- 您现在的位置：买卖IC网 > Sheet目录337 > LT3596EUHG#PBF (Linear Technology)IC LED DVR 300MA ADJ 52-VQFN
LT3596
APPLICATIONS INFORMATION
losses. Some applications require very low duty cycles to
drive a small number of LEDs from a high supply. Low
switching frequency allows a greater range of operational
duty cycle and so a lower number of LEDs can be driven.
In each case, the switching frequency can be tailored to
provide the optimum solution. When programming the
switching frequency, the total power losses within the IC
should be considered.
Table 8. R T Resistor Selection
R T VALUE (kΩ) SWITCHING FREQUENCY (MHz)
33.2 1.0
80.6 0.5
220 0.2
The SYNC pin must be grounded if the clock synchroniza-
tion feature is not used. When the SYNC pin is grounded,
the internal oscillator controls the switching frequency of
the converter.
Operating Frequency Trade-Offs
Selection of the operating frequency is a trade-off between
efficiency, component size, input voltage and maximum
output voltage. The advantage of high frequency operation
is smaller component size and value. The disadvantages
are lower efficiency and lower maximum output voltage
for a fixed input voltage. The highest acceptable switch-
ing frequency (f SW(MAX) ) for a given application can be
calculated as follows:
f SW ( MAX ) =
1.2
1.0
0.8
0.6
0.4
0.2
0
0
55
110
165
220
V D + V OUT
t ON ( MIN ) ( V D + V IN – V SW )
where V IN is the typical input voltage, V OUT is the output
voltage, V D is the catch diode drop (~0.5V) and V SW is the
internal switch drop (~0.4V at max load). This equation
shows that slower switching is necessary to accommodate
high V IN /V OUT ratios. The input voltage range depends on
the switching frequency due to the finite minimum switch
on and off times. The switch minimum on and off times
are 150ns.
R T (k )
3596 F10
Adaptive Loop Control
R1
Figure 10. Programming Switching Frequency
Switching Frequency Synchronization
The nominal operating frequency of the LT3596 is pro-
grammed using a resistor from the RT pin to ground. The
frequency range is 200kHz to 1MHz. In addition, the internal
oscillator can be synchronized to an external clock applied
to the SYNC pin. The synchronizing clock signal input to
the LT3596 must have a frequency between 240kHz and
1MHz, a duty cycle between 20% and 80%, a low state
below 0.4V and a high state above 1.6V. Synchronization
signals outside of these parameters cause erratic switching
behavior. For proper operation, an R T resistor is chosen
to program a switching frequency 20% slower than the
SYNC pulse frequency. Synchronization occurs at a fixed
delay after the rising edge of SYNC.
The LT3596 uses an adaptive control mechanism to set
the buck output voltage. This control scheme ensures
maximum efficiency while not compromising minimum
PWM pulse widths. When any PWM n is low, the output
of the buck rises to a maximum value set by an external
resistor divider to the FB pin. When all PWM n pins go
high, the output voltage is adaptively reduced until the
voltage across the LED current sink is about 1V. Figure
11 shows how the maximum output voltage is set by an
external resistor divider.
V OUT V OUT
R2 LT3596
FB
3596 F11
Figure 11. Programming Maximum V OUT
3596fa
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LT3597EUHG#PBF
IC LED DRIVER TRPL STP DWN 52QFN
LT3598IUF#PBF
IC LED DRIVR WHITE BCKLGT 24-QFN
LT3599IFE#PBF
IC LED DRVR WHITE BCKLGT 28TSSOP
LT3743EFE#PBF
IC LED DVR HP CONST CURR 28TSSOP
LT3745IUJ#TRPBF
IC LED DVR 16CH 50MA 40QFN
LT3746IUHH#TRPBF
IC LED DRIVER 32CHANNEL 56-QFN
LT3754IUH#TRPBF
IC LED DVR 16CH 50MA 32QFN
LT3755EMSE#PBF
IC LED DRVR HP CONS CURR 16-MSOP
相关代理商/技术参数
LT3596EUHG#TRPBF
功能描述:IC LED DVR 300MA ADJ 52-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
LT3596EUHG-PBF
制造商:LINER 制造商全称:Linear Technology 功能描述:60V Step-Down LED Driver
LT3596IUHG#PBF
功能描述:IC LED DVR 300MA ADJ 52-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
LT3596IUHG#TRPBF
功能描述:IC LED DVR 300MA ADJ 52-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
LT3597
制造商:LINER 制造商全称:Linear Technology 功能描述:60V Triple Step-Down LED Driver Programmable Temperature Protection
LT3597EUHG#PBF
功能描述:IC LED DRIVER TRPL STP DWN 52QFN 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
LT3597EUHG#TRPBF
功能描述:IC LED DRIVER 60V TRIPLE 52-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
LT3597IUHG#PBF
功能描述:IC LED DRIVER 60V TRIPLE 52-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