參數(shù)資料
型號(hào)： IR3628MPBF
廠商： International Rectifier
英文描述： HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER
中文描述： 高頻同步PWM降壓控制器
文件頁(yè)數(shù)： 6/22頁(yè)
文件大?。?/td> 581K
代理商： IR3628MPBF
IR3628MPbF
08/10/2007
Feedback Compensation
The IR3628 is a voltage mode controller; the
control loop is a single voltage feedback path
including error amplifier and error comparator. To
achieve fast transient response and accurate
output regulation, a compensation circuit is
necessary. The goal of the compensation
network is to provide a closed loop transfer
function with the highest 0dB crossing frequency
and adequate phase margin (greater than 45o).
The output LC filter introduces a double pole, –
40dB/decade gain slope above its corner
resonant frequency, and a total phase lag of 180o
(see figure 13). The resonant frequency of the LC
filter expressed as follows:
Figure 13 shows gain and phase of the LC filter.
Since we already have 180o phase shift just from
the output filter, the system risks being unstable.
The IR3628’s error amplifier is a differential-input
transconductance
amplifier.
The
output
is
available for DC gain control or AC phase
compensation.
The error amplifier can be compensated either in
type II or typeIII compensation. When it is used in
typeII
compensation
the
transconductance
properties of the error amplifier become evident
and can be used to cancel one of the output filter
poles. This will be accomplished with a series RC
circuit from Comp pin to ground as shown in
figure 14.
This method requires that the output capacitor
should have enough ESR to satisfy stability
requirements. In general the output capacitor’s
ESR generates a zero typically at 5kHz to 50kHz
which is essential for an acceptable phase
margin.
(11)
-
C
L
2
1
F
o
LC
=
π
Gain
FLC
0dB
Phase
0
FLC
-180
Frequency
-40dB/decade
Fig. 13: Gain and Phase of LC filter
The ESR zero of the output capacitor expressed
as follows:
The transfer function (Ve/Vo) is given by:
The (s) indicates that the transfer function varies
as a function of frequency. This configuration
introduces a gain and zero, expressed by:
The gain is determined by the voltage divider and
error amplifier’s transconductance gain.
First select the desired zero-crossover frequency
(Fo):
Use the following equation to calculate R3:
Where:
V
in = Maximum Input Voltage
V
osc = Oscillator Ramp Voltage
F
o = Crossover Frequency
F
ESR = Zero Frequency of the Output Capacitor
F
LC = Resonant Frequency of the Output Filter
R
8 and R9 = Feedback Resistor Dividers
g
m = Error Amplifier Transconductance
1.28 = Empirical number to compensate thermal,
process variations and components tolerances
(12)
-
C
ESR
2
1
F
o
ESR
*
π
=
Fig. 14: TypeII compensation network
and its asymptotic gain plot
(13)
-
sC
C
sR
1
R
g
s
H
4
3
8
9
m
+
+
=
*
)
(
()
[]
(15)
-
C
R
2
1
F
(14)
-
R
*
R
g
s
H
4
3
z
3
8
9
m
*
π
=
+
=
(
)
s
o
ESR
o
F
1/10
~
1/5
F
and
F
*
≤
>
(15A)
-
*
.
*
)
(
*
m
LC
in
ESR
o
osc
g
R
F
V
R
F
V
R
9
2
9
8
3
28
1
+
=
Ve
VOUT
VREF
R9
R8
R3
C4
E/A
FZ
H(s) dB
Frequency
Gain(dB)
Fb
Comp
CPOLE
14
相關(guān)PDF資料
PDF描述
IR3628MTRPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER
IR3629AMPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMTRPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629A HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629 HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
IR3628MTRPBF 功能描述:電壓模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
IR3629 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629A 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMPBF 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMTRPBF 功能描述:電壓模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*