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参数资料
| 型号： | ADP1822-EVAL |
| 厂商： | Analog Devices Inc |
| 文件页数： | 17/24页 |
| 文件大小： | 0K |
| 描述： | BOARD EVALUATION FOR ADP1822 |
| 标准包装： | 1 |
| 主要目的： | DC/DC，步降 |
| 输出及类型： | 1，非隔离 |
| 输出电压： | 1.8V |
| 电流 - 输出： | 10A |
| 输入电压： | 9 ~ 15 V |
| 稳压器拓扑结构： | 降压 |
| 频率 - 开关： | 300kHz |
| 板类型： | 完全填充 |
| 已供物品： | 板 |
| 已用 IC / 零件： | ADP1822 |
| 相关产品： | ADP1822ARQZ-R7DKR-ND - IC REG CTRLR BUCK PWM VM 24-QSOP ADP1822ARQZ-R7CT-ND - IC REG CTRLR BUCK PWM VM 24-QSOP ADP1822ARQZ-R7TR-ND - IC REG CTRLR BUCK PWM VM 24-QSOP |
f PC 2 =
f SW 1
2 π ( C COMP // C C 2 )( R COMP )
f ZC =
f LC 1
2 π ( C COMP )( R COMP )
C COMP =
4
2 π ( f CO )( R COMP )
C COMP ?
6 . 37
( f SW )( R COMP )
DataSheet
then use both the ESR zero and feed-forward zeros to stabilize
Feed-Forward Zeros section).
In all three cases, it is sometimes beneficial, although not required,
to add an additional compensation capacitor, C C2 , from COMP
to FB to reduce high frequency noise. This capacitor forms an
extra pole in the loop response. Choose this capacitor such that
the pole occurs at approximately 1/2 of the switching frequency, or
= (24)
2
Assuming C COMP >> C C2 , then solving for C C2 ,
ADP1822
or
= (30)
2
Solving for C COMP ,
(31)
In terms of the switching frequency and combining the constants,
(32)
or
C C 2 =
2
2 π ( f SW )( R COMP )
(25)
C COMP =
2
2 π ( f LC )( R COMP )
(33)
Compensation Using the ESR Zero
or whichever is greater.
R COMP
C C2
C COMP
V OUT
Compensation Using Feed-Forward
C C2
COMP
TO
PWM
FB
0.6V
R TOP
R BOT
COMP
R COMP
C COMP
FB
V OUT
R TOP
C FF
R FF
TO
INTERNAL ERROR AMPLIFIER
PWM
0.6V
R BOT
Figure 19. Compensation Using the ESR Zero
( R TOP ) ( V RAMP ) ( f ESRZ )( f CO )
V IN ( f LC ) 2
1
4 . 9 ( R TOP )( f ESRZ )( f SW ) ( L )( C )
( R TOP )( V RAMP )( f ZFF )( f CO )
V IN ( f LC ) 2
( R TOP )( f SW ) 2 ( L )( C )
R COMP ? 0 . 0705 (35)
If the output capacitor ESR zero is sufficiently low (less than or
equal to 1/2 of the crossover frequency), use the ESR to stabilize
Choose the compensation resistor to set the desired crossover
frequency, typically 1/10 of the switching frequency or
R COMP = (26)
where:
R COMP is the compensation resistor.
V RAMP is the internal ramp peak voltage, 1.25 V.
f ESRZ and f CO are the ESR zero and crossover frequencies.
V IN is the dc input voltage.
f LC is the characteristic frequency of the output LC filter, or
f LC = (27)
2 π LC
using known constants
R COMP ? (28)
V IN
Choose the compensation capacitor to set the compensation
zero, f ZC , to the lesser of 1/4 of the crossover frequency or 1/2 of
the LC resonant frequency, or
INTERNAL ERROR AMPLIFIER
Figure 20. Compensation Using Feed-Forward
If the ESR zero is at too high a frequency to be useful in
stabilizing the regulator, add a series RC network, as shown in
R TOP . This adds an additional zero and pole pair that is used to
increase the phase at crossover, thus improving stability.
Choose the feed-forward zero frequency for 1/7 of the crossover
frequency, and the feed-forward pole at 7× the crossover
frequency. This sets the ratio of pole-to-zero frequency of
approximately 50:1 for optimum stability.
Choose the compensation resistor, R COMP , to set the crossover
frequency by
R COMP = (34)
where f ZFF is the feed-forward zero frequency and is 1/7 of the
crossover frequency. Simplify the following equation:
V IN
f
f ZC =
f CO
4
= SW =
40
1
2 π ( C COMP )( R COMP )
(29)
Rev. D | Page 17 of 24
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相关代理商/技术参数 |
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| ADP1823 | 制造商:AD 制造商全称:Analog Devices 功能描述:Dual, Interleaved, Step-Down DC-to-DC Controller with Tracking |
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| ADP1823ACPZ-R7 | 功能描述:IC REG CTRLR BUCK PWM VM 32LFCSP 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) |
| ADP1823-EVAL | 功能描述:BOARD EVAL FOR ADP1823 RoHS:否 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 标准包装:1 系列:- 主要目的:DC/DC，步降 输出及类型:1，非隔离 功率 - 输出:- 输出电压:3.3V 电流 - 输出:3A 输入电压:4.5 V ~ 28 V 稳压器拓扑结构:降压 频率 - 开关:250kHz 板类型:完全填充 已供物品:板 已用 IC / 零件:L7981 其它名称:497-12113STEVAL-ISA094V1-ND |
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