Texas Instruments TIDA-050026-23881 Guide

PSE Daughter Card
54 V to
PSE_3.3 V
Buck
PSE Ports
MSP430
Daughter Card
MSP430
54-V bus
PSE I2C bus
USB2ANY Connector
GPIOs
Edge
Connector
_signal
I2C
54 V to
ISO_3.3 V
Isolated
DC/DC
JTAG
14 pin
Flash/Debug
PSE Control Signals
Edge
Connector
_Power
Isolation
UART SPI
Power
Supply 1
Power
Supply 2
Sensing
PG2
GPIOs
PG1
USB2ANY Connector
I2C Repeater
(Optional)
PSE System Motherboard
24-Port RJ45 Connectors
Edge
Connector
_Power
Edge
Connector
_signal
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24-Port (4 Pair) Power Sourcing Equipment Reference Design for Multi-port
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Design Guide: TIDA-050026-23881
24-Port (4 Pair) Power Sourcing Equipment Reference
Design for Multi-port Applications
Description
This reference design features an evaluation module
for the 24-port PSE system which contains a hardware
kit, a system firmware image, and a system firmware
GUI. The hardware kit consists of a motherboard
(PSEMTHR24EVM-081), an MSP430 daughtercard
(PSEMCUDAUEVM-082) and a PSE daughtercard
(TPS23881EVM-083). To evaluate the system (both
hardware and software), USB2ANY and MSP-FET
adapters are also needed.
NOTE: The MSP430F5234 on PSEMCUDAUEVM-082
are programmed with pre-production firmware for EVM
testing purposes. Follow the instructions in this user's
guide to flash the latest firmware from TI.com before
evaluation.
Resources
TIDA-050026-23881 Design Folder
TPS23881EVM-083 Tool Folder
PSEMTHR24EVM-081 Tool Folder
PSEMCUDAUEVM-082 Tool Folder
TPS23881 Product Folder
MSP430F5234 Product Folder
CSD19538Q3A Product Folder
ASK Our E2E™ Experts
Features
• Onboard power monitoring
• 24 4-pair port system, and expandable to 48 port
system
• Highly flexible system with configurable GUI and
selectable host interface (I2C or UART)
• Multiport power management
• Multiple power supplies
• Supports legacy powered devices (PDs)
Applications
•Campus and branch switches
•Edge router
•Video recorder

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An IMPORTANT NOTICE at the end of this TI reference design addresses authorized use, intellectual property matters and other
important disclaimers and information.
1 System Description
This reference design provides a competitive and alternative solution.
In a multiport PSE system, the system-level software is the biggest challenge. The software handles
complicated situations and addresses the following challenges:
• The power supply is usually not able to support all ports with a full load due to size and cost
constraints. The system software manages the port power with priority to keep the total power
consumption below the power budget.
• There are multiple power supplies in the system. These power supplies could be in sharing mode or
backup mode. The system software shuts down low-priority ports fast enough to keep the total power
consumption below the remaining power budget.
• There are some legacy PD devices that do not present the standard PoE PD signature. The system
software finds a way to supply power to these devices.
• System software limits the port power based on the PD class levels or host configuration.
• When there are load-step changes on multiple ports, the system software acts quickly enough to keep
the power consumption below the power budget.
1.1 Key System Specifications
Table 1. Key System Specifications
PARAMETER SPECIFICATIONS DETAILS
Input voltage 44 V–57 V
Port power limit 2 W–120 W > 90 W is considered as nonstandard power
Compliance IEEE 802.3bt Type 3 and Type 4
PD class level supported Class 0 to class 8
Number of power supply supported 1–2 In sharing mode and redundant mode
Max port number supported 48 Referred to RJ45 ports
1.2 Description
This reference design features the TPS23881 daughtercard, the octal channel, the TPS23881 device, and
the IEEE802.3bt ready PoE PSE controller. When paired with the PSE motherboard PSEMTHR24-081
(sold separately) and MCU daughtercard PSEMCUDAUEVM-082 (sold separately), users can evaluate
the TPS23881 device and PSE system firmware solution.
The full PoE evaluation ecosystem includes the following:
• PSEMTHR24EVM-081: motherboard for 24-port PoE PSE applications (sold separately)
• PSEMCUDAUEVM-082: MSP430 daughtercard for 24-port PoE PSE applications (sold separately)
• TPS23881EVM-083: TPS23881 daughtercard for 24 port Type 3 and Type 4 PSE applications (sold
separately)
• USB2ANY interface adapter: used with the PSE system firmware GUI for I2C/UART interaction with
the PSEMCUDAU-082 daughtercard (sold separately)
• MSP-FET programmer: used with Uniflash GUI for programming the MSP430 device
• PSE system firmware code image (request access through the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder)
• PSE system firmware GUI (request access through the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder)

PSE Daughter Card
54 V to
PSE_3.3 V
Buck
PSE Ports
MSP430
Daughter Card
MSP430
54-V bus
PSE I2C bus
USB2ANY Connector
GPIOs
Edge
Connector
_signal
I2C
54 V to
ISO_3.3 V
Isolated
DC/DC
JTAG
14 pin
Flash/Debug
PSE Control Signals
Edge
Connector
_Power
Isolation
UART SPI
Power
Supply 1
Power
Supply 2
Sensing
PG2
GPIOs
PG1
USB2ANY Connector
I2C Repeater
(Optional)
PSE System Motherboard
24-Port RJ45 Connectors
Edge
Connector
_Power
Edge
Connector
_signal
(see NOTE A)
(see NOTE B)
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NOTE: The MSP430F5234 on PSEMCUDAUEVM-082 is programmed with pre-production firmware
for EVM testing purposes. Follow the instructions in this user's guide to flash the latest
firmware from the TIDA-050026-23881 folder or the PSEMCUDAUEVM-082 tool folder
before evaluation.
2 System Overview
2.1 Block Diagram
Figure 1. TIDA-050026-23881 Block Diagram
A The 54-V to 3.3-V isolated DC/DC is for demonstration purposes only. It is not needed in a real system.
B Only connect a USB2ANY connector or JTAG to avoid GND loops.
2.2 Design Considerations
2.2.1 Input Power
2.2.1.1 Vpwr
DC input voltage is provided through J1 and J3. This board supports a dual power source in sharing mode
and redundant mode. If the power supplies are in redundant mode, make sure the main power supply is
connected to J1 and a backup power supply is connected to the J3 connector.
The minimum PSE port voltage is 44 VDC for Type 1, 50 V for Type 2 and Type 3, and 52 V for Type 4.
The maximum DC voltage at VPWR is 57 V for all types. During evaluation, choose the appropriate DC
power supply for the different type environment.
2.2.1.2 3.3 V
A local 3.3 V for local devices (labeled as 3.3 V) is provided by the onboard LM5017 buck converter. The
LM5017 device provides a basic power-on sequence and provides a well-controlled and consistent startup
to prevent erratic operation. In addition to 44 V to 57 V, the TPS238x requires 3.3 V for the digital circuitry
and each TPS2388x device consumes 6-mA typical and 12-mA maximum.

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2.2.1.3 3.3 V_ISO
The reference design kit provides galvanic isolation between PoE power side and host side using digital
isolators. The host side power is provided by 3.3 V_ISO.
2.2.2 Communication Interface
2.2.2.1 PSE I2C Communication
The motherboard provides two I2C interfaces communicating to PSE:
1. J10 on the motherboard (PSEMTHR24EVM-081) provides I2C access to all PSE devices directly. The
TPS2388x GUI can communicate to PSE devices with the USB2ANY interface adapter.
2. J11 and J12 on the motherboard (PSEMTHR24EVM-081) provides I2C access and system control
signal to the MSP430 daughtercard.
2.2.2.2 MCU - Host Communication
The MSP430 daughtercard provides I2C/UART communication port to host through J12 to J14 on
MSP430 daughtercard (PSEMCUDAUEVM-082). The PSE system GUI provides host configurations to the
PSE system.
Host interface protocol user's guide can be accessed from the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder.
2.2.3 MSP430F523x Hardware Design
Table 2. MSP430 GPIO Pin Assignment
PIN NUMBER
MSP430F5234 (48RGZ) TERMINAL FUNCTION COMMENT
COMMUNICATION
22 P3.0 I2C SDA USCI_B0 I2C to PSEs
23 P3.1 I2C SCL USCI_B0 I2C to PSEs
30 P4.1 I2C SDA USCI_B1 I2C to host
31 P4.2 I2C SCL USCI_B1 I2C to host
33 P4.4 UART TX USCI_A1 UART to host (debug only)
34 P4.5 UART RX USCI_A1 UART to host (debug only)
21 P2.7 SPI CLK USCI_A0 SPI to host (reserved)
24 P3.2 SPI slave TX enable, USCI_A0 SPI to host (reserved)
25 P3.3 UART TX,USCI_A0 or SPI
slave in, master out UART to host TX or SPI to host (reserved)
26 P3.4 UART RX, USCI_A0 or SPI
slave out, master in UART to host RX or SPI to host (reserved)
HARDWARE INTERRUPT
13 P1.0 PSE INT Connect to PSE INT pin
16 P1.3 OC Alert Connect to external current sensing circuit if not
used, connect to 3.3 V
18 P1.5 Power supply 1 Connect to power supply 1 power good signal. In
RPS mode, P1.5 must be connected to main power
supply. If there is only one power supply, the
power good signal must be connected to P1.5.
19 P1.6 Power supply 2 Connect to power supply 2 power good signal, if not
used, connect to GND. In RPS mode, P1.6 must be
connected to backup power supply
20 P1.7 Disable all ports This is for hardware disable ports (reserved)
GENERAL I/O
4 P5.0 RESET PSE RESET Connect to PSE RESET pin

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Table 2. MSP430 GPIO Pin Assignment (continued)
PIN NUMBER
MSP430F5234 (48RGZ) TERMINAL FUNCTION COMMENT
17 P1.4 OSS PSE OSS Connect to PSE OSS pin
46 P6.0 Interrupt pin to host
35 P4.6 BSL mode indication to host MCU configures as output. If MCU is in BSL mode,
output high. If in normal operation mode, output low.
48 P6.2 Guard-band indication Need an external LED
47 P6.1 Selection between I2C 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)
I2C high Don’t care
UART low low
SPI (CS ActiveLow) low high
2.3 Highlighted Products
2.3.1 TPS23881
The TPS2388x device is the main IC to handle PoE functions to deliver power to PDs through Ethernet
cable.
The TPS23881 device is an 8-channel power sourcing equipment (PSE) controller engineered to insert
power onto Ethernet cables in accordance with the IEEE 802.3bt (draft) standard. The eight individual
power channels can be configured in any combination of 2-pair (1-channel) or 4-pair (2-channels) PoE
ports. The PSE controller can detect PDs that have a valid signature, determine the power requirements
of the devices according to their classification, and apply power.
Programmable SRAM enables in field firmware upgradability over I2C to ensure IEEE compliance and
interoperability with the latest PoE enabled devices.
Dedicated per-port ADCs provide continuous port current monitoring and the ability to perform parallel
classification measurements for faster port turn on times. A ±2.5%accurate programmable port power limit
provides the ability to expand the maximum power sourced to 95 W without exceeding 100 W, and for
non-standard applications, the power limit may be set as high as 125 W. The 200-mΩcurrent sense
resistor and external FET architecture allows designs to balance size, efficiency, thermal, and solution
cost requirements.
Port remapping and pin-to-pin compatibility with the TPS23880 and TPS2388 devices eases migration
from previous generation PSE designs and enables interchangeable 2-layer PCB designs to
accommodate different system PoE power configurations.

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2.3.2 MSP430F523x
The TI MSP family of ultra-low-power microcontrollers consists of several devices featuring different sets
of peripherals targeted for various applications. The architecture, combined with extensive low-power
modes, is optimized to achieve extended battery life in portable measurement applications. The device
features a powerful 16-bit RISC CPU, 16-bit registers, and constant generators that contribute to
maximum code efficiency. The digitally controlled oscillator (DCO) allows the device to wake up from low-
power modes to active mode in 3.5 µs (typical). The MSP430F524x series are microcontroller
configurations with four 16-bit timers, a high-performance 10-bit ADC, two USCIs, a hardware multiplier,
DMA, a comparator, and an RTC module with alarm capabilities. The MSP430F523x series
microcontrollers include all of the peripherals of the MSP430F524x series except for the ADC.
MSP430F523x is the main controller to control PSE devices (TPS2388x) through the I2C bus and also
communicates to host CPU through I2C or UART to receive configurations and report system status.
2.3.3 ISO1541
The ISO1541 bidirectional isolator is used to isolate I2C signals between PSE devices and the MCU.
The ISO1540 and ISO1541 devices are low-power, bidirectional isolators that are compatible with I2C
interfaces. These devices have logic input and output buffers that are separated by TI's Capacitive
Isolation technology using a silicon dioxide (SiO2) barrier. When used with isolated power supplies, these
devices block high voltages, isolate grounds, and prevent noise currents from entering the local ground
and interfering with or damaging sensitive circuitry.
2.3.4 ISO7731
The ISO7731 digital isolator is used to isolate control signals (OSS, RESET, INT) between MSP430 and
PSE devices.
The ISO773x devices are high-performance, triple channel digital isolators with 5000 VRMS (DW package)
and 3000 VRMS (DBQ package) isolation ratings per UL 1577.
This family of devices has reinforced insulation ratings according to VDE, CSA, TUV, and CQC.
The ISO773x family of devices provides high electromagnetic immunity and low emissions at low power
consumption, while isolating CMOS or LVCMOS digital I/Os. Each isolation channel has a logic input and
output buffer separated by a silicon dioxide (SiO2) insulation barrier. This device comes with enable pins
which can be used to put the respective outputs in high impedance for multi-master driving applications
and to reduce power consumption. The ISO7730 device has all three channels in the same direction and
the ISO7731 device has two forward and one reverse-direction channel. If the input power or signal is lost,
the default output is high for devices without suffix F and low for devices with suffix F. See the device
Functional Modes section for further details.
Used in conjunction with isolated power supplies, this device helps prevent noise currents on a data bus
or other circuits from entering the local ground and interfering with or damaging sensitive circuitry.
Through innovative chip design and layout techniques, electromagnetic compatibility of the ISO773x
device is significantly enhanced to ease system-level ESD, EFT, surge, and emissions compliance.
2.3.5 CSD19538
This 100-V, 49-mΩ, SON 3.3-mm × 3.3-mm NexFET™ power MOSFET is designed to minimize
conduction losses and reduce the board footprint in PoE applications.

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2.3.6 LM5017
The LM5017 device is used to generate 3.3 V to supply PSE devices.
The LM5017 is a 100-V, 600-mA synchronous step-down regulator with integrated high-side and low-side
MOSFETs. The constant on-time (COT) control scheme employed in the LM5017 device requires no loop
compensation, provides excellent transient response, and enables very high step-down ratios. The on-time
varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range.
A high-voltage startup regulator provides bias power for internal operation of the IC and for integrated gate
drivers. A peak current limit circuit protects against overload conditions. The undervoltage lockout (UVLO)
circuit allows the input undervoltage threshold and hysteresis to be independently programmed. Other
protection features include thermal shutdown and bias supply undervoltage lockout (VCC UVLO).
2.3.7 LM5020
The LM5020 device is used to generate isolated LM5020 to supply MSP430 and isolators.
The LM5020 high-voltage pulse-width modulation (PWM) controller contains all of the features needed to
implement single-ended primary power converter topologies. Output voltage regulation is based on
current-mode control, which eases the design of loop compensation while providing inherent line feed-
forward. The LM5020 device includes a high-voltage start-up regulator that operates over a wide-input
range up to 100 V. The PWM controller is designed for high-speed capability including an oscillator
frequency range to 1 MHz and total propagation delays less than 100 ns. Additional features include an
error amplifier, precision reference, line undervoltage lockout, cycle-by-cycle current limit, slope
compensation, soft start, oscillator synchronization capability and thermal shutdown.
2.3.8 LM5050
The LM5050 device is used to support 2 power supplies in the system to work in backup mode.
The LM5050-1 and LM5050-1-Q1 high-side ORing FET controller operates in conjunction with an external
MOSFET as an ideal diode rectifier when connected in series with a power source. This ORing controller
allows MOSFETs to replace diode rectifiers in power distribution networks thus reducing both power loss
and voltage drops.
The LM5050-1 and LM5050-1-Q1 controllers provide charge pump MOSFET gate drive for an external N-
channel MOSFET and a fast response comparator to turn off the FET when current flows in the reverse
direction. The LM5050-1 and LM5050-1-Q1 devices can connect power supplies ranging from 5 V to 75 V
and can withstand transients up to 100 V.
2.3.9 INA240
The INA240 amplifier is used to measure the total current from the input to support fast shutdown in an
event of load step change.
The INA240 device is a voltage-output, current-sense amplifier with enhanced PWM rejection that can
sense drops across shunt resistors over a wide common-mode voltage range from –4 V to 80 V,
independent of the supply voltage. The negative common-mode voltage allows the device to operate
below ground, accommodating the flyback period of typical solenoid applications. Enhanced PWM
rejection provides high levels of suppression for large common-mode transients (ΔV/Δt) in systems that
use PWM signals (such as motor drives and solenoid control systems). This feature allows for accurate
current measurements without large transients and associated recovery ripple on the output voltage. This
device operates from a single 2.7-V to 5.5-V power supply, drawing a maximum of 2.4 mA of supply
current. Four fixed gains are available: 20 V/V, 50 V/V, 100 V/V, and 200 V/V. The low offset of the zero-
drift architecture enables current sensing with maximum drops across the shunt as low as 10-mV full-
scale.

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2.3.10 REF3425
The REF3425 device is used to provide a threshold to output the INA240 and generate a signal to MCU
for overcurrent alert.
The REF34xx device is a low temperature drift (6 ppm/°C), low-power, high-precision CMOS voltage
reference, featuring ±0.05% initial accuracy, low operating current with power consumption less than 95
μA. This device also offers very low output noise of 3.8 μVp-p/V, which enables its ability to maintain high
signal integrity with high-resolution data converters in noise critical systems. With a small SOT-23
package, the REF34xx offers enhanced specifications and pin-to-pin replacement for MAX607x and
ADR34xx. The REF34xx family is compatible to most of the ADC and DAC such as the ADS1287,
ADUCM360, and ADS1112 devices. Stability and system reliability are further improved by the low output-
voltage hysteresis of the device and low long-term output voltage drift. Furthermore, the small size and
low operating current of the devices (95 μA) can benefit portable and battery-powered applications.
2.3.11 TPS3890
The TPS3890 device is used to monitor the existence of the power supply and generate power good
signal to MCU. The MCU can adjust the total power budget of the system.
The TPS3890 device is a precision voltage supervisor with low-quiescent current that monitors system
voltages as low as 1.15 V, asserting an open-drain RESET signal when the SENSE voltage drops below a
preset threshold or when the manual reset (MR) pin drops to a logic low. The RESET output remains low
for the user-adjustable delay time after the SENSE voltage and manual reset (MR) return above the
respective thresholds. The TPS3890 family uses a precision reference to achieve 1% threshold accuracy.
The reset delay time can be user-adjusted between 40 μs and 30 s by connecting the CT pin to an
external capacitor. The TPS3890 device has a very low quiescent current of 2.1 μA and is available in a
small 1.5-mm × 1.5-mm package, making the device well-suited for battery-powered and space-
constrained applications.
3 Hardware, Software, Testing Requirement and Test Result
3.1 Required Hardware and Software
3.1.1 Hardware
The following hardware is required to get started with the reference design:
• PSEMTHR24EVM-081: motherboard for 24 port PoE PSE applications (sold separately)
• PSEMCUDAUEVM-082: MSP430 daughtercard for 24 Port PoE PSE applications (sold separately)
• TPS23881EVM-083: TPS23881 daughtercard for 24-port Type 3 and Type 4 PSE PoE PSE
applications (sold separately)
• USB2ANY interface adapter: used with PSE system firmware GUI for I2C/UART interaction with
PSEMCUDAU-082 daughtercard (sold separately)
• MSP-FET programmer: used with the Uniflash GUI for programming the MSP430 device
3.1.2 Software
• FirmPSE code image (request access to the code image through the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder)
• FirmPSE GUI (request access to the GUI through the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder)

PSEMTHR24EVM-081
TPS23881EVM-083
PSEMCUDAUEVM-082
J1 J3
J15 J55
USB2ANY
J13 J12 J14
xxx
xxx
xxx
xx
xx
xx
xx
xx
xxx
xxx
xxx
xxx
PC
Type 3/4 PDs Type 3/4 PDs
Power supply 1
Ethernet
Cable
Etherne t
Cable Ribbon
Cable
J1
MSP-FET
Ribbon
Cable
Power supply 2
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3.2 Testing and Results
3.2.1 Test Setup
3.2.1.1 Hardware Setup
Figure 2 shows the hardware test setup of the ecosystem.
Figure 2. Ecosystem Setup
NOTE: A 30-pin ribbon cable is required to enable the full features of PSE system firmware GUI.

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3.2.1.2 LED, Test Point, Jumper and Connector Settings
3.2.1.2.1 EVM LEDs
Table 4 lists the EVM LEDs and their descriptions.
Table 4. EVM LEDs
LED COLOR DESCRIPTION
PSEMTHR24EVM-081
J15, J55 Green, Yellow There is one green and yellow LED on each RJ45 port
PSEMCUDAUEVM-082
D1 Green The total power consumption is within the pre-configured guardband
3.2.1.2.2 EVM Test Points
Table 5 lists the EVM test points.
Table 5. EVM Test Points
TP LABEL DESCRIPTION
PSEMTHR24EVM-081
TP1 55VDC VPWR
TP2 GND VPWR ground
TP3 OC-ALERT System over current alert signal
TP4 SDA I2C data
TP5 SCL I2C clock
TP6 PG1 Power good signal for power supply #1
TP7 PG2 Power good signal for power supply #2
TP8 PSE_3.3V 3.3 V for PSE devices
TP9 GND PSE_3.3V ground
TP10 3.3V_ISO Isolated 3.3 V for MSP430
TP11 3.3V 3.3 V for debug
TPS12 , TP13 GND_ISO 3.3V_ISO ground
TP14 OSS OSS signal from MCU to PSE
TPS23881EM-083
TP1 VPWR VPWR
TP2 PSE_3.3 3.3 V for PSE devices
TP3, TP4, TP14, TP18 GND VPWR and PSE_3.3V ground
TP5 RESET Reset signal from MCU
TP6 OSS OSS signal from MCU
TP7 INT INT signal to MCU
TP8 SCL I2C clock from MCU
TP9 SDA I2C data from and to MCU
TP10 3.3V_ISO Isolated 3.3 V
TP11 PSE_RST Reset signal to PSE
TP12 PSE_OSS OSS signal to PSE
TP13 PSE_INT INT signal from PSE
TP15 GND_ISO 3.3V_ISO ground
TP16 PSE_SDA I2C data from or to PSE
TP17 PSE_SCL I2C clock to PSE

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3.2.1.2.3 EVM Jumpers
Table 6 lists the EVM test jumpers and their descriptions.
Table 6. EVM Test Jumpers
JUMPER DEFAULT PIN POSITION DESCRIPTION
PSEMTHR24EVM-081
J13 1-2 3.3 V comes from PSE daughtercard
J14 1-2 Connect 3.3V_ISO to supply the circuit
J17, J22, J38, J43, J19, J23, J32, J28, J52, J47,
J31, J26 1-2 Enable port LED
J45, J42, J24, J21, J44, J49, J53, J30, J33, J51, J54 1-2 Enable port LED
J57, J62, J78, J83, J59, J63, J72, J68, J92, J87,
J71, J66 1-2 Enable port LED
J85, J82, J64, J61, J84, J80, J89, J93, J70, J91, J94 1-2 Enable port LED
3.2.1.2.4 EVM Input and Output Connectors
Table 7 lists the EVM input and output connectors.
Table 7. EVM Input and Output Connectors
CONNECTOR DESCRIPTION
PSEMTHR24EVM-081
J1, J3 DC power supply input (44–57 V VDC, 41 A)
J2, J4, J6, J7 Edge connector for DC bus when connecting 2 boards together
J5 Power to PSE daughtercard
J8, J9 Edge connector for PSE signals (I2C, OSS, RESET and INT) when connecting 2 boards together
J10 Connector to USB2ANY for direct I2C access to PSE devices (for debug purpose only)
J11 Connectors to PSE daughter for PSE signals (I2C, OSS, RESET and INT)
J12 Connectors to MSP430 daughter for PSE signals (I2C, OSS, RESET and INT), system level
signals (OC-ALERT, PG) and isolated 3.3 V
J15, J55 PSE ports magjacks
J34, J35, J36, J74, J75, J76 PSE port connector to PSE daughtercard
J95, J96 For MSP430 daughtercard mechanical mounting purpose
TPS23881EM-083
J1 Pair with J5 on motherboard
J4 Pair with J11 on motherboard
J5 Pair with J34, J35, J36, J74, J75, J76 on motherboard
PSEMCUDAUEVM-082
J1 JTAG connector
J3, J7, J8, J9 Extended GPIO access
J11 Pair with J12 on motherboard
J12, J13, J14 USB2ANY connector (30 pin)
J17, J18 For MSP430 daughtercard mechanical mounting purpose

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3.2.1.3 System Firmware GUI Setup
3.2.1.3.1 PSE System Firmware GUI Installation
TI's PSE system firmware GUI is used with the PSE system EVM kit (PSEMTHR24EVM-081,
PSEMCUDAUEVM-082, TPS23881EVM-083) to configure the system, generate the code image and flash
to MSP430 device. Download the PSE system firmware GUI from the TIDA-050026-23881 folder or the
PSEMCUDAUEVM-082 tool folder.
3.2.1.3.2 PSE System Firmware GUI Operation
Start the PSE system firmware GUI by double clicking the GUI icon and clicking the start button. A window
similar to Figure 3 comes up. Offline mode is selected by default.
Figure 3. GUI Startup

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Select the MSP430 device you want to start with and then load the PSE system firmware code image
(request from the TIDA-050026-23881 folder or the PSEMCUDAUEVM-082 tool folder). Once finished,
click Proceed to go to the configuration page.
Figure 4. GUI Device Selection and Image Load
The configurations are split into 4 sections: system configuration, PPM (Port Power Management)
configuration, device configuration, and port configuration.
The system configuration is applied to the whole system. This tab is always available on the right side of
the GUI. The following parameters can be configured through the system configuration tab:
• Legacy detection functions
Legacy devices released prior to the PoE standard can be powered through the Ethernet cable. The
PSE system firmware detects these legacy PDs and powers on with protection.
• Use of external sensing circuit
The external sensing circuit is used to measure the total power consumption of the system. Once the
current exceeds the power budget, the MCU shuts down low priority ports. This increases the system
response to the load step change.
• System boot-up setting
1. Turn on the PSE port as soon as the power is up.
2. Turn on the PSE port after the PoE enable command is sent from the host
• Port overload retry mode
1. Re-enable immediately: after overload happens, the port is re-enabled immediately. If the overload
still presents, it will try at most 5 times and shuts down the port if the overload is not removed within
5 retries. The port is re-enabled after the PD is removed from the port and reconnects to the port.
2. Re-enable after PD is disconnected and connected: after overload happens, the port is disabled
immediately and is re-enabled after the PD is removed from the port and reconnects to the port.
3. Timer controlled: the port is re-enabled immediately after overload happens. The port keeps
retrying for a period (controller by timer) and is disabled after the timer expires. The port is re-
enabled after the PD is removed from the port and reconnects to the port.

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• OSS signal source (from MCU or CPLD):In a multi-power supply system, when one power supply has
faults and the remaining power supply is not able to supply the current power consumption, turn off low
priority ports to protect the remaining power supply. The OSS function of the PSE is used to fast
shutdown the low priority ports. There are 2 sources to generate the OSS signal:
1. MSP430 generates the OSS signal
2. CPLD generates the OSS signal
• Interrupt mask
The interrupt mask in Figure 5 can be configured to enable interrupt events to notify the host through
the MSP430 P6.0.
Figure 5. GUI System Configuration and PPM Configuration
PPM configuration is applied to the port power management mechanism. The following parameters can be
configured through the PPM configuration tab:
• Power limit mode: class limit mode and port limit mode
– Class limit mode: in class limit mode, the port power is limited by the class level of the PD. For
example, if the PD is class 8, the port power limit (PCUT) is set to 90 W.
– Port limit mode: in port limit mode, the port power is limited by the host. The host should set port
power limit before the port is powered on.
• Power policy:static and dynamic mode
– Static mode: in static mode, the port power allocation is set to port power limit. So in class limit
mode, port power allocation is class level power of the PD and in port limit mode, the port power
allocation is the port power limit configured from the host.
– Dynamic mode: in dynamic mode, the port power allocation equals to the actual consumed power
of the port. It allocates the unused power of the port to other ports.

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• Multi-power supply mode: RPS and sharing mode:
– Redundant power supply (RPS) mode: in RPS mode, the total power budget equals to the power
budget of the main power supply when both main power supply and backup power supply are
connected. The total power budget equals to backup the power budget of the power supply when
the main power supply is disconnected.
– Sharing power supply mode: in sharing mode, the total power budget equals to the sum of the
power budget of the two power supplies when both power supplies are connected. The total power
budget equals to the remaining power budget of the power supply if one of the power supplies is
disconnected.
• Total number of power supplies and the power budget of each power supply. If there is only one
power supply, the power good signal must be connected to P1.5.
• Power guard band: when the total allocated power < total power budget - guard band, there is no more
low priority ports to be turned on and the guard band LED will turn on.
Device configuration is mainly used to configure the mapping between the PSE device channels and the
logical RJ45 ports. When mapping a 4-pair port, only channels within the same quad (channel 1–4 or
channel 5–8) can be mapped to one 4-pair port.
Figure 6. GUI Device Configuration

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The Port Configuration is applied to the port by port settings, such as port PoE enable and disable, port
priority, and port power limit (only in port limit mode).
Figure 7. GUI Port Configuration
Once everything is configured, click the Proceed button. The summary page shows all the configurations
being set compared to the factory default configurations. Once everything is verified, you can generate the
hex file or flash the code to the MSP430 device directly.
Figure 8. GUI Configuration Summary

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Once configurations are reviewed, the GUI can generate the default code image and program the device
directly through MSP-FET.
Figure 9. GUI Program Device and Generate Hex
Once the code is successfully flashed to the MSP430 MCU, the system is up and running. The MSP-FET
can be disconnected from the laptop or PC. Connect the USB2ANY (with 30-pin ribbon cable) to a laptop
or PC and the GUI is in online mode after selecting the host interface protocol.
Figure 10. Host Interface Protocol Selection in Online Mode

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Once the device is connected to the GUI, real time changes can be made on the configuration page and
status page shows the real time system status. The status page shows the system, device, and port real-
time status. The user can also change the system configuration in the configuration page: each change is
converted to a host command to the MSP430 MCU. The user can also press the Save Configuration
button to save the current configuration as the default setting.
Figure 11. GUI Status Page
The BSL firmware update page provides the field firmware upgrade functions where the firmware can be
upgraded through the same I2C or UART port as the normal communication. This is beneficial to firmware
upgrade after the product is released to customers.

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Figure 12. BSL Firmware Update Page
Before using the BSL page to update the MSP430 firmware, BSL code must be flashed to the MSP430
MCU if it is not flashed. Download Uniflash from ti.com and use it to flash the BSL code with the following
steps:
1. Select the MCU device to MSP430F5234
Figure 13. MCU Device Selection Page

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2. Configure the flash section.
Figure 14. Configure Settings and Utilities Page
3. Load BSL code and flash to the MSP430 MCU.
Figure 15. Select and Load Images Page