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| 型号： | MAX8745ETJ+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 22/36页 |
| 文件大小： | 0K |
| 描述： | IC CNTRLR PWR SUP QUAD 32TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 60 |
| 应用： | 控制器，笔记本电脑电源系统 |
| 输入电压： | 6 V ~ 26 V |
| 输出数： | 4 |
| 输出电压： | 3.3V，5V，1 V ~ 26 V |
| 工作温度： | 0°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： | 管件 |
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High-Efficiency, Quad-Output, Main Power-
Supply Controllers for Notebook Computers
a broader efficiency vs. load curve, while higher values
result in higher full-load efficiency (assuming that the
coil resistance remains fixed) and less output-voltage
ripple. Penalties for using higher inductor values
include larger physical size and degraded load-tran-
sient response (especially at low input-voltage levels).
In discontinuous conduction (I OUT < I LOAD(SKIP) ), the
MAX8744/MAX8745 regulate the valley of the output
ripple, so the output voltage has a DC regulation level
higher than the error-comparator threshold. For PFM
operation (discontinuous conduction), the output volt-
age is approximately defined by the following equation:
Output Voltage
DC output accuracy specifications in the Electrical
Characteristics table refer to the error comparator’s
V OUT ( PFM ) = V NOM +
1 ? f SW ?
2 ? ? f OSC ? ?
I IDLE ESR
threshold. When the inductor continuously conducts,
the MAX8744/MAX8745 regulate the peak of the output
ripple, so the actual DC output voltage is lower than the
slope-compensated trip level by 50% of the output rip-
ple voltage. For PWM operation (continuous conduc-
tion), the output voltage is accurately defined by the
following equation:
where V NOM is the nominal output voltage, f OSC is the
maximum switching frequency set by the internal oscil-
lator, f SW is the actual switching frequency, and I IDLE is
the idle mode inductor current when pulse skipping .
Connect FB3 and FB5 to LDO5 to enable the fixed
SMPS output voltages (3.3V and 5V, respectively), set
by a preset, internal resistive voltage-divider connected
V OUT ( PWM ) = V NOM ? 1 ?
? ? ? ?
A SLOPE V RIPPLE ? ? V RIPPLE ?
?
?
?
?
?
V IN 2
between the output (CSL_) and analog ground.
Connect a resistive voltage-divider at FB_ between the
output (CSL_) and GND to adjust the respective output
where V NOM is the nominal output voltage, A SLOPE
equals 1%, and V RIPPLE is the output ripple voltage
(V RIPPLE = ESR x Δ I INDUCTOR , as described in the
Output Capacitor Selection section).
voltage between 2V and 5.5V (Figure 5). Choose R FBLO
(resistance from FB to GND) to be approximately 10k Ω
and solve for R FBHI (resistance from the output to FB)
using the equation:
R FBHI = R FBLO ?
? 1 ?
where V FB_ = 2V nominal.
TO ERROR
AMPLIFIER
? V OUT _
? V FB _
ADJUSTABLE
?
?
FB
OUTPUT
0
t ON(SKIP) =
V OUT
V IN f OSC
TIME
I PK
I LOAD = I PK /2
LDO5
OUT
9R
R
FIXED OUTPUT
FB = LDO5
ON-TIME
Figure 4. Pulse-Skipping/Discontinuous Crossover Point
Figure 5. Dual Mode Feedback Decoder
22
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8745ETJ+ | 功能描述:电流和电力监控器、调节器 Quad-Out Main Power Supply Controller RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX8745ETJ+T | 功能描述:电流和电力监控器、调节器 Quad-Out Main Power Supply Controller RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX874C/D | 功能描述:基准电压& 基准电流 RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数（典型值）:100 PPM / C 串联 VREF - 输入电压（最大值）: 串联 VREF - 输入电压（最小值）: 分流电流（最大值）:60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel |
| MAX874CPA | 功能描述:基准电压& 基准电流 RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数（典型值）:100 PPM / C 串联 VREF - 输入电压（最大值）: 串联 VREF - 输入电压（最小值）: 分流电流（最大值）:60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel |
| MAX874CPA+ | 功能描述:基准电压& 基准电流 RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数（典型值）:100 PPM / C 串联 VREF - 输入电压（最大值）: 串联 VREF - 输入电压（最小值）: 分流电流（最大值）:60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel |
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