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参数资料
| 型号： | ISL97631IHTZ-T7A |
| 厂商： | Intersil |
| 文件页数： | 6/8页 |
| 文件大小： | 0K |
| 描述： | IC LED DRIVR WHITE BCKLGT TSOT-6 |
| 标准包装： | 250 |
| 拓扑： | PWM，升压（升压） |
| 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： | 800kHz ~ 1.8MHz |
| 电源电压： | 2.7 V ~ 5.5 V |
| 输出电压： | 27V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | SOT-23-6 细型，TSOT-23-6 |
| 供应商设备封装： | TSOT-23-6 |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 85°C |
ISL97631
L1
22μH
90%
85%
22μH, V IN = 4V
V IN
2.7V~5.5V
V IN
LX
V OUT
LEDs
80%
75%
3LED
2LED
4LED
C1
1μF
OFF/ON
ISL97631
ENAB FB
GND
Dz
R1
R SET
4.75 ?
C2
0.22μF
70%
65%
60%
55%
5LED
6LED
50%
0
5
10
15
20
25
30
FIGURE 10. LED DRIVER WITH OVERVOLTAGE
PROTECTION CIRCUIT
Components Selection
The input capacitance is typically 0.22μF. The output
capacitor should be in the range of 0.22μF to 1μF. X5R or
X7R type of ceramic capacitors of the appropriate voltage
rating are recommended. The output capacitor value affects
PWM dimming performance. Lower output capacitor values
increase the range of PWM dimming. However, the ripple
voltage will be greater for lower values.
When choosing an inductor, make sure the average and
peak current ratings are adequate by using the following
formulas (80% efficiency assumed):
I LED (mA)
FIGURE 11. EFFICIENCY CURVE WITH 2, 3, 4, 5 AND 6 LEDs
LOAD
White LED Connections
One leg of LEDs connected in series will ensure brightness
uniformity. The 27V maximum output voltage specification
enables up to 6 LEDs to be placed in series.
In order to drive more LEDs, series/parallel connections are
used. A current mirror circuit (as shown in Figure 12) should
be used to balance LED currents.
Parallel strings of LEDs may draw significantly different
currents due to manufacturing and temperature differences.
I LED ? V OUT
0.8 ? V IN
I LPK = I LAVG + --- ? ? I L
? I L = ---------------------------------------------------
I LAVG = ---------------------------------
1
2
V IN ? ( V OUT – V IN )
L ? V OUT ? f OSC
(EQ. 6)
(EQ. 7)
(EQ. 8)
For correct operation of the current mirror circuit, the total
voltage between FB pin and the top of the primary LED
string must be equal to or greater than the other strings. To
ensure this, a small value resistor may be inserted between
FB pin and the primary LED string.
D1
L1
VOUT
ENAB FB
Where:
? ? I L is the peak-to-peak inductor current ripple in Amps
? L is the inductance in H.
? f OSC is the switching frequency, typically 1.35MHz
V IN
2.7V~5.5V
C1
OFF/ON
VIN
VDD LX
ISL97631
EL7630
ENAB FB
GND
R SET
LEDs
C2
The ISL97631 supports a wide range of inductance values
(22μH~82μH). For lower inductor values or lighter loads, the
boost inductor current may become discontinuous. For high
boost inductor values, the boost inductor current will be in
continuous mode.
The demo board efficiency bench test results are shown in
Figure 11. The input voltage is 4V and curves are shown for
2, 3, 4, 5 and 6 LEDs (boost inductor L = 22μH).
6
FIGURE 12. LEDs IN SERIES/PARALLEL WITH MIRROR
CURRENT BALANCE
FN7370.1
December 21, 2005
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL97632IRT14Z | 制造商:Intersil 功能描述:LED Driver with 1-Wire Dimming(3 LED) |
| ISL97632IRT14Z-T | 功能描述:IC LED DRIVR WHITE BCKLGT 8-TDFN 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 |
| ISL97632IRT14Z-TK | 功能描述:IC LED DRIVR WHITE BCKLGT 8-TDFN 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 |
| ISL97632IRT18Z | 制造商:Intersil 功能描述:LED Driver with 1-Wire Dimming(4 LED) |
| ISL97632IRT18Z-T | 功能描述:IC LED DRIVR WHITE BCKLGT 8-TDFN 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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