- 您现在的位置：买卖IC网 > PDF目录79713 > LT3511HMS#TRPBF (LINEAR TECHNOLOGY CORP) 0.43 A SWITCHING REGULATOR, 650 kHz SWITCHING FREQ-MAX, PDSO12 PDF资料下载
参数资料
| 型号： | LT3511HMS#TRPBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 0.43 A SWITCHING REGULATOR, 650 kHz SWITCHING FREQ-MAX, PDSO12 |
| 封装： | LEAD FREE, PLASTIC, MSOP-12/16 |
| 文件页数： | 8/26页 |
| 文件大小： | 298K |
| 代理商： | LT3511HMS#TRPBF |
LT3511
16
3511fb
DESIGN PROCEDURE/DESIGN EXAMPLE
Use the following design procedure as a guide to design-
ing applications for the LT3511. Remember, the unique
sampling architecture requires an iterative process for
choosing correct resistor values.
The design example involves designing a 15V output with
a 100mA load current and an input range from 36V to 72V.
VIN(MIN) = 36V, VIN(NOM) = 48V, VIN(MAX) = 72V, VOUT =
15V and IOUT = 100mA
Step 1: Select the transformer turns ratio.
NPS <
VSW(MAX) – VIN(MAX) – VLEAKAGE
VOUT + VF
VSW(MAX) = Max rating of internal switch = 150V
VLEAKAGE = Margin for transformer leakage spike = 40V
VF = Forward voltage of output diode = assume approxi-
mately ~ 0.5V
Example:
NPS <
150V – 72V – 40V
15V + 0.5V
NPS < 2.45
NPS = 2
The choice of turns ratio is critical in determining output
power as shown earlier in the Output Power section. At
this point, a third winding can be added to the transformer
to drive the BIAS pin of the LT3511 for higher efficiencies.
Choose a turns ratio that sets the third winding voltage
to regulate between 3.3V and 6V for maximum efficiency.
Choose a third winding ratio to drive BIAS winding with
5V. (Optional)
Example:
NTHIRD
NS
= VTHIRD
VOUT
= 5V
15V
= 0.33
The turns ratio of the transformer chosen is as follows
NPRIMARY: NSECONDARY: NTHIRD = 2:1:0.33.
Step 2: Calculate maximum power output at minimum
VIN.
POUT(VIN(MIN)) = η VIN(MIN) IIN = η VIN(MIN) D
IPEAK 0.5
D =
VOUT + VF
(
) NPS
VOUT + VF
(
) NPS + VIN(MIN)
η = Efficiency = ~75%
IPEAK = Peak switch current = 0.26A
Example:
D = 0.46
POUT(VIN(MIN)) = 1.62
IOUT(VIN(MIN)) = POUT(VIN(MIN))/VOUT = 0.11A
The chosen turns ratio satisfies the output current re-
quirement of 100mA. If the output current was too low,
the minimum input voltage could be adjusted higher. The
turns ratio in this example is set to its highest ratio given
switch voltage requirements and margin for leakage in-
ductance voltage spike.
Step 3: Determine primary inductance, switching fre-
quency and saturation current.
Primary inductance for the transformer must be set above
a minimum value to satisfy the minimum off and on time
requirements.
LPRI ≥
tOFF(MIN) NPS VOUT + VF
(
)
IPEAK(MIN)
tOFF(MIN) = 400ns
IPEAK(MIN) = 55mA
LPRI ≥
tON(MIN) VIN(MAX)
IPEAK(MIN)
tON(MIN) = 100ns
IPEAK(MIN) = 55mA
applicaTions inForMaTion
相关PDF资料 |
PDF描述 |
|---|---|
| LT3468ES5-1#PBF | SPECIALTY ANALOG CIRCUIT, PDSO5 |
| LTC2942IDCB#TRMPBF | POWER SUPPLY SUPPORT CKT, PDSO6 |
| LK4003-9RD8TB1 | 1-OUTPUT AC-DC PWR FACTOR CORR MODULE |
| LK4501-7EPD1TB1 | 1-OUTPUT 150 W AC-DC PWR FACTOR CORR MODULE |
| LS1501-9EPD5TB1 | 1-OUTPUT 100 W AC-DC REG PWR SUPPLY MODULE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3511IMS#PBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LT3511IMS#TRPBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LT3511MPMS#PBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LT3511MPMS#TRPBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LT3512 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic High Voltage Isolated Flyback Converter |
发布紧急采购，3分钟左右您将得到回复。