參數(shù)資料
型號: PM6670
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 1.4 A SWITCHING CONTROLLER, QCC24
封裝: 4 X 4 MM, LEAD FREE, VFQFN-24
文件頁數(shù): 17/53頁
文件大?。?/td> 799K
代理商: PM6670
Obsolete
Product(s)
- Obsolete
Product(s)
Obsolete
Product(s)
- Obsolete
Product(s)
Device description
PM6670
24/53
The design of the external feedback network depends on the output voltage ripple. If the
ripple is higher than approximately 20mV, the correct CINT capacitor is usually enough to
keep the loop stable. The stability of the system depends firstly on the output capacitor zero
frequency.
The following condition must be satisfied:
Equation 6
where k is a fixed design parameter (k > 3). It determines the minimum integrator capacitor
value:
Equation 7
where gm = 50
s is the integrator trans conductance.
In order to ensure stability it must be also verified that:
Equation 8
If the ripple on the COMP pin is greater than the integrator 150mV, the auxiliary capacitor
CFILT can be added. If q is the desired attenuation factor of the output ripple, CFILT is given
by:
Equation 9
In order to reduce the noise on the COMP pin, it is possible to add a resistor RINT that,
together with CINT and CFILT, becomes a low pass filter. The cutoff frequency fCUT must be
much greater (10 or more times) than the switching frequency:
Equation 10
If the ripple is very small (lower than approximately 20mV), a different compensation
network, called "Virtual-ESR" Network, is needed. This additional circuit generates a
triangular ripple that is added to the output voltage ripple at the input of the integrator. The
complete control scheme is shown in Figure 32.
ESR
C
2
k
f
k
f
out
Zout
SW
π
=
>
Vout
Vr
f
k
f
2
g
C
Zout
SW
m
INT
π
>
OUT
Zout
m
INT
V
Vr
f
2
g
C
π
>
q
)
q
1
(
C
INT
FILT
=
FILT
INT
FILT
INT
CUT
INT
C
f
2
1
R
+
π
=
相關(guān)PDF資料
PDF描述
PM6675ASTR 3 A SWITCHING CONTROLLER, QCC24
PM6675AS 3 A SWITCHING CONTROLLER, QCC24
PM6675ATR SWITCHING CONTROLLER, QCC24
PM6675TR SWITCHING CONTROLLER, QCC24
PM6675 SWITCHING CONTROLLER, QCC24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PM6670AS 功能描述:DC/DC 開關(guān)控制器 DDR 2/3 Memory Pwr Cntrl 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
PM6670ASTR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Complete DDR2/3 Mem Pwr supply controllr RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
PM6670ATR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Complete DDR2/3 Mem Pwr supply controllr RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
PM6670S 功能描述:DC/DC 開關(guān)控制器 DDR 2/3 Memory Pwr Cntrl 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
PM6670STR 功能描述:DC/DC 開關(guān)控制器 Complete DDR2/3 Mem Pwr supply controllr 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