- 您现在的位置：买卖IC网 > PDF目录1837 > MAX1531ETJ/V+T (Maxim Integrated Products)IC PS CTRLR MULTI-OUTPUT 32WQFN PDF资料下载
参数资料
| 型号： | MAX1531ETJ/V+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 28/33页 |
| 文件大小： | 0K |
| 描述： | IC PS CTRLR MULTI-OUTPUT 32WQFN |
| 标准包装： | 2,500 |
| 应用： | 五路电源监控器 |
| 电源电压： | 4.5 V ~ 28 V |
| 电流 - 电源： | 1.7mA |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-WFQFN 裸露焊盘 |
| 供应商设备封装： | 32-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页当前第28页第29页第30页第31页第32页第33页
Multiple-Output Power-Supply
Controllers for LCD Monitors
Because R11 is less than 100k Ω , use 100k Ω for R11
and recalculate C10 as (step 3):
Charge Pumps
Selecting the Number of Charge-Pump Stages
C 10 ≈
1
2 π × 4 . 3 kHz × 100 k Ω
= 370 pF
For highest efficiency, always choose the lowest num-
ber of charge-pump stages that meet the output
requirement. The number of positive charge-pump
stages is given by:
f CROSSOVER ≈
100 μ S × 4180
2 π × 470 pF × 2000
N POS = POS DROPOUT IN
Use the standard value of 470pF for C10 and recalcu-
late the crossover frequency as:
= 70 . 8 kHz
Since the crossover frequency is less than 1/5th the switch-
ing frequency, 470pF is an acceptable value for C10.
Because the high-frequency pole of the current-mode
control is at 64kHz, the feed-forward capacitor is (step 4):
V + V ? V
V IN ? 2 × V D
where N POS is the number of positive charge-pump
stages, V POS is the positive charge-pump output, V IN is
the input voltage of the step-down regulator, V D is the
forward voltage drop of the charge-pump diode, and
V DROPOUT is the dropout margin for the linear regula-
tor. Use V DROPOUT = 0.3V.
The number of negative charge-pump stages is given by:
C 23 ≈
1
2 π × 64 kHz × 17 . 8 k Ω
= 140 pF
N NEG =
? V NEG + V DROPOUT
V IN ? 2 × V D
R 1 = R 2 × ? OUT ? 1 ?
Use a standard value of 150pF for C23. The pole
formed by C23, R1 and R2 occur at 159kHz, above the
70.8kHz crossover frequency.
Because a ceramic output capacitor is used in the cir-
cuit of Figure1, the ESR zero occurs well above the
crossover frequency, so no additional compensation
capacitor (C2) is needed (step 5).
Output Voltage Selection
The MAX1530/MAX1531 step-down regulator’s output
voltage can be adjusted by connecting a resistive volt-
age-divider from the output to AGND with the center
tap connected to FB (Figure 1). Select R2 in the 5k Ω to
50k Ω range. Calculate R1 with the following equation:
? V ?
? V FB ?
where N NEG is the number of negative charge-pump
stages, V NEG is the negative charge-pump output, V IN
is the input voltage of the step-down regulator, V D is
the forward voltage drop of the charge-pump diode,
and V DROPOUT is the dropout margin for the linear reg-
ulator. Use V DROPOUT = 0.3V.
The above equations are derived based on the
assumption that the first stage of the positive charge
pump is connected to V IN and the first stage of the
negative charge pump is connected to ground.
Sometimes fractional stages are more desirable for bet-
ter efficiency. This can be done by connecting the first
stage to V OUT or another available supply. If the first
stage of the positive charger pump is powered from the
output of the step-down regulator V OUT , then the equa-
tion becomes:
where V FB = 1.238V, and V OUT may vary from 1.238V
to approximately 0.6 × V IN (V IN is up to 28V).
N POS =
? V POS + V DROPOUT ? V OUT
V IN ? 2 × V D
Boost-Supply Diode
A signal diode, such as the 1N4148, works well in most
applications. If the input voltage goes below 6V, use a
small 100mA Schottky diode for slightly improved effi-
If the first stage of the negative charge pump is pow-
ered from the output of the step-down regulator V OUT ,
then the equation becomes:
ciency and dropout characteristics. Do not use power
diodes, such as the 1N5817 or 1N4001, since high
junction capacitance can charge up VL to excessive
voltages.
N NEG =
? V NEG + V DROPOUT + V OUT
V IN ? 2 × V D
28
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1533AETJ+ | IC POWER SUPPLY CONTROLER 32TQFN |
| MAX1533ETJ+ | IC POWER SUPPLY CONTROLER 32TQFN |
| MAX1534ETE+ | IC PWR SUPPLY CONTROLLER 16TQFN |
| MAX1536ETI+ | IC REG BUCK SYNC ADJ 3.6A 28TQFN |
| MAX1538ETI+T | IC PWR SOURCE SELECTOR 28-TQFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1531EVKIT | 功能描述:电源管理IC开发工具 MAX1530/1 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 |
| MAX1532AETL | 制造商:Maxim Integrated Products 功能描述:DUAL-PHASE, QUICK-PWM CONTROLLER FOR IMVP CPU - Rail/Tube |
| MAX1532AETL+ | 制造商:Maxim Integrated Products 功能描述:DUAL-PHASE, QUICK-PWM CONTROLLER FOR IMVP CPU - Rail/Tube |
| MAX1532AETL+T | 制造商:Maxim Integrated Products 功能描述:DUAL-PHASE, QUICK-PWM CONTROLLER FOR IMVP CPU - Tape and Reel 制造商:Maxim Integrated Products 功能描述:MULTIPLE OUTPUT POWER-SUPPLY CTRL |
| MAX1532AETL-T | 制造商:Maxim Integrated Products 功能描述:DUAL-PHASE, QUICK-PWM CONTROLLER FOR IMVP CPU - Tape and Reel |
发布紧急采购，3分钟左右您将得到回复。