INFORMATION
I RMS(CIN),DISCONTINUOUS ≥
P OUT(MAX) 4 ? (3 ? D MAX )
V IN(MIN) ? h
V OUT + V D
V IN(MIN) + V OUT + V D
V OUT + V D D
1 ? D
V IN
I L1(MAX) = I IN(MAX) = I O(MAX) ?
I SW(MAX) = I L1(MAX) + I L2(MAX) = I O(MAX) ?
I SW(PEAK) = ? 1 + ? ? I O(MAX) ?
FlybackConverter:InputCapacitorSelection
The input capacitor in a flyback converter is subject to
a large RMS current due to the discontinuous primary
current. To prevent large voltage transients, use a low
ESR input capacitor sized for the maximum RMS current.
The RMS ripple current rating of the input capacitors in
discontinuous operation can be determined using the
following equation:
?
3 ? D MAX
SEPIC CONVERTER APPLICATIONS
The LT3758 can be configured as a SEPIC (single-ended
primary inductance converter), as shown in Figure 1. This
topology allows for the input to be higher, equal, or lower
than the desired output voltage. The conversion ratio as
a function of duty cycle is:
=
in continuous conduction mode (CCM).
In a SEPIC converter, no DC path exists between the input
and output. This is an advantage over the boost converter
for applications requiring the output to be disconnected
from the input source when the circuit is in shutdown.
Compared to the flyback converter, the SEPIC converter
has the advantage that both the power MOSFET and the
output diode voltages are clamped by the capacitors (C IN ,
C DC and C OUT ), therefore, there is less voltage ringing
across the power MOSFET and the output diodes. The
SEPIC converter requires much smaller input capacitors
than those of the flyback converter. This is due to the fact
that, in the SEPIC converter, the inductor L1 is in series
with the input, and the ripple current flowing through the
input capacitor is continuous.
SEPIC Converter: Switch Duty Cycle and Frequency
For a SEPIC converter operating in CCM, the duty cycle
of the main switch can be calculated based on the output
voltage (V OUT ), the input voltage (V IN ) and the diode
forward voltage (V D ).
The maximum duty cycle (D MAX ) occurs when the converter
has the minimum input voltage:
D MAX =
SEPIC Converter: Inductor and Sense Resistor Selection
As shown in Figure 1, the SEPIC converter contains two
inductors: L1 and L2. L1 and L2 can be independent, but can
also be wound on the same core, since identical voltages
are applied to L1 and L2 throughout the switching cycle.
For the SEPIC topology, the current through L1 is the
converter input current. Based on the fact that, ideally, the
output power is equal to the input power, the maximum
average inductor currents of L1 and L2 are:
D MAX
1 ? D MAX
I L2(MAX) = I O(MAX)
In a SEPIC converter, the switch current is equal to I L1 +
I L2 when the power switch is on, therefore, the maximum
average switch current is defined as:
1
1 ? D MAX
and the peak switch current is:
? c ? 1
? 2 ? 1 ? D MAX
The constant c in the preceding equations represents the
percentage peak-to-peak ripple current in the switch, rela-
tive to I SW(MAX) , as shown in Figure 9. Then, the switch
ripple current ?I SW can be calculated by:
?I SW = c ? I SW(MAX)
The inductor ripple currents ?I L1 and ?I L2 are identical:
?I L1 = ?I L2 = 0.5 ? ? I SW
The inductor ripple current has a direct effect on the
choice of the inductor value. Choosing smaller values of
?I L requires large inductances and reduces the current
loop gain (the converter will approach voltage mode).
3758afd
21
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3850EGN#PBF | IC REG CTRLR BUCK PWM CM 28-SSOP |
| RCA24DTMH | CONN EDGECARD 48POS R/A .125 SLD |
| AHA475M2AE16B-F | CAP ALUM 4.7UF 100V 20% SMD |
| GMM36DSXI | CONN EDGECARD 72POS DIP .156 SLD |
| RCA24DTMD | CONN EDGECARD 48POS R/A .125 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3758EDDTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller |
| LT3758EMSE#PBF | 功能描述:IC REG CTRLR PWM CM 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 特色产品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 标准包装:1 系列:PowerWise® PWM 型:电压模式 输出数:1 频率 - 最大:1MHz 占空比:81% 电源电压:4.5 V ~ 18 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-5°C ~ 125°C 封装/外壳:32-WFQFN 裸露焊盘 包装:Digi-Reel® 产品目录页面:1303 (CN2011-ZH PDF) 其它名称:LM3754SQDKR |
| LT3758EMSE#PBF | 制造商:Linear Technology 功能描述:DC-DC CONTROLLER INVERTING 1 制造商:Linear Technology 功能描述:DC-DC CONTROLLER, INVERTING, 1MHZ, MSOP- |
| LT3758EMSE#TRPBF | 功能描述:IC REG CTRLR PWM CM 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LT3758EMSEPBF | 制造商:Linear Technology 功能描述:100V Flyback SEPIC Controller MSOP10EP |
发布紧急采购，3分钟左右您将得到回复。