参数资料
型号: MAX5941AESE+
厂商: Maxim Integrated Products
文件页数: 11/24页
文件大小: 0K
描述: IC IEEE 802.3AF-COMP POE 16-SOIC
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 50
控制器类型: 以太网供电控制器(POE)
接口: IEEE 802.3af
电源电压: 48V
电流 - 电源: 1mA
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
供应商设备封装: 16-SOIC
包装: 管件
MAX5941A/MAX5941B
IEEE 802.3af-Compliant Power-Over-Ethernet
Interface/PWM Controller for Power Devices
______________________________________________________________________________________
19
4) The reset winding turns ratio (NR/NP) needs to be
low enough to guarantee that the entire energy in
the transformer is returned to V+ within the off cycle
at the maximum duty cycle. Use the following equa-
tion to determine the reset winding turns ratio:
where:
NR/NP = Reset winding turns ratio.
DMAX’ = Maximum value of maximum duty cycle:
Round NR to the nearest smallest integer.
The turns ratio of the reset winding (NR/NP) deter-
mines the peak voltage across the N-channel MOS-
FET.
Use the following equation to determine the maxi-
mum drain-source voltage across the N-channel
MOSFET:
VDSMAX = Maximum MOSFET drain-source voltage.
VIN_MAX = Maximum input voltage:
Choose MOSFETs with appropriate avalanche
power ratings to absorb any leakage energy.
5) Choose the tertiary winding turns ratio (NT/NP) so that
the minimum input voltage provides the minimum
operating voltage at VDD (13V). Use the following
equation to calculate the tertiary winding turns ratio:
where:
VDDMIN is the minimum VDD supply voltage (13V).
VDDMAX is the maximum VDD supply voltage (30V).
VIN_MIN is the minimum input voltage (30V).
VIN_MAX is the maximum input voltage (67V in this
design example).
NP is the number of turns of the primary winding.
NT is the number of turns of the tertiary winding:
Choose NT = 7.
6) Choose RSENSE according to the following equation:
where:
VILIM is the current-sense comparator trip threshold
voltage (0.465V).
NS/NP is the secondary side turns ratio (5/14 in this
example).
IOUTMAX is the maximum DC output current (10A in
this example):
7) Choose the inductor value so that the peak ripple
current (LIR) in the inductor is between 10% and
20% of the maximum output current:
where VD is the output Schottky diode forward volt-
age drop (0.5V) and LIR is the ratio of inductor rip-
ple current to DC output current:
8) The size and ESR of the output filter capacitor deter-
mine the output ripple. Choose a capacitor with a
low ESR to yield the required ripple voltage.
Use the following equations to calculate the peak-to-
peak output ripple:
VV
V
RIPPLE
RIPPLE ESR
RIPPLE C
=+
,,
22
L
-
()
×
()
××
=
5 5
1 0 198
0 4 275
10
401
..
.
kHz
A
H
L
V-
OUT
+
()×()
××
×
VD
LIR
kHz I
DMIN
OUTMAX
1
2
275
RSENSE
××
=
0 465
6
14
12 10
90 4
.
V
m
R
V
N
SENSE
ILIM
S
P
××
12
.IOUTMAX
13 7
4
36 7
14
639
7 67
..
30
1N
67
N
T
×≤
×
≤≤
V
NN
V
N
DDMIN
IN_MIN
PT
DDMAX
IN_MAX
P
+
×≤
+
×
07
.
V1 +
14
DSMAX ≥×
=
67
134
VV
1 +
N
DSMAX
IN_MAX
P
R
≥×
N1
1- 0.5
0.5
R ≤×
=
414
NN
1-D
D
RP
MAX
≤×
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MAX5941AESE+ 功能描述:输入/输出控制器接口集成电路 IEEE 802.3af POE Int/PWM Controller RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
MAX5941AESE+T 功能描述:输入/输出控制器接口集成电路 IEEE 802.3af POE Int/PWM Controller RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
MAX5941AESE-T 功能描述:电源开关 IC - POE / LAN RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻(最大值):7.3 Ohms 串话: 带宽: 开启时间(最大值):13 ns 关闭时间(最大值):20 ns 切换电压(最大): 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6
MAX5941BCSE 功能描述:电源开关 IC - POE / LAN RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻(最大值):7.3 Ohms 串话: 带宽: 开启时间(最大值):13 ns 关闭时间(最大值):20 ns 切换电压(最大): 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6
MAX5941BCSE+ 功能描述:输入/输出控制器接口集成电路 IEEE 802.3af POE Int/PWM Controller RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray