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参数资料
| 型号： | AS3691A EB |
| 厂商： | ams |
| 文件页数： | 14/23页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL AS3691A |
| 标准包装： | 1 |
| 电流 - 输出 / 通道： | 400mA |
| 输出及类型： | 4，非隔离 |
| 输出电压： | 最高 15V |
| 输入电压： | 10 ~ 12 V |
| 已供物品： | 板 |
| 已用 IC / 零件： | AS3691A |
AS3691
Datasheet
8.3 Automatic Supply Regulation
The purpose of the automatic supply regulation is to minimize the voltage supply to reduce the voltage across the
current sources of the AS3691 (CURR1-CURR4 to VSS) and therefore reduce the power dissipation of the
AS3691 and the complete system. The AS3691 automatically controls the minimum required supply voltage for
the different led strings to support very power efficient systems for lighting using the following circuit (any off-the-
shelf dcdc converter or ldo with adjustable output voltage can be used):
Figure 13 – Automatic Supply Regulation Circuit
From main
DCDC Converter
for VDD
VDDx
Csup
100nF
supply
Voltage Feedback
Vfb
R1
R3
R4
UVx
input for DCDC
R2
C1
UV1
CURR1
UV2
CURR2
Feedback resistor divider
(part of DCDC converter circuit)
Vc
Vc
AS3691
The function of this circuit is as follows:
All channels, which are connected to the supply VDDx should have their respective UV pin connected together to
UVx (see above Figure and Section ‘Application Schematic’). If any of these current sources has a too low
voltage, it gradually pulls the wire UVx low. (The analog gain between the current source CURRx and output UVx
is defined by the parameter V C,GAIN .)
Therefore the feedback pin Vfb of the dcdc converter is pulled low and the dcdc converter compensates this by
increasing the voltage on VDDx to obtain the same feedback voltage as before.
To stabilize this regulation loop, the low pass filter build by C1 and R4 is used (this should be the dominant pole
for the regulation loop).
The minimum output voltage VDDx min can be set accurately by the resistors R1 and R2. The maximum output
voltage VDDx max is set by R1, R2, R3 and R4 (Vref is the internal voltage reference of the DCDC converter;
usually Vref = Vfb):
VDDx MIN = Vref
VDDx MAX = Vref
R 1 + R 2
R 2
R 1 + R 2 ( R 3 + R 4 )
R 2 ( R 3 + R 4 )
Therefore even if a led string is broken (then UVx is forced to 0V) or some leds are shorted, the supply always
stays within the limits VDDx MIN and VDDx MAX .
www.austriamicrosystems.com (ptr)
Revision 2.3
13 - 22
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AS3691A-ZQFP | 功能描述:IC LED DVR 400MA RGB/WH 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 恒定电流:- 恒定电压:- 拓扑:升压（升压），切换式电容器（充电泵） 输出数:1 内部驱动器:是 类型 - 主要:背光 类型 - 次要:白色 LED 频率:625kHz ~ 875kHz 电源电压:2.7 V ~ 5.3 V 输出电压:5V 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-µMAX 包装:带卷 (TR) 工作温度:-40°C ~ 85°C |
| AS3691AZQFT | 制造商:ams 功能描述:QFN24 (4x4x0.5) |
| AS3691A-ZQFT | 功能描述:IC LED DRIVER 4X400MA 24-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 特色产品:LM3445 TRIAC Dimmable LED Driver 标准包装:55 系列:PowerWise® 恒定电流:是 恒定电压:- 拓扑:PWM，降压（降压） 输出数:1 内部驱动器:无 类型 - 主要:- 类型 - 次要:高亮度 LED（HBLED） 频率:30kHz ~ 1MHz 电源电压:8 V ~ 12 V 输出电压:- 安装类型:表面贴装 封装/外壳:14-SOIC（0.154"，3.90mm 宽） 供应商设备封装:14-SOICN 包装:管件 工作温度:-40°C ~ 125°C 产品目录页面:1285 (CN2011-ZH PDF) 其它名称:LM3445M |
| AS3691A-ZSDF | 制造商:AMSCO 制造商全称:austriamicrosystems AG 功能描述:4 Precision 400mA Current Sources for RGB and Single Color Leds |
| AS3691A-ZTSP | 功能描述:IC LED DVR 400MA RGB/WH 20ETSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 恒定电流:- 恒定电压:- 拓扑:升压（升压），切换式电容器（充电泵） 输出数:1 内部驱动器:是 类型 - 主要:背光 类型 - 次要:白色 LED 频率:625kHz ~ 875kHz 电源电压:2.7 V ~ 5.3 V 输出电压:5V 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-µMAX 包装:带卷 (TR) 工作温度:-40°C ~ 85°C |
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