参数资料
型号: LT1374IR-5#TRPBF
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: 8.5 A SWITCHING REGULATOR, 560 kHz SWITCHING FREQ-MAX, PSSO7
封装: PLASTIC, D2PAK-7
文件页数: 3/32页
文件大小: 698K
代理商: LT1374IR-5#TRPBF
11
LT1374
1374fd
When choosing an inductor you might have to consider
maximum load current, core and copper losses, allowable
component height, output voltage ripple, EMI, fault cur-
rent in the inductor, saturation, and of course, cost. The
following procedure is suggested as a way of handling
these somewhat complicated and conflicting requirements.
1. Choose a value in microhenries from the graphs of
maximum load current and core loss. Choosing a small
inductor may result in discontinuous mode operation
at lighter loads, but the LT1374 is designed to work
well in either mode. Keep in mind that lower core loss
means higher cost, at least for closed core geometries
like toroids. The core loss graphs show both absolute
loss and percent loss for a 5W output, so actual percent
losses must be calculated for each situation.
Assume that the average inductor current is equal to
load current and decide whether or not the inductor
must withstand continuous fault conditions. If maxi-
mum load current is 0.5A, for instance, a 0.5A inductor
may not survive a continuous 4.5A overload condition.
Dead shorts will actually be more gentle on the induc-
tor because the LT1374 has foldback current limiting.
2. Calculate peak inductor current at full load current to
ensure that the inductor will not saturate. Peak current
can be significantly higher than output current, espe-
cially with smaller inductors and lighter loads, so don’t
omit this step. Powdered iron cores are forgiving
because they saturate softly, whereas ferrite cores
saturate abruptly. Other core materials fall somewhere
in between. The following formula assumes continu-
ous mode of operation, but it errs only slightly on the
high side for discontinuous mode, so it can be used for
all conditions.
VIN = Maximum input voltage
f = Switching frequency, 500kHz
3. Decide if the design can tolerate an “open” core geom-
etry like a rod or barrel, with high magnetic field
radiation, or whether it needs a closed core like a toroid
to prevent EMI problems. One would not want an open
APPLICATIONS INFORMATION
WU
U
core next to a magnetic storage media, for instance!
This is a tough decision because the rods or barrels are
temptingly cheap and small and there are no helpful
guidelines to calculate when the magnetic field radia-
tion will be a problem.
4. Start shopping for an inductor (see representative
surface mount units in Table 2) which meets the
requirements of core shape, peak current (to avoid
Table 2
SERIES
CORE
VENDOR/
VALUE
DC
CORE
RESIS-
MATER-
HEIGHT
PART NO.
(
H)
(Amps)
TYPE
TANCE(
)
IAL
(mm)
Coiltronics
CTX2-1
2
4.1
Tor
0.011
KM
4.2
CTX5-4
5
4.4
Tor
0.019
KM
6.4
CTX8-4
8
3.5
Tor
0.020
KM
6.4
CTX2-1P
2
3.4
Tor
0.014
52
4.2
CTX2-3P
2
4.6
Tor
0.012
52
4.8
CTX5-4P
5
3.3
Tor
0.027
52
6.4
Sumida
CDRH125
10
4.0
SC
0.025
Fer
6
CDRH125
12
3.5
SC
0.027
Fer
6
CDRH125
15
3.3
SC
0.030
Fer
6
CDRH125
18
3.0
SC
0.034
Fer
6
Coilcraft
DT3316-222
2.2
5
SC
0.035
Fer
5.1
DT3316-332
3.3
5
SC
0.040
Fer
5.1
DT3316-472
4.7
3
SC
0.045
Fer
5.1
Pulse
PE-53650
4
4.8
Tor
0.017
Fer
9.1
PE-53651
5
5.4
Tor
0.018
Fer
9.1
PE-53652
9
5.5
Tor
0.022
Fer
10
PE-53653
16
5.1
Tor
0.032
Fer
10
Dale
IHSM-4825
2.7
5.1
Open
0.034
Fer
5.6
IHSM-4825
4.7
4.0
Open
0.047
Fer
5.6
IHSM-5832
10
4.3
Open
0.053
Fer
7.1
IHSM-5832
15
3.5
Open
0.078
Fer
7.1
IHSM-7832
22
3.8
Open
0.054
Fer
7.1
Tor = Toroid
SC = Semi-closed geometry
Fer = Ferrite core material
52 = Type 52 powdered iron core material
KM = Kool M
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相关代理商/技术参数
参数描述
LT1374IRPBF 制造商:Linear Technology 功能描述:DC-DC Converter Step-Down 5-25V DDPAK8
LT1374IR-SYNC 功能描述:IC REG BUCK ADJ 4.5A D2PAK 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
LT1374IR-SYNC#PBF 功能描述:IC REG BUCK ADJ 4.5A D2PAK 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
LT1374IS8 功能描述:IC REG BUCK ADJ 4.5A 8SOIC 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
LT1374IS8#PBF 功能描述:IC REG BUCK ADJ 4.5A 8SOIC 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