- 您现在的位置：买卖IC网 > PDF目录20753 > MAX17149ETE+T (Maxim Integrated)IC LED DRVR 6CH STEP UP 16QFN PDF资料下载
参数资料
| 型号： | MAX17149ETE+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 17/21页 |
| 文件大小： | 0K |
| 描述： | IC LED DRVR 6CH STEP UP 16QFN |
| 标准包装： | 2,500 |
| 系列： | Quick-PWM™ |
| 拓扑： | 开路漏极，PWM，升压（升压） |
| 输出数： | 6 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 车载，背光 |
| 类型 - 次要： | 白色 LED |
| 频率： | 可调节/可选择 |
| 电源电压： | 3 V ~ 26 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-WFQFN 裸露焊盘 |
| 供应商设备封装： | 16-TQFN（3x3） |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 85°C |
Low-Cost, 6-String WLED Drivers with
Quick-PWM Step-Up Converter
L DCM(MAX) = ? 1 ? ? ×
V OUT(MAX) ? ?
?
when LIR is higher than 2.0, and it works in CCM mode
when LIR is lower than 2.0. The best trade-off between
inductor size and converter efficiency for step-up regula-
tors generally has an LIR between 0.3 and 0.5. However,
depending on the AC characteristics of the inductor core
material and ratio of inductor resistance to other power-
path resistances, the best LIR can shift up or down. If the
inductor resistance is relatively high, more ripples can
be accepted to reduce the number of required turns and
increase the wire diameter. If the inductor resistance is
relatively low, increasing inductance to lower the peak
current can reduce losses throughout the power path. If
DCM mode (or the minimum inductor value for CCM
mode) is calculated with the following equation:
? V IN(MIN) ?
?
V IN(MIN) 2 × η
2 × f SW × V OUT(MAX) × I OUT(MAX)
The peak inductor current in DCM is calculated with the
following equation:
extremely thin high-resistance inductors are used, as is
common for LCD panel applications, an LIR higher than
2.0 can be chosen for DCM operating mode.
I PEAK_DCM =
I OUT(MAX) × 2 × ( V OUT(MAX) ? V IN(MIN)
L DCM × f SW × η
)
I OUT(MAX) × V OUT
I IN(DC,MAX) =
V IN(MIN) × ( V OUT(MAX) ? V IN(MIN) )
I RIPPLE =
7V 32V ? 7V 0.85 ?
? ? ?
??
L CCM = ? ? ? ?? ? = 10.59 μ H
120mA × 32V 7V × ( 32V ? 7V )
I PEAK_CCM = +
I PEAK_CCM IN(DC,MAX) + RIPPLE
= I
L DCM(MAX) = ? 1 ? ? ×
Once a physical inductor is chosen, higher and lower
values of the inductor should be evaluated for efficiency
improvements in typical operating regions. The detailed
design procedure for CCM can be described as:
Calculate the approximate inductor value using the
typical input voltage (V IN ), the maximum output cur-
rent (I OUT(MAX) ), the expected efficiency ( E TYP ) taken
from an appropriate curve in the Typical Operating
Characteristic s, and an estimate of LIR based on the
above discussion:
V IN(MIN) × η MIN
Choose an available inductor value from an appropriate
inductor family. Calculate the maximum DC input current
at the minimum input voltage V IN(MIN), using conserva-
tion of energy and the expected efficiency at that operat-
ing point ( E MIN ) taken from an appropriate curve in the
Typical Operating Characteristics :
Calculate the ripple current at that operating point and
the peak current required for the inductor:
L CCM × V OUT(MAX) × f SW
I
2
When DCM operating mode is chosen to minimize the
inductor value, the calculations are different from those
above in CCM mode. The maximum inductor value for
The inductor’s saturation current rating should exceed
I PEAK and the inductor’s DC current rating should
exceed I IN(DC,MAX) . For good efficiency, choose an
inductor with less than 0.1 I series resistance.
Considering the circuit with six 10-LED strings and
20mA LED full-scale current, the maximum load current
(I OUT(MAX) ) is 120mA with a 32V output and a minimal
input voltage of 7V.
Choosing a CCM operating mode with LIR = 0.8 at 1MHz
and estimating efficiency of 85% at this operating point:
2
? 32V ? ? 120mA × 1MHz ?? 0.8 ?
A 10 F H inductor is chosen and the peak inductor current
at minimum input voltage is calculated as follows:
7V × 0.85 2 × 10 μ H × 32V × 1MHz
= 0.92A
Alternatively, choose a DCM operating mode by using
lower inductance and estimating efficiency of 85% at this
operating point. Since DCM has higher peak inductor
current at lower input, it causes current limit when the
parameters are not chosen properly. Considering the
case with six 10-LED strings and 20mA LED full-scale
current to prevent excessive switch current from causing
current limit:
? 7V ? (7V) 2 × 0.85
? 32V ? 2 × 1MHz × 32V × 120mA
= 4.24 μ H
17
相关PDF资料 |
PDF描述 |
|---|---|
| ABB66DHHD-S578 | EDGECARD 132POS .050 SLD W/POSTS |
| TPSD337M004R0045 | CAP TANT 330UF 4V 20% 2917 |
| HSC40DRYN-S13 | CONN EDGECARD 80POS .100 EXTEND |
| HSC40DRYH-S13 | CONN EDGECARD 80POS .100 EXTEND |
| TPSD337K010H0100 | CAP TANT 330UF 10V 10% 2917 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1714AEEP | 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1714AEEP+ | 功能描述:电流型 PWM 控制器 Step-Down Controller for Notebook RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1714AEEP+T | 功能描述:电流型 PWM 控制器 Step-Down Controller for Notebook RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1714AEEP-T | 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1714AEEP-TG068 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
发布紧急采购，3分钟左右您将得到回复。