- 您现在的位置：买卖IC网 > PDF目录44983 > LT3430EFE-1 (LINEAR TECHNOLOGY CORP) 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 PDF资料下载
参数资料
| 型号： | LT3430EFE-1 |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封装： | 4.40 MM, PLASTIC, TSSOP-16 |
| 文件页数： | 18/28页 |
| 文件大小： | 321K |
| 代理商： | LT3430EFE-1 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页当前第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LT3430/LT3430-1
25
34301fa
APPLICATIONS INFORMATION
INDUCTOR VALUE
The criteria for choosing the inductor is typically based on
ensuring that peak switch current rating is not exceeded.
This gives the lowest value of inductance that can be
used, but in some cases (lower output load currents) it
may give a value that creates unnecessarily high output
ripple voltage.
The difculty in calculating the minimum inductor size
needed is that you must rst decide whether the switcher
will be in continuous or discontinuous mode at the critical
point where switch current reaches 3A. The rst step is to
use the following formula to calculate the load current above
which the switcher must use continuous mode. If your
load current is less than this, use the discontinuous mode
formula to calculate minimum inductor needed. If load
current is higher, use the continuous mode formula.
Output current where continuous mode is needed:
I
VI
VV
V
CONT
IN
P
IN
OUT
IN
OUT
F
>
++
+
() ( )
()(
)
22
4
Minimum inductor discontinuous mode:
L
VI
fI
MIN
OUT
P
=
2
()(
)
()( )
Minimum inductor continuous mode:
L
VV
fV
V
I
VV
V
MIN
IN
OUT
IN
OUT
P
OUT
F
IN
=
++
+
()(
)
()(
)
–
()
21
For a 40V to –12V converter using the LT3430/LT3430-
1 with peak switch current of 3A and a catch diode of
0.52V:
IA
CONT
=
++
+
=
() ( )
()(
.
)
.
40
3
4 4012 4012 0 52
1 148
22
For a load current of 0.5A, this says that discontinuous
mode can be used and the minimum inductor needed is
found from:
LH
MIN
==
212 0 5
200 10
3
67
32
()( . )
()( )
.
In practice, the inductor should be increased by about
30% over the calculated minimum to handle losses and
variations in value. This suggests a minimum inductor of
10H for this application.
Ripple Current in the Input and Output Capacitors
Positive-to-negative converters have high ripple current in
the input capacitor. For long capacitor lifetime, the RMS
value of this current must be less than the high frequency
ripple current rating of the capacitor. The following formula
will give an approximate value for RMS ripple current. This
formula assumes continuous mode and large inductor
value. Small inductors will give somewhat higher ripple
current, especially in discontinuous mode. The exact for-
mulas are very complex and appear in Application Note
44, pages 29 and 30. For our purposes here I have simply
added a fudge factor (ff). The value for ff is about 1.2 for
higher load currents and L ≥15H. It increases to about
2.0 for smaller inductors at lower load currents.
Capacitor I
ff I
V
RMS
OUT
IN
= ()(
)
ff = 1.2 to 2.0
The output capacitor ripple current for the positive-to-
negative converter is similar to that for a typical buck
regulator—it is a triangular waveform with peak-to-peak
OUTPUT**
–12V, 0.5A
INPUT
5.5V TO
44V
3430 F15
C2
0.68
F
CC
RC
D1
30BQ060
R1
36.5k
C1
100
F
16V TANT
C3
4.7
F
100V
CER
D2
MMSD914TI
L1*
10
H
CF
BOOST
LT3430
VIN
VSW
FB
GND
VC
D3
30BQ015
R2
4.12k
* INCREASE L1 FOR HIGHER CURRENT APPLICATIONS.
SEE APPLICATIONS INFORMATION
** MAXIMUM LOAD CURRENT DEPENDS ON MINIMUM INPUT VOLTAGE
AND INDUCTOR SIZE. SEE APPLICATIONS INFORMATION
+
D4
7V
Figure 15. Positive-to-Negative Converter
相关PDF资料 |
PDF描述 |
|---|---|
| LT3467AIDDB#PBF | 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3467AIDDB | 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3467IS6#TRM | 2.5 A SWITCHING REGULATOR, 1600 kHz SWITCHING FREQ-MAX, PDSO6 |
| LT3467IS6#TR | 2.5 A SWITCHING REGULATOR, 1600 kHz SWITCHING FREQ-MAX, PDSO6 |
| LT3467AIDDB#TRM | 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3430EFE-1#PBF | 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 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:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| LT3430EFE-1#TRPBF | 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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 |
| LT3430EFEPBF | 制造商:Linear Technology 功能描述:LT3430 adj 3A Buck SD dc-dc converter |
| LT3430IFE | 功能描述:IC REG BUCK ADJ 3A 16TSSOP RoHS:否 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 |
| LT3430IFE#PBF | 功能描述:IC REG BUCK ADJ 3A 16TSSOP RoHS:否 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 |
发布紧急采购，3分钟左右您将得到回复。