- 您现在的位置：买卖IC网 > Datasheet目录307 > A8509GLPTR-T (Allegro Microsystems Inc)IC LED DVR WHITE 4X120MA 24TSSOP Datasheet资料下载
参数资料
| 型号： | A8509GLPTR-T |
| 厂商： | Allegro Microsystems Inc |
| 文件页数： | 22/28页 |
| 文件大小： | 0K |
| 描述： | IC LED DVR WHITE 4X120MA 24TSSOP |
| 标准包装： | 8,000 |
| 拓扑： | PWM，SEPIC，升压（升压） |
| 输出数： | 4 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 背光 |
| 类型 - 次要： | 白色 LED |
| 频率： | 300kHz ~ 800kHz |
| 电源电压： | 9 V ~ 40 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 供应商设备封装： | 24-TSSOP 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 105°C |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页当前第22页第23页第24页第25页第26页第27页第28页
A8509
Wide Input Voltage Range, High Efficiency
4-Channel Fault Tolerant LED Driver
I IN (min) =
=
I L (min)
=
The minimum input current can be calculated as:
V OUT × I OUT
V IN (max) × η
34.65 V × 0.960 A
16 V × 0.90
= 2.31 A
(15)
V SENSE P
R SENSE =
0.086 V
4.28 A
= 0.02 Ω
(19)
STEP 4c: Determining the inductor value. To assure that the
inductor operates in continuous conduction mode, the value of
inductor must be set such that 1 / 2 of the inductor ripple current is
not greater than the average minimum input current.
0.018 Ω is a good value to use for the resistor.
STEP 4f: This step is used to verify that there is sufficient slope
compensation for the inductor chosen. The internal slope com-
pensation value is determined by the following formula:
As a first pass, take I ripple to be 30% of the maximum inductor
current:
? I L = I IN (max) × ( I ripple / I IN (max)) (16)
= 3.72 A × 0.30
Slope Compensation = 2.81×10 –7 × f SW
where f SW is in Hz. Substituting:
= 0.168 V / μ s
With R SENSE = 0.02 Ω this translates to:
(20)
I IN (min) > 1 × ? I L
V IN (min)
L used × f SW
= 1.1 A
Check to make sure that 1 / 2 of the inductor ripple current is less
than I IN (min):
2
2.31 A > 0.56 A
0.168 / 0.02 = 8.4 A/ μ s
Next invert equation 17 and insert the inductor value used in the
design:
? I Lused = × D (max)
(21)
where f SW is in MHz. Substituting:
V IN (min) (17)
× 0.745
=
× 0.745
=
? I Lused × 1 × 10 –6
Inductor Current Slope =
× (1 – D (max))
=
× (1 – 0.745)
The inductor value can be calculated as:
L = × D (max)
? I L × f SW
10 V
1.1 A × 600 kHz
= 10.62 μ H
A good inductor value to use would be L used = 10 μ H.
STEP 4d: Determining the inductor current rating. The inductor
10 V
10 μ H × 600 kHz
= 1.24 A
1
f SW
1.24 A × 1 × 10 –6
1
600 kHz
(22)
(18)
× ? I Lused
I L (min) = I IN (max) +
current rating must be greater than the I IN (max) value plus the
ripple current Δ I L , calculated as:
1
2
= 3.72 A + 0.56 A
= 4.28 A
STEP 4e: Choosing the RSENSE resistor. The sense resistor
value can be calculated as follows:
= 2.91 A / μ s
Note: that the 1×10 –6 is a constant multiplier. This slope should
be smaller than the internal slope compensation.
STEP 5: To determine the resistor values for a switching fre-
quency use figure 9.
STEP 6: Choosing the proper switching diode. The switching
diode must be chosen for three characteristics when it is used in
LED lighting circuitry: reverse voltage rating, current rating, and
reverse current characteristic of the diode.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
22
相关PDF资料 |
PDF描述 |
|---|---|
| A8510GECTR-T | IC LED DRVR BCKLGHT/WHT 26QFN-EC |
| A8511KLPTR-T | IC LED DVR 150MA AUTO 28-TSSOP |
| A8512ELBTR-T | IC LED DVR WHT/RGB BKLGT 24SOIC |
| A8513KLPTR-T | IC LED DRVR AUTO BCKLGHT 16TSSOP |
| A8514KLPTR-T | IC LED DVR WHT 4X80MA 16-ETSSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| A8510 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:Wide Input Voltage Range, High Efficiency |
| A8510GECTR-T | 功能描述:IC LED DRVR BCKLGHT/WHT 26QFN-EC RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 特色产品:LM3445 TRIAC Dimmable LED Driver 标准包装:55 系列:PowerWise® 恒定电流:是 恒定电压:- 拓扑:PWM，降压（降压） 输出数:1 内部驱动器:无 类型 - 主要:- 类型 - 次要:高亮度 LED（HBLED） 频率:30kHz ~ 1MHz 电源电压:8 V ~ 12 V 输出电压:- 安装类型:表面贴装 封装/外壳:14-SOIC（0.154"，3.90mm 宽） 供应商设备封装:14-SOICN 包装:管件 工作温度:-40°C ~ 125°C 产品目录页面:1285 (CN2011-ZH PDF) 其它名称:LM3445M |
| A8511 | 制造商:ROCKWE 功能描述: |
| A8511KLPTR-T | 功能描述:IC LED DVR 150MA AUTO 28-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 特色产品:LM3445 TRIAC Dimmable LED Driver 标准包装:55 系列:PowerWise® 恒定电流:是 恒定电压:- 拓扑:PWM，降压（降压） 输出数:1 内部驱动器:无 类型 - 主要:- 类型 - 次要:高亮度 LED（HBLED） 频率:30kHz ~ 1MHz 电源电压:8 V ~ 12 V 输出电压:- 安装类型:表面贴装 封装/外壳:14-SOIC（0.154"，3.90mm 宽） 供应商设备封装:14-SOICN 包装:管件 工作温度:-40°C ~ 125°C 产品目录页面:1285 (CN2011-ZH PDF) 其它名称:LM3445M |
| A8512 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:LED Backlight Driver for Medium/Large Displays |
发布紧急采购，3分钟左右您将得到回复。