参数资料
| 型号： | SP6651AEU-L |
| 厂商： | Exar Corporation |
| 文件页数： | 8/16页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 0.8A 10MSOP |
| 标准包装： | 50 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.8 V ~ 5 V |
| 输入电压： | 2.7 V ~ 5.5 V |
| 电流 - 输出： | 800mA |
| 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： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 10-MSOP |
| 其它名称： | 1016-1526-5 SP6651AEU-L-ND |
THEORY OF OPERATION : Continued
point RESET is held low until V OUT is above
regulation. Once RESET occurs T ON minimum
is reset, and the T OFF one-shot is triggered to
blank the loop comparator from starting a new
charge cycle for a minimum period. This blank-
ing period occurs during the noisy LX transition
to discharge, where spurious comparator states
may occur. For T OFF > T BLANK the loop is in a
discharge or wait state until the loop comparator
starts the next charge cycle by DRVON going
high.
If an over current occurs during charge the loop
is interrupted and DRVON is RESET. The off-
time one-shot pulse width is widened to T OFF =
K OFF / V OUT , which holds the loop in discharge
for that time. At the end of the off-time the loop
is released and controlled by VOLOW. In this
manner maximum inductor current is controlled
on a cycle-by-cycle basis. An assertion of UVLO
(undervoltage lockout) or TSD (thermal shut-
down) holds the loop in no-charge until the fault
has ended.
On-Time Control - Discharge Phase
The discharge phase follows with the high side
PMOS switch opening and the low side NMOS
switch closing to provide a discharge path for
the inductor current. The decreasing inductor
current and the load current cause the output
where:
L = Inductor value
I OUT = Load current
R CH = PMOS on resistance, 0.3 ? typ.
If the I OUT * R CH term is negligible compared
with (V IN - V OUT ), the above equation simplifies
to:
K ON
I LR ≈
L
For most applications, the inductor current ripple
controlled by the SP6651A is constant regard-
less of input and output voltage. Because the
output voltage ripple is equal to:
V OUT (ripple) = I LR * R ESR
where:
R ESR = ESR of the output capacitor
the output ripple of the SP6651A regulator is
independent of the input and output voltages.
For battery powered applications, where the
battery voltage changes significantly, the
SP6651A provides constant output voltage ripple
through-out the battery lifetime. This greatly
simplifies the LC filter design.
The maximum loop frequency in CCM is de-
fined by the equation:
voltage to drop. Under normal load conditions
when the inductor current is below the pro-
grammed limit, the off-time will continue until
F LP ≈
(V IN - V OUT ) * (V OUT + I OUT * R DC )
K ON * [V IN + I OUT * (R DC - R CH )]
the output voltage falls below the regulation
threshold, which initiates a new charge cycle via
the loop comparator.
The inductor current “floats” in continuous con-
duction mode. During this mode the inductor
peak current is below the programmed limit and
the valley current is above zero. This is to satisfy
load currents that are greater than half the mini-
mum current ripple. The current ripple, I LR , is
defined by the equation:
where:
F LP = CCM loop frequency
R DC = NMOS on resistance, 0.3 ? typ.
Ignoring conduction losses simplifies the loop
frequency to:
1 V OUT
F LP ≈ * * (V IN - V OUT )
K ON V IN
AND’ing the loop comparator and the on-timer
reduces the switching frequency for load cur-
I LR ≈
K ON
L
*
V IN - V OUT - I OUT * R CH
V IN - V OUT
rents below half the inductor ripple current. This
increases light load efficiency. The minimum
on-time insures that the inductor current ripple
Date: 5/25/04
SP6651A High Efficiency 800mA Synchronous Buck Regulator
8
? Copyright 2004 Sipex Corporation
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP6651AEU-L/TR | 功能描述:DC/DC 开关控制器 High Eff 800mA Synchronous RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| SP6651EB | 功能描述:电源管理IC开发工具 Eval Board for SP6651 Series 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 |
| SP6652 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:1A, High Efficiency, High Frequency Current Mode PWM Buck Regulator |
| SP6652_07 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:1A, High Efficiency, Fixed 1.4 MHz Current Mode PWM Buck Regulator |
| SP6652EB | 功能描述:电源管理IC开发工具 Eval Board for SP6652 Series 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 |
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