参数资料
型号: LTC3811EUHF#TRPBF
厂商: Linear Technology
文件页数: 35/48页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM CM 38-QFN
标准包装: 2,500
系列: PolyPhase®
PWM 型: 电流模式
输出数: 2
频率 - 最大: 850kHz
占空比: 90%
电源电压: 4.5 V ~ 30 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 38-WFQFN 裸露焊盘
包装: 带卷 (TR)
LTC3811
APPLICATIONS INFORMATION
will provide adequate phase margin at the unity-gain
frequency of the loop.
In a Type-II compensation scheme, the zero is typically
placed below the target unity-gain frequency, depending
upon the desired settling time of the converter, and the pole
is placed no higher than half the switching frequency in
order to attenuate the switching frequency from the loop.
The gain between the zero and pole is typically adjusted
until the desired phase margin is achieved.
In general, the output capacitor is chosen based on cost
and size considerations, given a certain error budget
due to output ripple voltage and load transient response.
Oftentimes, multiple capacitor types (such as ceramic
and special polymer) are connected in parallel in order
to achieve a good combination of bulk capacitance and
low ESR. In general, the output capacitor is not normally
chosen to optimize the bode response.
Due to their small case size and low ESR, ceramic output
capacitors are well suited to very low voltage, high current
applications. Their low ESR and relatively high RMS current
capability make them a good choice for today’s demand-
ing processor-based loads. A fully ceramic output stage,
however, will result in very low ESR, pushing the ESR zero
frequency relatively close to the unity-gain frequency of the
loop. In this case a Type-III compensation network using
3 poles and 2 zeros may be necessary (see Figure 24). For
particularly demanding applications requirements, please
consult Linear Technology’s Applications department.
C1
V OUT
C1
V OUT
R3
C2
R4
R3
C2
R2
R2
C3
R1
0.6V
EA
R1
0.6V
EA
? C1 + C2 ? ?
? C1 + C2 ? ?
fP1 =
f P2 =
fZ =
1
2 π ? R2 ( C1 + C2 )
1
? C1 ? C2 ?
2 π ? R3 ?
1
2 π ? R3 ? C2
fP1 =
fP2 =
fP3 =
1
2 π ? R2 ( C1 + C2 )
1
? C1 ? C2 ?
2 π ? R3 ?
1
2 π ? R4 ? C3
f Z1 =
f Z2 =
1
2 π ? R3 ? C2
1
2 π ? ( R2 + R4 ) ? C3
A V = 20 log ?
30
20
10
–20dB
DECADE
f Z
f P2
R3
R1
–20dB/DECADE
30
20
10
–20dB
f Z1
f Z2
f P2
f P3
–20dB/DECADE
f
f
90
45
DECADE
f
–45
0
–45
f
–90
3811 F23
–90
3811 F24
Figure 23. Type-II Compensation Network and
Frequency Response
Figure 24. Type-III Compensation Network and
Frequency Response
3811f
35
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相关代理商/技术参数
参数描述
LTC3812EFE5#PBF 制造商:Linear Technology 功能描述:
LTC3812EFE-5#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 特色产品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 标准包装:1 系列:PowerWise® PWM 型:电压模式 输出数:1 频率 - 最大:1MHz 占空比:81% 电源电压:4.5 V ~ 18 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-5°C ~ 125°C 封装/外壳:32-WFQFN 裸露焊盘 包装:Digi-Reel® 产品目录页面:1303 (CN2011-ZH PDF) 其它名称:LM3754SQDKR
LTC3812EFE-5#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR)
LTC3812IFE-5#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR)
LTC3812IFE-5#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR)