参数资料
型号: LT1371CT7
厂商: Linear Technology
文件页数: 9/16页
文件大小: 0K
描述: IC REG MULTI CONFIG ADJ TO220-7
标准包装: 50
类型: 降压(降压),升压(升压),反相,Cuk,回扫,正向转换器
输出类型: 可调式
输出数: 1
输出电压: 1.25 V ~ 35 V
输入电压: 2.7 V ~ 25 V
PWM 型: 电流模式
频率 - 开关: 500kHz
电流 - 输出: 3A
同步整流器:
工作温度: 0°C ~ 70°C
安装类型: 通孔
封装/外壳: TO-220-7 成形引线
包装: 管件
供应商设备封装: TO-220-7
LT1371
APPLICATIO S I FOR ATIO
) )
I PEAK = (I OUT ) OUT +
saturate abruptly and other core materials fall in be-
tween. The following formula assumes continuous
mode operation but it errs only slightly on the high side
for discontinuous mode, so it can be used for all
conditions.
V V IN (V OUT – V IN )
V IN 2(f)(L)(V OUT )
V IN = Minimum Input Voltage
f = 500kHz Switching Frequency
3. Decide if the design can tolerate an “open” core geom-
etry, like a rod or barrel, which has high magnetic field
radiation, or whether it needs a closed core, like a
toroid, to prevent EMI problems. One would not want an
open core next to a magnetic storage media, for in-
stance! This is a tough decision because the rods or
physically smaller capacitors have high ESR. The ESR
range needed for typical LT1371 applications is 0.025 ?
to 0.2 ? . A typical output capacitor is an AVX type TPS,
22 μ F at 25V (2 each), with a guaranteed ESR less than
0.2 ? . This is a “D” size surface mount solid tantalum
capacitor. TPS capacitors are specially constructed and
tested for low ESR, so they give the lowest ESR for a given
volume. To further reduce ESR, multiple output capaci-
tors can be used in parallel. The value in microfarads is
not particularly critical, and values from 22 μ F to greater
than 500 μ F work well, but you cannot cheat mother
nature on ESR. If you find a tiny 22 μ F solid tantalum
capacitor, it will have high ESR and output ripple voltage
will be terrible. Table 1 shows some typical solid tantalum
surface mount capacitors.
Table 1. Surface Mount Solid Tantalum Capacitor
ESR and Ripple Current
barrels are temptingly cheap and small and there are no
helpful guidelines to calculate when the magnetic field
radiation will be a problem.
4. Start shopping for an inductor which meets the re-
quirements of core shape, peak current (to avoid
saturation), average current (to limit heating) and fault
current. If the inductor gets too hot, wire insulation will
melt and cause turn-to-turn shorts. Keep in mind that
all good things like high efficiency, low profile and high
temperature operation will increase cost, sometimes
E CASE SIZE
AVX TPS, Sprague 593D
AVX TAJ
D CASE SIZE
AVX TPS, Sprague 593D
AVX TAJ
C CASE SIZE
AVX TPS
AVX TAJ
B CASE SIZE
AVX TAJ
ESR (MAX ? )
0.1 to 0.3
0.7 to 0.9
0.1 to 0.3
0.9 to 2.0
0.2 (Typ)
1.8 to 3.0
2.5 to 10
RIPPLE CURRENT (A)
0.7 to 1.1
0.4
0.7 to 1.1
0.36 to 0.24
0.5 (Typ)
0.22 to 0.17
0.16 to 0.08
dramatically.
5. After making an initial choice, consider the secondary
things like output voltage ripple, second sourcing, etc.
Use the experts in the LTC Applications Department if
you feel uncertain about the final choice. They have
experience with a wide range of inductor types and can
tell you about the latest developments in low profile,
surface mounting, etc.
Output Capacitor
The output capacitor is normally chosen by its effective
series resistance (ESR), because this is what determines
output ripple voltage. At 500kHz any polarized capacitor
Many engineers have heard that solid tantalum capacitors
are prone to failure if they undergo high surge currents.
This is historically true and AVX type TPS capacitors are
specially tested for surge capability, but surge ruggedness
is not a critical issue with the output capacitor. Solid
tantalum capacitors fail during very high turn-on surges,
which do not occur at the output of regulators. High
discharge surges, such as when the regulator output is
dead-shorted, do not harm the capacitors.
Single inductor boost regulators have large RMS ripple
current in the output capacitor, which must be rated to
handle the current. The formula to calculate this is:
is essentially resistive. To get low ESR takes volume, so
9
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LT1371CT7#PBF 功能描述:IC REG MULTI CONFIG ADJ TO220-7 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
LT1371HV 制造商:LINER 制造商全称:Linear Technology 功能描述:500kHz High Efficiency 3A Switching Regulator
LT1371HVCR 功能描述:IC REG MULTI CONFIG ADJ 3A 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
LT1371HVCR#PBF 功能描述:IC REG MULTI CONFIG ADJ 3A D2PAK 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
LT1371HVCR#PBF 制造商:Linear Technology 功能描述:SP-SWREG/Monolithic Hi Sw Vol 制造商:Linear Technology 功能描述:SP-SWREG/Monolithic, Hi Sw Volt 500kHz,3