LT3956
FEATURES
80V IN , 80V OUT
Constant-Current,
Constant-Voltage Converter
DESCRIPTION
3000:1 True Color PWM TM Dimming
High Power LED
Battery Charger
Accurate Current Limited Voltage Regulator
n
n Wide Input Voltage Range: 4.5V to 80V
n Output Voltage Up to 80V
n Internal 3.3A/84V Switch
n Constant-Current and Constant-Voltage Regulation
n 250mV High Side Current Sense
n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode,
SEPIC or Flyback Topology
n Adjustable Frequency: 100kHz to 1MHz
n Open LED Protection
n Programmable Undervoltage Lockout with Hysteresis
n Constant-Voltage Loop Status Pin
n PWM Disconnect Switch Driver
n CTRL Pin Adjusts High Side Current Sense Threshold
n Low Shutdown Current: <1μA
n Programmable Soft-Start
n  Available in the 36-Lead (5mm × 6mm) QFN Package
APPLICATIONS
n
n
n
TYPICAL APPLICATION
94% Efficient 25W White LED Headlamp Driver
The LT ? 3956 is a DC/DC converter designed to operate as
a constant-current source and constant-voltage regulator.
It is ideally suited for driving high current LEDs. It features
an internal low side N-channel power MOSFET rated for
84V at 3.3A and driven from an internal regulated 7.15V
supply. The fixed frequency, current-mode architecture
results in stable operation over a wide range of supply
and output voltages. A ground referenced voltage FB pin
serves as the input for several LED protection features,
and also makes it possible for the converter to operate
as a constant-voltage source. A frequency adjust pin
allows the user to program the frequency from 100kHz
to 1MHz to optimize efficiency, performance or external
component size.
The LT3956 senses output current at the high side of the
LED string. High side current sensing is the most flexible
scheme for driving LEDs, allowing boost, buck mode or
buck-boost mode configuration. The PWM input provides
LED dimming ratios of up to 3000:1, and the CTRL input
provides additional analog dimming capability.
L , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 7199560 and 7321203.
Efficiency vs V IN
V IN , 6V TO 60V
(80V TRANSIENT)
22μH
D1
100
2.2μF
2
332k
V IN
EN/UVLO
SW
PGND
2.2μF
5
96
100k
INTV CC
100k
332k
40.2k
V REF
CTRL
VMODE
PWM
SS
LT3956
ISP
ISN
FB
0.68
1M
16.2k
370mA
25W LED STRING
92
88
84
47nF
28.7k
375kHz
RT
V C
34k
4.7nF
PWMOUT
GND INTV CC
INTV CC
4.7μF
M1
80
0
20
40
V IN (V)
60
80
3956 TA01b
3956 TA01a
3956f
 
相关PDF资料
LTC3201EMS#TRPBF IC LED DRVR WHITE BCKLGT 10-MSOP
LTC3202EDD#PBF IC LED DRIVR WHITE BCKLGT 10-DFN
LTC3205EUF#TRPBF IC LED DRVR WT/RGB BCKLGT 24-QFN
LTC3206EUF#TRPBF IC LED DRVR WT/RGB BCKLGT 24-QFN
LTC3207EUF-1#TRPBF IC LED DRIVR QVGA DISPLAY 24-QFN
LTC3208EUH#TRPBF IC LED DRIVR QVGA DISPLAY 32-QFN
LTC3209EUF-2#TRPBF IC LED DRIVR QVGA DISPLAY 20-QFN
LTC3210EPD-1#TRPBF IC LED DRVR WHITE BCKLT 16-UTQFN
相关代理商/技术参数
LT3956EUHE#PBF 制造商:Linear Technology 功能描述:IC LED DRIVER BUCK-BOOST/FLYBACK QFN36
LT3956EUHE#TRPBF 功能描述:IC LED DVR BUCK BOOST 36-VQFN 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
LT3956EUHEPBF 制造商:Linear Technology 功能描述:80V Constant-Current/Voltage Conv. QFN36
LT3956EUHE-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:80VIN, 80VOUT Constant-Current, Constant-Voltage Converter
LT3956EUHE-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:80VIN, 80VOUT Constant-Current, Constant-Voltage Converter
LT3956IUHE#PBF 功能描述:IC LED DVR BUCK BOOST 36-VQFN 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
LT3956IUHE#TRPBF 功能描述:IC LED DVR BUCK BOOST 36-VQFN 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
LT3956IUHE-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:80VIN, 80VOUT Constant-Current, Constant-Voltage Converter