- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44986 > LT3740EDHC (LINEAR TECHNOLOGY CORP) 0.14 A SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | LT3740EDHC |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 0.14 A SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封裝： | 5 X 3 MM, PLASTIC, MO-229WJED-1, DFN-16 |
| 文件頁數(shù)： | 20/20頁 |
| 文件大?。?/td> | 234K |
| 代理商： | LT3740EDHC |
LT3740
9
3740fc
APPLICATIONS INFORMATION
Figure 1. MOSFET RDS(ON) vs. Temperature
The
ρT term is a normalization factor (unity at 25°C)
accounting for the signicant variation in on-resistance
with temperature, typically about 0.4%/°C as shown in
Figure 1. For a maximum junction temperature of 100°C,
using a value
ρT = 1.3 is reasonable.
Gate Drives
The top gate drive power is provided by BIAS which is about
7.8V higher than VIN. The top gate voltage can be as high
as 7.8V and can droop to about 5.5V if the on-time is long
enough. The bottom gate drive power is provided by the
BGDP pin. BGDP needs to be connected to 7V or higher
to get enough gate drive voltage for logic-level threshold
MOSFETs. BGDP can be connected to VIN, BIAS or an
external voltage supply. For input voltages lower than
7V, BGDP should be connected to BIAS to be able to use
logic-level threshold MOSFETs. For VIN higher than 7V,
BGDP can be connected to VIN to reduce power loss in the
bottom gate drive. For high BGDP voltages, the internal
clamp circuit limits the bottom gate drive voltage to about
8V to prevent the gate from overvoltage damage.
For the case BGDP is connected to VIN, if VIN voltage ramp
up slowly during startup, there will be a considerable period
of time that BGDP is below 7V and the circuit is operating.
The insufcient voltage on BGDP could cause malfunction
TJ – JUNCTION TEMPERATURE (°C)
–50
0
R
DS(ON)
–
ON
RESIST
ANCE
(NORMALIZED)
0.4
1.2
0.8
1.6
2.0
–25
0
50
25
75
3740 F01
100 125 150
VGS = 10V
ID = 14A
of the circuit. One of the solution circuits is shown in
Figure 2. The Zener diode and the small MOSFET limit the
SHDN voltage to be about 6V below VIN. This shuts down
the LT3740 for VIN lower than 7V. If VIN can ramp up to
7V quick enough, this circuit is not necessary.
For VIN higher than 14V, the high dv/dt at SW node and
the strong drive of BGATE can generate extra noise and
affect the operation. A resistor RBG of 1Ω-2Ω between
BGATE and the gate of the bottom MOSFET as shown in
Figure 3 can effectively reduce the noise.
The LT3740 uses adaptive dead time control to prevent
the top and bottom MOSFET shoot-through and minimize
the dead time. When the internal top MOSFET on signal
comes, the LT3740 delays the turn on of TGATE until
BGATE is off. When the internal bottom MOSFET on signal
comes, the LT3740 delays the turn on of BGATE until the
SW node swings down to ground. In the case of small
or negative inductor current that SW node cannot swing
below ground after TGATE turns off, BGATE will turn on
200ns after TGATE is off.
Figure 2. Circuit That Prevents Operation for VIN < 7V
Figure 3. Noise Reduction for Bottom MOSFET
VIN
SHDN
BGDP
LT3740
2N7002TA
100k
MMSZ52312BS
3740 F02
SW
PGND
BGATE
LT3740
RBG
M2
3740 F03
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3741EFE#PBF | SWITCHING CONTROLLER, 1070 kHz SWITCHING FREQ-MAX, PDSO20 |
| LT3741IFE#TRPBF | SWITCHING CONTROLLER, 1070 kHz SWITCHING FREQ-MAX, PDSO20 |
| LT3741EUF#PBF | SWITCHING CONTROLLER, 1070 kHz SWITCHING FREQ-MAX, PQCC20 |
| LT3741EUF#TRPBF | SWITCHING CONTROLLER, 1070 kHz SWITCHING FREQ-MAX, PQCC20 |
| LT3741IUF#PBF | SWITCHING CONTROLLER, 1070 kHz SWITCHING FREQ-MAX, PQCC20 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3740EDHC#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-DFN 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(chǎn)品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標(biāo)準(zhǔn)包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數(shù):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(chǎn)品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR |
| LT3740EDHC#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無 升壓:是 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:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LT3740EDHC-PBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Wide Operating Range, Valley Mode, No RSENSE? Synchronous Step-Down Controller |
| LT3740EDHC-TR | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Wide Operating Range, Valley Mode, No RSENSE? Synchronous Step-Down Controller |
| LT3740EDHC-TRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Wide Operating Range, Valley Mode, No RSENSE? Synchronous Step-Down Controller |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。