参数资料
型号: ISL97677IRZ
厂商: Intersil
文件页数: 11/23页
文件大小: 0K
描述: IC LED DVR PWM CTRL 8CH 32QFN
标准包装: 60
拓扑: 线性(LDO),PWM,升压(升压)
输出数: 8
内部驱动器:
类型 - 主要: 背光
类型 - 次要: RGB,白色 LED
频率: 500kHz ~ 1.5MHz
电源电压: 4.75 V ~ 26 V
输出电压: 45V
安装类型: 表面贴装
封装/外壳: 32-VFQFN 裸露焊盘
供应商设备封装: 32-QFN 裸露焊盘(5x5)
包装: 管件
工作温度: -40°C ~ 85°C
ISL97677
Typical Performance Curves (Continued)
V O (1V/DIV)
V O (500mV/DIV)
I LED (20mA/DIV)
I LED (20mA/DIV)
FIGURE 21. LOAD REGULATION WITH I LED CHANGES
FROM 0% TO 100% PWM DIMMING
FIGURE 22. LOAD REGULATION WITH I LED CHANGES
FROM 100% to 0% PWM DIMMING
V O (20V/DIV)
EN (5V/DIV)
I IN (1A/DIV)
I LED (50mA/DIV)
FIGURE 23. DISABLE PROFILE
Theory of Operation
PWM Boost Converter
The current mode PWM boost converter produces the
minimal voltage needed to enable the LED string with the
highest forward voltage drop to run at the programmed
current. The ISL97677 employs current mode control
boost architecture that has a fast current sense loop and
a slow voltage feedback loop. Such architecture achieves
a fast transient response that is essential for the
notebook backlight application where the power can be
several Li-ion cell batteries or instantly change to an
AC/DC adapter without rendering a noticeable visual
nuisance. The number of LEDs that can be driven by
ISL97677 depends on the type of LED chosen in the
application. The ISL97677 is capable of boosting up to
45V and drive 8 channels of LEDs at maximum of 45mA
per channel.
11
Current Matching and Current Accuracy
Each channel of the LED current is regulated by the
current source circuit, as shown in Figure 24.
The LED peak current is set by translating the R SET
current to the output with a scaling factor of 707.9/R SET .
The source terminals of the current source MOSFETs are
designed to run at 500mV to optimize power loss vs
accuracy requirements. The sources of errors of the
channel-to-channel current matching come from the
op amps offset, internal layout, reference, and current
source resistors. These parameters are optimized for
current matching and absolute current accuracy.
However, the absolute accuracy is additionally
determined by the external R SET . A 0.1% tolerance
resistor is recommended.
FN6996.1
November 13, 2009
相关PDF资料
PDF描述
ISL97678IRZ IC LED DVR PWM DIMMING 8CH 32QFN
ISL97686IRTZ IC LED DRVR BACKLIGHT 28TQFN
ISL97691IRTZ-TK IC LED DRVR BACKLIGHT 3D 16TQFN
ISL97693IRTZ-TK IC LED DRVR BACKLIGHT 16TQFN
ISL97901CRZ IC LED DRVR 1.5A 28QFN
相关代理商/技术参数
参数描述
ISL97677IRZ-T 功能描述:IC LED DVR PWM CTRL 8CH 32QFN 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
ISL97677IRZ-TK 功能描述:IC LED DVR PWM CTRL 8CH 32QFN 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
ISL97678IRZ 功能描述:IC LED DVR PWM DIMMING 8CH 32QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:60 系列:- 恒定电流:- 恒定电压:- 拓扑:线性(LDO),PWM,升压(升压) 输出数:8 内部驱动器:是 类型 - 主要:背光 类型 - 次要:RGB,白色 LED 频率:500kHz ~ 1.5MHz 电源电压:4.75 V ~ 26 V 输出电压:45V 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:* 工作温度:-40°C ~ 85°C
ISL97678IRZ-T 功能描述:IC LED DVR PWM DIMMING 8CH 32QFN 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
ISL97678IRZ-TK 功能描述:IC LED DVR PWM DIMMING 8CH 32QFN 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