- 您现在的位置：买卖IC网 > Sheet目录338 > LTC3453EUF#TRPBF (Linear Technology)IC LED DRIVER PHOTO FLASH 16-QFN
LTC3453
APPLICATIO S I FOR ATIO
The unity-gain frequency of the error amplifier with the
Type I compensation is given by:
Since the maximum continuous output current is limited
to 500mA, this sets a minimum limit on the parallel
f UG =
g m
2 ? π ? C VC
combination of R ISET1 and R ISET2 equal to
R MIN = (R ISET1 || R ISET2 )| MIN = 4(384[0.8V/500mA])
= 2458 ?
where g m is the error amp transconductance (typically
1/5.2k) and C VC is the external capacitor to GND at the
V C pin. For the white LED application, a 0.1 μ F or greater
capacitor value is recommended.
Paralleling LED Outputs for Higher Current
Two or more LED output pins can be connected together
in parallel to achieve higher output current in fewer than 4
LEDs. For a very high power LED such as a LumiLED, all
four outputs can be connected in parallel for maximum
total output current, as shown in the cover page applica-
tion of this datasheet.
Maximum LED Current
As described in the Operation section, the output LED
current with both enable pins logic high is equal to
I LED = 384 [0.8V/(R ISET1 || R ISET2 )]
Although the LTC3453 can safely provide this current
continuously, the external LED(s) may not be rated for this
high a level of continuous current. Higher current levels
are generally reserved for pulsed applications, such as
LED camera flash. This is accomplished by programming
a high current with one of the R ISET resistors and pulsing
the appropriate enable pin.
Varying LED Brightness
Continuously variable LED brightness control can be
achieved by interfacing directly to one or both of the I SET
pins. Figure 3 shows four such methods employing a
voltage DAC, a current DAC, a simple potentiometer or a
PWM input. It is not recommended to control brightness
by PWMing the enable pins directly as this will toggle the
LTC3453 in and out of shutdown and result in erratic
operation.
V IN
ENx
LED1
LTC3453
V OUT
V IN
ENx
LED1
LTC3453
V OUT
I SETx
LED4
I SETx
LED4
VOLTAGE
DAC
R SET ≥ R MIN
V DAC
I LED = 384
0.8V – V DAC
R SET
CURRENT
DAC
IDAC ≤
0.8V
R MIN
I LED = 384 ? IDAC
(a)
(b)
V IN
ENx
LED1
LTC3453
V OUT
V IN
ENx
LED1
LTC3453
V OUT
I SETx
LED4
I SETx
LED4
R MIN
I LED = 384
0.8V
R MIN + R POT
R SET
100
R SET ≥ R MIN
I LED = 384
0.8V – V PWM
R SET
R POT
V PWM
1 μ F
= 384
0.8V – (DC% ? V DVCC )
R SET
DV CC
f PWM ≥ 5kHz
(c)
(d)
3453 F03
Figure 3. Brightness Control Methods: (a) Using Voltage DAC, (b) Using Current DAC, (c) Using Potentiometer, (d) Using PWM Input
3453fa
10
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LTC3454EDD#TRPBF
IC LED DRIVER PHOTO FLASH 10-DFN
LTC3490EDD#PBF
IC LED DRIVER PHOTO FLASH 8-DFN
LTC3783EFE#PBF
IC LED DRVR PWM CONTROL 16-TSSOP
LV5026MC-AH
IC LED DRIVER 1CH HV 10SOIC
LV5213LP-TE-L-E
IC LED DVR 3CH CELL PHONE VCT16
LV5216CS-TE-L-E
IC LED DRIVER 10CH CELL 36WLP
LV5217GP-TE-L-E
IC LED DVR 3CH CELL PHONE VCT16
LV8498CT-TE-L-H
IC MOTOR DRIVER S111 WLP
相关代理商/技术参数
LTC3454
制造商:LINER 制造商全称:Linear Technology 功能描述:1A Synchronous Buck-Boost High Current LED Driver
LTC3454EDD
制造商:LINER 制造商全称:Linear Technology 功能描述:1A Synchronous Buck-Boost High Current LED Driver
LTC3454EDD#PBF
功能描述:IC LED DRIVER PHOTO FLASH 10-DFN 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
LTC3454EDD#TRPBF
功能描述:IC LED DRIVER PHOTO FLASH 10-DFN 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
LTC3454EDDPBF
制造商:Linear Technology 功能描述:LED Driver 1A Buck-Boost 3.3/5V DFN10EP
LTC3455
制造商:LINER 制造商全称:Linear Technology 功能描述:High Efficiency Battery Charger/USB Power Manager
LTC3455EUF
功能描述:IC CONV DC/DC DUAL USBBATT 24QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 标准包装:1 系列:- 应用:手持/移动设备 电流 - 电源:- 电源电压:3 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-WFDFN 裸露焊盘 供应商设备封装:14-LLP-EP（4x4） 包装:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名称:LP3905SD-30DKR
LTC3455EUF#PBF
功能描述:IC CONV DC/DC DUAL USBBATT 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 标准包装:1 系列:- 应用:手持/移动设备 电流 - 电源:- 电源电压:3 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-WFDFN 裸露焊盘 供应商设备封装:14-LLP-EP（4x4） 包装:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名称:LP3905SD-30DKR