- 您现在的位置：买卖IC网 > Sheet目录338 > LTC3210EUD#TRPBF (Linear Technology)IC LED DRIVR WHITE BCKLGT 16-QFN
LTC3210
APPLICATIONS INFORMATION
η IDEAL =
P LED ( V LED ? I LED ) V LED
P IN ( V BAT ? ( 1 . 5 ) ? I LED ) ( 1 . 5 ? V BAT )
? Theflyingcapacitorsmustbeplacedclosetothepart.
The traces from the pins to the capacitor pad should
be as wide as possible.
? V BAT , CPO traces must be wide to minimize inductance
and handle high currents.
? LED pads must be large and connected to other layers
of metal to ensure proper heat sinking.
? RM and RC pins are sensitive to noise and capacitance.
The resistors should be placed near the part with mini-
mum line width.
Power Efficiency
To calculate the power efficiency ( η ) of a white LED
driver chip, the LED power should be compared to the
input power. The difference between these two numbers
represents lost power whether it is in the charge pump
or the current sources. Stated mathematically, the power
efficiency is given by:
At moderate to high output power, the quiescent current
of the LTC3210 is negligible and the expression above is
valid.
Once dropout is detected at any LED pin, the LTC3210
enables the charge pump in 1.5x mode.
In 1.5x boost mode, the efficiency is similar to that of a
linear regulator with an effective input voltage of 1.5 times
the actual input voltage. This is because the input current
for a 1.5x charge pump is approximately 1.5 times the
load current. In an ideal 1.5x charge pump, the power
efficiency would be given by:
= =
Similarly, in 2x boost mode, the efficiency is similar to
that of a linear regulator with an effective input voltage
of 2 times the actual input voltage. In an ideal 2x charge
pump, the power efficiency would be given by:
( V LED ? I LED ) V LED
η=
P LED
P IN
η IDEAL =
P LED
P IN
=
=
( V BAT ? ( 2 ) ? I LED ) ( 2 ? V BAT )
= LED
P LED ( V LED ? I LED ) V
TheefficiencyoftheLTC3210dependsuponthemodein
which it is operating. Recall that the LTC3210 operates
as a pass switch, connecting V BAT to CPO, until dropout
is detected at the LED pin. This feature provides the op-
timum efficiency available for a given input voltage and
LED forward voltage. When it is operating as a switch, the
efficiency is approximated by:
η= =
P IN ( V BAT ? I BAT ) V BAT
since the input current will be very close to the sum of
the LED currents.
Thermal Management
For higher input voltages and maximum output current,
there can be substantial power dissipation in the LTC3210.
If the junction temperature increases above approximately
150°C the thermal shut down circuitry will automatically
deactivate the output current sources and charge pump.
To reduce maximum junction temperature, a good thermal
connection to the PC board is recommended. Connecting
the Exposed Pad to a ground plane and maintaining a solid
ground plane under the device will reduce the thermal
resistance of the package and PC board considerably.
3210fb
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LTC3212EDDB#TRPBF
IC LED DRIVER RGB 12-DFN
LTC3214EDD#TRPBF
IC LED DRIVR WHITE BCKLGT 10-DFN
LTC3215EDD#PBF
IC LED DRIVR WHITE BCKLGT 10-DFN
LTC3217EUD#TRPBF
IC LED DRVR FLASH TORCH 16QFN
LTC3218EDDB#TRPBF
IC LED DRVR FLASH TORCH 10DFN
LTC3219EUD#PBF
IC LED DRIVR QVGA DISPLAY 20-QFN
LTC3220EPF#PBF
IC LED DRVR QVGA DISPLAY 28UTQFN
LTC3230EUD#PBF
IC LED DRIVR WHITE BCKLGT 20-QFN
相关代理商/技术参数
LTC3210EUD-1#PBF
功能描述:IC LED DRIVR WHITE BCKLGT 16-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3210EUD-1#TRPBF
功能描述:IC LED DRIVR WHITE BCKLGT 16-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3210EUD-1-PBF
制造商:LINER 制造商全称:Linear Technology 功能描述:MAIN/CAM LED Controller with 64-Step Brightness Control in 3mm × 3mm QFN
LTC3210EUD-1-TRPBF
制造商:LINER 制造商全称:Linear Technology 功能描述:MAIN/CAM LED Controller with 64-Step Brightness Control in 3mm × 3mm QFN
LTC3210EUD-2#PBF
功能描述:IC LED DRIVR WHITE BCKLGT 16-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3210EUD-2#TRPBF
功能描述:IC LED DRIVR WHITE BCKLGT 16-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3210EUD-2-PBF
制造商:LINER 制造商全称:Linear Technology 功能描述:MAIN/CAM LED Controllers with 32-Step Brightness Control in 3mm × 3mm QFN
LTC3210EUD-2-TRPBF
制造商:LINER 制造商全称:Linear Technology 功能描述:MAIN/CAM LED Controllers with 32-Step Brightness Control in 3mm × 3mm QFN