- 您现在的位置：买卖IC网 > PDF目录20858 > LTC3783IFE#PBF (Linear Technology)IC LED DRVR PWM CONTROL 16-TSSOP PDF资料下载
参数资料
| 型号： | LTC3783IFE#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 18/24页 |
| 文件大小： | 0K |
| 描述： | IC LED DRVR PWM CONTROL 16-TSSOP |
| 标准包装： | 95 |
| 恒定电流： | 是 |
| 恒定电压： | 是 |
| 拓扑： | 回扫，PWM，SEPIC，降压（降压），升压（升压） |
| 输出数： | 1 |
| 内部驱动器： | 无 |
| 类型 - 主要： | 车载，通用 |
| 频率： | 20kHz ~ 1MHz |
| 电源电压： | 3 V ~ 36 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 供应商设备封装： | 16-TSSOP-EP |
| 包装： | 管件 |
| 工作温度： | -40°C ~ 125°C |
LTC3783
OPERATION
I L
I RMS(CIN) ; 0.3 ?
V IN(MIN)
? D MAX
I RMS(COUT) ; I OUT(MAX) ?
V + V D – V IN 25 + 0.4 – 12
Formanydesignsitispossibletochooseasinglecapacitor
type that satisfies both the ESR and bulk C requirements
for the design. In certain demanding applications, however,
the ripple voltage can be improved significantly by con-
necting two or more types of capacitors in parallel. For
example, using a low ESR ceramic capacitor can minimize
the ESR setup, while an electrolytic capacitor can be used
to supply the required bulk C.
Once the output capacitor ESR and bulk capacitance have
been determined, the overall ripple voltage waveform
should be verified on a dedicated PC board (see Board
Layout section for more information on component place-
ment). Lab breadboards generally suffer from excessive
series inductance (due to inter-component wiring), and
these parasitics can make the switching waveforms look
significantly worse than they would be on a properly
designed PC board.
The output capacitor in a boost regulator experiences
high RMS ripple currents. The RMS output capacitor
ripple current is:
V OUT – V IN(MIN)
V IN(MIN)
Note that the ripple current ratings from capacitor manu-
facturers are often based on only 2000 hours of life. This
makes it advisable to further derate the capacitor or to
choose a capacitor rated at a higher temperature than
required. Several capacitors may also be placed in parallel
to meet size or height requirements in the design.
Boost Converter: Input Capacitor Selection
I IN
3783 F10
Figure 10. Inductor and Input Currents
The RMS input capacitor ripple current for a boost
converter is:
L ? f
Please note that the input capacitor can see a very high
surge current when a battery is suddenly connected to
the input of the converter, and solid tantalum capacitors
can fail catastrophically under these conditions. Be sure
to specify surge-tested capacitors!
Boost Converter Design Example
The design example given here will be for the circuit shown
in Figure 1. The input voltage is 12V, and the output voltage
is 25V at a maximum load current of 0.7A (1A peak).
1. The duty cycle is:
D = OUT = = 53%
V OUT + V D 25 + 0.4
2. The operating frequency is chosen to be 1MHz to
maximize the PWM dimming range. From Figure 2, the
resistor from the FREQ pin to ground is 6k.
3. An inductor ripple current of 40% of the maximum load
current is chosen, so the peak input current (which is also
the minimum saturation current) is:
I IN(PEAK) = ? 1 + ? ?
? c ? I OUT(MAX)
?
2 ?
1 – D MAX
? I L = c ?
I OUT(MAX) 0.7
1 ? D MAX
1 ? 0.53
The input capacitor of a boost converter is less critical
than the output capacitor, due to the fact that the inductor
is in series with the input, and hence, the input current
waveform is continuous (see Figure 10). The input volt-
age source impedance determines the size of the input
capacitor, which is typically in the range of 10μF to 100μF.
A low ESR capacitor is recommended, although it is not
as critical as for the output capacitor.
The inductor ripple current is:
= 0.4 ?
= 1.2 ?
0.7
1 – 0.53
= 0.6A
= 1.8A
3783fb
18
相关PDF资料 |
PDF描述 |
|---|---|
| P51-300-G-S-I36-20MA-000-000 | SENSOR 300PSI 1/4-18NPT 4-20MA |
| P51-3000-S-F-I12-4.5V-000-000 | SENSOR 3000PSI 1/4-18NPT .5-4.5V |
| BAS16W-7 | DIODE SWITCH 75V 200MW SC70-3 |
| REC7.5-4815DRW/H2/A/M | CONV DC/DC 7.5W 36-72VIN +/-15V |
| P51-2000-S-S-MD-4.5V-000-000 | SENSOR 2000PSI 1/4-18NPT 4.5V |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3785EUF#PBF | 功能描述:IC REG CTRLR BST PWM VM 24-QFN 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 |
| LTC3785EUF#TRPBF | 功能描述:IC REG CTRLR BST PWM VM 24-QFN 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) |
| LTC3785EUF-1#PBF | 功能描述:IC REG CTRLR BST PWM VM 24-QFN 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) |
| LTC3785EUF-1#TRPBF | 功能描述:IC REG CTRLR BST PWM VM 24-QFN 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:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 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:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3785EUFPBF | 制造商:Linear Technology 功能描述:10V Synch Buck-Boost Controller LTC3785 |
发布紧急采购，3分钟左右您将得到回复。