收藏本站
ISL97801
TABLE 4. BOOST MODE COMPENSATION 12V OPERATION
VOUT (V)
7
10.5
14
17.5
21
24.5
28
VFB
I OUT
LED’s
2
3
4
5
6
7
8
50mV
50mA
Electrolytic
Ceramic
DMIN
DMIN
DMIN
60μF
40μF
40μF
40μF
100mV
100mA
Electrolytic
47μF
47μF
Ceramic
DMIN
DMIN
DMIN
40μF
20μF
40μF
40μF
200mV
350mA
Electrolytic
47μF
47μF
Ceramic
DMIN
DMIN
DMIN
40μF
20μF
40μF
40μF
200mV
1A
Electrolytic
47μF
47μF
Ceramic
DMIN
DMIN
DMIN
20μF
20μF
40μF
40μF
A Note about Ceramic Capacitors:
Many ceramic capacitors have strong voltage and
temperature coefficients which reduces effective
capacitance as the applied voltage or operating temperature
is increased. Pay careful attention when selecting ceramic
capacitor type. X5R and X7R families provide much better
stability than Y5V, which should generally be avoided unless
additional capacitance is added to compensate for the
significant changes in value which occurs over voltage and
temperature.
TABLE 5. CERAMIC CAPACITOR VARIABILITY
? Feedback signals levels are small to improve efficiency.
Ensure the reference connection (GND or VIN) between
the sense resistor and IC pin doesn't carry switching
current.
? Place several via holes (thermal vias) under the chip to a
backside ground plane to improve heat dissipation
? Maximize the copper area around the thermal vias to
spread heat away from the chip.
Cost-Sensitive Applications
For cost-sensitive applications, the BOM can be reduced
considerably by:
CAPACITOR TYPE
X7R, 10V
X5R, 25V
Y5V, 6.3V
TYPICAL VOLTAGE
VARIATION
-30% at 10V
-50% at 25V
-90% at 6.3V
TEMPERATURE
VARIATION
-15% at +125°C
-9% at +85°C
-65% at +85°C
1. Removing temperature compensation
2. Removing the fault-protection switch
3. Removing the load isolation switch
4. Switching the FB into internal fixed bias mode (400mV
across V FB )
Layout Considerations
PCB layout is very important for the converter to function
properly. The following general guidelines should be
followed:
? Separate the Power Ground and Signal Ground; connect
them only at one point close to the GND pin.
? Maximize the Power Ground area as much as possible. It
is essential to ensure th Power Ground return between
Cin, Cout, and SWS1,2 as least obstructive as possible.
? Place the input capacitor close to VIN and SWS1,2 pins in
boost mode.
? Make the following PC traces as short as possible:
- from SWD1,2 to the inductor in boost mode
- from SWS1,2 to the inductor in buck mode
- from Cout to PGND
15
In this configuration, light level may be controlled using the
EN/PWM input to modulate the output current.
In the absence of the load isolation switch, LED bias current
will vary with PWM duty cycle, due to the discharge of the
output capacitor by the LED’s during the PWM off time
therefore low dimming frequencies can only be used in such
application.
FN6428.1
April 2, 2007
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ISLA118P50IR72EV1Z EVAL BOARD FOR ISLA118P50IR74
ISLA224IR72EV1Z BOARD EVALUATION FOR ISLA224P
ISPTPKIT SCREW KIT TAMPER RESISTANT 9PCS
ITCSN-0400-25-U HEATSHRINK ITCSN 2/5" X 25'
JC2AF-TM-DC24V-F RELAY GEN PURPOSE DPST 10A 24V
JJM1A-12V RELAY AUTOMOTIVE SPST 20A 12V
JM1AN-ZTM-DC5V-F RELAY GEN PURPOSE SPST 20A 5V
JQ1P-18V-F RELAY GEN PURPOSE SPDT 10A 18V
相关代理商/技术参数
ISL97900CRZ 功能描述:LED照明驱动器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
ISL97900CRZ-T 功能描述:LED照明驱动器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
ISL97900CRZ-T7A 功能描述:LED照明驱动器 High Current RGB Driver/Controller, 28L 4x5 QFN,Commercial T RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
ISL97900CRZ-TK 功能描述:LED照明驱动器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
ISL97901CRZ 功能描述:IC LED DRVR 1.5A 28QFN 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
ISL97901CRZ-T 功能描述:IC LED DRVR 1.5A 28QFN 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
ISL97901CRZ-T7A 制造商:Intersil Corporation 功能描述:HIGH CURRENT RGGB DRIVER/CONTROLLER, 28L 4X5 QFN FOR COMMERC - Tape and Reel 制造商:Intersil Corporation 功能描述:IC LED DRVR 1.5A 28QFN
ISL97901CRZ-TK 功能描述:IC LED DRVR 1.5A 28QFN 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