参数资料
型号: IR3811MTR1PBF
厂商: International Rectifier
文件页数: 14/21页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 7A QFN
产品培训模块: SupIRBuck? Family and POL Design Tools Overview
产品变化通告: (EP) Parts Discontinuation 25/May/2012
标准包装: 750
系列: SupIRBuck™
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.6 V ~ 12 V
输入电压: 2.5 V ~ 21 V
PWM 型: 电压模式
频率 - 开关: 600kHz
电流 - 输出: 7A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 15-PowerVQFN
包装: 带卷 (TR)
供应商设备封装: PQFN(5x6)
PD-60334
IR3811MPbF
To cancel one of the LC filter poles, place the
zero before the LC filter resonant frequency pole:
Z IN
V OUT
C 3
F z = 0 . 75 *
F z = 75 % F LC
1
2 π L o * C o
- - - (17)
C 7
R 10
R 8
R 3
C 4
Z f
Use equations (15) and (16) to calculate C4.
One more capacitor is sometimes added in
parallel with C4 and R3. This introduces one
R 9
Fb
E/A
Comp
Ve
more pole which is mainly used to suppress the
switching noise.
Gain(dB)
V REF
F P =
2 π * R 3 * 4
The additional pole is given by:
1
C * C POLE
C 4 + C POLE
H(s) dB
F Z 1
F Z 2
F P 2
F P 3
Frequency
The pole sets to one half of switching frequency
which results in the capacitor C POLE :
Fig.15: Compensation network with local
=
C POLE
For F P <<
1
π * R 3 * F s ?
F s
2
1
C 4
?
1
π * R 3 * F s
feedback and its asymptotic gain plot
As known, the transconductance amplifier has
high impedance (current source) output,
therefore, consideration should be taken when
loading the error amplifier output. It may exceed
For a general solution for unconditional stability
for any type of output capacitors, in a wide range
of ESR values we should implement local
feedback with a compensation network (type III).
The typically used compensation network for
voltage-mode controller is shown in figure 15.
In such a configuration, the transfer function is
its source/sink output current capability, so that
the amplifier will not be able to swing its output
voltage over the necessary range.
The compensation network has three poles and
two zeros and they are expressed as follows:
F P 1 = 0
1 ? g m Z f
V e
2 π * R 3 ? ? 4
? C * C 3 ?
C 4 + C 3 ? ?
given by:
=
V o 1 + g m Z IN
The error amplifier gain is independent of the
transconductance under the following condition:
g m * Z f >> 1 and g m * Z in >> 1
- - - (18)
F P 2 =
F P 3 =
F z 1 =
1
2 π * R 10 * C 7
1
?
1
2 π * R 3 * C 4
?
?
1
2 π * R 3 * C 3
By replacing Z in and Z f according to figure 15, the
transformer function can be expressed as:
F z 2 =
1
2 π * C 7 * ( R 8 + R 10 )
?
1
2 π * C 7 * R 8
1 ( 1 + sR 3 C 4 ) * 1 + sC 7 ( R 8 + R 10 ) ]
sR 8 ( C 4 + C 3 ) ?
? C 4 * C 3 ? ?
? 1 + sR 3 ? ? ? * ( 1 + sR 10 C 7 )
F o = R 3 * C 7 *
V in 1
V osc 2 π * L o * C o
H ( s ) =
*
? ? C 4 + C 3 ? ?
Cross over frequency is expressed as:
*
10/04/08
14
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相关代理商/技术参数
参数描述
IR3811MTRPBF 功能描述:直流/直流开关调节器 7A SupIRBuck Reg 600kHz, 2.5-21V in RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
IR3812MPBF 制造商:International Rectifier 功能描述:
IR3812MPBF_08 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGHLY INTEGRATED 4A WIDE-INPUT VOLTAGE, SYNCHRONOUS BUCK REGULATOR
IR3812MTR1PBF 功能描述:直流/直流开关调节器 4A SupIRBuck Reg 600kHz, 2.5-21V in RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
IR3812MTRPBF 功能描述:直流/直流开关调节器 4A SupIRBuck Reg 600kHz, 2.5-21V in RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5