- 您现在的位置：买卖IC网 > PDF目录79981 > LTC3407AIDD#PBF (LINEAR TECHNOLOGY CORP) DUAL SWITCHING CONTROLLER, PDSO10 PDF资料下载
参数资料
| 型号： | LTC3407AIDD#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | DUAL SWITCHING CONTROLLER, PDSO10 |
| 封装： | 3 X 3 MM, LEAD FREE, PLASTIC, MO-229WEED-2, DFN-10 |
| 文件页数： | 15/16页 |
| 文件大小： | 283K |
| 代理商： | LTC3407AIDD#PBF |
LTC3407A
8
3407afa
Inductor Selection
Although the inductor does not inuence the operat-
ing frequency, the inductor value has a direct effect on
ripple current. The inductor ripple current ΔIL decreases
with higher inductance and increases with higher VIN or
VOUT:
IL =
VOUT
fO L
1–
VOUT
VIN
Accepting larger values of ΔIL allows the use of low
inductances, but results in higher output voltage ripple,
greater core losses, and lower output current capability. A
reasonable starting point for setting ripple current is ΔIL =
0.3 ILIM, where ILIM is the peak switch current limit. The
largest ripple current ΔIL occurs at the maximum input
voltage. To guarantee that the ripple current stays below a
specied maximum, the inductor value should be chosen
according to the following equation:
L =
VOUT
fO IL
1–
VOUT
VIN(MAX)
The inductor value will also have an effect on Burst Mode
operation. The transition from low current operation
begins when the peak inductor current falls below a level
set by the burst clamp. Lower inductor values result in
higher ripple current which causes this transition to occur
at lower load currents. This causes a dip in efciency in
the upper range of low current operation. In Burst Mode
operation, lower inductance values will cause the burst
frequency to increase.
Inductor Core Selection
Different core materials and shapes will change the size/
current and price/current relationship of an inductor. Toroid
or shielded pot cores in ferrite or permalloy materials are
small and don’t radiate much energy, but generally cost
more than powdered iron core inductors with similar elec-
trical characterisitics. The choice of which style inductor
to use often depends more on the price vs size require-
ments and any radiated eld/EMI requirements than on
what the LTC3407A requires to operate. Table 1 shows
some typical surface mount inductors that work well in
LTC3407A applications.
Table 1. Representative Surface Mount Inductors
MANUF-
ACTURER
PART NUMBER
VALUE
MAX DC
CURRENT
DCR
HEIGHT
Taiyo
Yuden
CB2016T2R2M
CB2012T2R2M
CB2016T3R3M
2.2μH
3.3μH
510mA
530mA
410mA
0.13Ω
0.33Ω
0.27Ω
1.6mm
1.25mm
1.6mm
Panasonic
ELT5KT4R7M
4.7μH
950mA
0.2Ω
1.2mm
Sumida
CDRH2D18/LD
4.7μH
630mA
0.086Ω
2mm
Murata
LQH32CN4R7M23 4.7μH
450mA
0.2Ω
2mm
Taiyo
Yuden
NR30102R2M
NR30104R7M
2.2μH
4.7μH
1100mA
750mA
0.1Ω
0.19Ω
1mm
FDK
FDKMIPF2520D
4.7μH
3.3μH
2.2μH
1100mA
1200mA
1300mA
0.11Ω
0.1Ω
0.08Ω
1mm
TDK
VLF3010AT4R7-
MR70
VLF3010AT3R3-
MR87
VLF3010AT2R2-
M1R0
4.7μH
3.3μH
2.2μH
700mA
870mA
1000mA
0.28Ω
0.17Ω
0.12Ω
1mm
Input Capacitor (CIN) Selection
In continuous mode, the input current of the converter is a
square wave with a duty cycle of approximately VOUT/VIN.
To prevent large voltage transients, a low equivalent series
resistance (ESR) input capacitor sized for the maximum
RMS current must be used. The maximum RMS capacitor
current is given by:
IRMS ≈IMAX
VOUT(VIN –VOUT)
VIN
where the maximum average output current IMAX equals
the peak current minus half the peak-to-peak ripple cur-
rent, IMAX = ILIM – ΔIL/2.
APPLICATIONS INFORMATION
Figure 1. LTC3407A General Schematic
VOUT2
RUN/SS2
VIN
VIN = 2.5V TO 5.5V
VOUT1
RUN/SS1
POR
SW1
VFB1
GND
VFB2
SW2
MODE/SYNC
LTC3407A
CIN
R7
POWER-ON
RESET
C1
C2
L1
L2
R4
R2
R1
R3
COUT2
C4
C3
COUT1
3407A F01
PULSESKIP*
BURST*
*MODE/SYNC = 0V: PULSE SKIP
MODE/SYNC = VIN: Burst Mode
R6
R5
相关PDF资料 |
PDF描述 |
|---|---|
| LS5320-7ERD9TB1 | 2-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
| LM3700XCBP-290/NOPB | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PBGA9 |
| LM385BLPRE3-1-2 | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.235 V, PBCY3 |
| LM385LPRE3-1-2 | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.235 V, PBCY3 |
| LX1570CM | 1 A SWITCHING CONTROLLER, 100 kHz SWITCHING FREQ-MAX, PDIP8 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3407AIDD-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Synchronous 600mA, 1.5MHz Step-Down DC/DC Regulator |
| LTC3407AIMSE#PBF | 功能描述:IC REG BUCK SYNC ADJ 1A 10MSOP 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 |
| LTC3407AIMSE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 1A 10MSOP 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 |
| LTC3407AIMSE-2 | 制造商:Linear Technology 功能描述:Conv DC-DC Dual Step Down 2.5V to 5.5V 10-Pin MSOP EP |
| LTC3407AIMSE-2#PBF | 功能描述:IC REG BUCK SYNC ADJ 1A 10MSOP 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 |
发布紧急采购，3分钟左右您将得到回复。