参数资料
| 型号： | SP7650ER-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 7/16页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 3A 26DFN |
| 标准包装： | 3,000 |
| 系列： | Power Blox™ |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.8 V ~ 27 V |
| 输入电压： | 2.5 V ~ 28 V |
| PWM 型： | 电压模式 |
| 频率 - 开关： | 300kHz |
| 电流 - 输出： | 3A |
| 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： | 26-VFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 26-DFN（7x4） |
| 其它名称： | SP7650ER-L/TR-ND |
APPLICATIONS INFORMATION
Inductor Selection
There are many factors to consider in selecting
the inductor including core material, inductance
vs. frequency, current handling capability, effi-
I PEAK = I OUT (max) +
I PP
2
ciency, size and EMI. In a typical SP7650 cir-
cuit, the inductor is chosen primarily for value,
saturation current and DC resistance. Increasing
the inductor value will decrease output voltage
ripple, but degrade transient response. Low in-
ductor values provide the smallest size, but
cause large ripple currents, poor efficiency and
require more output capacitance to smooth out
the larger ripple current. The inductor must be
able to handle the peak current at the switching
frequency without saturating, and the copper
resistance in the winding should be kept as low
as possible to minimize resistive power loss. A
good compromise between size, loss and cost is
to set the inductor ripple current to be within
20% to 40% of the maximum output current.
The switching frequency and the inductor oper-
ating point determine the inductor value as fol-
lows:
...and provide low core loss at the high switch-
ing frequency. Low cost powdered iron cores
have a gradual saturation characteristic but can
introduce considerable AC core loss, especially
when the inductor value is relatively low and the
ripple current is high. Ferrite materials, although
more expensive, and have an abrupt saturation
characteristic with the inductance dropping
sharply when the peak design current is ex-
ceeded. Nevertheless, they are preferred at high
switching frequencies because they present very
low core loss while the designer is only required
to prevent saturation. In general, ferrite or
molypermalloy materials are a better choice for
all but the most cost sensitive applications.
Optimizing Efficiency
The power dissipated in the inductor is equal to
the sum of the core and copper losses. To mini-
where:
L =
V OUT ( V IN (max) V OUT )
V IN (max) F S K r I OUT ( max)
mize copper losses, the winding resistance needs
to be minimized, but this usually comes at the
expense of a larger inductor. Core losses have a
more significant contribution at low output cur-
rent where the copper losses are at a minimum,
f S = switching frequency
Kr = ratio of the AC inductor ripple current to
the maximum output current
The peak to peak inductor ripple current is:
and can typically be neglected at higher output
currents where the copper losses dominate. Core
loss information is usually available from the
magnetics vendor. Proper inductor selection can
affect the resulting power supply efficiency by
more than 15%!
The copper loss in the inductor can be calculated
I PP =
V OUT ( V IN (max) V OUT )
V I N (max) F S L
using the following equation:
P L ( Cu ) = I L 2 ( RMS ) R WINDING
where I L(RMS) is the RMS inductor current that
can be calculated as follows:
I L(RMS) = I OUT(max) 1 + 1
(
Once the required inductor value is selected, the
proper selection of core material is based on
peak inductor current and efficiency require-
3
I PP
I OUT(max)
)
2
ments. The core must be large enough not to
saturate at the peak inductor current...
2/16/06
Date: / 5/06
WideInputInput Range3A, 3A, BuckBuck
SP7650 SP7650 Wide Voltage Voltage Range 300kHz, 300kHz, Regulator Regulator
7
? ? Copyright 2006 Sipex Corporation
相关PDF资料 |
PDF描述 |
|---|---|
| SP7651ER-L | IC REG BUCK SYNC ADJ 3A 26DFN |
| SP7652ER-L/TR | IC REG BUCK SYNC ADJ 6A 26DFN |
| SP7653ER-L | IC REG BUCK SYNC ADJ 3A 26DFN |
| SP7655ER-L/TR | IC REG BUCK SYNC ADJ 8A 26DFN |
| SP7656EN2-L/TR | IC REG BUCK ADJ 3A 8HNSOIC |
相关代理商/技术参数 |
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| SP7651 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP7651_06 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP7651_07 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range 3Amp 900kHz Buck Regulator |
| SP7651EB | 功能描述:电源管理IC开发工具 Wide In Volt Range 3A 900kHz Buck Reg RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| SP7651ER | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
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