- 您现在的位置：买卖IC网 > Datasheet目录338 > LTC3452EUF#TRPBF (Linear Technology)IC LED DRIVER PHOTO FLASH 20-QFN Datasheet资料下载
参数资料
| 型号： | LTC3452EUF#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC LED DRIVER PHOTO FLASH 20-QFN |
| 标准包装： | 2,500 |
| 拓扑： | PWM，降压（降压），升压（升压） |
| 输出数： | 7 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 背光，闪灯/白光 |
| 类型 - 次要： | 白色 LED |
| 频率： | 900kHz ~ 1.1MHz |
| 电源电压： | 2.7 V ~ 5.5 V |
| 输出电压： | 4.5V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-WFQFN 裸露焊盘 |
| 供应商设备封装： | 20-QFN 裸露焊盘（4x4） |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 85°C |
LTC3452
APPLICATIO S I FOR ATIO
Optional Schottky Diodes
Schottky diodes across the synchronous switches B and
The unity-gain frequency of the error amplifier with the
Type I compensation is given by:
D are not required, but provide a lower drop during the
break-before-make time (typically 20ns) of the NMOS to
PMOS transition, improving efficiency. Use a Schottky
f UG =
g m
2 ? π ? C VC
diode such as an MBRM120T3 or equivalent. Do not use
ordinary rectifier diodes, since the slow recovery times
will compromise efficiency.
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.
Closing the Feedback Loop
The LTC3452 incorporates voltage mode PWM control.
The control to output gain varies with operation region
(Buck, Boost, Buck/Boost), but is usually no greater than
15. The output filter exhibits a double pole response
given by:
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 7
LEDs. For a very high power LED such as a LumiLED, all
7 outputs can be connected in parallel for maximum total
output current, as shown in the back page application of
f FILTER _ POLE =
1
2 ? π ? L ? C OUT
Hz
this data sheet.
Maximum LED Current
where C OUT is the output filter capacitor.
The output filter zero is given by:
As described in the Operation section, the maximum
output LED currents are equal to:
I MAXL = 256 ?
? R ISETL ?
f FILTER _ ZERO =
1
2 ? π ? R ESR ? C OUT
Hz
? 0 . 8 V ?
?
I MAXH = 768 ?
? R ISETH ?
=
f RHPZ
V IN
R MINL = 256 ?
= 8192 ?
where R ESR is the capacitor equivalent series resistance.
A troublesome feature in Boost mode is the right-half
plane zero (RHP), and is given by:
2
Hz
2 ? π ? I OUT ? L ? V OUT
The loop gain is typically rolled off before the RHP zero
frequency.
A simple Type I compensation network can be incorpo-
and
? 0 . 8 V ?
?
Since the maximum LED current for the low power bank is
25mA, this sets a minimum limit on R ISETL of:
? 0 . 8 V ?
? 25 mA ? ?
Similarly, for the high power bank:
R MINH = 768 ?
rated to stabilize the loop but at a cost of reduced band-
width and slower transient response. To ensure proper
phase margin, the loop is required to be crossed over a
? 0 . 8 V ?
? 150 mA ? ?
= 4096 ?
decade before the LC double pole.
In addition, since the maximum continuous output current
for the buck-boost is limited to 425mA, this may impose
higher resistor value minimums if all outputs are used.
3452f
12
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3453EUF#TRPBF | IC LED DRIVER PHOTO FLASH 16-QFN |
| 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 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3453 | 制造商:LINER 制造商全称:Linear Technology 功能描述:700mA Low Noise High Current LED Charge Pump |
| LTC3453EUF | 制造商:Linear Technology 功能描述:LED DRVR 4Segment 3.3V/5V 16-Pin QFN EP |
| LTC3453EUF#PBF | 功能描述:IC LED DRIVER PHOTO FLASH 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 |
| LTC3453EUF#TRPBF | 功能描述:IC LED DRIVER PHOTO FLASH 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 |
| LTC3454 | 制造商:LINER 制造商全称:Linear Technology 功能描述:1A Synchronous Buck-Boost High Current LED Driver |
发布紧急采购，3分钟左右您将得到回复。