- 您现在的位置：买卖IC网 > PDF目录1809 > IR3628MPBF (International Rectifier)IC CTLR PWM BUCK SYNC 12-MLPD PDF资料下载
参数资料
| 型号： | IR3628MPBF |
| 厂商： | International Rectifier |
| 文件页数： | 14/22页 |
| 文件大小： | 0K |
| 描述： | IC CTLR PWM BUCK SYNC 12-MLPD |
| 标准包装： | 122 |
| 应用： | 控制器，DDR |
| 输入电压： | 4.5 V ~ 14 V |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 9.94 V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 12-VFDFN 裸露焊盘 |
| 供应商设备封装： | 12-MLPD |
| 包装： | 管件 |
IR3628MP b F
Feedback Compensation
The IR3628 is a voltage mode controller; the
The ESR zero of the output capacitor expressed
as follows:
control loop is a single voltage feedback path
including error amplifier and error comparator. To
achieve fast transient response and accurate
V O UT
F ESR =
1
2 ? π * ESR * C o
- - - (12)
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 45 o ).
The output LC filter introduces a double pole, –
R 8
R 9
F b
V REF
E/A
Comp
C 4
R 3
Ve
C POLE
40dB/decade gain slope above its corner
resonant frequency, and a total phase lag of 180 o
(see figure 13). The resonant frequency of the LC
filter expressed as follows:
Gain(dB)
H(s) dB
F Z
F LC =
1
2 ? π L o ? C o
- - - (11)
Frequency
Fig. 14: TypeII compensation network
H ( s ) = ? ? g m *
? *
R 9 + R 8 ? ?
Figure 13 shows gain and phase of the LC filter.
Since we already have 180 o phase shift just from
the output filter, the system risks being unstable.
Gain Phase
and its asymptotic gain plot
The transfer function (Ve/Vo) is given by:
? R 9 ? 1 + sR 3 C 4
- - - (13)
? sC 4
0dB
-40dB/decade
0
The (s) indicates that the transfer function varies
as a function of frequency. This configuration
introduces a gain and zero, expressed by:
[ H ( s ) ] = ? g m
? * R 3 - - - (14)
F LC Frequency
-180
F LC
Frequency
?
*
R 9 ?
R 9 + R 8 ? ?
Fig. 13: Gain and Phase of LC filter
F z =
1
2 π * R 3 * C 4
- - - (15)
V osc * F o * F ESR * ( R 8 + R 9 ) * 1 . 28
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.
08/10/2007
The gain is determined by the voltage divider and
error amplifier’s transconductance gain.
First select the desired zero-crossover frequency
(Fo):
F o > F ESR and F o ≤ ( 1/5 ~ 1/10 ) * F s
Use the following equation to calculate R3:
R 3 = - - - (15A)
V in * F LC 2 * R 9 * g m
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 R 9 = Feedback Resistor Dividers
g m = Error Amplifier Transconductance
1.28 = Empirical number to compensate thermal,
process variations and components tolerances
14
相关PDF资料 |
PDF描述 |
|---|---|
| IR3629AMTRPBF | IC CTLR PWM SYNC BUCK 12-MLPD |
| IR3637ASTRPBF | IC REG CTRLR BUCK PWM VM 8-SOIC |
| IR3637STRPBF | IC REG CTRLR BUCK PWM VM 8-SOIC |
| IR3638STRPBF | IC REG CTRLR BUCK PWM VM 14-SOIC |
| IR3640MPBF | IC REG CTRLR BUCK PWM VM 20-MLPQ |
相关代理商/技术参数 |
参数描述 |
|---|---|
| IR3628MTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 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 |
| IR3629 | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629A | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMPBF | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 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 |
发布紧急采购，3分钟左右您将得到回复。