參數(shù)資料
型號: PM6675STR
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 3 A SWITCHING CONTROLLER, QCC24
封裝: 4 X 4 MM, LEAD FREE, VFQFPN-24
文件頁數(shù): 36/53頁
文件大小: 2632K
代理商: PM6675STR
PM6675S
Application information
41/53
The saturation current of the inductor should be greater than IL,PEAK as well as for case of
hard saturation core inductors. Using soft-ferrite cores is possible (but not advisable) to push
the inductor working near its saturation current.
In Table 11 some inductors suitable for notebook applications are listed.
In Pulse-Skip Mode, low inductance values produce a better efficiency versus load curve,
while higher values result in higher full-load efficiency because of the smaller current ripple.
8.1.2
Input capacitor selection
In a buck topology converter the current that flows through the input capacitor is pulsed and
with zero average value. The RMS input current can be calculated as follows:
Equation 34
Neglecting the second term, the equation 10 is reduced to:
Equation 35
The losses due to the input capacitor are thus maximized when the duty-cycle is 0.5:
Equation 36
The input capacitor should be selected with a RMS rated current higher than ICINRMS(max).
Tantalum capacitors are good in terms of low ESR and small size, but they occasionally can
burn out if subjected to very high current during operation. Multi-Layers-Ceramic-Capacitors
(MLCC) have usually a higher RMS current rating with smaller size and they remain the best
choice. The drawback is their quite high cost.
Table 11.
Evaluated inductors (@fsw = 400 kHz)
Manufacturer
Series
Inductance (
H)
+40 °C RMS
current (A)
-30 % saturation
current (A)
COILCRAFT
MLC1538-102
1
13.4
21.0
COILCRAFT
MLC1240-901
0.9
12.4
24.5
COILCRAFT
MVR1261C-112
1.1
20
WURTH
7443552100
1
16
20
COILTRONICS
HC8-1R2
1.2
16.0
25.4
2
L
2
LOAD
RMS
Cin
)
I
(
D
12
1
)
D
1
(
D
I
+
=
)
D
1
(
D
I
LOAD
RMS
Cin
=
2
LOAD
Cin
2
CinRMS
Cin
loss
(max))
I
5
.
0
(
ESR
(max)
I
ESR
P
=
=
相關(guān)PDF資料
PDF描述
PM6675S 3 A SWITCHING CONTROLLER, QCC24
PM6681ATR 0.4 A DUAL SWITCHING CONTROLLER, QCC32
PMA4118HSF/C 1-OUTPUT 18 W DC-DC REG PWR SUPPLY MODULE
PMA4118LSF/B 1-OUTPUT 14.4 W DC-DC REG PWR SUPPLY MODULE
PMA4218GSF/B 1-OUTPUT 21.6 W DC-DC REG PWR SUPPLY MODULE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PM6675TR 功能描述:低壓差控制器 - LDO High eff SD CNRL RoHS:否 制造商:Micrel 最大輸入電壓:5.5 V 輸出電壓:Adjustable 輸出電流:10 mA 負(fù)載調(diào)節(jié): 輸出類型:Adjustable, Fixed 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-6
PM6680 功能描述:DC/DC 開關(guān)控制器 No Rsense dual StepDwn Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
PM6680_08 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:No Rsense dual step-down controller with adjustable voltages for notebook system power
PM6680A 功能描述:DC/DC 開關(guān)控制器 Dual sync controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
PM6680ATR 功能描述:DC/DC 開關(guān)控制器 Dual sync controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK