参数资料
型号: MAX15020
厂商: Maxim Integrated Products, Inc.
元件分类: DC/DC变换器
英文描述: 2A, 40V Step-Down DC-DC Converter with Dynamic Output-Voltage Programming
中文描述: 2A、40V降压型DC-DC转换器,可动态设置输出电压
文件页数: 15/19页
文件大小: 363K
代理商: MAX15020
M
2A, 40V Step-Down DC-DC Converter with
Dynamic Output-Voltage Programming
______________________________________________________________________________________
15
Compensation when f
C
> f
ZESR
For larger ESR capacitors such as tantalum and alu-
minum electrolytics, f
ZESR
can occur before f
C
. If f
ZESR
< f
C
, then f
C
occurs between f
P2
and f
P3
. f
Z1
and f
Z2
remain the same as before, however, f
P2
is now set
equal to f
ZESR
. The output capacitor’s ESR zero fre-
quency is higher than f
LC
but lower than the closed-
loop crossover frequency. The equations that define
the error amplifier’s poles and zeros (f
Z1
, f
Z2
, f
P1
, f
P2
,
and f
P3
) are the same as before. However, f
P2
is now
lower than the closed-loop crossover frequency. Figure
4 shows the error-amplifier feedback as well as its gain
response for circuits that use higher-ESR output capac-
itors (tantalum or aluminum electrolytic).
Pick a value for the feedback resistor R9 in Figure 4
(values between 1k
and 10k
are adequate).
C12 is then calculated as:
The error-amplifier gain between f
P2
and f
P3
is approxi-
mately equal to R9 / R6 (given that R6 << R7). R6 can
then be calculated as:
C11 is then calculated as:
Since R7 >> R6, R7 + R6 can be approximated as R7.
R7 is then calculated as:
f
P3
is set at 5 x f
C
. Therefore, C13 is calculated as:
Based on the calculations above, the following com-
pensation values are recommended when the switch-
ing frequency of DC-DC converter ranges from 100kHz
to 500kHz. (
Note: The compensation parameters in
Figure 2 are strongly recommended if the switching
frequency is from 300kHz to 500kHz.
)
C
C
×
C
R
f
P
13
12
2
12
9
1
3
=
×
×
π
R
f
C
LC
7
1
2
11
=
×
×
π
C
C
ESR
R
OUT
11
6
=
×
R
R
f
f
LC
C
6
9 10
2
2
=
×
C
f
R
LC
12
1
×
2
0 8
.
9
=
×
×
π
C12
SS
FB
f
Z1
f
Z2
f
C
f
P2
f
P3
CLOSED-LOOP
GAIN
FREQUENCY (Hz)
ERROR-
AMPLIFIER
GAIN
GAIN
(dB)
C13
C11
R9
V
OUT
COMP
R6
R7
R8
ERROR
AMPLIFIER
Figure 3. Error-Amplifier Compensation Circuit (Closed-Loop
and Error-Amplifier Gain Plot) for Ceramic Capacitors
C12
SS
f
Z1
f
Z2
f
P2
f
P3
CLOSED-LOOP
GAIN
ERROR-
AMPLIFIER
GAIN
C13
C11
R9
V
OUT
COMP
R6
R7
R8
ERROR
AMPLIFIER
f
C
FREQUENCY (Hz)
GAIN
(dB)
FB
Figure 4. Error-Amplifier Compensation Circuit (Closed-Loop
and Error-Amplifier Gain Plot) for Higher ESR Output Capacitors
相关PDF资料
PDF描述
MAX1508YETA TV 5C 5#20 PIN RECP
MAX1508 Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN
MAX1508Y Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN
MAX1508Z Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN
MAX1508ETA Linear Li Battery Charger with Integrated Pass FET, Thermal Regulation, and ACOKin 3mm x 3mm TDFN
相关代理商/技术参数
参数描述
MAX15020ATP+ 功能描述:直流/直流开关转换器 2A 40V Step-Down w/Dynamic Output-V RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX15020ATP+T 功能描述:直流/直流开关转换器 2A 40V Step-Down w/Dynamic Output-V RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX15020EVKIT+ 功能描述:电源管理IC开发工具 MAX15020 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MAX15021ATB+ 功能描述:直流/直流开关调节器 DUAL 4A/2A 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
MAX15021ATI/V+ 制造商:Maxim Integrated Products 功能描述:DUAL, 4A/2A, 4MHZ, STEP-DOWN DC-DCREGULATOR WITH TRACKING/SE - Rail/Tube