- 您現(xiàn)在的位置：買賣IC網(wǎng) > Datasheet目錄43 > MAX5986AETE+ (Maxim Integrated)IC POE SWITCH PSE 16TQFN Datasheet資料下載
參數(shù)資料
| 型號(hào)： | MAX5986AETE+ |
| 廠商： | Maxim Integrated |
| 文件頁數(shù)： | 16/23頁 |
| 文件大?。?/td> | 843K |
| 描述： | IC POE SWITCH PSE 16TQFN |
| 標(biāo)準(zhǔn)包裝： | 60 |
| 類型： | 以太網(wǎng)供電控制器 PD 開關(guān)（PoE） |
| 應(yīng)用： | 供電設(shè)備（PSE） |
| 內(nèi)部開關(guān)： | 是 |
| 電流限制： | 201mA |
| 電源電壓： | 8.7 V ~ 60 V |
| 工作溫度： | -40°C ~ 85°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 16-WQFN 裸露焊盤 |
| 供應(yīng)商設(shè)備封裝： | 16-TQFN-EP（5x5） |
| 包裝： | 管件 |
MAX5986AMAX5986C/MAX5987A
IEEE 802.3af-Compliant, High-Efficiency, Class 1/
Class 2, PDs with Integrated DC-DC Converter
16
Maxim Integrated
Inductor Selection
Choose an inductor with the following equation:
where LIR is the ratio of the inductor ripple current to
full load current at the minimum duty cycle. Choose LIR
between 20% to 40% for best performance and stability.
Use an inductor with the lowest possible DC resistance
that fits in the allotted dimensions. Powdered iron ferrite
core types are often the best choice for performance.
With any core material, the core must be large enough
not to saturate at the current limit of the devices.
V
CC
Input Capacitor Selection
The input capacitor reduces the current peaks drawn
from the input power supply and reduces switching noise
in the IC. The total input capacitance must be equal or
greater than the value given by the following equation
to keep the input-ripple voltage within specification and
minimize the high-frequency ripple current being fed
back to the input source:
where V
IN-RIPPLE
is the maximum allowed input ripple
voltage across the input capacitors and is recommended
to be less than 2% of the minimum input voltage. D is the
duty cycle (V
OUT
/V
IN
) and T
S
is the switching period (1/
f
S
).
The impedance of the input capacitor at the switching
frequency should be less than that of the input source so
high-frequency switching currents do not pass through
the input source, but are instead shunted through the
input capacitor. The input capacitor must meet the ripple
current requirement imposed by the switching currents.
The RMS input ripple current is given by:
where I
RIPPLE
is the input RMS ripple current.
Output Capacitor Selection
The key selection parameters for the output capacitor are
capacitance, ESR, ESL, and voltage-rating requirements.
These affect the overall stability, output ripple voltage,
and transient response of the DC-DC converter. The out-
put ripple occurs due to variations in the charge stored in
the output capacitor, the voltage drop due to the capaci-
tors ESR, and the voltage drop due to the capacitors
ESL. Estimate the output-voltage ripple due to the output
capacitance, ESR, and ESL:
V
RIPPLE
= V
RIPPLE(C)
+ V
RIPPLE(ESR)
+V
RIPPLE(ESL)
where the output ripple due to output capacitance, ESR,
and ESL is:
or whichever is larger. The peak-to-peak inductor current
(I
P-P
)
Use these equations for initial output capacitor selec-
tion. Determine final values by testing a prototype or an
evaluation circuit. A smaller ripple current results in less
output-voltage ripple. Since the inductor ripple current is
a factor of the inductor value, the output-voltage ripple
decreases with larger inductance. Use ceramic capaci-
tors for low ESR and low ESL at the switching frequency
of the converter. The ripple voltage due to ESL is negli-
gible when using ceramic capacitors.
Load-transient response depends on the selected output
capacitance. During a load transient, the output instantly
changes by ESR x I
LOAD
. Before the controller can
respond, the output deviates further, depending on the
inductor and output capacitor values. After a short time,
the controller responds by regulating the output voltage
back to its predetermined value. The controller response
time depends on the closed-loop bandwidth. A higher
bandwidth yields a faster response time, preventing the
output from deviating further from its regulating value.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX6509CAZK/V+T | IC TEMP SWITCH RES-PROG 5TSOT |
| MAX6513TT075+T | IC TEMP SWITCH REMOTE 6-TDFN |
| MAX6581TG9A+ | IC TEMP SENSOR 8-CH PREC 24-TQFN |
| MAX6602UE9A+T | IC TEMP MONITOR 5CH 16-TSSOP |
| MAX6604ATA+TW | IC TEMP SENSOR DDR MEMORY 8TDFN |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX5986AETE+ | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 IEEE802.3 af PD w/ DC/DC Conv RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| MAX5986AETE+T | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 IEEE802.3 af PD w/ DC/DC Conv RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| MAX5986BETE+ | 功能描述:以太網(wǎng) IC IEEE802.3 AF HI EFFICIENCY PD RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray |
| MAX5986BETE+T | 功能描述:PMIC 解決方案 IEEE802.3 AF HI EFFICIENCY PD RoHS:否 制造商:Texas Instruments 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-24 封裝:Reel |
| MAX5986EVKIT# | 功能描述:電源管理IC開發(fā)工具 MAX5986 Eval Kit RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。