参数资料
型号: A8514KLPTR-T
厂商: Allegro Microsystems Inc
文件页数: 31/42页
文件大小: 0K
描述: IC LED DVR WHT 4X80MA 16-ETSSOP
标准包装: 8,000
拓扑: PWM,SEPIC,升压(升压)
输出数: 4
内部驱动器:
类型 - 主要: 车载,背光
类型 - 次要: 白色 LED
频率: 580kHz ~ 2MHz
电源电压: 5 V ~ 40 V
安装类型: 表面贴装
封装/外壳: 20-TSSOP(0.173",4.40mm 宽)裸露焊盘
供应商设备封装: 20-TSSOP-EP
包装: 带卷 (TR)
工作温度: -40°C ~ 125°C
A8514
Wide Input Voltage Range, High Efficiency
Fault Tolerant LED Driver
tions, due to stringent EMI requirements, the system must operate
then:
V OUT(OVP) + V d
V IN (min)
in continuous conduction mode throughout the whole input volt-
age range.
Step 4a Determining the duty cycle, calculated as follows:
D (max) = (38)
V IN (min) + V OUT(OVP) + V d
L =
=
Δ I L f SW
D (max)
5 (V)
0.254 (A) 2 (MHz)
0.765 = 7.53 μ H
(43)
=
15.9 (V) + 0.4 (V)
5 (V) + 15.9 (V) + 0.4 (V)
= 76.5%
Step 4d Double-check to make sure the ? current ripple is less
than I IN (min):
Step 4b Determining the maximum and minimum input current
to the system. The minimum input current will dictate the induc-
tor value. The maximum current rating will dictate the current
rating of the inductor. First, the maximum input current, given:
I IN (min) > 1 / 2 Δ I L
0.265 A > 0.127 A
A good inductor value to use would be 10 μ H.
(44)
I OUT = # CHANNELS
I LED
(39)
Step 4e Next insert the inductor value used in the design to deter-
then:
= 4
0.060 (A) = 0.240 A
mine the actual inductor ripple current:
I IN (max) =
=
V OUT(OVP) I OUT
V IN (min)
15.9 (V)  0.24 (A)
5 (V) 0.90
= 0.848 A
(40)
Δ I Lused =
=
V IN (min) D (max)
L used f SW
5 (V) 0.765
10 ( μ H) 2.0 (MHz)
= 0.191 A
(45)
V IN (max)
where η is efficiency.
Next, calculate minimum input current, as follows:
V OUT(OVP) I OUT
I IN (min) =
(41)
Step 4f Determining the inductor current rating. The inductor
current rating must be greater than the I IN (max) value plus half of
the ripple current Δ I L , calculated as follows:
L (min) = I IN (max) + 1 / 2 Δ I Lused (46)
=
15.9 (V)
16 (V)
0.24 (A)
0.90
= 0.265 A
= 0.848 (A) + 0.096 (A) = 0.944 A
Step 5 Determining the resistor value for a particular switching
Step 4c Determining the inductor value. To ensure that the induc-
tor operates in continuous conduction mode, the value of the
inductor must be set such that the ? inductor ripple current is not
greater than the average minimum input current. As a first pass
assume I ripple to be 30% of the maximum inductor current:
frequency. Use the R FSET values shown in figure 7. For example,
a 10 k Ω resistor will result in a 2 MHz switching frequency.
Step 6 Choosing the proper switching diode. The switching diode
must be chosen for three characteristics when it is used in LED
Δ I L = I IN (max) × I ripple
= 0.848 × 0.30 = 0.254 A
(42)
lighting circuitry. The most obvious two are: current rating of the
diode and reverse voltage rating.
31
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
相关PDF资料
PDF描述
A8515GLPTR-T IC LED DVR WHT/RGB BKLGT 16TSSOP
A8516ELPTR-T IC LED DVR BACKLIGHT MON 24TSSOP
A8740EEETR-T IC PHOTOFLASH CAP CHARGER 8DFN
AC162049-2 MOD PROGR UNIV MPLAB ICD2 ICD3
AC162049 MODULE SOCKET FOR ICD2 DIP
相关代理商/技术参数
参数描述
A8515 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:The A8515 is a multi-output white LED (WLED) driver for LCD backlighting in consumer and industrial displays.
A8515GLPTR-T 功能描述:IC LED DVR WHT/RGB BKLGT 16TSSOP 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
A8516 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:The A8516 is a multi-output WLED/RGB driver for backlighting LCD monitors and televisions.
A85169-000 制造商:TE Connectivity 功能描述:MPCB-20.0-0-E563 - Cable Rools/Shrink Tubing
A8516ELBTR-T 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:The A8516 is a multi-output WLED/RGB driver for backlighting LCD monitors and televisions.