参数资料
型号: LTC3810HUH-5#PBF
厂商: Linear Technology
文件页数: 25/38页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM CM 32-QFN
标准包装: 73
PWM 型: 电流模式
输出数: 1
频率 - 最大: 1MHz
占空比: 99%
电源电压: 4.35 V ~ 60 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 150°C
封装/外壳: 32-WFQFN 裸露焊盘
包装: 管件
LTC3810-5
APPLICATIONS INFORMATION
degrees. Refer to your SPICE manual for details of how
to generate this plot.
*3810-5 modulator gain/phase
*2006 Linear Technology
GAIN
*this file simulates a simplified model of
*the LTC3810-5 for generating a v(out)/
v(ith)
*bode plot
.param rdson=.0135 ;MOSFET rdson
.param Vrng=2 ;use 1.4 for INTVCC and
0
PHASE
FREQUENCY (Hz)
0
–90
–180
38105 F13
ESR ? C OUT ? ? R
? V SENSE(MAX) ? ? 1 + s ? R
? ? ?
H(s) = ?
1.2 ? R DS(ON) ? ? 1 + s ? R L ? C OUT ? ?
(2)
?
K = tan ?
+ 45 ° ?
C2 =
R2 =
V REF (R FB1 )
V OUT ? V REF
0.7  for  ground
.param vsnsmax={0.173*Vrng-0.026}
.param Imax={vsnsmax/rdson}
.param DL=4 ;inductor ripple current
*inductor current
gl out 0 value={(v(ith)-1.2)*Imax/1.2+DL/2}
*output cap
cout out out2 270u ;capacitor value
resr out2 0 0.018 ;capacitor ESR
*load
Rout out 0 2 ; load resistor
vstim ith 0 0 ac 1 ;ac stimulus
.ac dec 100 100 10meg
.probe
.end
Mathematical software such as MATHCAD or MATLAB
can also be used to generate plots using the following
transfer function of the modulator:
L
s = j2 π f
With the gain/phase plot in hand, a loop crossover fre-
quency can be chosen. Usually the curves look something
like Figure 13. Choose the crossover frequency about 25%
of the switching frequency for maximum bandwidth. Al-
though it may be tempting to go beyond f SW /4, remember
that significant phase shift occurs at half the switching
frequency that isn’t modeled in the above H(s) equation
and PSPICE code. Note the gain (GAIN, in dB) and phase
Figure 13. Transfer Function of Buck Modulator
(PHASE, in degrees) at this point. The desired feedback
amplifier gain will be –GAIN to make the loop gain at 0dB
at this frequency. Now calculate the needed phase boost,
assuming 60° as a target phase margin:
BOOST = – (PHASE + 30°)
If the required BOOST is less than 60°, a Type 2 loop can
be used successfully, saving two external components.
BOOST values greater than 60° usually require Type 3
loops for satisfactory performance.
Finally, choose a convenient resistor value for R FB1 (10k is
usually a good value). Now calculate the remaining values:
(K is a constant used in the calculations)
f = chosen crossover frequency
G = 10 (GAIN/20) (this converts GAIN in dB to G in
absolute gain)
TYPE 2 Loop:
? BOOST ?
? 2 ?
1
2 π ? f ? G ? K ? R FB1
C1 = C2 ( K 2 ? 1 )
K
2 π ? f ? C1
R FB2 =
38105fd
25
相关PDF资料
PDF描述
LTC3834EUFD#PBF IC REG CTRLR BUCK PWM CM 20-QFN
RLB9012-152KL INDUCTOR HI CURRNT RADIAL 1500UH
RBA32DCBD CONN EDGECARD 64POS R/A .125 SLD
LTC1929CG-PG#PBF IC REG CTRLR BUCK PWM CM 28-SSOP
RBA32DCBH CONN EDGECARD 64POS R/A .125 SLD
相关代理商/技术参数
参数描述
LTC3810IG 制造商:Linear Technology 功能描述:
LTC3810IG#PBF 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP 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)
LTC3810IG#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP 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)
LTC3810IUH-5#PBF 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN 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)
LTC3810IUH-5#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN 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)