参数资料
型号: SP6127EK1-L
厂商: Exar Corporation
文件页数: 8/12页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 6TSOT
标准包装: 1
PWM 型: 电压模式
输出数: 1
频率 - 最大: 1.05MHz
占空比: 100%
电源电压: 4.5 V ~ 29 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 125°C
封装/外壳: SOT-23-6 细型,TSOT-23-6
包装: 散装
其它名称: 1016-1392
______________________________________________________ GENERAL OVERVIEW
Output Capacitor Selection
Note that a smaller inductor results in a higher
I 2 ? I 1
? ?
Cout = L × ? ?
? Vos - Vout ?
Select the output capacitor for voltage rating,
capacitance and Equivalent Series Resistance
(ESR). Nominally the voltage rating is selected to
be twice as large as the output voltage. Select
the capacitance to satisfy the specification for
output voltage overshoot/undershoot caused by
current step load. A steady-state output current
I OUT corresponds to inductor stored energy of ? L
I OUT2 . A sudden decrease in I OUT forces the
energy surplus in L to be absorbed by C OUT . This
causes an overshoot in output voltage that is
corrected by the reduced duty cycle of the power
switch. Use the following equation to calculate
C OUT :
2 2
?
2 2 ?
Where:
L is the output inductance
I 2 is the step load high current
I RIP , therefore requiring a larger C OUT and/or
lower ESR in order to meet V RIP .
Input Capacitor Selection
Select the input capacitor for Voltage,
Capacitance, ripple current, ESR and ESL.
Voltage rating is nominally selected to be twice
the input voltage. The RMS value of the input
capacitor current, assuming a low inductor ripple
current ( I RIP ), can be calculated from:
Icin = Iout × D ( 1 ? D )
In general, total input voltage ripple should be
kept below 1.5% of V IN (not to exceed 180mV).
Input voltage ripple has three components: ESR
and ESL cause a step voltage drop upon turn on
of the MOSFET. During on time, the capacitor
discharges linearly as it supplies I OUT -I IN . The
contribution to Input voltage ripple by each term
can be calculated from:
I 1 is the step load low current
Vos is output voltage including overshoot
V OUT is steady state output voltage
? V , Cin =
Iout × Vout × ( Vin ? Vout )
fs × Cin × Vin 2
( Iout ? 0 . 5 Irip )
Output voltage undershoot calculation is more
complicated. Test results for SP6127 buck
circuits show that undershoot is approximately
equal to overshoot. Therefore the above equation
provides a satisfactory method for calculating
C OUT .
Select ESR such that output voltage ripple (V RIP )
specification is met. There are two components to
V RIP : The first component arises from charge
transferred to and from C OUT during each cycle.
The second component of V RIP is due to inductor
ripple current flowing through the output
capacitor’s ESR. It can be calculated from:
? V , ESR = ESR ( Iout ? 0 . 5 Irip )
? V , ESL = ESL
Trise
Where T RISE is the rise time of current through
capacitor
Total input voltage ripple is sum of the above:
? V , Tot = ? V , Cin + ? V , ESR + ? V , ESL
In circuits where converter input voltage is
applied via a mechanical switch, excessive
Vrip = Irip × ESR + ? ?
? ?
? 1 ?
2
? 8 × Cout × fs ?
Where:
I RIP is inductor ripple current
f s is switching frequency
C OUT is output capacitor calculated above
2
ringing may be present at turn-on that may
interfere with smooth startup of the SP6127. The
addition of an inexpensive 100 μ F Aluminum
Electrolytic capacitor at the input will help reduce
ringing and restore a smooth startup.
Jan28-08 RevE
SP6127 TSOT-6 PFET Buck Controller
Page 8
? 2007 Exar Corporation
相关PDF资料
PDF描述
MIC2124YMM IC REG CTRLR BUCK PWM CM 10-MSOP
XRP6124ES0.5-F IC REG CTRLR BUCK PWM SOT23-5
SPD62-122M INDUCTOR PWR SHIELDED 1.20UH SMD
4590R-686K INDUCTOR HIGH CURRENT 68000UH
4590R-107K INDUCTOR HIGH CURRENT 100000UH
相关代理商/技术参数
参数描述
SP6127EK1L/TR 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High-Voltage, Step-Down Controller in TSOT6
SP6127EK1-L/TR 功能描述:电压模式 PWM 控制器 High-Voltage Step Down Controller RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
SP6128A 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Low Voltage, Synchronous Step Down PWM Controller Ideal for 2A to 10A, Small Footprint, DC-DC Power Converters
SP6128A_05 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Low Voltage, Synchronous Step Down PWM Controller Ideal for 2A to 10A, Small Footprint, DC-DC Power Converters
SP6128AB 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Non-Isolated DC-DC SIP Modules:3.0Vdc-5.5Vdc In, 0.9Vdc-3.3Vdc out, 10A