- 您现在的位置：买卖IC网 > Datasheet目录307 > A8515GLPTR-T (Allegro Microsystems Inc)IC LED DVR WHT/RGB BKLGT 16TSSOP Datasheet资料下载
参数资料
| 型号： | A8515GLPTR-T |
| 厂商： | Allegro Microsystems Inc |
| 文件页数： | 29/34页 |
| 文件大小： | 0K |
| 描述： | IC LED DVR WHT/RGB BKLGT 16TSSOP |
| 标准包装： | 8,000 |
| 拓扑： | PWM，升压（升压） |
| 输出数： | 2 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 背光 |
| 类型 - 次要： | 白色 LED |
| 频率： | 600kHz ~ 2.5MHz |
| 电源电压： | 5 V ~ 40 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 供应商设备封装： | 16-TSSOP-EP |
| 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页第22页第23页第24页第25页第26页第27页第28页当前第29页第30页第31页第32页第33页第34页
A8515
Design Example for SEPIC Configuration
Wide Input Voltage Range, High Efficiency
Fault Tolerant LED Driver
of the A8515 is 720 mV. A constant term, 2 V, is added to give
This section provides a method for selecting component values
margin to the design due to noise and output voltage ripple.
when designing an application using the A8515 in SEPIC (Sin-
gle-Ended Primary-Inductor Converter) circuit. SEPIC topology
has the advantage that it can generate a positive output voltage
V OUT(OVP) = # SERIESLEDS × V f + V LED + 2 (V)
= 4 × 3.3 (V) + 0.72 (V) + 2 (V) = 15.9 V
(31)
either higher or lower than the input voltage. The resulting design
is diagrammed in figure 33.
Assumptions: For the purposes of this example, the following are
given as the application requirements:
? V BAT : 6 to 14 V ( V IN (min): 5 V and V IN (max): 16 V )
? Quantity of LED channels, # CHANNELS : 2
? Quantity of series LEDs per channel, # SERIESLEDS : 4
? LED current per channel, I LED : 120 mA
? LED V f at 120 mA: ≈ 3.3 V
? f SW : 2 MHz
? T A (max): 65°C
? PWM dimming frequency: 200 Hz, 1% duty cycle
Procedure: The procedure consists of selecting the appropriate
configuration and then the individual component values, in an
ordered sequence.
Step 1 Connect LEDs to pins LED1 and LED2. If only one of
Then the OVP resistor is:
R OVP = ( V OUT(OVP) – V OVP(th) ) / I OVPH (32)
= (15.9 (V) – 8.1 (V)) / 0.199 (mA) = 39.196 k Ω
where both I OVPH and V OVP(th) are taken from the Electrical
Characteristics table.
In this case a value of 39.2 k Ω was selected. Below is the actual
value of the minimum OVP trip level with the selected resistor:
V OUT(OVP) = 39.2 (k Ω ) × 0.199 (mA) + 8.1 (V) = 15.9 V
Step 3b At this point a quick check must be done to determine if
the conversion ratio is acceptable for the selected frequency.
D max = 1 – t SWOFFTIME × f SW (33)
= 1 – 1.5 × 47 (ns) × 2 (MHz) = 85.9%
where the minimum off-time (t SWOFFTIME ) is found in the Electri-
cal Characteristics table.
The Theoretical Maximum V OUT is then calculated as:
– 0.4 (V) = 30.3 V
the LED channels is needed, the unused LEDx pin should be
pulled to ground using a 1.5 k Ω resistor.
Step 2 Determining the LED current setting resistor R ISET :
R ISET = ( V ISET × A ISET ) / I LED
(30)
V OUT (max) = V IN (min)
= 5 (V)
D max
1 – D max
0.86
1 – 0.86
– V d
(34)
= (1.003 (V) × 980) / 0.120 (A) = 8.19 k Ω
Choose an 8.25 k Ω 1% resistor (or 16.2 k Ω if LED current is
60 mA/channel).
Step 3 Determining the OVP resistor. The OVP resistor is
connected between the OVP pin and the output voltage of the
converter.
Step 3a The first step is determining the maximum voltage
based on the LED requirements. The regulation voltage, V LED ,
where V d is the diode forward voltage.
The Theoretical Maximum V OUT value must be greater than
the value V OUT(OVP) . If this is not the case, it may be necessary
to reduce the frequency to allow the boost to convert the volt-
age ratios.
Step 4 Selecting the inductor. The inductor must be chosen such
that it can handle the necessary input current. In most applica-
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
29
相关PDF资料 |
PDF描述 |
|---|---|
| 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 |
| AC163020 | ADAPTER PROGRAMMER PIC10F2XX |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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. |
| A8516ELPTR-T | 功能描述:IC LED DVR BACKLIGHT MON 24TSSOP 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 |
| A8517KLPTR-T | 功能描述:LED 驱动器 IC 10 输出 DC DC 稳压器 升压（升压） PWM 调光 60mA 28-TSSOP-EP 制造商:allegro microsystems, llc 系列:汽车级，AEC-Q100 包装:剪切带（CT） 零件状态:停产 类型:DC DC 稳压器 拓扑:升压（升压） 内部开关:是 输出数:10 电压 - 供电（最低）:4.5V 电压 -?供电（最高）:36V 电压 - 输出:- 电流 - 输出/通道:60mA 频率:400kHz ~ 2.3MHz 调光:PWM 应用:汽车级 工作温度:-40°C ~ 125°C（TA） 安装类型:表面贴装 封装/外壳:28-SOIC（0.173"，4.40mm 宽）裸露焊盘 供应商器件封装:28-TSSOP-EP 标准包装:1 |
发布紧急采购，3分钟左右您将得到回复。