- 您现在的位置：买卖IC网 > Datasheet目录340 > MAX17061ETI+T (Maxim Integrated)IC LED DRVR WHITE BCKLGT 28-TQFN Datasheet资料下载
参数资料
| 型号： | MAX17061ETI+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 22/26页 |
| 文件大小： | 0K |
| 描述： | IC LED DRVR WHITE BCKLGT 28-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 拓扑： | PWM，升压（升压） |
| 输出数： | 8 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 车载，背光 |
| 类型 - 次要： | 白色 LED |
| 频率： | 1MHz |
| 电源电压： | 4.5 V ~ 26 V |
| 输出电压： | 5V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（4x4） |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 85°C |
8-String White LED Driver with
SMBus for LCD Panel Applications
I PEAK =
7 V × ( 35 . 9 V ? 7 V )
2 × 10 μ H × 35 . 9 V × 0 . 9 MHz
L DCM ( MAX ) = ? 1 ?
?
( 7 V ) 2 × 0 . 85
2 × 0 . 825 MHz × 35 . 9 V × 100 mA
The peak-inductor current at minimum input voltage is
calculated as follows:
100 mA × 35 . 9 V
7 V × 0 . 85
+ = 0 . 92 A
Alternatively, choosing a DCM operating mode at 750kHz
and estimating efficiency of 85% at this operating point:
? 7 V ?
? 35 . 9 V + 0 . 4 V ?
× = 5 . 6 μ H
A 4.7μH inductor is chosen. The peak inductor current
at minimum input voltage is calculated as follows:
Rectifier Diode Selection
The MAX17061’s high switching frequency demands a
high-speed rectifier. Schottky diodes are recommend-
ed for most applications because of their fast recovery
time and low forward voltage. The diode should be
rated to handle the output voltage and the peak switch
current. Make sure that the diode’s peak current rating
is at least I PEAK calculated in the Inductor Selection
section and that its breakdown voltage exceeds the
output voltage.
Overvoltage Protection Determination
The OV protection circuit should ensure the circuit safe
operation; therefore, the controller should limit the out-
put voltage within the ratings of all MOSFET, diode, and
output capacitor components, while providing sufficient
output voltage for LED current regulation. The OV pin is
tied to the center tap of a resistive voltage-divider (R1
I PEAK =
100mA × 2 × 35.9V × ( 35.9V + 0.4V ? 7V )
4 . 7 uH × 0 . 675 MHz × 0 . 85 × ( 35 . 9 V + 0 . 4 V )
= 1 . 47 A
and R2 in Figure 1) from the high-voltage output. When
the controller detects the OV pin voltage reaching the
threshold V OV_TH , typically 1.23V, OV protection is acti-
V OUT ( OVP ) = V OV _ TH × ? 1 +
?
Output Capacitor Selection
The total output voltage ripple has two components: the
capacitive ripple caused by the charging and discharging
on the output capacitor, and the ohmic ripple due to the
capacitor’s equivalent series resistance (ESR):
V RIPPLE = V RIPPLE ( C ) + V RIPPLE ( ESR )
vated. Hence, the step-up converter output overvoltage
protection point is:
? R 1 ?
? R 2 ?
In Figure 1, the output OVP voltage is set to:
? ?
V RIPPLE ( C ) ≈
I OUT ( MAX ) ? V OUT ( MAX ) ? V IN ( MIN ) ?
C OUT ? V OUT ( MAX ) f OSC ?
V OUT ( OVP ) = 1 . 236 V × ( 1 +
2 . 21 M Ω
61 . 9 k Ω
) ≈ 45 V
and:
V RIPPLE ( ESR ) ≈ I PEAK R ESR ( COUT )
Input Capacitor Selection
The input capacitor (C IN ) filters the current peaks
drawn from the input supply and reduces noise injec-
where I PEAK is the peak inductor current (see the
Inductor Selection section).
The output voltage ripple should be low enough for the
FB_ current-source regulation. The ripple voltage should
be less than 200mV P-P . For ceramic capacitors, the out-
put voltage ripple is typically dominated by V RIPPLE(C) .
The voltage rating and temperature characteristics of the
output capacitor must also be considered. The actual
capacitance of a ceramic capacitor is reduced by DC
voltage biasing. Ensure the selected capacitor has
enough capacitance at actual DC biasing.
tion into the IC. A 10μF ceramic capacitor is used in the
Typical Operating Circuit (Figure 1) because of the
high source impedance seen in typical lab setups.
Actual applications usually have much lower source
impedance since the step-up regulator often runs
directly from the output of another regulated supply. In
some applications, C IN can be reduced below the val-
ues used in the Typical Operating Circuit (Figure 1).
Ensure a low-noise supply at IN by using adequate C IN .
Alternatively, greater voltage variation can be tolerated
on C IN if IN is decoupled from C IN using an RC low-
pass filter.
22
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX17105ETG+T | IC LED DRVR WHITE BCKLGT 24-TQFN |
| MAX17127ETP+ | IC WLED DVR SIX STRING 20TQFN |
| MAX17149ETE+ | IC LED DRVR 6CH STEP UP 16QFNEP |
| MAX17410EVKIT+ | KIT EVAL FOR MAX17410 CTLR |
| MAX17605AUA+ | IC MOSFET DRVR 4A DUAL 8UMAX |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX17061EVCMAXQU+ | 功能描述:LED 照明开发工具 Evaluation Kit/Evaluation System for the MAX17061 RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| MAX17061EVKIT+ | 功能描述:LED 照明开发工具 MAX17061 Eval Kit RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| MAX17062ETB+ | 制造商:Maxim Integrated Products 功能描述: 制造商:Maxim Integrated Products 功能描述:TFT-LCD STEP-UP DC-DC CONVERTER - Rail/Tube |
| MAX17062ETB+T | 功能描述:直流/直流开关转换器 TFT-LCD Step-Up DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX17062EVKIT | 功能描述:电源管理IC开发工具 MAX17062 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
发布紧急采购，3分钟左右您将得到回复。