參數(shù)資料
型號: LT3782IFE
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: 4 A SWITCHING CONTROLLER, 533 kHz SWITCHING FREQ-MAX, PDSO28
封裝: 4.40 MM, PLASTIC, TSSOP-28
文件頁數(shù): 4/20頁
文件大?。?/td> 223K
代理商: LT3782IFE
LT3782
12
3782fg
The gate drive voltage is set by the 10V GBIAS regulator.
Consequently, 10V rated MOSFETs are required in most
high voltage LT3782 applications.
Pay close attention to the BVDSS specications for the
MOSFETs relative to the maximum actual switch voltage
in the application. The switch node can ring during the
turn-off of the MOSFET due to layout parasitics. Check the
switching waveforms of the MOSFET directly across the
drain and source terminals using the actual PC board layout
(not just on a lab breadboard!) for excessive ringing.
Calculating Power MOSFET Switching and Conduction
Losses and Junction Temperatures
In order to calculate the junction temperature of the power
MOSFET, the power dissipated by the device must be known.
This power dissipation is a function of the duty cycle, the
load current and the junction temperature itself (due to
the positive temperature coefcient of its RDS(ON)). As a
result, some iterative calculation is normally required to
determine a reasonably accurate value. Care should be
taken to ensure that the converter is capable of delivering
the required load current over all operating conditions (line
voltage and temperature), and for the worst-case speci-
cations for VSENSE(MAX) and the RDS(ON) of the MOSFET
listed in the manufacturer’s data sheet.
The power dissipated by the MOSFET in a 2-phase boost
converter is:
PFET =
IO(MAX)
2
1– D
(
)
2
RDS(ON) D T
+k VO
2
IO(MAX)
2
1– D
(
)
CRSS f
The rst term in the equation above represents the I2R
losses in the device, and the second term, the switching
losses. The constant, k = 1.7, is an empirical factor inversely
related to the gate drive current and has the dimension
of 1/current. The
ρT term accounts for the temperature
coefcient of the RDS(ON) of the MOSFET, which is typically
0.4%/°C. Figure 4 illustrates the variation of normalized
RDS(ON) over temperature for a typical power MOSFET.
JUNCTION TEMPERATURE (°C)
–50
ρ
TNORMALIZED
ON
RESISTANCE
1.0
1.5
150
3782 F06
0.5
0
50
100
2.0
Figure 4. Normalized RDS(ON) vs Temperature
APPLICATIONS INFORMATION
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相關代理商/技術參數(shù)
參數(shù)描述
LT3782IFE#PBF 功能描述:IC REG CTRLR BST PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LT3782IFE#TRPBF 功能描述:IC REG CTRLR BST PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LT3782IFE-PBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:2-Phase Step-UP DC/DC Controller
LT3782IFE-TR 制造商:LINER 制造商全稱:Linear Technology 功能描述:2-Phase Step-UP DC/DC Controller
LT3782IFE-TRPBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:2-Phase Step-UP DC/DC Controller