Hardware, Software, Testing Requirement and Test Result
8
TIDA032 – October 2019
Copyright © 2019, Texas Instruments Incorporated
24-Port (2 pair) Power Sourcing Equipment Reference Design for Multi-port
Applications
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
μ
A. This device also offers very low output noise of 3.8
μ
Vp-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
μ
A) 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
μ
s and 30 s by connecting the CT pin to an
external capacitor. The TPS3890 device has a very low quiescent current of 2.1
μ
A 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)
•
TPS23882EVM-084: TPS23882 daughtercard for 24-port Type 3 (2 pair) PoE PSE applications (sold
separately)
•
USB2ANY interface adapater: used with PSE system firmware GUI for I
2
C/UART interaction with
PSEMCUDAU-082 daughtercard (sold separately)
•
MSP-FET programmer: used with the
GUI for programming the MSP430 device
3.1.2
Software
•
FirmPSE code image (request access to the code image through the
or the
)
•
FirmPSE GUI (request access to the GUI through the
or the
)
