- 您现在的位置：买卖IC网 > PDF目录11561 > MAX5945CAX+T (Maxim Integrated Products)IC NETWORK PWR CTRL 36-SSOP PDF资料下载
参数资料
| 型号： | MAX5945CAX+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 6/44页 |
| 文件大小： | 0K |
| 描述： | IC NETWORK PWR CTRL 36-SSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 1,000 |
| 控制器类型： | 网络电源控制器 |
| 接口： | I²C |
| 电源电压： | 3.3V |
| 电流 - 电源： | 4.2mA |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 36-BSOP（0.295"，7.50mm 宽） |
| 供应商设备封装： | 36-SSOP |
| 包装： | 带卷 (TR) |
第1页第2页第3页第4页第5页当前第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页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页
MAX5945
Setting R19h[PWR_ON_] (Table 21) high immediately
terminates detection/classification routines and turns on
power to the port(s).
R14h[DET_EN_, CLASS_EN_] default to low in SEMI
mode.
Use
software
to
set
R14h[DET_EN_,
CLASS_EN_] to high to start the detection and/or classi-
fication routines. R14h[DET_EN_, CLASS_EN_] are
reset every time the software commands a power-off of
the port (either through reset or PWR_OFF). In any other
case, the status of the bits is left unchanged (including
when the state machine turns off the power because a
load disconnect or a fault condition is encountered).
MANUAL Mode
Enter MANUAL mode by setting R12h[P_M1,P_M0] to
[0,1] during normal operation (see Tables 15 and 15a).
MANUAL mode allows the software to dictate any
sequence of operation. Write a 1 to both R14h[DET_ EN_]
and R14h[CLASS_EN_] start detection and classifica-
tion operations, respectively, and in that priority order.
After execution, the command is cleared from the regis-
ter(s). PWR_ON_ has highest priority. Setting PWR_ON_
high at any time causes the device to immediately enter
the powered mode. Setting DET_EN and CLASS_EN
high at the same time causes detection to be per-
formed first. Once in the powered state, the device
ignores DET_EN_ or CLASS_EN_ commands.
When switching to MANUAL mode from another mode,
DET_EN_, CLASS_EN_ default to low. These bits
become pushbutton rather than configuration bits (i.e.,
writing ones to these bits while in MANUAL mode com-
mands the device to execute one cycle of detection
and/or classification. The bits are reset back to zeros at
the end of the execution). Putting the MAX5945 into
shutdown mode immediately turns off power and halts
all operations to the corresponding port. The event and
status bits of the affected port(s) are also cleared. In
SHUTDOWN mode, the DET_EN_, CLASS_EN_, and
PWR_ON_ commands are ignored.
In SHUTDOWN mode, the serial interface operates
normally.
Watchdog
R1Dh, R1Eh, and R1Fh registers control watchdog oper-
ation. The watchdog function, when enabled, allows the
MAX5945 to gracefully take over control or securely shut
down the power to the ports in case of software/firmware
crashes. Contact the factory for more details.
PD Detection
When PD detection is activated, the MAX5945 probes
the output for a valid PD. After each detection cycle,
the device sets the DET_END_ bit R04h/05h[3:0] high
and reports the detection results in the status registers
R0Ch[2:0], R0Dh[2:0], R0Eh[2:0], and R0Fh[2:0]. The
DET_END_ bit is reset to low when read through R05h
or after a port reset. Both DET_END_ bit status registers
are cleared after the port powers down.
A valid PD has a 25k discovery signature characteris-
tic as specified in the IEEE 802.3af standard. Table 1
shows the IEEE 802.3af specification for a PSE detect-
ing a valid PD signature (see the Typical Application
Circuit and Figure 2). The MAX5945 can probe and cat-
egorize different types of devices connected to the port
such as a valid PD, an open circuit, a low resistive load,
a high resistive load, a high capacitive load, a positive
DC supply, or a negative DC supply.
During detection, the MAX5945 turns off the external
MOSFET and forces two probe voltages through the
DET_ input. The current through the DET_ input is mea-
sured as well as the voltage at OUT_. A two-point slope
measurement is used as specified by the IEEE 802.3af
standard to verify the device connected to the port. The
MAX5945 implements appropriate settling times and a
100ms digital integration to reject 50Hz/60Hz power-
line noise coupling.
An external diode, in series with the DET_ input,
restricts PD detection to the 1st quadrant as specified
by the IEEE 802.3af standard. To prevent damage to
non-PD devices and to protect itself from an output
short circuit, the MAX5945 limits the current into DET_
to less than 2mA maximum during PD detection.
In midspan mode, the MAX5945 waits 2.2s before
attempting another detection cycle after every failed
detection. The first detection, however, happens imme-
diately after issuing the detection command.
Power Device Classification
(PD Classification)
During the PD classification mode, the MAX5945 forces
a probe voltage (-18V) at DET_ and measures the cur-
rent into DET_. The measured current determines the
class of the PD.
After each classification cycle, the device sets the
CL_END_ bit (R04h/05h[7:4]) high and reports the clas-
sification results in the status registers R0Ch[6:4],
R0Dh[6:4], R0Eh[6:4], and R0Fh[6:4]. The CL_END_ bit
is reset to low when read through register R05h or after
a port reset. Both CL_END_ bit status registers are
cleared after the port powers down.
Quad Network Power Controller
for Power-Over-LAN
14
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| VE-253-IX-S | CONVERTER MOD DC/DC 24V 75W |
| VE-2TX-IX-S | CONVERTER MOD DC/DC 5.2V 75W |
| VE-2TV-IX-S | CONVERTER MOD DC/DC 5.8V 75W |
| PIC16LF1783-E/ML | IC MCU 8BIT 7KB FLASH 28-QFN |
| PIC16LF1782-E/SP | IC MCU 8BIT 3.5KB FLASH 28-SPDIP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5945EAX | 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| MAX5945EAX+ | 功能描述:热插拔功率分布 IEEE 802.3af Quad Net Pwr Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| MAX5945EAX+T | 功能描述:热插拔功率分布 IEEE 802.3af Quad Net Pwr Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| MAX5945EAX-T | 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| MAX5945EVKIT | 功能描述:电源管理IC开发工具 Evaluation Kit/Evaluation System for the MAX5945 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 |
发布紧急采购，3分钟左右您将得到回复。