MAX5952CUAX+【PDF 22/50 页】IC PSE CNTRLR FOR POE 36-SSOP

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录43

18页 19页 20页 21页 [22页]23页 24页 25页 26页

Watchdog

R1Dh, R1Eh, and R1Fh registers control the watchdog

operation. The watchdog function, when enabled, allows

the MAX5952 to gracefully take over control or securely

shuts down the power to the ports in case of software/

firmware crashes. Contact the factory for more details.

Address Inputs

A3, A2, A1, and A0 represent the four LSBs of the chip

address. The complete chip address is 7 bits (see

Table 4).

The four LSBs latch on the low-to-high transition of RESET

or after a power-supply start (either on V

or V

Address inputs default high through an internal 50k&

pullup resistor to V

. The MAX5952 also responds to the

call through a global address 30h (see the Global

Addressing and Alert Response Protocol section).

C-Compatible Serial Interface

The MAX5952 operates as a slave that sends and

receives data through an I

C-compatible, 2-wire or

3-wire interface. The interface uses a serial-data input

line (SDAIN), a serial-data output line (SDAOUT), and a

serial-clock line (SCL) to achieve bidirectional commu-

nication between master(s) and slave(s). A master (typ-

ically a microcontroller) initiates all data transfers to and

from the MAX5952, and generates the SCL clock that

synchronizes the data transfer. In most applications,

connect the SDAIN and the SDAOUT lines together to

form the serial-data line (SDA).

Using the separate input and output data lines allows

optocoupling with the controller bus when an isolated

supply powers the microcontroller.

The MAX5952 SDAIN line operates as an input. The

MAX5952 SDAOUT operates as an open-drain output. A

pullup resistor, typically 4.7k&, is required on SDAOUT.

The MAX5952 SCL line operates only as an input. A

pullup resistor, typically 4.7k&, is required on SCL if

there are multiple masters, or if the master in a single-

master system has an open-drain SCL output.

High-Power, Quad, PSE Controller

for Power-Over-Ethernet

22 ______________________________________________________________________________________

R/W

Table 4. MAX5952 Address

Figure 4. 2-Wire Serial Interface Timing Details

SCL

SDAIN

LOW

HIGH

BUF

START

CONDITION

STOP

CONDITION

REPEATED START CONDITION

START CONDITION

HD, STA

SU, DAT

HD, DAT

SU, STA

HD, STA

SU, STO

Figure 5. 3-Wire Serial Interface Timing Details

SCL

SDAIN/SDA

LOW

HIGH

BUF

START

CONDITION

STOP

CONDITION

REPEATED START CONDITION

START CONDITION

HD, STA

SU, DAT

HD, DAT

SU, STA

HD, STA

SU, STO

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式