Texas Instruments TIDA-050026-23882, Руководство по конструкции

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System Overview
5 TIDA032 – October 2019
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24-Port (2 pair) Power Sourcing Equipment Reference Design for Multi-port
Applications
Table 2. MSP430 GPIO Pin Assignment (continued)
PIN NUMBER
MSP430F5234 (48RGZ)
TERMINAL FUNCTION COMMENT
47 P6.1 Selection between I
2
C and
SPI/UART
(Need to pullup or pulldown)
PROGRAM DOWNLOAD AND DEBUG
44 PJ.3 TCK JTAG clock input
43 PJ.2 TMS JTAG state control
42 PJ.1 TDI/TCLK JTAG data input, TCLK input
41 PJ.0 TDO JTAG data output
40 TEST/SBWTCK Enable JTAG pins
45 RSTDVCC/SBWTDIO External reset
EXTERNAL CRYSTAL
7 P5.4 XTIN External low frequency clock (use if needed)
8 P5.5 XTOUT External low frequency clock (use if needed)
Pre-configure the host interface protocol through hardware as Table 3 shows.
Table 3. Host Interface Protocol
P6.1 CS(P3.2)
I
2
C high Don’t care
UART low low
SPI (Reserved) low high
2.3 Highlighted Products
2.3.1 TPS23882
The TPS2388x device is the main IC to handle PoE functions to deliver power to PDs through Ethernet
cable.
The TPS23882 is an 8-channel power sourcing equipment (PSE) controller engineered to insert power
onto Ethernet cables in accordance with the IEEE 802.3bt standard. The PSE controller can detect
powered devices (PDs) that have a valid signature, determine the power requirements of the devices
according to their classification, and apply power. The TPS23882 improves on the TPS2388 with reduced
current sense resistors, selectable Autonomous operation, SRAM programmability, programmable power
limiting, capacitance measurement, and compatibility with TI's FirmPSE system firmware (see Device
Comparison Table). Dedicated per port ADCs provide continuous port current monitoring and the ability to
perform parallel classification measurements for faster port turn on times. A 1.25A port current limit and
adjustable power limiting allows for the support of non-standard applications above 60W sourced. The 200
m
Ω current sense resistor and external FET architecture allow designs to balance size, efficiency, thermal,
and solution cost requirements. Port remapping and pin-to-pin compatibility with the TPS2388/80/81
devices eases migration from previous generation PSE designs and enables interchangeable 2-layer PCB
designs to accommodate different system PoE power configurations.