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参数资料
| 型号： | SP7661ER-L |
| 厂商： | Exar Corporation |
| 文件页数： | 11/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 3A 26DFN |
| 产品变化通告： | SP76(55,61)ER-L/(TR) Obsolescence 29/Jul/2011 |
| 标准包装： | 500 |
| 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 ~ 20.2 V |
| 输入电压： | 4.75 V ~ 22 V |
| PWM 型： | 电压模式 |
| 频率 - 开关： | 600kHz |
| 电流 - 输出： | 3A |
| 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： | 26-VFDFN 裸露焊盘 |
| 包装： | 散装 |
| 供应商设备封装： | 26-DFN（7x4） |
APPLICATIONS INFORMATION
√ (
)
I PP ? (1 – D)
2
+ ( I PP ?R ESR )
? s ? C OUT
R ESR ≤ ? V OUT
P CIN = I CIN(RMS) ? R ESR(CIN)
OutputCapacitorSelection
The required ESR (Equivalent Series Re -
sistance) and capacitance drive the selec -
tion of the type and quantity of the output
capacitors. The ESR must be small enough
that both the resistive voltage deviation due
to a step change in the load current and
the output ripple voltage do not exceed
the tolerance limits expected on the output
voltage. During an output load transient,
the output capacitor must supply all the ad -
ditional current demanded by the load until
the SP7661 adjusts the inductor current to
the new value.
In order to maintain V OUT ,the capacitance
must be large enough so that the output
voltage is held up while the inductor cur -
rent ramps to the value corresponding
to the new load current. Additionally, the
ESR in the output capacitor causes a step
in the output voltage equal to the current.
Because of the fast transient response and
inherent 100% to 0% duty cycle capability
provided by the SP7661 when exposed to
output load transients, the output capacitor
is typically chosen for ESR, not for capaci -
tance value.
The ESR of the output capacitor, combined
with the inductor ripple current, is typically
the main contributor to output voltage ripple.
The maximum allowable ESR required to
maintain a specified output voltage ripple can
be calculated by:
I PK - PK
where:
? V OUT = Peak-to-Peak O utput Voltage Ripple
I PK - PK = Peak-to-Peak Inductor Ripple Current
The total output ripple is a combination of
the ESR and the output capacitance value
and can be calculated as follows:
2
?V OUT =
? s = Switching Frequency
D = Duty Cycle
C OUT = O utput Capacitance Value
Input Capacitor Selection
The input capacitor should be selected for
ripple current rating, capacitance and volt-
age rating. The input capacitor must meet
the ripple current requirement imposed
by the switching current. In continuous
conduction mode, the source current of
the high-side MOSFET is approximately a
square wave of duty cycle V OUT /V IN . More
accurately, the current wave form is trap -
ezoidal, given a finite turn-on and turn-off,
switch transition slope. Most of this current
is supplied by the input bypass capaci -
tors. The RMS current handling capability
of the input capacitors is determined at
maximum output current and under the
assumption that the peak-to-peak inductor
ripple current is low, it is given by:
I CIN(RMS) = I OUT(MAX) ? √ D(1 - D)
The worst case occurs when the duty cycle
D is 50% and gives an RMS current value
equal to I OUT /2. Select input capacitors with
adequate ripple current rating to ensure reli -
able operation.
The power dissipated in the input capaci -
tor is:
2
This can become a significant part of power
losses in a converter and hurt the overall
energy transfer efficiency. The input volt -
age ripple primarily depends on the input
Mar -07 Rev N
SP766 Wide Input Voltage Range 3A, 600kHz Buck Regulator
? 2007 Sipex Corporation
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP7661ERL/TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range 3A, 600kHz, Buck Regulator |
| SP7661ER-L/TR | 功能描述:开关变换器、稳压器与控制器 WIDE INPUT VOLTAGE Range A600KHz RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| SP7662 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP7662_07 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range 12A, 300kHz, Buck Regulator |
| SP7662_1 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
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