参数资料
型号: MAX8745ETJ+
厂商: Maxim Integrated Products
文件页数: 30/36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
High-Efficiency, Quad-Output, Main Power-
Supply Controllers for Notebook Computers
INPUT CAPACITOR RMS CURRENT
vs. INPUT VOLTAGE
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
IN PHASE
50/50 INTERLEAVING
40/60 OPTIMAL
INTERLEAVING
6
8
10
12
14
16
18
20
V IN (V)
INPUT RMS CURRENT FOR INTERLEAVED OPERATION:
? I IN ) ( D LX 5 ? D OL ) + ( I OUT 3 ? I IN ) ( D LX 3 ? D OL ) + ( I OUT 5 + I OUT 3 ? I IN
I RMS =
( OUT 5
2 2
)
2
D OL + I IN 2 ( 1 ? D LX 5 ? D LX 3 + D OL
)
D LX 5 = OUT 5
D LX 3 = OUT 3
V
V IN
V
V IN
D OL = DUTY ? CYCLE OVERLAP FRACTION
I IN =
V OUT5 I OUT5 + V OUT3 I OUT3
V IN
INPUT RMS CURRENT FOR SINGLE-PHASE OPERATION:
I RMS = I LOAD ?
?
(
?
?
?
?
V IN
V OUT V IN ? V OUT
) ? ?
?
?
Figure 8. Input RMS Current
The 40/60 optimal interleaved architecture of the
MAX8744/MAX8745 allows the input voltage to go as
low 8.3V before the duty cycles begin to overlap. This
offers improved efficiency over a regular 180° out-of-
phase architecture where the duty cycles begin to
overlap below 10V. Figure 8 shows the input-capacitor
RMS current vs. input voltage for an application that
requires 5V/5A and 3.3V/5A. This shows the improve-
ment of the 40/60 optimal interleaving over 50/50 inter-
leaving and in-phase operation.
For most applications, nontantalum chemistries (ceram-
ic, aluminum, or OS-CON) are preferred due to their
resistance to power-up surge currents typical of sys-
tems with a mechanical switch or connector in series
with the input. Choose a capacitor that has less than
10°C temperature rise at the RMS input current for opti-
mal reliability and lifetime.
Power-MOSFET Selection
Most of the following MOSFET guidelines focus on the
challenge of obtaining high load-current capability
when using high-voltage (> 20V) AC adapters. Low-
current applications usually require less attention.
The high-side MOSFET (N H ) must be able to dissipate
the resistive losses plus the switching losses at both
V IN(MIN) and V IN(MAX) . Ideally, the losses at V IN(MIN)
should be roughly equal to the losses at V IN(MAX) , with
lower losses in between. If the losses at V IN(MIN) are
significantly higher, consider increasing the size of N H .
Conversely, if the losses at V IN(MAX) are significantly
higher, consider reducing the size of N H . If V IN does not
vary over a wide range, maximum efficiency is achieved
by selecting a high-side MOSFET (N H ) that has conduc-
tion losses equal to the switching losses.
30
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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