参数资料
型号: LT3517EUF#TRPBF
厂商: Linear Technology
文件页数: 10/20页
文件大小: 0K
描述: IC LED DRIVER AUTOMOTIVE 16-QFN
标准包装: 2,500
系列: True Color PWM™
恒定电流:
恒定电压:
拓扑: PWM,降压(降压),升压(升压)
输出数: 1
内部驱动器:
类型 - 主要: 车载,背光
类型 - 次要: 白色 LED
频率: 250kHz ~ 2.5MHz
电源电压: 3 V ~ 30 V
输出电压: 7V
安装类型: 表面贴装
封装/外壳: 16-WQFN 裸露焊盘
供应商设备封装: 16-QFN(4x4)
包装: 带卷 (TR)
工作温度: -40°C ~ 125°C
LT3517
APPLICATIONS INFORMATION
Table 1 provides some recommended inductor vendors.
Table 1. Inductor Manufacturers
VENDOR PHONE WEB
Sumida (408) 321-9660 www.sumida.com
Toko (408) 432-8281 www.toko.com
Cooper (561) 998-4100 www.cooperet.com
Vishay (402) 563-6866 www.vishay.com
Input Capacitor Selection
For proper operation, it is necessary to place a bypass
capacitor to GND close to the V IN pin of the LT3517. A
1μF or greater capacitor with low ESR should be used. A
ceramic capacitor is usually the best choice.
In the buck mode configuration, the capacitor at the input
to the power converter has large pulsed currents due to
the current returned though the Schottky diode when the
switch is off. For best reliability, this capacitor should have
low ESR and ESL and have an adequate ripple current
rating. The RMS input current is:
I IN(RMS) = I LED ? (1 – D) ? D (8)
where D is the switch duty cycle. A 2.2μF ceramic type
capacitor is usually sufficient.
Output Capacitor Selection
The selection of output capacitor depends on the load
and converter configuration, i.e., step-up or step-down.
For LED applications, the equivalent resistance of the LED
is typically low, and the output filter capacitor should be
sized to attenuate the current ripple.
To achieve the same LED ripple current, the required filter
capacitor value is larger in the boost and buck-boost mode
applications than that in the buck mode applications. For
LED buck mode applications, a 1μF ceramic capacitor
is usually sufficient. For the LED boost and buck-boost
mode applications, a 2.2μF ceramic capacitor is usually
sufficient. Very high performance PWM dimming appli-
cations may require a larger capacitor value to support
the LED voltage during PWM transitions.
Use only ceramic capacitors with X7R, X5R or better dielec-
tric as they are best for temperature and DC bias stability
of the capacitor value. All ceramic capacitors exhibit loss
of capacitance value with increasing DC voltage bias, so it
may be necessary to choose a higher value capacitor to get
the required capacitance at the operation voltage. Always
check that the voltage rating of the capacitor is sufficient.
Table 2 shows some recommended capacitor vendors.
Table 2. Ceramic Capacitor Manufacturers
VENDOR PHONE WEB
Taiyo Yuden (408) 573-4150 www.t-yuden.com
AVX (843) 448-9411 www.avxcorp.com
Murata (770) 436-1300 www.murata.com
TDK (847) 803-6100 www.tdk.com
Loop Compensation
The LT3517 uses an internal transconductance error ampli-
fier whose VC output compensates the control loop. The
external inductor, output capacitor, and the compensa-
tion resistor and capacitor determine the loop stability.
The inductor and output capacitor are chosen based on
performance, size and cost. The compensation resistor
and capacitor at VC are selected to optimize control loop
stability. For typical LED applications, a 10nF compensation
capacitor at VC is adequate and a series resistor is not
required. A compensation resistor may be used to increase
the slew rate on the VC pin to maintain tighter regulation
of LED current during fast transients on V IN or CTRL.
Diode Selection
The Schottky diode conducts current during the interval
when the switch is turned off. Select a diode rated for
the maximum SW voltage. If using the PWM feature for
dimming, it is important to consider diode leakage, which
increases with the temperature, from the output during the
PWM low interval. Therefore, choose the Schottky diode
with sufficiently low leakage current. Table 3 has some
recommended component vendors.
3517fg
10
For more information www.linear.com/LT3517
相关PDF资料
PDF描述
P51-2000-S-G-MD-4.5V-000-000 SENSOR 2000PSI 1/8-27NPT .5-4.5V
P51-1500-S-Z-D-4.5V-000-000 SENSOR 1500PSI 1/4-18NPT .5-4.5V
REC3-4815SRW/H6/A/SMD/CTRL-R CONV DC/DC 3W 36-72VIN 15VOUT
REC5-2415DRWZ/H2/A/SMD/CTRL CONV DC/DC 5W 9-36VIN +/-15VOUT
P51-1500-A-I-M12-4.5OVP-000-000 SENSOR 1500PSI 7/16-20UNF 4.5V
相关代理商/技术参数
参数描述
LT3517HFE#PBF 功能描述:IC LED DRIVR AUTOMOTIVE 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:True Color PWM™ 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
LT3517HFE#TRPBF 功能描述:IC LED DRIVR AUTOMOTIVE 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:True Color PWM™ 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
LT3517HFE-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Full-Featured LED Driver with 1.5A Switch Current
LT3517HFE-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Full-Featured LED Driver with 1.5A Switch Current
LT3517HUF#PBF 功能描述:IC LED DRIVER AUTOMOTIVE 16-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:True Color PWM™ 标准包装:60 系列:- 恒定电流:- 恒定电压:- 拓扑:线性(LDO),PWM,升压(升压) 输出数:8 内部驱动器:是 类型 - 主要:背光 类型 - 次要:RGB,白色 LED 频率:500kHz ~ 1.5MHz 电源电压:4.75 V ~ 26 V 输出电压:45V 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:* 工作温度:-40°C ~ 85°C