- 您現在的位置：買賣IC網 > PDF目錄30768 > LT3782AEFE (LINEAR TECHNOLOGY CORP) SWITCHING CONTROLLER, PDSO28 PDF資料下載
LT3782A
14
3782af
For a given VIN and VOUT, we can calculate the duty cycle D
and then derive the output RMS ripple current from Figure
6. After choosing output capacitors with sufcient RMS
ripple current rating, we also need to consider the ESR
requirement if electrolytic caps, tantulum caps, POSCAPs
or SP CAPs are selected. Given the required output ripple
voltage spec ΔVOUT (in RMS value) and the calculated RMS
ripple current ΔIOUT, one can estimate the ESR value of
the output capacitor to be
ESR ≤
ΔVOUT
ΔIOUT
External Regulator to Bias Gate Drivers
For applications with VINhigherthan24V,theICtemperature
may get too high. To reduce heat, an external regulator
between 12V to 14V should be used to override the internal
VGBIAS regulator to supply the current needed for BGATE1
and BGATE2 (see Figure 7).
Efciency Considerations
The efciency of a switching regulator is equal to the out-
put power divided by the input power (100%). Percent
efciency can be expressed as:
% Efciency = 100% – (L1 + L2 + L3 + …),
where L1, L2, etc. are the individual loss components
as a percentage of the input power. It is often useful to
analyze individual losses to determine what is limiting
the efciency and which change would produce the most
improvement. Although all dissipative elements in the
circuit produce losses, four main sources usually account
for the majority of the losses in LT3782A application
circuits:
1. The supply current into VIN. The VIN current is the sum
of the DC supply current IQ (given in the Electrical Char-
acteristics) and the MOSFET driver and control currents.
The DC supply current into the VIN pin is typically about
7mA and represents a small power loss (much less
than 1%) that increases with VIN. The driver current
results from switching the gate capacitance of the power
MOSFET; this current is typically much larger than the
DC current. Each time the MOSFET is switched on and
then off, a packet of gate charge QG is transferred from
GBIAS to ground. The resulting dQ/dt is a current that
must be supplied to the GBIAS capacitor through the
VIN pin by an external supply. In normal operation:
IQ(TOT) ≈ IQ = f QG
PIC = VIN (IQ + f QG)
2. Power MOSFET switching and conduction losses:
PFET =
IO(MAX)
2
1– DMAX
2
RDS(ON) DMAX T
+ k VO
2
IO(MAX)
2
1– DMAX
CRSS f
Figure 7
3782A F07
2μF
12V
+
GBIAS
GBIAS1
GBIAS2
LT3782A
APPLICATIONS INFORMATION
相關PDF資料 |
PDF描述 |
|---|---|
| LT3782AEUFD | SWITCHING CONTROLLER, PQCC28 |
| LT4356CMS-1#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10 |
| LT4356CDE-2#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO12 |
| LT4356IDE-1#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO12 |
| LT4356HDE-2#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO12 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| LT3782AEFE#PBF | 功能描述:IC REG CTRLR BST PWM CM 28-TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 特色產品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標準包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數:1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 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:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR |
| LT3782AEFE#PBF | 制造商:Linear Technology 功能描述:Switch Regulator IC |
| LT3782AEFE#TRPBF | 功能描述:IC REG CTRLR BST PWM CM 28-TSSOP 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: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 |
| LT3782AEFE-PBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:2-Phase Step-Up DC/DC Controller |
| LT3782AEFE-TR | 制造商:LINER 制造商全稱:Linear Technology 功能描述:2-Phase Step-Up DC/DC Controller |
發(fā)布緊急采購，3分鐘左右您將得到回復。